Coronary microembolization

Atherosclerotic plaque rupture is a key event in the pathogenesis of acute coronary syndromes and during coronary interventions. Atherosclerotic plaque rupture does not always result in complete thrombotic occlusion of the entire epicardial coronary artery with subsequent acute myocardial infarction, but may in milder forms result in the embolization of atherosclerotic and thrombotic debris into the coronary microcirculation. This review summarizes the available morphological evidence for coronary microembolization in patients who died from coronary artery disease, most notably from sudden death. Then the experimental pathophysiology of coronary microembolization in animal models of acute coronary syndromes is detailed. Finally, the review presents the available clinical evidence for coronary microembolization in patients, highlights its key features—arrhythmias, contractile dysfunction, microinfarcts and reduced coronary reserve—, compares these features to those of the experimental model and addresses its prevention by mechanical protection devices and glycoprotein IIb/IIIa antagonism.