Results of Emergency Coronary Artery Bypass Grafting for Acute Myocardial Infarction: Importance of Intraoperative and Postoperative Cardiac Medical Therapy

BACKGROUND: The results of emergency coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) are less than satisfactory, and readmission for cardiac events is common. METHODS AND RESULTS: 105 patients underwent emergency CABG for AMI. We examined the long-term results of emergency CABG for AMI from the viewpoints of preoperative, intraoperative, and postoperative factors. The operative mortality rate was 11.4%. Risk factors for early death were age ≥80 years, shock, veno-arterial bypass, creatine kinase isoenzyme Mb ≥100 U/L, non-use of a left internal thoracic artery graft and an extracorporeal circulation time ≥120 min. Risk factors for late cardiac events were ejection fraction <40%, non-use of human atrial natriuretic peptide (hANP) therapy, angiotensin II receptor blockers (ARB) and aldosterone blockers, and a 3-month postoperative brain natriuretic peptide level ≥200 pg/ml. CONCLUSIONS: Early results of this study are similar to those seen in previous reports, whereas late phase results yield some new and interesting findings. We suggest that intraoperative hANP, and postoperative aldosterone blocker and ARB, following CABG for AMI, will, through control of the renin-angiotensin-aldsterone system, inhibit left ventricular remodelling, reduce the extent of infarction, and improve cardiac function, yielding a favourable long-term prognosis.