Spotty calcification typifies the culprit plaque in patients with acute myocardial infarction - An intravascular ultrasound study

Background - Calcification is a common finding in human coronary arteries; however, the relationship between calcification patterns, plaque morphology, and patterns of remodeling of culprit lesions in a comparison of patients with acute coronary syndromes (ACS) and those with stable conditions has not been documented. Methods and Results - Preinterventional intravascular ultrasound (IVUS) images of 178 patients were studied, 61 with acute myocardial infarction (AMI), 70 with unstable angina pectoris (UAP), and 47 with stable angina pectoris ( SAP). The frequency of calcium deposits within an arc of less than 90degrees for all calcium deposits was significantly different in culprit lesions of patients with AMI, UAP, and SAP ( P < 0.0001). Moreover, the average number of calcium deposits within an arc of <90degrees per patient was significantly higher in AMI than in SAP ( P < 0.0005; mean +/- SD, AMI 1.4 +/- 1.3, SAP 0.5 +/- 0.8). Conversely, calcium deposits were significantly longer in SAP patients ( P < 0.0001; mean +/- SD, AMI 2.2 +/- 1.6, UAP 1.9 +/- 1.8, and SAP 4.3 +/- 3.2 mm). In AMI patients, the typical pattern was spotty calcification, associated with a fibrofatty plaque and positive remodeling. In ACS patients showing negative remodeling, no calcification was the most frequent observation. Conversely, SAP patients had the highest frequency of extensive calcification. Conclusions - Our observations show that IVUS allows the identification of vulnerable plaques in coronary arteries, not only by identifying a fibrofatty plaque and positive remodeling, but also by identifying a spotty pattern of calcification.