MYOCARDIAL INFARCTION FOLLOWING CAROTID ENDARTERECTOMY

Myocardial infarction has been the major cause of mortality following operation for cerebrovascular insufficiency. In our institution, a clinical diagnosis of coronary artery disease was made in 37 of 125 (29.6%) consecutive male patients having carotid endarterectomy. Six of these 37 patients developed postoperative myocardial infarction. In contrast, none of the 88 patients without coronary artery disease developed myocardial infarction. A more recently treated group of 20 patients who had undergone carotid artery surgery and had previously undergone coronary artery bypass for angina did not develop postoperative myocardial infarction. These data suggest that in patients with both coronary artery and carotid artery disease, prior or concomitant coronary artery bypass should be considered. Myocardial infarction has been the leading cause of early and late death following operation for cerebrovascular insufficiency.(1) DeBakey(2) found operative mortality in patients having surgery for cerebrovascular insufficiency directly related to the incidence of coronary artery disease. An increased operative mortality due to reinfarction has been found in patients recovering from recent myocardial infarction.(3) Cooley(4) found that in patients having aortocoronary bypass there was no increased operative mortality 30 days after myocardial infarction and this may apply to patients having carotid endarterectomy. Subendocardial postoperative infarction associated with minor T wave changes and slight enzyme elevation had a better prognosis than did transmural infarction causing significant Q waves, sequential ST and T wave changes and marked enzyme elevations.(5) The purpose of this study was to document our experience with myocardial infarction in patients undergoing carotid artery operation for clinical coronary artery disease. Consideration of the role of saphenous vein bypass in those patients with coronary artery disease was the background for this review even though the evidence that myocardial infarction can be prevented with saphenous vein bypass operation is only preliminary at the present time.(6)