http://repub.eur.nl/res/aut/12456/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/27287/ 2010-05-01T00:00:00Z BACKGROUND-: Identification of patients at risk for primary and secondary manifestations of atherosclerotic disease progression is based mainly on established risk factors. The atherosclerotic plaque composition is thought to be an important determinant of acute cardiovascular events, but no prospective studies have been performed. The objective of the present study was to investigate whether atherosclerotic plaque composition is associated with the occurrence of future vascular events. METHODS AND RESULTS-: Atherosclerotic carotid lesions were collected from patients who underwent carotid endarterectomy and were subjected to histological examination. Patients underwent clinical follow-up yearly, up to 3 years after carotid endarterectomy. The primary outcome was defined as the composite of a vascular event (vascular death, nonfatal stroke, nonfatal myocardial infarction) and vascular intervention. The cumulative event rate at 1-, 2-, and 3-year follow-up was expressed by Kaplan-Meier estimates, and Cox proportional hazards regression analyses were performed to assess the independence of histological characteristics from general cardiovascular risk factors. During a mean follow-up of 2.3 years, 196 of 818 patients (24%) reached the primary outcome. Patients whose excised carotid plaque revealed plaque hemorrhage or marked intraplaque vessel formation demonstrated an increased risk of primary outcome (risk difference=30.6% versus 17.2%; hazard ratio [HR] with [95% confidence interval]=1.7 [1.2 to 2.5]; and risk difference=30.0% versus 23.8%; HR=1.4 [1.1 to 1.9], respectively). Macrophage infiltration (HR=1.1 [0.8 to 1.5]), large lipid core (HR=1.1 [0.7 to 1.6]), calcifications (HR=1.1 [0.8 to 1.5]), collagen (HR=0.9 [0.7 to 1.3]), and smooth muscle cell infiltration (HR=1.3 [0.9 to 1.8]) were not associated with clinical outcome. Local plaque hemorrhage and increased intraplaque vessel formation were independently related to clinical outcome and were independent of clinical risk factors and medication use. CONCLUSIONS-: The local atherosclerotic plaque composition in patients undergoing carotid endarterectomy is an independent predictor of future cardiovascular events. http://repub.eur.nl/res/pub/28353/ 2010-05-01T00:00:00Z Objectives: Cryoplasty combines conventional angioplasty - percutaneous transluminal angioplasty (PTA) - with cold thermal energy. In this animal study, we investigated if preventive cryoplasty could reduce intimal hyperplasia (IH) at the venous anastomosis. Design: We investigated cryoplasty versus PTA of the venous anastomosis in a validated porcine, bilateral, arteriovenous graft model. Animals and methods: In 12 pigs, 24 expanded polytetrafluoroethylene (ePTFE) grafts were bilaterally inserted between the common carotid artery and internal jugular vein. Directly after surgery, one venous anastomosis was treated with cryoplasty at -10 °C, the contralateral anastomosis with conventional PTA. At 4 weeks, graft flow was measured, quantitative angiography was performed and grafts with adjacent vessels were excised for histological analysis. Results: Due to a number of thromboses, data for paired analysis were available from eight pigs. Angiographic outflow vein diameter and graft blood flow were not different between treatment groups. Compared with the control group, IH at the venous anastomosis was reduced by 47% (P = 0.21) and intima/media ratio was reduced by 45% (P = 0.07) by cryoplasty. Effects were most profound in those animals that tended to develop most IH. Conclusion: Our results suggest that preventive cryoplasty of the venous anastomosis might help to reduce IH in those cases that develop most profound IH. http://repub.eur.nl/res/pub/9885/ 2002-04-09T00:00:00Z BACKGROUND: Intravascular ultrasound elastography assesses the local strain of the atherosclerotic vessel wall. In the present study, the potential to identify different plaque components in vivo was investigated. METHODS AND RESULTS: Atherosclerotic external iliac and femoral arteries (n=24) of 6 Yucatan pigs were investigated. Before termination, elastographic data were acquired with a 20-MHz Visions catheter. Two frames acquired at end-diastole with a pressure differential of approximately 4 mm Hg were acquired to obtain the elastograms. Before dissection, x-ray was used to identify the arterial segments that had been investigated by ultrasound. Specimens were stained for collagen, fat, and macrophages. Plaques were classified as absent, early fibrous lesion, early fatty lesion, or advanced fibrous plaque. The average strains in the plaque-free arterial wall (0.21%) and the early (0.24%) and advanced fibrous plaques (0.22%) were similar. Higher average strain values were observed in fatty lesions (0.46%) compared with fibrous plaques (P=0.007). After correction for confounding by lipid content, no additional differences in average strain were found between plaques with and without macrophages (P=0.966). Receiver operating characteristic analysis revealed a sensitivity and a specificity of 100% and 80%, respectively, to identify fatty plaques. The presence of a high-strain spot (strain >1%) has 92% sensitivity and 92% specificity to identify macrophages. CONCLUSIONS: To the best of our knowledge, this is the first time that intravascular ultrasound elastography has been validated in vivo. Fatty plaques have an increased mean strain value. High-strain spots are associated with the presence of macrophages.