Objective: This study was designed to test the hypothesis that in patients without obstructive coronary artery disease, segments with endothelial dysfunction are associated with tissue characteristics of plaque vulnerability.
Background: It is not clear whether coronary endothelial dysfunction is associated with a complicated coronary plaque, although it is known as early process of atherosclerosis as well as predictor of adverse cardiovascular outcomes.
Methods: Fifty seven lesions of eight patients (3 men, mean 44 years), who underwent coronary vascular reactivity evaluation by graded administration of intracoronary acetylcholine, were analyzed for intravascular ultrasound (IVUS) radiofrequency data using IVUS-virtual histology software. All lesions were divided into two groups according to the presence of endothelial dysfunction.
Results: Thirty lesions in the 10 segments showing decreased epicardial coronary arterial diameter response to acetylcholine had smaller lumen (8.0±1.7mm2 vs. 11.5±2.6mm2, p<0.001) and vessel area (13.0±3.3mm2 vs. 15.6±3.7mm2, p<0.01), but larger plaque burden (37.2±9.1% vs. 26.5±3.9 %, p<0.001) compared to 27 lesions in the 9 segments without decreased diameter changes. Those lesions with endothelial dysfunction had higher fibrous (1.27±1.4mm2 vs. 0.56±0.8mm2, p<0.05), dense calcium (0.12±0.25mm2 vs. 0.01±0.02mm2, p<0.05), and necrotic core plaques (0.32±0.4mm2 vs. 0.06±0.1mm2, p<0.01) than those without endothelial dysfunction. Multivariate analysis identified fibrous (β=-0.355, p<0.005) and necrotic core plaques (β=-0.526, p<0.005) are independently associated with coronary endothelial dysfunction, while smaller lumen area is associated with coronary endothelial dysfunction.
Conclusions: Coronary endothelial dysfunction is associated with segments with necrotic core and fibrous plaques. This study suggests that coronary endothelial dysfunction is associated with localized tissue characteristics of vulnerable plaques.
|
