Thrombosis on an atherosclerotic plaque is the primary pathophysiological mechanism underlying acute coronary syndromes, including myocardial infarction, unstable angina, and sudden ischemic death.
V irtually all regional acute myocardial infarcts are caused by thrombosis developing on a culprit coronary atherosclerotic plaque. The very rare exceptions to this are spontaneous coronary artery dissection, coronary arteritis, coronary emboli, coronary spasm, and compression by myocardial bridges. Thrombosis is also the major initiating factor in unstable angina, particularly when rest pain is recent and increasing in severity. Necropsy studies suggest that a new thrombotic coronary event underlies 50-70% of sudden deaths caused by ischaemic heart disease.
Melanie J. Davies (2000) studied this question.