Long-term survival following postoperative myocardial infraction after coronary artery bypass surgery

Background: Postoperative myocardial infraction (MI) is a serious complication among patients undergoing Coronary Artery Bypass Grafting (CABG). Data on the impact of postoperative MI on patients undergoing CABG, specifically with respect to their long term outcomes are sparse. Methods: We retrospectively analyzed all patients who underwent isolated CABG between January 2014 and December 2016 and identified those who fulfilled the definition of the type 5 MI following CABG according to the Fourth Universal Definition of Myocardial Infarction. Results: A total of 4,642 CABG patients were identified, of whom 141 (3.04%) were diagnosed with postoperative MI. The mean follow-up time was 5.1 +/- 2.07 years (range, 4.4-6.9 years). Postoperative MI was more common in patients with recent acute coronary syndrome, when compared to stable angina (22.8% vs. 31.9%; P=0.011) and in those with non-elective versus planned surgery (28.4% vs. 18.4%; P=0.003). Postoperative MI after CABG was associated with an increased rate of postoperative complications, including cardiac tamponade and re exploration for bleeding. Mortality after postoperative MI was higher at short-term follow-up (up to one year) and long-term follow-up (up to five years). The risk factors for postoperative MI after CABG were incomplete revascularization (IR) [OR (95% CI): 2.25 (1.59-3.12), P=0.001], non-elective surgery [OR (95% CI): 1.68 (1.10-2.54), P=0.015] and female gender [OR (95% CI): 1.48 (1.01-2.18), P=0.045]. Conclusions: PMI after CABG is associated with reduced short-and long-term survival. The main risk factors for postoperative MI are IR, female gender, and non-elective surgery.