Extensive development of vulnerable plaques as a pan-coronary process in patients with myocardial infarction: an angioscopic study

OBJECTIVES To test our hypothesis that the development of vulnerable plaques is not limited to the culprit lesions, but is a pan-coronary process, we directly observed all three major coronary arteries by angioscopy and evaluated the prevalence of yellow plaques in patients with myocardial infarction (MI). BACKGROUND Although pathologic studies have suggested that the disruption of atheromatous plaque plays a major role in the development of acute MI, the prevalence of yellow plaques in the whole coronary arteries of patients with MI has not been clarified. METHODS Thirty-two patients undergoing follow-up catheterization one month after the onset of MI were prospectively and consecutively enrolled in this study. The prevalence of yellow plaques and thrombus in the major coronary arteries was successfully evaluated in 20 patients (58 coronary arteries, 21 culprit lesions) by coronary angioscopy. The diameter stenosis (DS) of the culprit lesions and the maximal diameter stenosis (maxDS) of nonculprit segments were angiographically measured for each coronary artery. RESULTS The DS of the culprit lesions and maxDS were 27 ± 17% and 19 ± 13%, respectively. Yellow plaques and thrombus were detected in 19 (90%) and 17 (81%) of 21 culprit lesions, respectively. Yellow plaques were equally prevalent in the infarct-related and non–infarct-related coronary arteries (3.7 ± 1.6 vs. 3.4 ± 1.8 plaques/artery). However, thrombus was only detected in the nonculprit segments of one (2%) coronary artery. CONCLUSIONS In patients with MI, all three major coronary arteries are widely diseased and have multiple yellow though nondisrupted plaques. Acute MI may represent the pan-coronary process of vulnerable plaque development.