Myocardial infarction complicating aortic valve replacement.

One hundred consecutive aortic valve replacements were studied. Fifteen patients had a myocardial infarction as a result of the operation, and four of the five deaths in the series stemmed from this group. In the four deaths from infarction, autopsy revealed occlusion of a main coronary artery. This was attributable to coronary perfusion in three instances. All of the 11 survivors who sustained an infarct were free of angina and left ventricular failure 6 weeks after the operation. Patients with infarcts had longer bypass times and larger aortic systolic gradients than the patients who did not have an infarct. It is suggested that an infarct can occur as the result of occlusion of a main coronary artery; this is a fatal event commonly related to trauma from the coronary perfusion cannula. Alternatively, infarction may result from regional ischemia, perhaps without vessel occlusion, and is associated with long bypass times and with large aortic valve gradients. In such cases the prognosis is good. However, myocardial infarction was the major cause of death in this series.