Myocardial revascularization for acute myocardial infarction

Coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) is associated with increased morbidity and mortality compared with CABG in non-AMI patients. We describe the surgical results of these high-risk patients. Sixteen patients (nine male and seven female) underwent CABG after recent onset of acute myocardial infarction. The mean age was 64.7 (range: 51 to 78). Seven patients (43.8%) had at least one myocardial infarction in the past, three (18.8%)--diabetes mellitus, two (12.5%)--chronic renal failure after nephrectomy. Five patients (31.3%) were preoperatively in cardiogenic shock, and six patients (37.5%) required preoperative intraaortic balloon pump (IABP) for stabilization. Two patients (12.5%) had postinfarction ventricular septum perforation (VSD) and three patients (18.8%) hed left main artery trunk stenosis. Mean ejection fraction was 46%. During the first 24 hours six patients were operated, during the second day two, up to the seventh day five more and last three between 8th and 21st day after AMI. The operations were performed with extracorporal circulation in middle hypothermia (34 degrees C). The mean number of grafts per patient was 2.9, and the left internal thoracic artery was used in 11 patients (68.8%). In two patients VSD was closed with Dacron patch. All the patients needed longer time of reperfusion and inotropic drugs and eight (50%) of them mechanical support (IABP) during weaning from cardiopulmonary bypass. Three patients (18.8%) died (both with VSD) because of low output syndrome and multiorgan failure, all were over 70 years old (72, 73, 78).

emergency coronary artery bypass grafting for acute myocardial infarction is associated with increased operative mortality and morbidity especially in the first 48 hours. The only risk factors for postoperative mortality in this group of patients are age over 70 years, cardiogenic shock, left main artery stenosis and the shortness of the interval between acute myocardial infarction onset and surgery.