Intraluminal thrombosis of coronary arteries in fatal myocardial infarctions and in failed aortocoronary saphenous vein grafts.

A review of autopsies of 648 patients who died of acute myocardial infarction showed the presence of intraluminal thrombi in 314 (48%). The left anterior descending coronary artery was principally involved in 172 cases, the left circumflex in 30, and the right coronary in 112. The length of survival after admission was identical for patients with thrombotic occlusion and those with atherosclerotic occlusion or severe stenosis: 28% of the former and 29% of the latter died during the first 24 hours after admission. The incidence of intraluminal thrombotic occlusion of surgically excised, failed aortocoronary vein grafts was 42 (66%) in 64 patients with nonfibrotic, patent grafts. Most of these vessels were severely atherosclerotic. The presence of intraluminal thrombi in about half of patients who died of acute myocardial infarction and in two thirds of excised, nonfibrotic, previously patent vein grafts indicates how many patients may benefit from thrombolytic therapy.