Regar, E.S.

Bioresorbable scaffold in myocardial infarction: Has the time come? (Article)

2013-04-02T00:00:00Z

In vivo comparison of arterial lumen dimensions assessed by co-registered three-dimensional (3D) quantitative coronary angiography, intravascular ultrasound and optical coherence tomography (Article)

2012-01-19T00:00:00Z

This study sought to compare lumen dimensions as assessed by 3D quantitative coronary angiography (QCA) and by intravascular ultrasound (IVUS) or optical coherence tomography (OCT), and to assess the association of the discrepancy with vessel curvature. Coronary lumen dimensions often show discrepancies when assessed by X-ray angiography and by IVUS or OCT. One source of error concerns a possible mismatch in the selection of corresponding regions for the comparison. Therefore, we developed a novel, real-time co-registration approach to guarantee the point-to-point correspondence between the X-ray, IVUS and OCT images. A total of 74 patients with indication for cardiac catheterization were retrospectively included. Lumen morphometry was performed by 3D QCA and IVUS or OCT. For quantitative analysis, a novel, dedicated approach for co-registration and lumen detection was employed allowing for assessment of lumen size at multiple positions along the vessel. Vessel curvature was automatically calculated from the 3D arterial vessel centerline. Comparison of 3D QCA and IVUS was performed in 519 distinct positions in 40 vessels. Correlations were r = 0.761, r = 0.790, and r = 0.799 for short diameter (SD), long diameter (LD), and area, respectively. Lumen sizes were larger by IVUS (P < 0.001): SD, 2.51 ± 0.58 mm versus 2.34 ± 0.56 mm; LD, 3.02 ± 0.62 mm versus 2.63 ± 0.58 mm; Area, 6.29 ± 2.77 mm2versus 5.08 ± 2.34 mm2. Comparison of 3D QCA and OCT was performed in 541 distinct positions in 40 vessels. Correlations were r = 0.880, r = 0.881, and r = 0.897 for SD, LD, and area, respectively. Lumen sizes were larger by OCT (P < 0.001): SD, 2.70 ± 0.65 mm versus 2.57 ± 0.61 mm; LD, 3.11 ± 0.72 mm versus 2.80 ± 0.62 mm; Area 7.01 ± 3.28 mm2versus 5.93 ± 2.66 mm2. The vessel-based discrepancy between 3D QCA and IVUS or OCT long diameters increased with increasing vessel curvature. In conclusion, our comparison of co-registered 3D QCA and invasive imaging data suggests a bias towards larger lumen dimensions by IVUS and by OCT, which was more pronounced in larger and tortuous vessels.

Head-to-head comparison of the neointimal response between metallic and bioresorbable everolimus-eluting scaffolds using optical coherence tomography (Article)

2011-12-01T00:00:00Z

The metallic everolimus drug-eluting stents (DES) and polymeric everolimus bioresorbable vascular scaffolds (BVS) are coated with the same antiproliferative drug. It is uncertain if, during the bioresorption process, the neointimal response of everolimus BVS differs from that of everolimus DES. A total of 31 lesions treated with a single everolimus BVS, and 19 lesions treated with everolimus DES and imaged with optical coherence tomography at 1 year, were investigated. Neointimal response was assessed as a percentage of uncovered struts, neointimal thickness, in-stent/scaffold area obstruction, and pattern of neointima. Both scaffolds presented with similar neointimal response. However, the everolimus BVS presented with a trend toward higher proportion of intraluminal masses than everolimus DES did. This study sought to compare the neointimal response of metallic everolimus drug-eluting stents (DES) and polymeric everolimus bioresorbable vascular scaffolds (BVS) by optical coherence tomography at 1 year. DES decrease the risk of restenosis by reducing the neointimal response. However, DES may impair strut coverage, and this has been associated with late stent/scaffold thrombosis. BVS may overcome the risk of stent/scaffold thrombosis when completely resorbed. It is unknown if, during the bioresorption process, the neointimal response of the everolimus BVS (Absorb, Abbott Vascular, Santa Clara, California) differs from that of the metallic everolimus DES (Xience, Abbott Vascular). A total of 19 lesions were treated with a single everolimus DES, and 31 lesions were treated with everolimus BVS and imaged with optical coherence tomography at 1 year. Neointimal response was assessed as percentage of uncovered struts, neointimal thickness, in-stent/scaffold area obstruction, and pattern of neointima. At 1 year, no significant differences in the angiographic lumen loss were seen for the everolimus DES and everolimus BVS (0.18 ± 0.20 mm vs. 0.29 ± 0.36 mm; p = 0.42). optical coherence tomography analysis of 951 cross sections and 8,385 struts demonstrated similar rates of uncovered struts (5.3% everolimus DES vs. 4.5% everolimus BVS; p = 0.11), mean neointimal thickness (120.6 ± 46.0 μm vs. 136.1 ± 71.4 μm; p = 0.82) and in-stent/scaffold area obstruction (12.5 ± 7.1% vs. 13.6 ± 9.7%; p = 0.91), respectively. There was a trend of higher heterogenic tissue pattern of neointima (21.1% vs. 6.5%; p = 0.12) and less intraluminal masses (0% vs. 12.9%; p = 0.10) with everolimus DES than with everolimus BVS. The everolimus BVS (Absorb) demonstrated a similar neointimal response as the everolimus DES (Xience). However, the presence of intraluminal masses at 12 months in a small proportion of patients warranted watchful follow-up of these cases.

Long-term tissue coverage of a biodegradable polylactide polymer-coated biolimus-eluting stent: Comparative sequential assessment with optical coherence tomography until complete resorption of the polymer (Article)

2011-11-01T00:00:00Z

Background: Biolimus-eluting stents (BESs) with a biodegradable polymer in abluminal coating achieve more complete coverage at 9 months compared with sirolimus-eluting stents (SESs) with a durable polymer, as assessed by optical coherence tomography (OCT). Whether this advantage persists or augments after complete resorption of the polymer (>12 months) is unknown. Methods: The LEADERS trial compared the performance of BES with that of SES. Patients were randomly allocated to a sequential angiographic follow-up, including OCT in selected sites, at 9 and 24 months. Struts coverage was compared using Bayesian hierarchical models as the primary outcome for the OCT substudy. Results: Fifty-six patients (26 BES, 30 SES) were enrolled in the OCT substudy. Twenty-one patients (10 BES, 11 SES) agreed to perform a second OCT follow-up at 24 months. Eleven lesions and 12 stents were analyzed sequentially in the BES group (2,455 struts at 9 months, 2,131 struts at 24 months) and 11 lesions and 18 stents in the SES group (3,421 struts at 9 months, 4,170 struts at 24 months). The previously reported advantage of BES over SES in terms of better strut coverage at 9 months was followed by improvement in coverage of the SES, resulting in identical coverage in both BES and SES at 24 months: 1.5% versus 1.8% uncovered struts, difference -0.2%, 95% credibility interval, -3.2% to 2.6%, P =.84. Conclusions: More complete strut coverage of BES as compared with SES at 9 months was followed by improvement of coverage in SES between 9 and 24 months and a similar long-term coverage in both stent types at 24 months.

Acute coronary syndrome in 3 dimensions: The culprit exposed (Article)

2011-10-11T00:00:00Z

Tissue coverage of a hydrophilic polymer-coated zotarolimus-eluting stent vs. a fluoropolymer-coated everolimus-eluting stent at 13-month follow-up: An optical coherence tomography substudy from the RESOLUTE All Comers trial (Article)

2011-10-01T00:00:00Z

Aim s To compare the tissue coverage of a hydrophilic polymer-coated zotarolimus-eluting stent (ZES) vs. a fluoropolymer-coated everolimus-eluting stent (EES) at 13 months, using optical coherence tomography (OCT) in an 'all-comers population of patients, in order to clarify the mechanism of eventual differences in the biocompatibility and thrombogenicity of the devices. Methods and resultsPatients randomized to angiographic follow-up in the RESOLUTE All Comers trial (NCT00617084) at pre-specified OCT sites underwent OCT follow-up at 13 months. Tissue coverage and apposition were assessed strut by strut, and the results in both treatment groups were compared using multilevel logistic or linear regression, as appropriate, with clustering at three different levels: patient, lesion, and stent. Fifty-eight patients (30 ZES and 28 EES), 72 lesions, 107 stents, and 23 197 struts were analysed. Eight hundred and eighty-seven and 654 uncovered struts (7.4 and 5.8, P 0.378), and 216 and 161 malapposed struts (1.8 and 1.4, P 0.569) were found in the ZES and EES groups, respectively. The mean thickness of coverage was 116 ± 99 m in ZES and 142 ± 113 m in EES (P 0.466). No differences in per cent neointimal volume obstruction (12.5 ± 7.9 vs. 15.0 ± 10.7) or other areasvolumetric parameters were found between ZES and EES, respectively.ConclusionNo significant differences in tissue coverage, malapposition, or lumen/stent areas and volumes were detected by OCT between the hydrophilic polymer-coated ZES and the fluoropolymer-coated EES at 13-month follow-up.

Three-dimensional reconstruction of the post-dilated ABSORB everolimus-eluting bioresorbable vascular scaffold in a true bifurcation lesion for flow restoration (Article)

2011-10-01T00:00:00Z

Serial analysis of the malapposed and uncovered struts of the new generation of everolimus-eluting bioresorbable scaffold with optical coherence tomography (Article)

2011-09-01T00:00:00Z

Objectives: The aim of this study is to assess the serial changes in strut apposition and coverage of the bioresorbable vascular scaffolds (BVS) and to relate this with the presence of intraluminal masses at 6 months with optical coherence tomography (OCT). Background: Incomplete strut/scaffold apposition (ISA) and uncovered struts are related to a higher risk of scaffold thrombosis. Bioresorbable vascular scaffolds can potentially avoid the risk of scaffold thrombosis because of its complete resorption. However, during the resorption period, the risk of scaffold thrombosis is unknown. Methods: OCT was performed in 25 patients at baseline and 6 months. Struts were classified according to apposition, coverage, and presence of intraluminal masses. Persistent ISA was defined as malapposed struts present at baseline and follow-up, and late acquired ISA as ISA developing at follow-up, and scaffold pattern irregularities when the strut distribution suggested scaffold fracture. Results: At baseline, 3,686 struts were analyzed: 128 (4%) were ISA, and 53 (1%) were located over side-branches (SB). At 6 months, 3,905 struts were analyzed: 32 (1%) ISA, and 35 (1%) at the SB. Persistent ISA was observed more frequently than late acquired-ISA (81% vs. 16%, respectively; 3% were unmatchable). Late acquired ISA was associated with scaffold pattern irregularities, which were related to overstretching of the scaffold. Uncovered struts (63 struts, 2%) were more frequently observed in ISA and SB struts, compared with apposed struts (29% vs. 1%; p < 0.01). Intraluminal masses (14 cross-sections, 3%; in 6 patients, 24%) were more frequently located at the site of ISA and/or uncovered struts (39% vs. 2% and 13% vs. 2%, respectively; p < 0.01). Conclusions: The lack of strut apposition at baseline is related to the presence of uncovered struts and intraluminal masses at 6 month. An appropriate balloon/artery ratio respecting the actual vessel size and avoiding the overstretching of the scaffold can potentially decrease the risk of scaffold thrombosis. (ABSORB Clinical Investigation, Cohort B [ABSORB B]; NCT00856856)

3-Dimensional optical frequency domain imaging for the evaluation of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction (Article)

2011-08-18T00:00:00Z

Delayed coverage in malapposed and side-branch struts with respect to well-apposed struts in drug-eluting stents: In vivo assessment with optical coherence tomography (Article)

2011-08-02T00:00:00Z

Background-Pathology studies on fatal cases of very late stent thrombosis have described incomplete neointimal coverage as common substrate, in some cases appearing at side-branch struts. Intravascular ultrasound studies have described the association between incomplete stent apposition (ISA) and stent thrombosis, but the mechanism explaining this association remains unclear. Whether the neointimal coverage of nonapposed side-branch and ISA struts is delayed with respect to well-apposed struts is unknown. Methods and Results-Optical coherence tomography studies from 178 stents implanted in 99 patients from 2 randomized trials were analyzed at 9 to 13 months of follow-up. The sample included 38 sirolimus-eluting, 33 biolimus-eluting, 57 everolimus-eluting, and 50 zotarolimus-eluting stents. Optical coherence tomography coverage of nonapposed side-branch and ISA struts was compared with well-apposed struts of the same stent by statistical pooled analysis with a random-effects model. A total of 34 120 struts were analyzed. The risk ratio of delayed coverage was 9.00 (95% confidence interval, 6.58 to 12.32) for nonapposed side-branch versus well-apposed struts, 9.10 (95% confidence interval, 7.34 to 11.28) for ISA versus well-apposed struts, and 1.73 (95% confidence interval, 1.34 to 2.23) for ISA versus nonapposed side-branch struts. Heterogeneity of the effect was observed in the comparison of ISA versus well-apposed struts (H=1.27; I2=38.40) but not in the other comparisons. Conclusions-Coverage of ISA and nonapposed side-branch struts is delayed with respect to well-apposed struts in drug-eluting stents, as assessed by optical coherence tomography. Clinical Trial Registration-http://www. clinicaltrials.gov. Unique identifier: NCT00389220, NCT00617084.

Invasive imaging technologies: Can we reconcile light and sound? (Article)

2011-08-01T00:00:00Z

Since the introduction of intravascular, catheter-based invasive imaging and diagnostic tools in the catheterization laboratories two decades ago, the functional assessment of angiographically moderate or ambiguous lesions by fractional flow reserve measurements represents the established standard of care today. Likewise, intravascular ultrasound (IVUS) is widely accepted to guide treatment strategy in complex lesions, such as long or left main stem lesions. Developments are driven by the clinical interest to optimize treatment, prevent periprocedural complications, understand treatment failure and understand progression of atherosclerosis. As a result, a variety of devices are now clinically available that enable detection and monitoring of specific plaque features over time, such as the presence of necrotic core by IVUS-VH, a lipid-core plaque by near infrared (NIR) spectroscopy or a thin fibrous cap atheroma by optical coherence tomography (OCT). As the physical boundaries for both light and sound are different, these imaging technologies offer different advantages and limitations. Light-based technologies offer unparalleled high image resolution (OCT) or unparalleled high sensitivity and specificity for distinct plaque components (NIR spectroscopy), whereas conventional IVUS offers a much better tissue penetration. From a clinical perspective, both types of information are valuable. Ideally, this information should easily and in real time be available in the catheterization laboratory, consisting of co-registered datasets gained during a single catheter pullback. On this background, a combined NIR spectroscopy and IVUS catheter has recently been introduced for clinical use. The article discusses the potential and limitations of these different technologies. They may allow advanced coronary plaque diagnosis in a fast, accurate, reliable, user- and patient-friendly manner and, as such, can help to improve clinical practice today and therapeutic options in the future.

Relation between plaque type and dissections at the edges after stent implantation: An optical coherence tomography study (Article)

2011-07-15T00:00:00Z

Background: Stent implantation can create vessel damage such as edge dissections. The objectives were i) to evaluate the frequency of edge dissections after stenting visible by intracoronary optical coherence tomography (OCT) in comparison with angiography. ii) to assess with OCT the plaque type left at the stent edges after implantation, and iii) to study whether there is an association between plaque type and dissections at stent edges. Methods: Seventy-three consecutive patients (80 vessels) with OCT post-stent implantation were included in the study. By OCT, plaque type at stent edges and presence of edge dissection were assessed. Angiograms were analyzed by two independent observers to assess the presence of edge dissections. Results: Distal and proximal edges were visible by OCT in 72/80 and 45/80 vessels respectively. OCT and angiography agreed in the detection of 7 dissections at distal edge (κ = 0.32) and 1 dissection at proximal edge (κ = 0.22). Plaque type at distal edge was: fibrotic 55.6%, fibrocalcific 22.2%, fibroatheroma 15.3% and thin-cap fibroatheroma (TCFA) 6.9%. At proximal edge plaque type was: fibrotic 31.1%, fibrocalcific 33.3%, fibroatheroma 28.9% and TCFA 6.7%. In the distal edge, presence of edge dissection was significantly more frequent when the plaque type at the edge was fibrocalcific (43.8%) or lipid rich (37.5%) than when the plaque was fibrous (10%) p = 0.009. Conclusions: OCT showed higher sensitivity compared to angiography for the identification of edge dissections. A high proportion of patients showed lipid-rich plaques at stent edges. Plaque type at the stent edges has impact on the presence of edge dissections.

6-month clinical outcomes following implantation of the bioresorbable everolimus-eluting vascular scaffold in vessels smaller or larger than 2.5 mm (Article)

2011-07-12T00:00:00Z

Objectives: We investigated the 6-month clinical outcomes after implantation of second-generation 3.0-mm bioresorbable everolimus-eluting vascular scaffolds (BVS) in small coronary vessels (<2.5 mm). Background: BVS are a novel approach to treating coronary lesions and are untested in small vessels. Methods: The ABSORB Cohort B Trial is a multicenter, single-arm, prospective, open-label trial assessing the performance of the second-generation BVS, in which 101 patients were enrolled. The pre-procedural reference vessel diameter (RVD) was assessed by quantitative coronary angiography during post hoc analysis. The vessel size was overestimated, by visual assessment, in 41 patients before implantation of 3.0-mm BVS in vessels with a pre-procedural RVD <2.5 mm. The study population was divided into 2 groups, group I (n = 41) with RVD <2.5 mm and group II (n = 60) with RVD <2.5 mm. The composite endpoint of ischemia-driven major adverse cardiac events, defined as ischemia-driven target lesion revascularization, myocardial infarction, or cardiac death, was assessed. Of the 45 patients scheduled for 6-month coronary angiography, 42 patients had the procedure performed, with intravascular ultrasound undertaken in 40 of these patients. Results: At 6 months, no significant differences in ischemia-driven major adverse cardiac events (3 of 41 [7.3%] cases vs. 2 of 60 [3.3%] cases; p = 0.3933) were observed in the small- and large-vessel groups, respectively. No cardiac deaths or episodes of in-scaffold thromboses were seen. Angiographic and intravascular ultrasound follow-up demonstrated no differences in late lumen loss (0.16 ± 0.18 mm vs. 0.21 ± 0.17 mm; p = 0.3525) or percentage lumen area stenosis (17.6 ± 6.0% vs. 19.8 ± 8.5%; p = 0.3643). Conclusions: The second-generation 3.0-mm BVS appears to be safe in small vessels, with similar clinical and angiographic outcomes compared with those of large vessels.

The diagnostic value of intracoronary optical coherence tomography (Article)

2011-07-11T00:00:00Z

Optical coherence tomography (OCT) is a novel light-based imaging modality for application in the coronary circulation. Compared to conventional intravascular ultrasound, OCT has a ten-fold higher image resolution. This advantage has seen OCT successfully applied in the assessment of atherosclerotic plaque, stent apposition, and tissue coverage, heralding a new era in intravascular coronary imaging. The present article discusses the diagnostic value of OCT, both in cardiovascular research as well as in potential clinical application. The unparalleled high image resolution and strong contrast between the coronary lumen and the vessel wall structure enable fast and reliable image interpretation. OCT makes it possible to visualize the presence of atherosclerotic plaque in order to characterize the structure and extent of coronary plaque and to quantify lumen dimensions, as well as the extent of lumen narrowing, in unprecedented detail. Based on optical properties, OCT is able to distinguish different tissue types, such as fibrous, lipid-rich, necrotic, or calcified tissue. Furthermore, OCT is able to cover the visualization of a variety of features of atherosclerotic plaques that have been associated with rapid lesion progression and clinical events, such as thin cap fibroatheroma, fibrous cap thickness, dense macrophage infiltration, and thrombus formation. These unique features allow the use of OCT to assess patients with acute coronary syndrome and to study the dynamic nature of coronary atherosclerosis in vivo and over time. This permits new insights into plaque progression, regression, and rupture, as well as the study of effects of therapies aimed at modulating these developments. Today's OCT technology allows high detail resolution as well as fast and safe clinical image acquisition. These unique features have established OCT as the gold standard for the assessment of coronary stents. This technique makes it possible to study stent expansion, peri-procedural vessel trauma, and the interaction of the stent with the vessel wall down to the level of individual stent struts, both acutely as well as in the long term, where it is has proven extremely sensitive to the detection of even minor amounts of tissue coverage. These qualities render OCT indispensable to addressing vexing clinical questions such as the relationship of drug-eluting stent deployment, vascular healing, the true time course of endothelial stent coverage, and late stent thrombosis. This may also better guide the optimal duration of dual anti-platelet therapy that currently remains unclear and relatively empirical. In the future, OCT might emerge, parallel to its undisputed position in research, as the tool of choice in all clinical scenarios where angiography is limited by its nature as a two-dimensional luminogram.

Assessment of coronary atherosclerosis progression and regression at bifurcations using combined IVUS and OCT (Article)

2011-07-01T00:00:00Z

Objectives: The aim of this study was to evaluate the progression of atherosclerotic coronary plaques at bifurcations, using combined intravascular ultrasoundvirtual histology (IVUS-VH) and optical coherence tomography (OCT). Background: Pathological findings reveal that atherosclerotic plaques characterized by the presence of large necrotic cores (NCs) with fibrous cap thicknesses < 65 μm are more prone to rupture. Accuracy in the detection of high-risk plaques could be improved by the combined use of IVUS-VH and OCT. Methods: IVUS-VH and OCT are 2 imaging modalities with different lateral resolutions and different depths of penetration. To provide a precise matching of the images, bifurcations were used as landmarks. IVUS-VH and OCT were performed in 56 bifurcations from 24 patients at baseline and at 6-month follow-up. All patients were treated with standard medical therapy. Bifurcations were studied at the proximal, in-bifurcation, and distal regions. Plaques were classified according to their composition as assessed by IVUS-VH and fibrous cap thickness as quantified by OCT. Results: At baseline, 27 NC-rich plaques were found. At 6-month follow-up, 22 (81%) did not show any significant change. Four new NC-rich lesions developed. At both time points, percent NC was higher and the fibrous cap was thinner at the proximal bifurcation rim compared with the distal. There were no significant changes in percent NC and fibrous cap thickness in the 3 bifurcation regions between baseline and follow-up examinations. No major cardiovascular events due to bifurcation lesion progression were observed. Conclusions: The combined use of IVUS-VH and OCT is a reliable tool to serially assess plaque progression and regression, and in the present study it was demonstrated to be safe and feasible. At 6-month follow-up, in this postpercutaneous coronary intervention patient population, most high-risk plaques remained unchanged, retaining their imaging classifications, nevertheless appearing to have remained clinically silent.

Pitfalls in plaque characterization by OCT: Image artifacts in native coronary arteries (Article)

2011-07-01T00:00:00Z

NIRS and IVUS for characterization of atherosclerosis in patients undergoing coronary angiography (Article)

2011-06-01T00:00:00Z

Objectives: The aim of this study was to compare the findings of near-infrared spectroscopy (NIRS), intravascular ultrasound (IVUS) virtual histology (VH), and grayscale IVUS obtained in matched coronary vessel segments of patients undergoing coronary angiography. Background: Intravascular ultrasound VH has been developed to add tissue characterization to the grayscale IVUS assessment of coronary plaques. Near-infrared spectroscopy is a new imaging technique able to identify lipid core-containing coronary plaques (LCP). Methods: We performed NIRS and IVUS-VH pullbacks in a consecutive series of 31 patients with a common region of interest (ROI) between 2 side branches. For each ROI, we analyzed the chemogram blocks by NIRS, plaque area and plaque burden by grayscale IVUS, and tissue types by IVUS-VH. The chemogram block is a summary metric of a 2-mm vertical slice of the chemogram. The value ranges from 0 to 1 according to the presence of lipids and represents the probability of LCP with a color scale from red (low probability) through orange and tan to yellow (high probability). Results: Plaque area (mm2) increases as percentage VH derived-necrotic core (NC) content (4.6 ± 2.7 vs. 7.4 ± 3.5 vs. 8.6 ± 3.4 vs. 7.9 ± 3.3, grouped in percentage NC quartiles, p < 0.001) and chemogram block probability color bin thresholds increase (4.9 ± 3.8 red, 7.3 ± 3.6 orange, 8.1 ± 3.4 tan, and 8.7 ± 3.4 yellow, p < 0.001). The correlation between the block chemogram detection of lipid core and percentage NC content by VH was weak (r = 0.149). Correction for the presence of calcium does not improve this correlation. Conclusions: Larger plaque area by grayscale IVUS was more often associated with either elevated percentage VH-NC or LCP by NIRS; however, the correlation between the detection of LCP by NIRS and necrotic core by VH is weak.

Six-month clinical follow-up of the Tryton side branch stent for the treatment of bifurcation lesions: A two center registry analysis (Article)

2011-05-01T00:00:00Z

Background: Treatment of bifurcation lesions with the Tryton Sidebranch stent has been shown to be feasible with an acceptable clinical outcome and low side branch late loss in the first in man trial. Objective: To report acute procedural and six month clinical follow-up after the use of the Tryton Sidebranch stent in an "all comer" registry. Methods: The first 100 coronary bifurcation lesions assigned for treatment with the Tryton stent were included in a prospective registry. Procedural and angiographic success rates were determined from patient charts and pre- and postprocedural quantitative coronary angiography. Results: Totally, 96 patients with 100 lesions were included in the study. Seventy-two percent presented with stable angina, 25% with unstable angina/NSTEMI, and 3% STEMI. The bifurcation was located in the left main in 8%. Two lesions were chronic total occlusions. Sixty-nine percent were true bifurcation lesions. One failure of stent delivery occurred. Acute gain in SB was 0.76 ± 0.64mm and three patients had residual stenosis of >30%. Angiographic success rate was 95%; procedural success rate reached 94%. Peri-procedural MI occurred in two and there was one cardiac death during hospitalization. At a median six months follow-up, TLR rate was 4%, MI 3%, and cardiac death 1%. The percentage MACE-free survival at six months was 94%. No cases of definite stent thrombosis occurred. Conclusions: In a real world the use of the Tryton Sidebranch stent is associated with good procedural safety and angiographic success rate and acceptable outcome at six months of follow-up.

Witnessed coronary plaque rupture during cardiac catheterization (Article)

2011-04-01T00:00:00Z

Comparison of adenosine magnetic resonance perfusion imaging with invasive coronary flow reserve and fractional flow reserve in patients with suspected coronary artery disease (Article)

2011-02-17T00:00:00Z

A comparative assessment by optical coherence tomography of the performance of the first and second generation of the everolimus-eluting bioresorbable vascular scaffolds (Article)

2011-02-01T00:00:00Z

AimsThe first generation of the everolimus-eluting bioresorbable vascular scaffold (BVS 1.0) showed an angiographic late loss higher than the metallic everolimus-eluting stent Xience V due to scaffold shrinkage. The new generation (BVS 1.1) presents a different design and manufacturing process than the BVS 1.0. This study sought to evaluate the differences in late shrinkage, neointimal response, and bioresorption process between these two scaffold generations using optical coherence tomography (OCT).Methods and resultsA total of 12 lesions treated with the BVS 1.0 and 12 selected lesions treated with the revised BVS 1.1 were imaged at baseline and 6-month follow-up with OCT. Late shrinkage and neointimal area (NIA) were derived from OCT area measurements. Neointimal thickness was measured in each strut. Strut appearance has been classified as previously described. Baseline clinical, angiographic, and OCT characteristics were mainly similar in the two groups. At 6 months, absolute and relative shrinkages were significantly larger for the BVS 1.0 than for the BVS 1.1 (0.98 vs. 0.07 mm2and 13.0 vs. 1.0, respectively; P 0.01). Neointimal area was significantly higher in the BVS 1.0 than in the BVS 1.1 (in-scaffold area obstruction of 23.6 vs. 12.3; P < 0.01). Neointimal thickness was also larger in the BVS 1.0 than in the BVS 1.1 (166.0 vs. 76.4 m; P < 0.01). Consequently, OCT, intravascular ultrasound, and angiographic luminal losses were higher with the BVS 1.0 than with the BVS 1.1. At 6 months, strut appearance was preserved in only 2.9 of the BVS 1.0 struts, but remained unchanged with the BVS 1.1 indicating different state of strut microstucture and/or their reflectivity.ConclusionThe BVS 1.1 has less late shrinkage and less neointimal growth at 6-month follow-up compared with the BVS 1.0. A difference in polymer degradation leading to changes in microstructure and reflectivity is the most plausible explanation for this finding.

Morphological and functional evaluation of the bioresorption of the bioresorbable everolimus-eluting vascular scaffold using IVUS, echogenicity and vasomotion testing at two year follow-up: a patient level insight into the ABSORB A clinical trial (Article)

2010-12-01T00:00:00Z

The aim of this study was to describe vaso-reactivity (by Acetylcholine and Methergine tests) at 2 year follow-up in parallel with the individual changes in the echogenicity characteristics of the polymer struts of the everolimus eluting bioresorbable vascular scaffold (BVS), from post-treatment to 2 year follow-up, in patients enrolled in the ABSORB Cohort A study. Intravascular ultrasound assessment was performed with a phased array catheter (EagleEye, Volcano Corporation, Cordova, CA, USA) with automated pullback at 0.5 mm per second. The % ratio at 6 months and 2 years [(Scaffold Area post PCI- Lumen Area)/Scaffold Area post PCI] was calculated as a measure of scaffold shrinkage. The % change of hyperechogenicity was defined as: ([post-procedural hyperechogenicity] - [2 year follow up hyperechogenicity])/[post-procedural hyperechogenicity]) × 100. The vasomotion test with intracoronary acetylcholine (10-6M) or intravenous methergine (0.4 mg) was performed at 2 years. Overall nine patients received all these analyses and were enrolled in the present analysis. A 50-96% reduction in hyperechogenicity was observed between baseline and 2 years, which corresponded to a change in vasoreactivity between 2 and 22%. A vasoconstriction of the scaffolded segment was observed in the 5 patients, who underwent the methergine test, with a mean decrease in lumen diameter after methergine of 9 ± 7% (P = 0.06), while vasodilatation occurred in the 4 patients who underwent the acetylcholine test with a mean increase in lumen diameter after acetylcholine of 8 ± 5% (P = 0.125). Bioresorption of the BVS is accompanied by re-establishment of both endothelial and non-endothelial dependent vasomotion.

Intracoronary optical coherence tomography and histology at 1 month and 2, 3, and 4 years after implantation of everolimus-eluting bioresorbable vascular scaffolds in a porcine coronary artery model: An attempt to decipher the human optical coherence tomography images in the ABSORB trial (Article)

2010-11-30T00:00:00Z

Background-: With the use of optical coherence tomography (OCT), alterations of the reflectance characteristics of everolimus-eluting bioresorbable vascular scaffold (BVS) struts have been reported in humans. In the absence of histology, the interpretation of the appearances of the struts by OCT remains speculative. We therefore report OCT findings with corresponding histology in the porcine coronary artery model immediately after and at 28 days and 2, 3, and 4 years after BVS implantation. Methods and results-: Thirty-five polymeric BVS (3.0×12.0 mm) were singly implanted in the main coronary arteries of 17 pigs that underwent OCT and were then euthanized immediately (n=2), at 28 days (n=2), at 2 years (n=3), at 3 years (n=5), or at 4 years (n=5) after implantation. All BVS-implanted arteries in these animals were evaluated by histology except for 5 arteries examined at 2 years with gel permeation chromatography to assess the biodegradation of the polymeric device. Fourteen arteries with BVS from an additional 6 pigs were examined by gel permeation chromatography at 1 (n=1), 1.5 (n=2), and 3 (n=2) years. Corresponding OCT and histology images were selected with the distal and proximal radiopaque markers used as landmarks. At 28 days, by OCT, 82% of struts showed sharply defined, bright reflection borders, best described as a box-shaped appearance. Histologically, all struts appeared intact with no evidence of resorption. At 2 years, by OCT, 60±20 struts were discernible per BVS with 80.4% of the strut sites as a box-shaped appearance. Despite their defined appearance by OCT, by histology, these structures appeared to be composed of proteoglycan, with polymeric material being at such low level as to be no longer quantifiable by chromatography. At 3 years, by OCT, recognizable struts decreased to 28±9 struts per BVS: 43.7% showed dissolved black box; 34.8%, dissolved bright box; 16.1%, open box; and 5.4%, preserved box appearance. Histology shows that connective tissue cells within a proteoglycan-rich matrix replaced the areas previously occupied by the polymeric struts and coalesced into the arterial wall. At 4 years, by OCT, 10±6 struts were recognizable as either dissolved black or dissolved bright box. In histology, these struts are minimally discernible as foci of low-cellular-density connective tissue. Relative to the prediction of histological type by OCT appearance, the preserved box appearance of OCT corresponds well with 2-year histology (86.4%), whereas the dissolved bright and black box appearances correspond to 3-year histology (88.0% and 90.7%, respectively). Struts indiscernible by OCT correspond to the integrated strut footprints seen at 4 years (100%). Conclusions-: Struts that are still discernible by OCT at 2 years are compatible with largely bioresorbed struts, as demonstrated by histological and gel permeation chromatography analysis. At 3 and 4 years, both OCT and histology confirm complete integration of the struts into the arterial wall.

Evaluation of the second generation of a bioresorbable everolimus drug-eluting vascular scaffold for treatment of de novo coronary artery stenosis: Six-month clinical and imaging outcomes (Article)

2010-11-30T00:00:00Z

Background-: The first generation of the bioresorbable everolimus drug-eluting vascular scaffold showed signs of shrinkage at 6 months, which largely contributed to late luminal loss. Nevertheless, late luminal loss was less than that observed with bare metal stents. To maintain the mechanical integrity of the device up to 6 months, the scaffold design and manufacturing process of its polymer were modified. Methods and results-: Quantitative coronary angiography, intravascular ultrasound with analysis of radiofrequency backscattering, and as an optional assessment, optical coherence tomography (OCT) were performed at baseline and at a 6-month follow-up. Forty-five patients successfully received a single bioresorbable everolimus drug-eluting vascular scaffold. One patient had postprocedural release of myocardial enzyme without Q-wave occurrence; 1 patient with OCT-diagnosed disruption of the scaffold caused by excessive postdilatation was treated 1 month later with a metallic drug-eluting stent. At follow-up, 3 patients declined recatheterization, 42 patients had quantitative coronary angiography, 37 had quantitative intravascular ultrasound, and 25 had OCT. Quantitative coronary angiography disclosed 1 edge restenosis (1 of 42; in-segment binary restenosis, 2.4%). At variance with the ultrasonic changes seen with the first generation of bioresorbable everolimus drug-eluting vascular scaffold at 6 months, the backscattering of the polymeric struts did not decrease over time, the scaffold area was reduced by only 2.0% with intravascular ultrasound, and no change was noted with OCT. On an intention-to-treat basis, the late lumen loss amounted to 0.19±0.18 mm with a limited relative decrease in minimal luminal area of 5.4% on intravascular ultrasound. OCT showed at follow-up that 96.8% of the struts were covered and that malapposition of at least 1 strut, initially observed in 12 scaffolds, was detected at follow-up in only 3 scaffolds. Mean neointimal growth measured by OCT between and on top of the polymeric struts equaled 1.25 mm, or 16.6% of the scaffold area. Conclusion-: Modified manufacturing process of the polymer and geometric changes in the polymeric platform have substantially improved the medium-term performance of this new generation of drug-eluting scaffold to become comparable to those of current drug eluting stents.

A comparison of the conformability of everolimus-eluting bioresorbable vascular scaffolds to metal platform coronary stents (Article)

2010-11-01T00:00:00Z

Objectives The aim of this study was to assess the differences in terms of curvature and angulation of the treated vessel after the deployment of either a metallic stent or a polymeric scaffold device. Background Conformability of metallic platform stents (MPS) is the major determinant of geometric changes in coronary arteries caused by the stent deployment. It is not known how bioresorbable polymeric devices perform in this setting. Methods This retrospective study compares 102 patients who received an MPS (Multi-link Vision or Xience V, Abbott Vascular, Santa Clara, California) in the SPIRIT FIRST and II trials with 89 patients treated with the Revision 1.1 everolimus-eluting bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) from cohort B of the ABSORB (A bioabsorbable everolimus-eluting coronary stent system) trial. All patients were treated with a single 3 × 18 mm device. Curvature and angulation were measured with dedicated software by angiography. Results Both the MPS and BVS groups had significant changes in relative region curvature (MPS vs. BVS: 28.7% vs. 7.5%) and angulation (MPS vs. BVS: 25.4% vs. 13.4%) after deployment. The unadjusted comparisons between the 2 groups showed for BVS a nonsignificant trend for less change in region curvature after deployment (MPS vs. BVS: 0.085 cm-1 vs. 0.056 cm-1, p = 0.06) and a significantly lower modification of angulation (MPS vs. BVS 6.4° vs. 4.3°, p = 0.03). By multivariate regression analysis, the independent predictors of changes in curvature and angulation were the pre-treatment region curvature, the pre-treatment region angulation, and the used device. Conclusions Bioresorbable vascular scaffolds have better conformability than conventional MPS. The clinical significance of the observed differences will require further investigation.

In vivo 3D distribution of lipid-core plaque in human coronary artery as assessed by fusion of near infrared spectroscopy-intravascular ultrasound and multislice computed tomography scan (Article)

2010-11-01T00:00:00Z

The fate of bioresorbable struts located at a side branch ostium: Serial three-dimensional optical coherence tomography assessment (Article)

2010-09-01T00:00:00Z

3-dimensional optical coherence tomography assessment of jailed side branches by bioresorbable vascular scaffolds: A proposal for classification (Article)

2010-08-01T00:00:00Z

Objectives The purpose of this study is to assess jailing of side branches (SB) by the everolimuseluting, bioresorbable vascular scaffold (BVS) with 3-dimensional (3D) optical coherence tomography (OCT) reconstruction. Background Because BVS struts at the SB orifice are suspected of being bioresorbed and/or forming a neointimal bridge, OCT has been used to evaluate the struts in detail at that particular site. Our understanding of the 3D relationship of the strut and the SB orifice is limited by the use of 2-dimensional OCT images. Fourier-domain OCT enables reliable 3D reconstruction of coronary vessels. Methods The ABSORB Cohort B (A Clinical Evaluation of the Bioabsorbable Everolimus Eluting Coronary Stent System in the Treatment of Patients With de Novo Native Coronary Artery Lesions) trial is a multicenter single-arm trial to assess the safety and performance of the BVS. Fourier-domain OCT pullbacks (C7-XR system, LightLab Imaging Inc., Westford, Massachusetts) are obtained at pullback speed of 20 mm/s and 3D renderings are performed. The orifices of the SB are assessed visually. The area of SB orifice and the number of strut-free compartments delineated by the BVS struts are evaluated. Results Fifty-one OCT pullbacks were acquired: 33 pullbacks were imaged with Fourier-domain OCT and 27 treated segments had 46 side branches. Three-dimensional assessment was feasible in 87% (40 of 46) of pullbacks. The mean area of the SB orifice was 1.16 ± 1.02 mm2. The mean number of strut-free compartments was 2.0 ± 1.1. The classification of the overhanging struts is proposed. Conclusions This study demonstrates that 3D OCT reconstruction is feasible to evaluate the orifices of SB jailed with BVS.

First-in-man clinical use of combined near-infrared spectroscopy and intravascular ultrasound: A potential key to predict distal embolization and no-reflow? (Article)

2010-07-20T00:00:00Z

IVUS radiofrequency analysis in the evaluation of the polymeric struts of the bioabsorbable everolimus-eluting device during the bioabsorption process (Article)

2010-05-01T00:00:00Z

Background: In the ABSORB study cohort A the changes in the amount of dense calcium and necrotic core have not been reported in comparison to the prestenting phase; this evaluation could be useful to better clarify the bioabsorption process. Aim of this study was therefore to evaluate the dynamic changes in plaque size and plaque tissue composition observed between 6 months and 2 years follow-up, and to compare these findings to the prestenting phase. Methods: Angiography, intravascular ultrasound and derived parameters (virtual histology, palpography, and echogenicity) were serially assessed postprocedure, at 6 months and at 2 years in 20 patients. In a subset of 8 patients the same measurements were also recorded in the prestenting phase. Results: In the total population a reduction of 18% in the plaque area was observed between 6 month and 2 year follow-up (7.56 ± 2.32 mm2at 6 months vs. 6.16 ± 2.10 mm2at 2 year follow-up; P < 0.01). In the subgroup of eight patients who underwent IVUS during the pre-stenting phase, the plaque area at 2 year follow-up was not significantly different when compared to the prestenting plaque area (7.29 ± 2.29 mm2at prestenting vs. 7.48 ± 1.45 mm2at 2 year follow-up, P 5 NS). Necrotic core area was reduced by 24% between the 6 month and 2 year follow-up (0.97 ± 0.66 mm2at 6 months vs. 0.74 ± 0.53 mm2at 2 year follow-up; P 5 NS), whilst dense calcium was reduced by 14% from 6 month to 2 year follow-up (0.83 ± 0.50 mm2at 6 months vs 0.72 ± 0.64 mm2at 2 year follow-up; P 5 NS). Whilst the necrotic core at 2 years follow-up was not significantly different when compared to the pre-stenting phase (0.62 ± 0.42 mm2prestenting vs 1.07 ± 0.56 mm2at 2 year follow-up; P 5 NS), the area of dense calcium was significantly higher at follow-up compared to prestenting (0.35 ± 0.35 mm2pre-stenting vs. 0.84 ± 0.66 mm2at 2 year follow-up; P < 0.05). Conclusions: The reduction in the necrotic core component between 6 month and two year followup could be related to a synergistic effect of the bio-absorption process and the antiinflammatory action of everolimus.

Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro (Article)

2010-04-15T00:00:00Z

This study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods have greatly enhanced the diagnostic capabilities for the detection of high-risk atherosclerotic plaques. IVUS RF data analysis and OCT are two techniques focusing on plaque morphology and composition. Regions of interest were selected and imaged with OCT and IVUS in 50 sections, from 14 human coronary arteries, sectioned post-mortem from 14 hearts of patients dying of non-cardiovascular causes. Plaques were classified based on IVUS RF data analysis (VH-IVUSTM), OCT and the combination of those. Histology was the benchmark. Imaging with both modalities and coregistered histology was successful in 36 sections. OCT correctly classified 24; VH-IVUS 25, and VH-IVUS/OCT combined, 27 out of 36 cross-sections. Systematic misclassifications in OCT were intimal thickening classified as fibroatheroma in 8 cross-sections. Misclassifications in VH-IVUS were mainly fibroatheroma as intimal thickening in 5 cross-sections. Typical image artifacts were found to affect the interpretation of OCT data, misclassifying intimal thickening as fibroatheroma or thin-cap fibroatheroma. Adding VH-IVUS to OCT reduced the error rate in this study.

Three-dimensional visualization of intracoronary thrombus during stent implantation using the second generation, fourier domain optical coherence tomography (Article)

2010-03-01T00:00:00Z

Preoxygenated hemoglobin-based oxygen carrier HBOC-201 annihilates myocardial ischemia during brief coronary artery occlusion in pigs (Article)

2010-03-01T00:00:00Z

Because of their ability to perfuse remote regions and deliver oxygen, hemoglobin-based oxygen carriers (HBOCs) may be considered in the treatment of several ischemic conditions such as acute coronary syndromes or high-risk percutaneous intervention. Here we studied the effects of intracoronary infusion of ex vivo preoxygenated HBOC-201 during brief total coronary artery occlusion (CAOs) on myocardial oxygenation and left ventricular (LV) function in a large animal model and investigated the influence of HBOC-201 temperature and infusion rate on these effects. Thirteen open-chest anesthetized swine were instrumented for measurement of global and regional LV function and metabolism. CAOs were induced by inflating an intracoronary balloon catheter; preoxygenated HBOC-201 (12 g/dL) was infused distally through the central lumen of the balloon catheter. Animals underwent consecutive 3-min CAOs interspersed by 30 min of reperfusion, accompanied by different HBOC-201 infusion rates (0, 15, 23, 30, 40, and 50 ml/min) and/or two infusion temperatures (18° C or 37° C) in random order. CAO elicited immediate loss of systolic shortening (SS) in the ischemic region (19 ± 1% at baseline vs. -3 ± 2% at end of CAO), resulting in decreases in maximum rate of rise in LV pressure (15 ± 5%) and stroke volume (12 ± 4%; all P < 0.05). Balloon deflation resulted in marked coronary reactive hyperemia (to 472 ± 74% of baseline), increases in coronary venous concentrations of adenosine + inosine (to 218 ± 26% of baseline; both P < 0.05) and rapid restoration of SS toward baseline. HBOC-201 ameliorated the CAO-induced changes in SS, stroke volume, reactive hyperemia, and coronary venous adenosine ± inosine. The effects were temperature and flow dependent with full preservation of SS at 50 ml/min HBOC-201 of 37° C. In conclusion, intracoronary preoxygenated HBOC-201 preserved myocardial oxygenation and LV function in swine during CAO in a dose- and temperature-dependent manner. In our study setting, preoxygenated HBOC-201 can match the oxygen delivery role of endogenous blood in the heart on an almost equivalent-volume basis. Copyright

Monitoring in vivo absorption of a drug-eluting bioabsorbable stent with intravascular ultrasound-derived parameters: A feasibility study (Article)

2010-03-01T00:00:00Z

Objectives: The aim of this study was to investigate the feasibility of using quantitative differential echogenicity to monitor the in vivo absorption process of a drug-eluting poly-l-lactic-acid (PLLA) bioabsorbable stent (BVS, Abbott Vascular, Santa Clara, CA). Background: A new bioabsorbable, balloon-expanded coronary stent was recently evaluated in a first-in-man study. Little is known about the absorption process in vivo in diseased human coronary arteries. Methods: In the ABSORB (Clinical Evaluation of the BVS everolimus eluting stent system) study, 30 patients underwent treatment with the BVS coronary stent system and were examined with intracoronary ultrasound (ICUS) after implantation, at 6 months and at 2-year follow-up. Quantitative ICUS was used to measure dimensional changes, and automated ICUS-based tissue composition software (differential echogenicity) was used to quantify plaque compositional changes over time in the treated regions. Results: The BVS struts appeared as bright hyperechogenic structures and showed a continuous decrease of their echogenicity over time, most likely due to the polymer degradation process. In 12 patients in whom pre-implantation ICUS was available, at 2 years the percentage-hyperechogenic tissue was close to pre-implantation values, indicating that the absorption process was either completed or the remaining material was no longer differentially echogenic from surrounding tissues. Conclusions: Quantitative differential echogenicity is a useful plaque compositional measurement tool. Furthermore, it seems to be valuable for monitoring the absorption process of bioabsorbable coronary stents made of semi-crystalline polymers.

Expert review document on methodology, terminology, and clinical applications of optical coherence tomography: Physical principles, methodology of image acquisition, and clinical application for assessment of coronary arteries and atherosclerosis (Article)

2010-02-01T00:00:00Z

Optical coherence tomography (OCT) is a novel intravascular imaging modality, based on infrared light emission, that enables a high resolution arterial wall imaging, in the range of 10-20 microns. This feature of OCT allows the visualization of specific components of the atherosclerotic plaques. The aim of the present Expert Review Document is to address the methodology, terminology and clinical applications of OCT for qualitative and quantitative assessment of coronary arteries and atherosclerosis.

Multi-modality intra-coronary plaque characterization: A pilot study (Article)

2010-01-07T00:00:00Z

Background: The risk of rupture and subsequent thrombosis of the atherosclerotic coronary plaques is related to the presence of necrotic core with high lipid content. We conducted an exploratory pilot trial to compare the capability for lipid tissue detection using four intra-coronary diagnostic techniques: greyscale intravascular ultrasound (GS IVUS), IVUS radiofrequency data (IVUS RFD) analysis, optical coherence tomography (OCT) and intravascular magnetic resonance spectroscopy (IVMR). Methods: Twenty-four matched target plaques were analyzed with the 4 techniques in non-culprit lesions in five patients with stable angina. Following IVUS pullback, OCT and IVMR was performed. Plaque composition was assessed using established criteria of each technology. Results: Atherosclerotic plaques classified as soft by GS IVUS were mainly composed by fibro-fatty (80%) or necrotic core (20%) by IVUS RFD. These soft plaques were classified as "lipid-rich" by OCT in the majority of cases (80%). IVMR confirmed the presence of lipid with a lipid fraction index ranging between 36 and 79 in these soft plaques. Besides this good agreement for soft plaques, GS IVUS, IVUS RFD and OCT had 100% agreement in the identification of calcified plaques. Conclusion: The present study explored multi-modality imaging of atherosclerotic plaque in-vivo. Assessing specifically lipid-rich plaques, there was generally good agreement for plaque components identified as soft by traditional GS IVUS with RFD and OCT whereas IVMR showed a varying amount of lipid in these regions. Nevertheless there continues to remain inherent variation, namely as a result of the different imaging resolutions and the lack of common nomenclature and classification.

An optical coherence tomography study of a biodegradable vs. durable polymer-coated limus-eluting stent: A LEADERS trial sub-study (Article)

2010-01-01T00:00:00Z

AimsIncomplete endothelialization has been found to be associated with late stent thrombosis, a rare but devastating phenomenon, more frequent after drug-eluting stent implantation. Optical coherence tomography (OCT) has 10 times greater resolution than intravascular ultrasound and thus appears to be a valuable modality for the assessment of stent strut coverage. The LEADERS trial was a multi-centre, randomized comparison of a biolimus-eluting stent (BES) with biodegradable polymer with a sirolimus-eluting stent (SES) using a durable polymer. This study sought to evaluate tissue coverage and apposition of stents using OCT in a group of patients from the randomized LEADERS trial.Methods and resultsFifty-six consecutive patients underwent OCT during angiographic follow-up at 9 months. OCT images were acquired using a non-occlusive technique at a pullback speed of 3 mm/s. Data were analysed using a Bayesian hierarchical random-effects model, which accounted for the correlation of lesion characteristics within patients and implicitly assigned analytical weights to each lesion depending on the number of struts observed per lesion. Primary outcome was the difference in percentage of uncovered struts between BESs and SESs. Twenty patients were included in the analysis in the BES group (29 lesions with 4592 struts) and 26 patients in the SES group (35 lesions with 6476 struts). A total of 83 struts were uncovered in the BES group and 407 out of 6476 struts were uncovered in the SES group [weighted difference-1.4, 95 confidence interval (CI)-3.7 to 0.0, P = 0.04]. Results were similar after adjustment for pre-procedure lesion length, reference vessel diameter, number of implanted study stents, and presence of stent overlap. There were three lesions in the BES group and 15 lesions in the SES group that had ≥5 of all struts uncovered (difference-33.1, 95 CI-61.7 to-10.3, P < 0.01).ConclusionStrut coverage at an average follow-up of 9 months appears to be more complete in patients allocated to BESs when compared with SESs. The impact of this difference on clinical outcome and, in particular, on the risk of late stent thrombosis is yet to be determined. © Published on behalf of the European Society of Cardiology. All rights reserved.

Fully automatic three-dimensional quantitative analysis of intracoronary optical coherence tomography: Method and validation (Article)

2009-12-01T00:00:00Z

Objectives and background: Quantitative analysis of intracoronary optical coherence tomography (OCT) image data (QOCT) is currently performed by a time-consuming manual contour tracing process in individual OCT images acquired during a pullback procedure (frame-based method). To get an efficient quantitative analysis process, we developed a fully automatic three-dimensional (3D) lumen contour detection method and evaluated the results against those derived by expert human observers. Methods: The method was developed using Matlab (The Mathworks, Natick, MA). It incorporates a graphical user interface for contour display and, in the selected cases where this might be necessary, editing. OCT image data of 20 randomly selected patients, acquired with a commercially available system (Lightlab imaging, Westford, MA), were pulled from our OCT database for validation. Results: A total of 4,137 OCT images were analyzed. There was no statistically significant difference in mean lumen areas between the two methods (5.03 ± 2.16 vs. 5.02 ± 2.21 mm2; P = 0.6, human vs. automated). Regression analysis showed a good correlation with an r value of 0.99. The method requires an average 2-5 sec calculation time per OCT image. In 3% of the detected contours an observer correction was necessary. Conclusion: Fully automatic lumen contour detection in OCT images is feasible with only a select few contours showing an artifact (3%) that can be easily corrected. This QOCT method may be a valuable tool for future coronary imaging studies incorporating OCT.

Optical coherence tomography assessment of the acute effects of stent implantation on the vessel wall: A systematic quantitative approach (Article)

2009-12-01T00:00:00Z

Objective: To observe and characterise vessel injury after stenting using optical coherence tomography (OCT), to propose a systematic OCT classification for periprocedural vessel trauma, to evaluate its frequency in stable versus unstable patients and to assess its clinical impact during the hospitalisation period. Setting: Stenting causes vessel injury. Design and interventions: All consecutive patients in whom OCT was performed after stent implantation were included in the study. Qualitative and quantitative assessment of tissue prolapse, intra-stent dissection and edge dissection were performed. Results: Seventy-three patients (80 vessels) were analysed. Tissue prolapse within the stented segment was visible in 78/80 vessels (97.5%). Median number of tissue prolapse sites was 8 (IQR 4-19), mean (SD) area 1.04 (0.9) mm2. Intra-stent dissection flaps were visible in 69/80 vessels (86.3%) (median number 3 (IQR 1.25-6), maximum flap length 450 (220) μm). Fifty-five out of 80 vessels (68.8%) showed dissection cavities (median number 2 (IQR 0-4.75), maximum depth 340 (170) μm). Edge dissection was visible in 20 vessels (mean (SD) length flap 744 (439) μm). The frequency of tissue prolapse or intra-stent dissection was similar in stable and unstable patients (95.6% vs 100%, p = 0.5 for tissue prolapse; 91.1% vs 82.9%, p = 0.3 for intra-stent dissection). There were no events during the hospitalisation period. Conclusions: OCT allows a detailed visualisation of vessel injury after stent implantation and enables a systematic classification and quantification in vivo. In this study, frequency of tissue prolapse or intra-stent dissections after stenting was high, irrespective of the clinical presentation of the patients, and was not associated with clinical events during hospitalisation.

Imaging atherosclerotic plaque composition with intracoronary optical coherence tomography (Article)

2009-11-01T00:00:00Z

Optical coherence tomography (OCT) allows highly accurate diagnosis of atherosclerotic plaques, including measurement of the thickness of fibrous caps, permitting an assessment of the risk of rupture. While the OCT image presents morphological information in highly resolved detail, it relies on interpretation by trained readers for the identification of tissue type. We developed a method for quantitative classification of atherosclerotic plaque constituents. The optical attenuation coefficient μtdistinguishes different tissue types: necrotic core and macrophage infiltration exhibit strong attenuation, μt≥10 mm-1, while calcific and fibrous tissue have a lower μt≈2-5 mm-1.

Optical coherence tomography patterns of stent restenosis (Article)

2009-08-01T00:00:00Z

Background: Stent restenosis is an infrequent but poorly understood clinical problem in the drug-eluting stent era. The aim of the study was to evaluate the morphologic characteristics of stent restenosis by optical coherence tomography (OCT). Methods: Patients (n = 24, 25 vessels) presenting with angiographically documented stent restenosis were included. Quantitative OCT analysis consisted of lumen and stent area measurement and calculation of restenotic tissue area and burden. Qualitative restenotic tissue analysis included assessment of tissue structure, backscattering and symmetry, visible microvessels, lumen shape, and presence of intraluminal material. Results: By angiography, restenosis was classified as diffuse, focal, and at the margins in 9, 11, and 5 vessels, respectively. By OCT, restenotic tissue structure was layered in 52%, homogeneous in 28%, and heterogeneous in 20%. The predominant backscatter was high in 72%. Microvessels were visible in 12%. Lumen shape was irregular in 28% and there was intraluminal material in 20%. The mean restenotic tissue symmetry ratio was 0.58 ± 0.19. Heterogeneous and low scattering restenotic tissue was more frequent in focal (45.5% and 54.5%, respectively) than in diffuse (0 and 11.1%) and margin restenosis (0 and 0%) (P = .005 for heterogeneous, P = .03 for low scattering). Restenosis patients with unstable angina symptoms presented more frequently irregular lumen shape (60 vs 6.7%, P = .007). Stents implanted ≤12 months ago had more frequently restenotic tissue with layered appearance (84.6% vs 16.7%, P = .003). Conclusions: We demonstrate the ability of OCT to identify differential patterns of restenotic tissue after stenting. This information could help in understanding the mechanism of stent restenosis.

Virtual histology and optical coherence tomography: From research to a broad clinical application (Article)

2009-08-01T00:00:00Z

MAHOROBA, first-in-man study: 6-month results of a biodegradable polymer sustained release tacrolimus-eluting stent in de novo coronary stenoses (Article)

2009-06-01T00:00:00Z

AimsTo report the 4-month angiographic and 6-month clinical follow-up in first-in-man study using the tacrolimus-eluting bioabsorbable polymer-coated cobalt-chromium MAHOROBA™ stent.Methods and resultsA total of 47 patients with either stable angina or unstable angina, or silent myocardial ischaemia, based on a de novo coronary stenosis that could be covered by a single 18 mm stent in a native coronary artery with a diameter between 3.0 and 3.5 mm were enrolled at three sites. The primary endpoint was in-stent late loss at 4 months. The secondary endpoints include volume obstruction of the stents assessed by intravascular ultrasound (IVUS) at 4 months and major adverse cardiac events (MACE) at 6 months. Forty-seven patients were enrolled. Procedural success was achieved in 97.9. At 4-month follow-up, in-stent late loss was 0.99 ± 0.46 mm, whereas in-stent volume obstruction in IVUS was 34.8 ± 15.8. At 6 months, there were no deaths, but 2 patients suffered from a myocardial infarction and 11 patients required ischaemia-driven repeat revascularization. The composite MACE rate was 23.4.ConclusionThis tacrolimus-eluting stent failed to prevent neointimal hyperplasia, despite the theoretical advantages of the tacrolimus, which has less inhibitory effects on endothelial cells than smooth muscle cells.

Incomplete Stent Apposition and Delayed Tissue Coverage Are More Frequent in Drug-Eluting Stents Implanted During Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction Than in Drug-Eluting Stents Implanted for Stable/Unstable Angina. Insights From Optical Coherence Tomography (Article)

2009-05-01T00:00:00Z

Objectives: The aim of this study was to compare the frequency of incomplete stent apposition (ISA) and struts not covered by tissue at long-term follow-up (as assessed by optical coherence tomography [OCT]) in drug-eluting stents (DES) implanted during primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) versus DES implanted for unstable and stable angina. Background: Incomplete stent apposition and the absence of strut endothelialization might be linked to stent thrombosis. DES implanted for STEMI might have a higher risk of thrombosis. Methods: Consecutive patients in whom OCT was performed at least 6 months after DES implantation were included in the study. Stent struts were classified on the basis of the presence or absence of ISA and tissue coverage. Results: Forty-seven lesions in 43 patients (1,356 frames, 10,140 struts) were analyzed (49% stable angina, 17% unstable angina, 34% STEMI). Median follow-up time was 9 (range 7 to 72) months. Drug-eluting stents implanted during primary PCI presented ISA more often than DES implanted in stable/unstable angina patients (75% vs. 25.8%, p = 0.001). The frequency of uncovered struts was also higher in the STEMI group (93.8% vs. 67.7%, p = 0.048). On multivariate analysis, DES implantation in STEMI was the only independent predictor of ISA (odds ratio: 9.8, 95% confidence interval: 2.4 to 40.4, p = 0.002) and the presence of uncovered struts at follow-up (odds ratio: 9.5, 95% confidence interval: 1.0 to 90.3, p = 0.049). Conclusions: DES implanted for STEMI had a higher frequency of incompletely apposed struts and uncovered struts as assessed by OCT at follow-up. DES implantation during primary PCI in STEMI was an independent predictor of ISA and the presence of uncovered struts at follow-up.

First case of stenting of a vulnerable plaque in the SECRITT I trial-the dawn of a new era? (Article)

2009-05-01T00:00:00Z

BACKGROUND: A 63-year-old man presented with class II anginal symptoms. INVESTIGATIONS: Cardiac catheterization, intravascular ultrasound (IVUS) virtual histology, optical coherence tomography and off-line palpography. DIAGNOSIS: The patient was diagnosed as having a culprit lesion in the left circumflex artery and a vulnerable plaque in the left anterior descending artery. MANAGEMENT: The culprit lesion was treated with two overlapping drug-eluting stents. The vulnerable plaque was then treated with a self-expanding stent tailored to shield vulnerable plaques (vProtect Luminal Shield). After dilatation of the stent with a low-pressure balloon, IVUS and optical coherence tomography showed excellent apposition of the stent to the vessel wall, with no signs of tissue prolapse or edge dissections. At the 6-month follow-up appointment, the stent showed complete tissue coverage without signs of in-stent restenosis. CONCLUSIONS: Six months of follow-up has demonstrated that a patient with an IVUS-derived, thin capped fibroatheroma was successfully treated with a stent tailored to shield vulnerable plaques.

Optical Coherence Tomography to Guide Treatment of Chronic Occlusions? (Article)

2009-04-01T00:00:00Z

In Vivo Assessment of High-Risk Coronary Plaques at Bifurcations With Combined Intravascular Ultrasound and Optical Coherence Tomography (Article)

2009-04-01T00:00:00Z

Objectives: This study sought to evaluate the in vivo frequency and distribution of high-risk plaques (i.e., necrotic core rich) at bifurcations using a combined plaque assessment with intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT). Background: Pathological examinations have shown that atherosclerotic plaque rich in necrotic core is prone to develop at bifurcations. High-risk plaque detection could be improved by the combined use of a technique able to detect necrotic core (IVUS-VH) and a high-resolution technique that allows the measurement of the fibrous cap thickness (OCT). Methods: From 30 patients imaged with IVUS-VH and OCT, 103 bifurcations were selected. The main branch was analyzed at the proximal rim of the ostium of the side branch, at the in-bifurcation segment and at the distal rim of the ostium of the side branch. Plaques with more than 10% confluent necrotic core by IVUS-VH were selected and classified as fibroatheroma (FA) or thin-cap fibroatheroma (TCFA) depending on the thickness of the fibrous cap by OCT (>65 or ≤65 μm for FA and TCFA, respectively). Results: Twenty-seven FA (26.2%) and 18 TCFA (17.4%) were found out of the 103 lesions studied. Overall the percentage of necrotic core decreases from proximal to distal rim (16.8% vs. 13.5% respectively, p = 0.01), whereas the cap thickness showed an inverse tendency (130 ± 105 μm vs. 151 ± 68 μm for proximal and distal rim, respectively, p = 0.05). The thin caps were more often located in the proximal rim (15 of 34, 44.1%), followed by the in-bifurcation segment (14 of 34, 41.2%), and were less frequent in the distal rim (5 of 34, 14.7%). Conclusions: The proximal rim of the ostium of the side branch has been identified as a region more likely to contain thin fibrous cap and a greater proportion of necrotic core.

A bioabsorbable everolimus-eluting coronary stent system (ABSORB): 2-year outcomes and results from multiple imaging methods (Article)

2009-03-18T00:00:00Z

Background: Drug-eluting metallic coronary stents predispose to late stent thrombosis, prevent late lumen vessel enlargement, hinder surgical revascularisation, and impair imaging with multislice CT. We assessed the safety of the bioabsorbable everolimus-eluting stent (BVS). Methods: 30 patients with a single de-novo coronary artery lesion were followed up for 2 years clinically and with multiple imaging methods: multislice CT, angiography, intravascular ultrasound, derived morphology parameters (virtual histology, palpography, and echogenicity), and optical coherence tomography (OCT). Findings: Clinical data were obtained from 29 of 30 patients. At 2 years, the device was safe with no cardiac deaths, ischaemia-driven target lesion revascularisations, or stent thromboses recorded, and only one myocardial infarction (non-Q wave). 18-month multislice CT (assessed in 25 patients) showed a mean diameter stenosis of 19% (SD 9). At 2-year angiography, the in-stent late loss of 0·48 mm (SD 0·28) and the diameter stenosis of 27% (11) did not differ from the findings at 6 months. The luminal area enlargement on OCT and intravascular ultrasound between 6 months and 2 years was due to a decrease in plaque size without change in vessel size. At 2 years, 34·5% of strut locations presented no discernible features by OCT, confirming decreases in echogenicity and in radiofrequency backscattering; the remaining apparent struts were fully apposed. Additionally, vasomotion occurred at the stented site and adjacent coronary artery in response to vasoactive agents. Interpretation: At 2 years after implantation the stent was bioabsorbed, had vasomotion restored and restenosis prevented, and was clinically safe, suggesting freedom from late thrombosis. Late luminal enlargement due to plaque reduction without vessel remodelling needs confirmation. Funding: Abbott Vascular (USA).

Intracoronary optical coherence tomography and the evaluation of stents (Article)

2009-01-01T00:00:00Z

The application of optical coherence tomography to the cardiovascular system has led to intense interest, both clinically and also on the research front. Based on sound optical physics, intracoronary, in vivo imaging with high resolution (15 µm) has given unique insights into not only atherosclerotic plaques but also the tissue responses underlying stent implantation. This article will introduce the application of optical coherence tomography technology to coronary arteries, with particular reference to the evaluation of stents, and will also give a glimpse into current and future developments that will see optical coherence tomography remain a key tool in the armamentarium of researchers and interventional cardiologists alike

Comprehensive Assessment of Coronary Artery Stenoses. Computed Tomography Coronary Angiography Versus Conventional Coronary Angiography and Correlation With Fractional Flow Reserve in Patients With Stable Angina (Article)

2008-08-19T00:00:00Z

Objectives: We sought to determine the diagnostic accuracy of noninvasive visual (computed tomography coronary angiography [CTCA]) and quantitative computed tomography coronary angiography (QCT) to predict the hemodynamic significance of a coronary stenosis, using intracoronary fractional flow reserve (FFR) as the reference standard. Background: It has been demonstrated that CTCA provides excellent diagnostic sensitivity for identifying coronary stenoses, but may lack accurate delineation of the hemodynamic significance. Methods: We investigated 79 patients with stable angina pectoris who underwent both 64-slice or dual-source CTCA and FFR measurement of discrete coronary stenoses. CTCA and conventional coronary angiography (CCA), and QCT and quantitative coronary angiography (QCA), were performed to determine the severity of a stenosis that was compared with FFR measurements. A significant anatomical or functional stenosis was defined as ≥50% diameter stenosis or an FFR <0.75. Stented segments and bypass grafts were not included in the analysis. Results: A total of 89 stenoses were evaluated of which 18% (16 of 89) had an FFR <0.75. The diagnostic accuracy of CTCA, QCT, CCA, and QCA to detect a hemodynamically significant coronary lesion was 49%, 71%, 61%, and 67%, respectively. Correlation between QCT and QCA with FFR measurement was weak (R values of -0.32 and -0.30, respectively). Correlation between QCT and QCA was significant, but only moderate (R = 0.53; p < 0.0001). Conclusions: The anatomical assessment of the hemodynamic significance of coronary stenoses determined by visual CTCA, CCA, or QCT or QCA does not correlate well with the functional assessment of FFR. Determining the hemodynamic significance of an angiographically intermediate stenosis remains relevant before referral for revascularization treatment.

Assessment of Culprit and Remote Coronary Narrowings Using Optical Coherence Tomography With Long-Term Outcomes (Article)

2008-08-15T00:00:00Z

Much currently known information about vulnerable plaque stems from postmortem studies that identified several characteristics making them prone to rupture, including the presence of a thin fibrous cap and a large lipid core. This study used optical coherence tomography (OCT) to assess culprit and remote coronary narrowings and investigate whether intracoronary OCT in living patients was able to visualize morphologic features associated with vulnerable plaque in postmortem studies. Twenty-three patients successfully underwent OCT before percutaneous coronary intervention. The culprit lesion and mild to moderate coronary narrowings remote from the target stenosis were investigated. Using OCT, the culprit lesion was found to be fibrous in 39.1%, fibrocalcific in 34.4%, and lipid rich in 26.1% of cases. Two patients met criteria for thin-cap fibroatheroma (TCFA; defined as the presence of a signal-rich fibrous cap covering a signal-poor lipid/necrotic core with cap thickness <0.2 mm). Most plaques at remote segments were proximal to the culprit lesion (73.9%) and predominantly fibrous and lipid rich. OCT identified 7 TCFA lesions in 6 patients with a mean cap thickness of 0.19 ± 0.05 mm, extending for 103° ± 49° of the total vessel circumference. At 24 months of clinical follow-up, the only event occurred in a patient with in-stent restenosis who underwent repeated percutaneous revascularization. There were no clinically apparent plaque rupture-related events in the 6 patients found to have remote TCFA. This study showed that OCT can be safely applied to image beyond the culprit lesion and can detect in vivo morphologic features associated with plaque vulnerability using retrospective pathologic examination. In conclusion, detection of TCFA, particularly in stable patients, is desirable and may principally allow for early intervention and prevention of adverse events.

Optical coherence tomography assessment of vulnerable plaque rupture: Predilection for the plaque 'shoulder' (Article)

2008-08-01T00:00:00Z

A novel approach for quantitative analysis of intracoronary optical coherence tomography: High inter-observer agreement with computer-assisted contour detection (Article)

2008-08-01T00:00:00Z

Objective: This study aims to examine observer-related variability of quantitative optical coherence tomography (OCT) derived measurements from both in vitro and in vivo pullback data. Background: Intravascular OCT is a new imaging modality using infrared light and offering 10 times higher image resolution (15 μm) compared to intravascular ultrasound. The quantitative analysis of in vivo intracoronary OCT imaging is complicated by the presence of blood, motion artifacts and the large quantity of information that has to be processed. Methods: We developed a standardized, automated quantification process for intracoronary OCT pullback data with inter-observer variability assessed both in vitro by using postmortem human coronary arteries and in vivo by studying simple and complex coronary pathology and outcomes following stent implantation. The consensus between measurements by two observers was analyzed using the intraclass and interclass correlation coefficient and the reliability coefficients. Bland-Altman plots were generated to assess the relationship between variability and absolute measurements. Results: In vitro OCT assessment was performed in nine postmortem coronary arteries. The time needed for semiautomated contour detection of a 15-mm long coronary segment was ∼40 min. The absolute and relative difference between lumen area measurements derived from two observers was low [0.02 ± 0.10 mm2; (0.3 ± 0.5)% respectively] with excellent correlation confirmed by linear regression analysis (R2= 0.99; P < 0.001). Similarly, in vivo measurements demonstrated a high correlation with the main source of inter-observer variation occurring as a result of coronary dissection and motion artifact. The absolute and relative difference between measurements were 0.11 ± 0,33 mm2(1.57 ± 0.05)% for lumen area (R2= 0.98; P < 0.001), 0.17 ± 0.68 mm2(1.44 ± 0.08)% for stent area (R2= 0.94; P < 0.001), and 0.26 ± 0.72 mm2(14.05 ± 0.37)% for neointimal area (R2= 0.78; P < 0.001). Conclusions: Highly accurate computer-assisted quantitative analysis of intracoronary OCT pullbacks is feasible with low inter-observer variability. The presented approach allows for observer independent analysis of detailed vessel structures, and may be a valuable tool for future longitudinal studies incorporating OCT,

Optical Coherence Tomography Findings in Very Late (4 Years) Paclitaxel-Eluting Stent Thrombosis (Article)

2008-08-01T00:00:00Z

A bioabsorbable everolimus-eluting coronary stent system for patients with single de-novo coronary artery lesions (ABSORB): a prospective open-label trial (Article)

2008-03-20T00:00:00Z

Background: A fully bioabsorbable drug-eluting coronary stent that scaffolds the vessel wall when needed and then disappears once the acute recoil and constrictive remodelling processes have subsided has theoretical advantages. The bioasorbable everolimus-eluting stent (BVS) has a backbone of poly-L-lactic acid that provides the support and a coating of poly-D,L-lactic acid that contains and controls the release of the antiproliferative agent everolimus. We assessed the feasibility and safety of this BVS stent. Methods: In this prospective, open-label study we enrolled 30 patients who had either stable, unstable, or silent ischaemia and a single de-novo lesion that was suitable for treatment with a single 3·0×12 mm or 3·0×18 mm stent. Patients were enrolled from four academic hospitals in Auckland, Rotterdam, Krakow, and Skejby. The composite endpoint was cardiac death, myocardial infarction, and ischaemia-driven target lesion revascularisation. Angiographic endpoints were available for 26 patients and intravascular-ultrasound endpoints for 24 patients. Clinical endpoints were assessed in all 30 patients at 6 and 12 months. In a subset of 13 patients, optical coherence tomography was undertaken at baseline and follow-up. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00300131. Findings: Procedural success was 100% (30/30 patients), and device success 94% (29/31 attempts at implantation of the stent). At 1 year, the rate of major adverse cardiac events was 3·3%, with only one patient having a non-Q wave myocardial infarction and no target lesion revascularisations. No late stent thromboses were recorded. At 6-month follow-up, the angiographic in-stent late loss was 0·44 (0·35) mm and was mainly due to a mild reduction of the stent area (-11·8%) as measured by intravascular ultrasound. The neointimal area was small (0·30 [SD 0·44] mm2), with a minimal area obstruction of 5·5%. Interpretation: This study shows the feasibility of implantation of the bioabsorbable everolimus-eluting stent, with an acceptable in-stent late loss, minimal intrastent neointimal hyperplasia, and a low stent area obstruction. Funding: Abbott Vascular.

Diagnosis and treatment of coronary vulnerable plaques (Article)

2008-02-01T00:00:00Z

Thin-capped fibroatheroma is the morphology that most resembles plaque rupture. Detection of these vulnerable plaques in vivo is essential to being able to study their natural history and evaluate potential treatment modalities and, therefore, may ultimately have an important impact on the prevention of acute myocardial infarction and death. Currently, conventional grayscale intravascular ultrasound, virtual histology and palpography data are being collected with the same catheter during the same pullback. A combination of this catheter with either thermography capability or additional imaging, such as optical coherence tomography or spectroscopy, would be an exciting development. Intravascular magnetic resonance imaging also holds much promise. To date, none of the techniques described above have been sufficiently validated and most importantly, their predictive value for adverse cardiac events remains elusive. Very rigorous and well-designed studies are compelling for defining the role of each diagnostic modality. Until we are able to detect in vivo vulnerable plaques accurately, no specific treatment is warranted.

Proof-of-concept trial to evaluate haemoglobin based oxygen therapeutics in elective percutaneous coronary revascularisation. Rationale, protocol design and haemodynamic results. (Article)

2008-01-01T00:00:00Z

AIMS: To test the hypothesis that intracoronary infusion of pre-oxygenated HBOC-201 during brief, total coronary artery occlusion would preserve left ventricular function. METHODS: Immediately following a successful PCI, the target coronary artery was occluded without ("dry occlusion")--or with--infusion of pre-oxygenated HBOC-201 distal to the stent via the guidewire shaft of an over-the-wire balloon for up to three minutes at an infusion rate of 48 ml/min. A cross-over design was applied. Early signs of myocardial ischaemia were evaluated by left ventricular pressure-volume loops and intracoronary ECG. A 12-lead Holter ECG was activated before the PCI and deactivated four hours after the study period. Primary endpoints were change in left ventricular relaxation indices and in the sum of ST segment deviations. RESULTS: None of the measured parameters differed significantly from their respective baseline values during HBOC-201 infusion. By contrast, ejection fraction (EF), cardiac output (CO) and minimal rate of LV pressure change (dP/dTMIN) decreased significantly and the end diastolic pressure (EDP) and time constant of relaxation increased significantly during dry occlusions (P<0.05). The end diastolic pressure-volume relationship (EDPVR) at the fixed pressure level of 30 mmHg (V30), an index of myocardial compliance, reflected greater myocardial stiffness during dry occlusions compared to occlusions with HBOC-201 infusion. CONCLUSIONS: Intracoronary infusion of oxygenated HBOC-201 is capable of preserving left ventricular function, likely through maintenance of myocardial oxygenation. It is hypothesised, that in an acute setting, HBOC-201 could serve as an oxygen bridge to reperfusion by PCI extending the "golden" time period during which permanent myocardial damage is unlikely.

Three-dimensional and quantitative analysis of atherosclerotic plaque composition by automated differential echogenicity (Article)

2007-12-01T00:00:00Z

Objective: To validate automated and quantitative three-dimensional analysis of coronary plaque composition using intracoronary ultrasound (ICUS). Background: ICUS displays different tissue components based on their acoustic properties in 256 grey-levels. We hypothesised that computer-assisted image analysis (differential echogenicity) would permit automated quantification of several tissue components in atherosclerotic plaques. Methods and Results: Ten 40-mm-long left anterior descending specimens were excised during autopsy of which eight could be successfully imaged by ICUS. Histological sections were taken at 5 mm intervals and analyzed. Since most of the plaques were calcified and having a homogeneous appearance, one specimen with a more heterogeneous composition was further examined: at each interval of 5 mm, 15 additional sections (every 100 μm) were evaluated. Plaques were scored for echogenicity against the adventitia: brighter (hyperechogenic) or less bright (hypoechogenic). Areas of hypoechogenicity correlated with the presence of smooth muscle cells. Areas of hyperechogenicity correlated with presence of collagen, and areas of hyperechogenicity with acoustic shadowing correlated with calcium. None of these comparisons showed statistical significant differences. Conclusion: This ex vivo feasibility study shows that automated three-dimensional differential echogenicity analysis of ICUS images allows identification of different tissue types within atherosclerotic plaques. This technology may play a role as an additional tool in longitudinal studies to trace possible changes in plaque composition.

Comparison of Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography in Women Versus Men With Angina Pectoris (Article)

2007-11-15T00:00:00Z

We compared the diagnostic accuracy of 64-slice computed tomographic (CT) coronary angiography to detect significant coronary artery disease (CAD) in women and men. The 64-slice CT coronary angiography was performed in 402 symptomatic patients, 123 women and 279 men, with CAD prevalence of 51% and 68%, respectively. Significant CAD, defined as ≥50% coronary stenosis on quantitative coronary angiography, was evaluated on a patient, vessel, and segment level. The sensitivity and negative predictive value to detect significant CAD was very good, both for women and men (100% vs 99%, p = NS; 100% vs 98%, p = NS), whereas diagnostic accuracy (88% vs 96%; p <0.01), specificity (75% vs 90%, p <0.05), and positive predictive value (81% vs 95%, p <0.001) were lower in women. The per-segment analysis demonstrated lower sensitivity in women compared with men (82% vs 93%, p <0.001). The sensitivity in women did not show a difference in proximal and midsegments, but was significantly lower in distal segments (56% vs 85%, p <0.05) and side branches (54% vs 89%, p <0.001). In conclusion, CT coronary angiography reliably rules out the presence of obstructive CAD in both men and women. Specificity and positive predictive value of CT coronary angiography were lower in women. The sensitivity to detect stenosis in small coronary branches was lower in women compared with men.

From Postmortem Characterization to the In Vivo Detection of Thin-Capped Fibroatheromas: The Missing Link Toward Percutaneous Treatment. What If Diogenes Would Have Found What He Was Looking For?**Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American... (Article)

2007-09-04T00:00:00Z

Short- and long-term clinical outcome after drug-eluting stent implantation for the percutaneous treatment of left main coronary artery disease: insights from the Rapamycin-Eluting and Taxus Stent Evaluated At Rotterdam Cardiology Hospital registries (RESEARCH and T-SEARCH). (Article)

2005-03-22T00:00:00Z

BACKGROUND: The impact of drug-eluting stent (DES) implantation on the incidence of major adverse cardiovascular events in patients undergoing percutaneous intervention for left main (LM) coronary disease is largely unknown. METHODS AND RESULTS: From April 2001 to December 2003, 181 patients underwent percutaneous coronary intervention for LM stenosis at our institution. The first cohort consisted of 86 patients (19 protected LM) treated with bare metal stents (pre-DES group); the second cohort comprised 95 patients (15 protected LM) treated exclusively with DES. The 2 cohorts were well balanced for all baseline characteristics. At a median follow-up of 503 days (range, 331 to 873 days), the cumulative incidence of major adverse cardiovascular events was lower in the DES cohort than in patients in the pre-DES group (24% versus 45%, respectively; hazard ratio [HR], 0.52 [95% CI, 0.31 to 0.88]; P=0.01). Total mortality did not differ between cohorts; however, there were significantly lower rates of both myocardial infarction (4% versus 12%, respectively; HR, 0.22 [95% CI, 0.07 to 0.65]; P=0.006) and target vessel revascularization (6% versus 23%, respectively; HR, 0.26 [95% CI, 0.10 to 0.65]; P=0.004) in the DES group. On multivariate analysis, use of DES, Parsonnet classification, troponin elevation at entry, distal LM location, and reference vessel diameter were independent predictors of major adverse cardiovascular events. CONCLUSIONS: When percutaneous coronary intervention is undertaken at LM lesions, routine DES implantation, which reduces the cumulative incidence of myocardial infarction and the need for target vessel revascularization compared with bare metal stents, should currently be the preferred strategy.

[New insights towards catheter-based identification of vulnerable plaque] (Article)

2005-01-01T00:00:00Z

Sudden cardiac death or unheralded acute coronary syndromes are common initial manifestations of coronary atherosclerosis and most such events occur at sites of non-flow limiting coronary atherosclerosis. Autopsy data suggests that plaque composition is a key determinant of the propensity of atherosclerotic lesions to provoke clinical events. Most of these events are related to plaque rupture and subsequent thrombotic occlusion at the site of non-flow limiting atherosclerotic lesions in epicardial coronary arteries. Detection of these non-obstructive, lipid rich, high-risk plaques may have an important impact on the prevention of acute myocardial infarction and sudden death. Currently, there are several intravascular tools capable of locally evaluating determinants of plaque vulnerability such as the size of the lipid core, thickness of the fibrous cap, inflammation within the cap and positive remodeling. These new modalities have the potential to provide insights into the pathophysiology of the natural history of coronary plaque by means of prospective studies.

One year clinical follow up of paclitaxel eluting stents for acute myocardial infarction compared with sirolimus eluting stents (Article)

2005-01-01T00:00:00Z

OBJECTIVE: To compare clinical outcome of paclitaxel eluting stents (PES) versus sirolimus eluting stents (SES) for the treatment of acute ST elevation myocardial infarction. DESIGN AND PATIENTS: The first 136 consecutive patients treated exclusively with PES in the setting of primary percutaneous coronary intervention for acute myocardial infarction in this single centre registry were prospectively clinically assessed at 30 days and one year. They were compared with 186 consecutive patients treated exclusively with SES in the preceding period. SETTING: Academic tertiary referral centre. RESULTS: At 30 days, the rate of all cause mortality and reinfarction was similar between groups (6.5% v 6.6% for SES and PES, respectively, p = 1.0). A significant difference in target vessel revascularisation (TVR) was seen in favour of SES (1.1% v 5.1% for PES, p = 0.04). This was driven by stent thrombosis (n = 4), especially in the bifurcation stenting (n = 2). At one year, no significant differences were seen between groups, with no late thrombosis and 1.5% in-stent restenosis (needing TVR) in PES versus no reinterventions in SES (p = 0.2). One year survival free of major adverse cardiac events (MACE) was 90.2% for SES and 85% for PES (p = 0.16). CONCLUSIONS: No significant differences were seen in MACE-free survival at one year between SES and PES for the treatment of acute myocardial infarction with very low rates of reintervention for restenosis. Bifurcation stenting in acute myocardial infarction should, if possible, be avoided because of the increased risk of stent thrombosis.

Incidence of High-Strain Patterns in Human Coronary Arteries: Assessment With Three-Dimensional Intravascular Palpography and Correlation With Clinical Presentation (Article)

2004-06-08T00:00:00Z

BACKGROUND: Rupture of thin-cap fibroatheromatous plaques is a major cause of acute myocardial infarction (AMI). Such plaques can be identified in vitro by 3D intravascular palpography with high sensitivity and specificity. We used this technique in patients undergoing percutaneous intervention to assess the incidence of mechanically deformable regions. We further explored the relation of such regions to clinical presentation and to C-reactive protein levels. METHOD AND RESULTS: Three-dimensional palpograms were derived from continuous intravascular ultrasound pullbacks. Patients (n=55) were classified by clinical presentation as having stable angina, unstable angina, or AMI. In every patient, 1 coronary artery was scanned (culprit vessel in stable and unstable angina, nonculprit vessel in AMI), and the number of deformable plaques assessed. Stable angina patients had significantly fewer deformable plaques per vessel (0.6+/-0.6) than did unstable angina patients (P=0.0019) (1.6+/-0.7) or AMI patients (P<0.0001) (2.0+/-0.7). Levels of C-reactive protein were positively correlated with the number of mechanically deformable plaques (R2=0.65, P<0.0001). CONCLUSIONS: Three-dimensional intravascular palpography detects strain patterns in human coronary arteries that represent the level of deformation in plaques. The number of highly deformable plaques is correlated with both clinical presentation and levels of C-reactive protein. Further studies will assess the potential role of the technique to identify patients at risk of future clinical events

Intravascular ultrasound evaluation after sirolimus eluting stent implantation for de novo and in-stent restenosis lesions (Article)

2004-01-01T00:00:00Z

AIMS: The aim of this study is to compare the efficacy of sirolimus-eluting stents (SES) on neointimal growth and vessel remodelling for in-stent restenosis versus de novo coronary artery lesions using serial intravascular ultrasound (IVUS). METHODS AND RESULTS: The study population consisted of 86 patients with in-stent restenosis (ISR) (n=41) or de novo lesions (n=45) treated with SES and evaluated by IVUS post-procedure and at follow-up. One 18-mm SES was used for de novo lesions while 16 patients with ISR received >1SES (total stented length 17.9 mm vs 22.0 mm respectively; P=0.004). At follow-up, no differences were observed between the ISR and de novo groups with respect to changes in the mean external elastic membrane (1.7% vs 1.3%; P=0.53), plaque behind the stent (1.2% vs 3.4%; P=0.49), and lumen areas (0.7% vs 1.9%; P=0.58). No positive remodelling or edge effect was observed. A gap between stents was observed in two patients with ISR, where more prominent, though non-obstructive, neointimal proliferation was noted. CONCLUSION: Sirolimus-eluting stenting is equally effective at inhibiting neointimal proliferation in de novo and ISR lesions without inducing edge restenosis or positive vascular remodelling.

Sonotherapy; antirestenotic therapeutic ultrasound in coronary arteries: the first clinical experience. (Article)

2003-09-01T00:00:00Z

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty-seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in-stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 ± 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6-month follow-up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 ± 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% ± 11%. IST can be applied safely and with high acute procedural success. Sonotherapy-related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies.

TAXUS III Trial: In-Stent Restenosis Treated With Stent-Based Delivery of Paclitaxel Incorporated in a Slow-Release Polymer Formulation (Article)

2003-02-04T00:00:00Z

BACKGROUND: The first clinical study of paclitaxel-eluting stent for de novo lesions showed promising results. We performed the TAXUS III trial to evaluate the feasibility and safety of paclitaxel-eluting stent for the treatment of in-stent restenosis (ISR). METHODS AND RESULTS: The TAXUS III trial was a single-arm, 2-center study that enrolled 28 patients with ISR meeting the criteria of lesion length < or =30 mm, 50% to 99% diameter stenosis, and vessel diameter 3.0 to 3.5 mm. They were treated with one or more TAXUS NIRx paclitaxel-eluting stents. Twenty-five patients completed the angiographic follow-up at 6 months, and 17 of these underwent intravascular ultrasound (IVUS) examination. No subacute stent thrombosis occurred up to 12 months, but there was one late chronic total occlusion, and additional 3 patients showed angiographic restenosis. The mean late loss was 0.54 mm, with neointimal hyperplasia volume of 20.3 mm3. The major adverse cardiac event rate was 29% (8 patients; 1 non-Q-wave myocardial infarction, 1 coronary artery bypass grafting, and 6 target lesion revascularization [TLR]). Of the patients with TLR, 1 had restenosis in a bare stent implanted for edge dissection and 2 had restenosis in a gap between 2 paclitaxel-eluting stents. Two patients without angiographic restenosis underwent TLR as a result of the IVUS assessment at follow-up (1 incomplete apposition and 1 insufficient expansion of the stent). CONCLUSIONS: Paclitaxel-eluting stent implantation is considered safe and potentially efficacious in the treatment of ISR. IVUS guidance to ensure good stent deployment with complete coverage of target lesion may reduce reintervention.

Sirolimus-eluting stent for treatment of complex in-stent restenosis: the first clinical experience. (Article)

2003-01-15T00:00:00Z

The treatment of ISR remains a therapeutic challenge, since many pharmacological and mechanical approaches have shown disappointing results. The SESs have been reported to be effective in de-novo coronary lesions.

Intravascular palpography for high-risk vulnerable plaque assessment. (Article)

2003-01-01T00:00:00Z

Prevention of restenosis in coronary arteries: ionic radiation, non-ionic radiation and drug eluting stents (Doctoral Thesis)

2002-12-18T00:00:00Z

Over the last decade, coronary stents have revolutionized the field of interventional cardiology. Stent implantation has become the new standard angioplasty procedure1-3. This popularity has grown because of 2 main reasons: first, the unique capability to master a major complication of balloon angioplasty - (sub) acute vessel closure - and second, a superior long-term outcome in comparison to balloon angioplasty4-8. The high reliability of the acute angioplasty result allowed for a continuos expansion of the indication for catheter-based intervention (including ostial lesions9, bifurcation lesions10, 11, left main lesions12, 13, multiple lesions14). In-stent restenosis However, in-stent restenosis remains the major limitation of coronary stenting. The absolute number of in-stent restenotic lesions is increasing in parallel with the steadily increasing number of stenting procedures and with the complexity of culprit lesions. The treatment of instent restenosis is technically challenging and costly. In subsets of lesions (such as small vessel size and diffuse disease) an anticipated high risk for restenosis may even prevent the use of stents. Restenosis represents a local vascular manifestation of the general biologic response to injury15. Injury consists of denuding the intima and stretching the media. Current concepts describe three mechanisms of the restenotic process: early elastic recoil, late vessel remodeling and neointimal growth16, 17. We could demonstrate (chapter 2) that coronary stents provide mechanical scaffolding that virtually eliminates recoil and remodeling18. However, neointimal growth continues to be a major problem. New strategies for the prevention of in-stent restenosis Over the last 2 decades, efforts for the prevention of restenosis were focused on optimizing stent characteristics and implantation technique19, 20. The growing understanding of vascular biology and the observation that exaggerated neointimal formation shows similarities to tumor growth triggered the development of new treatment strategies

Value of coronary stenotic flow velocity acceleration in prediction of angiographic restenosis following balloon angioplasty (Article)

2002-12-01T00:00:00Z

INTRODUCTION: Quantitative angiographic assessment after balloon angioplasty is a poor predictor of immediate and long-term outcome. However, the measurement of blood flow velocity during angioplasty has been proved clinically useful. AIMS: To analyse the value of the maximal stenotic flow velocity and the presence of stenotic flow velocity acceleration (aSV) for the long-term outcome after balloon angioplasty. METHODS AND RESULTS: Patients undergoing single lesion angioplasty within the DEBATE trial were included. aSV was defined as acceleration in the stenotic coronary flow velocity >50% baseline velocity assessed at a reference site of the target vessel. After balloon angioplasty diameter stenosis, minimal lumen diameter (MLD) and coronary flow velocity reserve were similar between the aSV (n=54) and non-aSV group (n=125). At follow-up, the aSV group had a higher restenosis rate (52% vs 30%, P=0.006) The presence of aSV was the strongest independent predictor of restenosis (OR 3.08, 95% CI 1.35 to 7.05, P=0.008). The best predictive cut-off value of SV was 101cm.s(-1) (sensitivity of 46%, specificity of 81%, positive predictive value of 85% and a negative predictive value of 58%). CONCLUSION: Following angioplasty, SV appears to be exquisitely sensitive to the changes experienced at the treated area without depending on the status of the microcirculation.

Angiographic Findings of the Multicenter Randomized Study With the Sirolimus-Eluting Bx Velocity Balloon-Expandable Stent (RAVEL) (Article)

2002-10-08T00:00:00Z

BACKGROUND: Restenosis remains the major limitation of coronary catheter-based intervention. In small vessels, the amount of neointimal tissue is disproportionately greater than the vessel caliber, resulting in higher restenosis rates. In the Randomized Study With the Sirolimus-Eluting Bx Velocity Balloon-Expandable Stent (RAVEL) trial, approximately 40% of the vessels were small (<2.5 mm). The present study evaluates the relationship between angiographic outcome and vessel diameter for sirolimus-eluting stents. METHODS AND RESULTS: Patients were randomized to receive either an 18-mm bare metal Bx VELOCITY (BS group, n=118), or a sirolimus-eluting Bx VELOCITY stent (SES group, n=120). Subgroups were stratified into tertiles according to their reference diameter (RD; stratum I, RD <2.36 mm; stratum II, RD 2.36 mm to 2.84 mm; stratum III, RD >2.84 mm). At 6-month follow-up, the restenosis rate in the SES group was 0% in all strata (versus 35%, 26%, and 20%, respectively, in the BS group). In-stent late loss was 0.01+/-0.25 versus 0.80+/-0.43 mm in stratum I, 0.01+/-0.38 versus 0.88+/-0.57 mm in stratum II, and -0.06+/-0.35 versus 0.74+/-0.57 mm in stratum III (SES versus BS). In SES, the minimal lumen diameter (MLD) remained unchanged (Delta -0.72 to 0.72 mm) in 97% of the lesions and increased (=late gain, DeltaMLD <-0.72 mm) in 3% of the lesions. Multivariate predictors for late loss were treatment allocation (P<0.001) and postprocedural MLD (P= 0.008). CONCLUSIONS: Sirolimus-eluting stents prevent neointimal proliferation and late lumen loss irrespective of the vessel diameter. The classic inverse relationship between vessel diameter and restenosis rate was seen in the bare stent group but not in the sirolimus-eluting stent group.

Persistent inhibition of neointimal hyperplasia after sirolimus-eluting stent implantation: long-term (up to 2 years) clinical, angiographic, and intravascular ultrasound follow-up. (Article)

2002-09-24T00:00:00Z

Background— Early results of sirolimus-eluting stent implantation showed a nearly complete abolition of neointimal hyperplasia. The question remains, however, whether the early promising results will still be evident at long-term follow-up. The objective of our study was to evaluate the efficiency of sirolimus-eluting stent implantation for up to 2 years of follow-up. Methods and Results— Fifteen patients with de novo coronary artery disease were treated with 18-mm sirolimus-eluting Bx-Velocity stents (Cordis) loaded with 140 µg sirolimus/cm2 metal surface area in a slow release formulation. Quantitative angiography (QCA) and intravascular ultrasound (IVUS) were performed according to standard protocol. Sirolimus-eluting stent implantation was successful in all 15 patients. During the in-hospital course, 1 patient died of cerebral hemorrhage after periprocedural administration of abciximab, and 1 patient underwent repeat stenting after 2 hours because of edge dissection that led to acute occlusion. Through 6 months and up to 2 years of follow-up, no additional events occurred. QCA analysis revealed no significant change in stent minimal lumen diameter or percent diameter stenosis, and 3-dimensional IVUS showed no significant deterioration in lumen volume. In 2 patients, additional stenting was performed because of significant lesion progression remote from the sirolimus-eluting stent. Conclusion— Sirolimus-eluting stents showed persistent inhibition of neointimal hyperplasia for up to 2 years of follow-up.

A new intracoronary measurement catheter, MetriCath, compared to intravascular ultrasound and quantitative coronary angiography in a stented porcine coronary model. (Article)

2002-09-01T00:00:00Z

The purpose of this study was to compare measurements by MetriCath to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). The MetriCath system consists of a low-pressure (200 mm Hg) balloon catheter connected to a pressure transducer and infusion pump linked to a computer that records pressure-volume curves. Cross-sectional area of blood vessels is obtained directly from the unrestrained and in-stent pressure-volume measurements. We compared stent cross-sectional area measurements by MetriCath, IVUS, and QCA in a porcine stented coronary artery model. Comparison of area measurements in 14 stents showed no significant differences between the three methods (P = 0.66). On average, values differed 0.37 ± 0.60mm2 between MetriCath and QCA, 0.13 ± 0.55 mm2 between MetriCath and IVUS, and 0.22 ± 0.80 mm2 between IVUS and QCA. This corresponds to 6.2% ± 10%, 3.0% ± 9.0%, and 3.1% ± 12.9% relative difference from the average of two corresponding measurements. Linear regression analysis showed excellent correlation between measurements (r ± 0.99 for all comparisons). The differences in in-stent area measurements between MetriCath and both QCA and IVUS were small. Considering the ease and rapidity of obtaining MetriCath results, this technique may form an alternative to the others in evaluating stent expansion. Based on these findings, clinical evaluation seems warranted.

Routine intracoronary beta-irradiation. Acute and one year outcome in patients at high risk for recurrence of stenosis (Article)

2002-07-01T00:00:00Z

AIMS: Intracoronary radiation is a promising therapy potentially reducing restenosis following catheter-based interventions. Currently, only limited data on this treatment are available. The feasibility and outcome in daily routine practice, however, is unknown. METHODS AND RESULTS: In 100 consecutive patients, intracoronary beta-radiation was performed with a (90)Strontium system (Novoste Beta-Cathtrade mark) following angioplasty. Predominantly complex (73% type B2 and C) and long lesions (length 24.3+/-15.3 mm) were included (37% de novo, 19% restenotic and 44% in-stent restenotic lesions). Radiation success was 100%. Mean prescribed dose was 19.8+/-2.5 Gy. A pullback procedure was performed in 19% lesions. Geographic miss occurred in 8% lesions. Periprocedural thrombus formation occurred in four lesions, dissection in nine lesions. During hospital stay, no death, acute myocardial infarction, or repeat revascularization was observed. Major adverse cardiac events occurred predominantly between 6 and 12 months after the index procedure with major adverse cardiac event-free survival of 66% at 12 months (one death, 10 Q-wave myocardial infarctions, 23 target vessel revascularizations; ranked for worst event). CONCLUSION: Routine catheter-based intracoronary beta-radiation therapy after angioplasty is safe and feasible with a high acute procedural success. The clinical 1-year follow-up showed delayed occurrence of major adverse cardiac events between 6 and 12 months after the index procedure

Flow velocity and predictors of a suboptimal coronary flow velocity reserve after coronary balloon angioplasty. (Article)

2002-01-01T00:00:00Z

AIMS: This study was conducted to analyse flow velocity parameters and predictors of a suboptimal coronary flow reserve (<2.5) following balloon angioplasty. METHODS: Two hundred and twenty-five patients underwent sequential intracoronary Doppler as part of the DEBATE I study. Of these, 183, with complete angiography and Doppler at the 6-month follow-up, were included. Univariate and multivariate logistic analysis was performed to identify independent predictors of post-procedural suboptimal coronary flow reserve, defined as coronary flow reserve <2.5. RESULTS: Forty-eight per cent (n=88) of the patients achieved a suboptimal coronary flow reserve. These patients had higher baseline velocities (cm.s(-1)) before balloon angioplasty (18+/-9 vs 14+/-6, P=0.004), after balloon angioplasty (22+/-11 vs 14+/-5, P<0.001) and at follow-up (19+/-9 vs 16+/-6, P=0.011) than the optimal coronary flow reserve group. Although the suboptimal group had lower hyperaemic velocities (cm.s(-1)) after balloon angioplasty than the optimal group (42+/-17 vs 49+/-16, P=0.008), these velocities became similar at follow-up. Increasing age (odds ratio, OR 1.071, P=0.0002), female gender (OR 2.52, P=0.014) and increasing pre-procedural baseline average peak velocities (OR 1.056, P<0.001) were found to be independent predictors of a suboptimal coronary flow reserve following balloon angioplasty. CONCLUSION: A suboptimal coronary flow reserve was associated with (1) a chronically elevated baseline average peak velocity (2) a transient deficit in the hyperaemic average peak velocity (3) the elderly, and female gender.

Rapamycin eluting stent: the onset of a new era in interventional cardiology (Article)

2002-01-01T00:00:00Z

Persistent inhibition of neointimal hyperplasia after sirolimus-eluting stent implantation: long-term (up to 2 years) clinical, angiographic, and intravascular ultrasound follow-up (Article)

2002-01-01T00:00:00Z

BACKGROUND: Early results of sirolimus-eluting stent implantation showed a nearly complete abolition of neointimal hyperplasia. The question remains, however, whether the early promising results will still be evident at long-term follow-up. The objective of our study was to evaluate the efficiency of sirolimus-eluting stent implantation for up to 2 years of follow-up. METHODS AND RESULTS: Fifteen patients with de novo coronary artery disease were treated with 18-mm sirolimus-eluting Bx-Velocity stents (Cordis) loaded with 140 microg sirolimus/cm2 metal surface area in a slow release formulation. Quantitative angiography (QCA) and intravascular ultrasound (IVUS) were performed according to standard protocol. Sirolimus-eluting stent implantation was successful in all 15 patients. During the in-hospital course, 1 patient died of cerebral hemorrhage after periprocedural administration of abciximab, and 1 patient underwent repeat stenting after 2 hours because of edge dissection that led to acute occlusion. Through 6 months and up to 2 years of follow-up, no additional events occurred. QCA analysis revealed no significant change in stent minimal lumen diameter or percent diameter stenosis, and 3-dimensional IVUS showed no significant deterioration in lumen volume. In 2 patients, additional stenting was performed because of significant lesion progression remote from the sirolimus-eluting stent. CONCLUSION: Sirolimus-eluting stents showed persistent inhibition of neointimal hyperplasia for up to 2 years of follow-up.

The pattern of restenosis and vascular remodelling after cold-end radioactive stent implantation. (Article)

2001-08-22T00:00:00Z

Background Edge restenosis is a major problem after radioactive stenting. The cold-end stent has a radioactive mid-segment (15·9mm) and non-radioactive proximal and distal 5·7mm segments. Conceptually this may negate the impact of negative vascular remodelling at the edge of the radiation. Method and Results ECG-gated intravascular ultrasound with three-dimensional reconstruction was performed post-stent implantation and at the 6-month follow-up to assess restenosis within the margins of the stent and at the stent edges in 16 patients. Angiographic restenosis was witnessed in four patients, all in the proximal in-stent position. By intravascular ultrasound in-stent neointimal hyperplasia, with a >50% stented cross-sectional area, was seen in eight patients. This was witnessed proximally (n=2), distally (n=2) and in both segments (n=4). Echolucent tissue, dubbed the ‘black hole’ was seen as a significant component of neointimal hyperplasia in six out of the eight cases of restenosis. Neointimal hyperplasia was inhibited in the area of radiation: Δ neointimal hyperplasia=3·72mm3(8·6%); in-stent at the edges of radiation proximally and distally Δ neointimal hyperplasia was 7·9mm3(19·0%) and 11·4mm3(25·6%), respectively (P=0·017). At the stent edges there was no significant change in lumen volume. Conclusions Cold-end stenting results in increased neointimal hyperplasia in in-stent non-radioactive segments.

Value of coronary stenotic flow velocity acceleration on the prediction of long-term improvement in functional status after angioplasty. (Article)

2001-07-01T00:00:00Z

Background The coronary flow velocity acceleration at the stenotic site (SVA), defined as a ≥50% increase in resting stenotic velocity when compared with the reference segment, has been shown to be highly sensitive and specific for the diagnosis of a hemodynamically significant stenosis. In this study, we describe the value of postprocedural SVA for the prediction of a lack of improvement in functional activity at long-term follow-up balloon angioplasty (BA). Methods We investigated the improvement in functional activity in patients undergoing single native vessel angioplasty and intracoronary Doppler (before BA, after BA, and again at 6-month follow-up) as part of the Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) I trial. Lack of improvement was defined as no change in Duke Activity Status Index (DASI) at 6-month follow-up, whereas SVA was defined as ≥50% elevation in resting velocity at the treated area compared with the distal measurement. Results SVA was found more frequently in patients without improvement in DASI (45% vs 31%, P = .03). Similar percent diameter stenosis and coronary flow velocity reserve were observed in patients with and those without improvement in DASI at follow-up. By multivariate regression analysis, the presence of SVA (P = .029; odds ratio, 1.97; 95% confidence interval, 1.07 to 3.63) and an elevated DASI at baseline (P < .001; odds ratio, 1.05; 95% confidence interval, 1.03 to 1.07) were associated with a lack of improvement at follow-up. Conclusions The detection of SVA was associated with failure of improvement in functional activity at follow-up after coronary intervention.

Uncomplicated moderate coronary artery dissections after balloon angioplasty: good outcome without stenting (Article)

2001-01-01T00:00:00Z

OBJECTIVE: To study the relation between moderate coronary dissections, coronary flow velocity reserve (CFVR), and long term outcome. METHODS: 523 patients undergoing balloon angioplasty and sequential intracoronary Doppler measurements were examined as part of the DEBATE II trial (Doppler endpoints balloon angioplasty trial Europe). After successful balloon angioplasty, patients were randomised to stenting or no further treatment. Dissections were graded at the core laboratory by two observers and divided into four categories: none, mild (type A-B), moderate (type C), severe (types D to F). Patients with severe dissections (n = 128) or without available reference vessel CFVR (n = 139) were excluded. The remaining 256 patients were divided into two groups according to the presence (group A, n = 45) or absence (group B, n = 211) of moderate dissection. RESULTS: Following balloon angioplasty, there was no difference in CFVR between the two groups. At 12 months follow up, a higher rate of major adverse cardiac events was observed overall in group A than in group B (10 (22%) v 23 (11%), p = 0.041). However, the risk of major adverse events was similar in the subgroups receiving balloon angioplasty (group A, 6 (19%) v group B, 16 (16%), NS). Among group A patients, the adverse events risk was greater in those randomised to stenting (odds ratios 6.603 v 1.197, p = 0.046), whereas there was no difference in risk if the group was analysed according to whether the CFVR was < 2.5 or >/= 2.5 after balloon angioplasty. CONCLUSIONS: Moderate dissections left untreated result in no increased risk of major adverse cardiac events. Additional stenting does not improve the long term outcome.

"Edge Effect" of 32P Radioactive Stents Is Caused by the Combination of Chronic Stent Injury and Radioactive Dose Falloff (Article)

2001-01-01T00:00:00Z

BACKGROUND: Radioactive stents have been reported to reduce in-stent neointimal thickening. An unexpected increase in neointimal response was observed, however, at the stent-to-artery transitions, the so-called "edge effect." To investigate the factors involved in this edge effect, we studied stents with 1 radioactive half and 1 regular nonradioactive half, thereby creating a midstent radioactive dose-falloff zone next to a nonradioactive stent-artery transition at one side and a radioactive stent-artery transition at the other side. METHODS AND RESULTS: Half-radioactive stents (n=20) and nonradioactive control stents (n=10) were implanted in the coronary arteries of Yucatan micropigs. Animals received aspirin and clopidogrel as antithrombotics. After 4 weeks, a significant midstent stenosis was observed by angiography in the half-radioactive stents. Two animals died suddenly because of coronary occlusion at this mid zone at 8 and 10 weeks. At 12-week follow-up angiography, intravascular ultrasound and histomorphometry showed a significant neointimal thickening at the midstent dose-falloff zone of the half-radioactive stents, but not at the stent-to-artery transitions at both extremities. Such a midstent response (mean angiographic late loss 1.0 mm) was not observed in the nonradioactive stents (mean loss 0.4 to 0.6 mm; P< 0.01). CONCLUSIONS: The edge effect of high-dose radioactive stents in porcine coronary arteries is associated with the combination of stent injury and radioactive dose falloff.

Coronary stent implantation in a septal perforator artery: case report and review of the literature. (Article)

2000-01-01T00:00:00Z

Septal perforator arteries play an important role in the blood supply of the anterior interventricular septum. Their intramyocardial course makes them inaccessible for coronary bypass revascularization. Although modern catheter-based techniques might be superior to coronary bypass grafting in offering the most complete revascularization in selected patient populations, a systematic review of the literature revealed a paucity of data regarding the outcome of these patients. The present report describes coronary stent implantation in a dominant septal perforator artery and the analysis of the anatomic relationship between the stent and the intraventricular septum using a new imaging technique, catheter-based intracardiac ultrasound.

Distal Embolization: A Threat to the Coronary Artery? (Article)

2000-01-01T00:00:00Z

A67-year-old man with a history of hypertension and hypercholesterolemia was scheduled for elective direct stent implantation for a severe proximal left descending artery stenosis. Using the femoral approach, a 7-French Judkins left guiding catheter was placed in the left coronary ostium. To keep the activated clotting time >300 s, 10 000 IU of heparin and 250 mg of aspirin were given intravenously. After introducing an intermediate guide wire (Guidant Inc), we placed an AngioguardTM (Angioguard Inc) distal to the target lesion. This guidewire-based, filter-type device captures embolic debris while maintaining distal perfusion by means of an expandable umbrella. Successful direct stenting was performed with an Tristar 3.5/18-mm premounted stent (Guidant Inc) at an inflation pressure of 18 atm.

Influence of a history of smoking on short term (six month) clinical and angiographic outcome after successful coronary angioplasty (Article)

2000-01-01T00:00:00Z

OBJECTIVES: To assess the influence of smoking on restenosis after coronary angioplasty. DESIGN AND PATIENTS: The incidence of smoking on restenosis was investigated in 2948 patients. They were prospectively enrolled in four major restenosis trials in which quantitative angiography was used before and immediately after successful angioplasty and again at six months. RESULTS: Within the study population there were 530 current smokers, 1690 ex-smokers, and 728 non-smokers. Smokers were more likely to be men (85.9% v 87. 5% v 65.3%, current v ex- v non-, p < 0.001), to be younger (54.0 (9. 0) v 57.0 (9.1) v 59.9 (9.4) years, p < 0.001), to have peripheral vascular disease (7.2% v 5.5% v 2.3%, p < 0.001), and have sustained a previous myocardial infarction (42.9% v 43.9% v 37.9%, p = 0.022), but were less likely to be diabetic (9.1% v 9.5% v 12.6%, p = 0.043) or hypertensive (24.9% v 29.3% v 37.2, p < 0.001). There was no significant difference in the categorical restenosis rate (> 50% diameter stenosis) at six months (35.28% v 35.33% v 37.09%, current v ex- v non-), or the absolute loss (0.29 (0.54) v 0.33 (0.52) v 0. 35 (0.55) mm, respectively; p = 0.172). CONCLUSIONS: Although smokers have a lower incidence of known predisposing risk factors for atherosclerosis, they require coronary intervention almost six years earlier than non-smokers and three years earlier than ex-smokers. Once they undergo successful coronary angioplasty, there appears to be no evidence that smoking influences their short term (six month) outcome, but because of the known long term effects of smoking, patients should still be encouraged to discontinue the habit.

Coronary stent implantation in a septal perforator artery: case report and review of the literature (Article)

2000-01-01T00:00:00Z