[Clinical relevance of coronary artery calcification, as a risk factor for plaque rupture: viewpoint from pathology]

Atherosclerotic calcification is usually associated with long - standing atherosclerosis. There is accumulating evidence that both apoptosis and osteogenic differentiation of vascular smooth muscle cells contribute to arterial calcification. Our long experience of cardiovascular pathology over many years revealed that ruptured plaques were closely associated with areas of small calcium deposits. To further clarify the association between patterns of coronary arterial calcification and morphology of atherosclerotic plaques, we studied preinterventional intravascular ultrasound (IVUS) images at the site of culprit lesions in patients with acute myocardial infarction (AMI), unstable angina pectoris, or stable angina pectoris. Our study demonstrated that small calcium deposits within an arc of < 90° significantly more frequent in the culprit lesion segments of AMI patients. Thus, our study revealed that the spotty calcification pattern of the coronary culprit segment is associated with unstable plaques in AMI patients.