Coronary artery bypass grafting for postinfarction angina pectoris

The variables that predict increased operative risk and postoperative morbidity among patients who undergo coronary artery bypass grafting (CABG) early after myocardial infarction for persistent or recurrent ischemia are incompletely defined. In a recent 3-year interval (1985-1987), 240 patients underwent CABG within 30 days of a documented myocardial infarction. Thirty-day mortality was 3.3% (eight patients). Twenty variables were examined by univariate and multivariate analysis for their effects on early mortality. Left main coronary artery disease (p = 0.0003), female sex (p = 0.0059), and preoperative left ventricular dysfunction (increased left ventricular wall motion score) (p = 0.0135) were significant independent predictors of increased 30-day mortality. Postoperative inotropic support for low cardiac output was required for 55.6% of patients operated upon within 24 hours of infarction as compared with 11.6% of patients operated upon between 1 and 30 days (p less than 0.01). Significantly more patients undergoing emergent CABG required postoperative intra-aortic balloon pumping and inotropic support than those patients who underwent urgent or elective operation (23.8% vs. 4.6% and 52.4% vs. 10%, respectively) (p less than 0.01). Other studies confirm that preoperative left ventricular dysfunction, presence of cardiogenic shock, or intra-aortic balloon pumping are important predictors of operative risk. Other variables that may be important include advanced age, female sex, left main coronary artery disease, and anterior transmural infarction. The timing and urgency of operation have not been shown to be significant and independent determinants of increased operative risk.(ABSTRACT TRUNCATED AT 250 WORDS)