Hamburger, J.N.

Vascular responses at proximal and distal edges of paclitaxel-eluting stents (Article)

2004-02-10T00:00:00Z

BACKGROUND: On the basis of brachytherapy experience, edge stenosis has been raised as a potential limitation for drug-eluting stents. We used serial intravascular ultrasound (IVUS) to prospectively analyze vessel responses in adjacent reference segments after implantation of polymer-controlled paclitaxel-eluting stents. METHODS AND RESULTS: TAXUS II was a randomized, double-blind trial with 2 consecutive patient cohorts that compared slow-release (SR) and moderate-release (MR) paclitaxel-eluting stents with control bare metal stents (BMS). By protocol, all patients had postprocedure and 6-month follow-up IVUS. Quantitative IVUS analysis was performed by an independent core laboratory, blinded to treatment allocation, in 5-mm vessel segments immediately proximal and distal to the stent. Serial IVUS was available for 106 SR, 107 MR, and 214 BMS patients. For all 3 groups, a significant decrease in proximal-edge lumen area was observed at 6 months. The decrease was comparable (by ANOVA, P=0.194) for patients in the SR (-0.54+/-2.1 mm2) and MR (-0.88+/-1.9 mm2) groups compared with the BMS (-1.02+/-1.9 mm2) group. For the distal edge, a significant decrease in lumen area was only observed with BMS (-0.91+/-2.0 mm2, P<0.0001); this decrease was significantly attenuated with SR (0.08+/-2.0 mm2) and MR (-0.19+/-1.7 mm2) stents (P<0.0001 by ANOVA). Negative vessel remodeling was observed at the proximal (-0.48+/-2.2 mm2, P=0.011) but not the distal edges of BMS and at neither edge of SR or MR stents. CONCLUSIONS: The marked reduction in in-stent restenosis with SR or MR stents is not associated with increased edge stenosis at 6-month follow-up IVUS. In fact, compared with BMS, there is instead a significant reduction in late lumen loss at the distal edge with TAXUS stents.

Clinical and angiographical follow-up after implantation of a 6--12 microCi radioactive stent in patients with coronary artery disease. (Article)

2001-07-19T00:00:00Z

AIMS: This study is the contribution by the Thoraxcenter, Rotterdam, to the European(32)P Dose Response Trial, a non-randomized multicentre trial to evaluate the safety and efficacy of the radioactive Isostent in patients with single coronary artery disease. METHODS AND RESULTS: The radioactivity of the stent at implantation was 6--12 microCi. All patients received aspirin indefinitely and either ticlopidine or clopidogrel for 3 months. Quantitative coronary angiography measurements of both the stent area and the target lesion (stent area and up to 5 mm proximal and distal to the stent edges) were performed pre- and post-procedure and at the 5-month follow-up. Forty-two radioactive stents were implanted in 40 patients. Treated vessels were the left anterior descending coronary artery (n=20), right coronary artery (n=10) or left circumflex artery (n=10). Eight patients received additional non-radioactive stents. Lesion length measured 10+/-3 mm with a reference diameter of 3.07+/-0.69 mm. Minimal lumen diameter increased from 0.98+/-0.53 mm pre-procedure to 2.29+/-0.52 mm (target lesion) and 2.57+/-0.44 mm (stent area) post-procedure. There was one procedural non-Q wave myocardial infarction, due to transient thrombotic closure. Thirty-six patients returned for angiographical follow-up. Two patients had a total occlusion proximal to the radioactive stent. Of the patent vessels, none had in-stent restenosis. Edge restenosis was observed in 44%, occurring predominantly at the proximal edge. Target lesion revascularization was performed in 10 patients and target vessel revascularization in one patient. No additional clinical end-points occurred during follow-up. The minimal lumen diameter at follow-up averaged 1.66+/-0.71 mm (target lesion) and 2.12+/-0.72 (stent area); therefore late loss was 0.63+/-0.69 (target lesion) and 0.46+/-0.76 (stent area), resulting in a late loss index of 0.65+/-1.15 (target lesion) and 0.30+/-0.53 (stent area). CONCLUSION: These results indicate that the use of radioactive stents is safe and feasible, however, the high incidence of edge restenosis makes this technique currently clinically non-applicable.

Validation of the local shortening function as assessed by nonfluoroscopic electromechanical mapping: a comparison with computerized left ventricular angiography. (Article)

2001-01-30T00:00:00Z

Background: Nonfluoroscopic electromechanical mapping (NEM) has been proposed as a new technique for the evaluation of electrical and mechanical functioning of the myocardium. In this system, linear local shortening (LLS) is the parameter used for assessment of local mechanical properties. To validate this parameter, we compared LLS with regional wall motion (RWM) data derived from contrast left ventriculograms acquired in the same patients. Methods and results: Angiographic left ventricular RWM was analyzed using the area–length method. The right anterior oblique view was divided in five segments, the left anterior oblique view in two. Through a comparison of enddiastolic and endsystolic areas drawn from a computer-defined central point to the respective wall delineation, RWM was calculated as change in area. In the first approach, we compared area changes to comparable NEM segments. In the second part of the study, LLS values for normokinetic, hypokinetic, akinetic and dyskinetic segments were correlated to the change in angiographic RWM. In the first approach, the overall comparison of segments yielded a correlation coefficient of 0.67 (P<0.0005). In the second part of the study, differences in LLS values between dyskinetic (LLS=−3.68±8.86%), akinetic (2.84±3.96%), hypokinetic (9.35±4.27%) and normokinetic (13.66±7.98%) segments were highly significant (overall ANOVA: P<0.0005). Conclusion: NEM is a powerful tool for invasive electromechanical assessment of myocardial function.

Comparison of mechanical properties of the left ventricle in patients with severe coronary artery disease by nonfluoroscopic mapping versus two-dimensional echocardiograms. (Article)

2000-11-01T00:00:00Z

In 40 patients, we compared linear local shortening assessed with nonfluoroscopic electromechanical mapping as a function of regional wall motion with echocardiographic data in a subset of patients with severe coronary artery disease and subsequently decreased left ventricular function. Our study showed that nonfluoroscopic electromechanical mapping can accurately assess regional wall motion. In addition, this study showed a significant decrease in unipolar voltages among segments with declining regional function.

Total occlusion trial with angioplasty by using laser guidewire. The TOTAL trial. (Article)

2000-01-01T00:00:00Z

AIMS: A randomized trial was performed to assess the safety and efficacy of a laser guidewire, in the treatment of chronic coronary occlusions. METHODS AND RESULTS: In 18 European centres, 303 patients with a chronic coronary occlusion were randomized to treatment with either the laser guidewire (n=144) or conventional guidewires (mechanical guidewire, n=159). The primary end-point of the study was treatment success, defined as reaching the true lumen distal to the occlusion by the allocated wire within 30 min of fluoroscopic time: laser guidewire vs mechanical guidewire; 52.8% (n=76) vs 47.2% (n=75), P=0.33. Serious adverse events following the initial guidewire attempt were 0% (laser guidewire) and 0.6% (mechanical guidewire), respectively. Angioplasty (performed following successful guidewire crossing) was successful in 179 patients (91%, laser guidewire n=79, mechanical guidewire n=100), followed by stent implantation in 149 (79%). At the 6-month angiographic follow-up, the difference in binary restenosis rate (laser guidewire vs mechanical guidewire; 45.5% vs 38.3 %, P=0.72) or reocclusion rate (25.8% vs 16.1%, P=0.15) did not reach statistical significance. At 1, 6 and 12 months, angina and event-free survival were 69%, 35% and 24% (laser guidewire) vs 74%, 40% and 31% (mechanical guidewire). CONCLUSION: Although laser guidewire technology was safe, the increase in crossing success did not reach statistical significance.

The battle of Vladimir (Article)

2000-01-01T00:00:00Z

In 1966, the Russian director Andrej Tarkovski produced a feature ﬁlm on the life of Andrej Roeblov, a 15th century monk and icon painter. Halfway through this 3 hour production, which is full of esoteric discussions on religion and art, the world comes suddenly to an end when the city of Vladimir, without any warning, is raided and destroyed by the Tartars.

Helical Velocity Patterns in a Human Coronary Artery (Article)

2000-01-01T00:00:00Z

A74-year-old man was referred to our catheterization laboratory for elective angioplasty of the right coronary artery (RCA). One year earlier, he had suffered an acute inferior myocardial infarction, which was successfully treated with intravenous streptokinase. Only minor creatinine phosphokinase elevations were found.

Helical velocity patterns in a human coronary artery: a three-dimensional computational fluid dynamic reconstruction showing the relation with local wall thickness (Article)

2000-01-01T00:00:00Z

Improved regional wall motion 6 months after direct myocardial revascularization (DMR) with the NOGA DMR system (Article)

2000-01-01T00:00:00Z

A60-year-old man was referred to our intervention laboratory for direct myocardial revascularization (DMR). He had received maximal medical therapy and had undergone coronary bypass surgery 10 years earlier, and his peripheral coronary anatomy was now found to be unsuited for surgical revascularization.

New Aspects of Excimer Laser Coronary Angioplasty: Physical aspects and clinical results (Doctoral Thesis)

1999-09-03T00:00:00Z

Long term outcome after coronary stent implantation: a 10 year single centre experience of 1000 patients (Article)

1999-01-01T00:00:00Z

OBJECTIVE: To describe the long term clinical outcome (up to 11 years) after coronary stenting. DESIGN: A single centre observational study encompassing 1000 consecutive patients with a first stent implantation (1560 stents) between 1986 and 1996, who were followed for at least one year with a median follow up of 29 months (range 12-132 months). RESULTS: Up to July 1997 the cumulative incidence of the major adverse cardiac events (MACE) of death, non-fatal acute myocardial infarction, coronary artery bypass grafting, and repeat percutaneous transluminal coronary angioplasty was 8.2%, 12.8%, 13.1%, and 22.4%, respectively. Survival at one, three, and five years was 95%, 91%, and 86%, respectively. Comparison of MACE incidence during the "anticoagulant era" and the "ticlopidine era" revealed significantly improved event free survival with ticlopidine (27% v 13%; p < 0.005). Multivariable analyses showed that ejection fraction < 50% (relative risk (RR) 4. 1), multivessel disease (RR 3.0), diabetes (RR 2.9), implantation in saphenous vein graft (RR 2.1), indication for unstable angina (RR 1. 9), and female sex (RR 1.7) were independent predictors of increased mortality after stenting. Independent predictors of any MACE were multivessel stenting (RR 2.0), implantation in saphenous bypass graft (RR 1.6), diabetes (RR 1.5), anticoagulant treatment (versus ticlopidine and aspirin) (RR 1.5), bailout stenting (RR 1.5), multivessel disease (RR 1.4), and multiple stent implantation (RR 1. 5). CONCLUSIONS: Long term survival and infarct free survival was good, particularly in non-diabetic men with single vessel disease and good ventricular function, who had a single stent implanted in a native coronary artery. A dramatic improvement was observed in event free survival, both early and late, with the replacement of anticoagulation by ticlopidine. This, of course, cannot be separated from improved stent implantation techniques between 1986 and 1995. Ultimately, almost 40% of the patients experienced an adverse cardiac event (mainly repeat intervention) in the long term. New advances in restenosis treatments and in secondary prevention must be directed at this aspect of patient management after stenting.

Simultaneous Morphological and Functional Assessment of a Renal Artery Stent Intervention With Intravascular Ultrasound. (Article)

1998-01-01T00:00:00Z

A 73-year-old woman with a history of high blood pressure and hypercholesterolemia developed medically uncontrolled hypertension (200/100 mm Hg). Serum creatinine level was 145 [micro sign]mol/L, and creatinine clearance was 34 mL/min. Renal ultrasound demonstrated a small right kidney (80 mm long) compared with the left one (92 mm long). Left ventricular hypertrophy was present on the ECG and was confirmed by echocardiography. On isotope radiography with99m Tc-mercaptoacetyltriglycine after oral intake of 25 mg captopril, the right kidney was small, with delayed excretion and impaired function (36%). Renal arteriography showed subocclusive ostial stenosis of the right renal artery.