Coronary artery erosion and dissection: an unusual complication of mitral annular calcification.

This article describes a 42-year-old male patient with a longstanding history of insulin-dependent diabetes mellitus, systemic arterial hypertension, and chronic renal failure. The patient had severe mitral annular calcification (MAC) identified at autopsy. This MAC was of an amorphous, caseous-appearing type; it displaced the posterior mitral valve leaflet and extruded into the myocardium of the lateral and posterolateral left ventricle to involve the epicardial surface. The MAC produced extramural erosion of the wall, and dissection into the media, of the first left/obtuse marginal coronary artery. This coronary artery involvement by, and other complications of, MAC are discussed.