Predictors of perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting

Background Perioperative myocardial infarction (PMI) increases morbidity and mortality after off-pump coronary artery bypass grafting (CABG). The objective of the current study was to characterize patients with PMI after off-pump CABG and identify its predictors. Results We included 1181 patients who had off-pump CABG from 2010 to 2020; 59 patients (5%) had PMI. We compared patients with PMI to those without PMI. Patients with PMI were older (57 (25th–75th percentiles: 51–63) vs. 54 (48–60) years; P = 0.01) and had higher NYHA class (28 (47.46%) vs. 326 (29.06%): P = 0.01). The distal anastomosis time was longer in patients with PMI (28 (23–35) vs. 24 (16–30) min; P ˂ 0.001). Patients with PMI had higher postoperative low cardiac output (10 (18.18%) vs. 1 (0.1%): P ˂ 0.001), prolonged ventilation (12 (8–39) vs. 8 (6–10) h, P ˂ 0.001), ICU (71 (46–138) vs. 24 (23–42) h; P ˂ 0.001), and hospital stay (9 (6–15) vs. 7 (6–8) days; P ˂ 0.001). Mortality was significantly higher in patients with PMI (20 (33.9%) vs. 6 (0.53%); P ˂ 0.001). Older age (OR: 1.05 (95% CI: 1.01–1.1); P = 0.02), increased number of distal anastomoses (OR: 1.74 (95% CI: 1.20–2.50); P = 0.003), preoperative congestive heart failure (OR: 10.27 (95% CI: 2.58–40.95); P = 0.001), and thrombolysis within 24 h of surgery (OR: 15.34 (1.93–121.9); P = 0.01) were associated with increased PMI, while PMI was lower in male patients (OR: 0.42 (95% CI: 0.19–0.93); P = 0.03) and with higher body surface area (BSA) (OR: 0.08 (95% CI: 0.07–0.86); P = 0.04). Conclusions Post-off-pump CABG PMI was associated with increased morbidity and mortality. Risk factors for PMI were older age, lower BSA, females, increased distal anastomoses, preoperative heart failure, and thrombolysis.