Background: We evaluated the incidence and predictors of single and multiple plaque ruptures in acute myocardial infarction (AMI) and stable angina pectoris (SAP).
Methods and results: We performed 3-vessel intravascular ultrasound (IVUS) examination in 235 patients: 122 had AMI, and 113 had SAP. Plaque rupture of infarct-related or target lesions occurred in 80 AMI patients (66%) and in 31 SAP patients (27%) (P<0.001). Non-infarct-related or non-target artery plaque ruptures occurred in 21 AMI patients (17%) and 6 SAP patients (5%) (P=0.008). Multiple plaque ruptures were observed in 24 AMI (20%) and 7 SAP patients (6%) (P=0.004). Therefore, at least 1 plaque rupture in any coronary artery was noted in 84 AMI patients (69%) and 35 SAP patients (31%) (P<0.001). Overall, the only independent clinical predictor of plaque rupture in the infarct-related/target lesion was AMI (P<0.01; OR, 4.867; 95% CI, 2.734 to 8.661). The only independent clinical predictor of plaque rupture in AMI patients was an elevated C-reactive protein (CRP) level (P=0.035; OR, 2.139; 95% CI, 1.053 to 4.343). Conversely, in SAP patients, the only independent clinical predictor of plaque rupture was diabetes mellitus (P=0.034; OR, 2.553; 95% CI, 1.071 to 6.085). The only independent clinical predictor of multiple plaque ruptures was AMI (P=0.003; OR, 3.752; 95% CI, 1.546 to 9.105).
Conclusions: Three-vessel IVUS imaging showed that culprit lesion plaque rupture, secondary remote plaque ruptures, and multiple plaque ruptures were all more common in AMI patients than SAP patients. In AMI patients, plaque rupture was associated with a high CRP level, whereas in SAP patients, plaque rupture was more common in those with diabetes.