Predictors of adverse effects after coronary artery bypass grafting in patients with reduced left ventricular ejection fraction

Background To determine adverse outcome and its specific perioperative predictors after coronary artery bypass grafting (CABG) in patients with reduced preoperative ejection fraction (EF). Methods This study included two propensity-score matched groups, each of 50 patients. Group I included patients with EF <50% and group II included patients with EF ≥50%. All patients underwent isolated, elective on-pump CABG between November 2014 and October 2016, at Assiut and Minia university hospitals. Preoperative, operative, postoperative and follow-up (6 months) data were collected and analyzed. The primary outcome was early 30 days mortality. Results Early mortality was 8% in group I and 4% in patients in group II. The proportion of low cardiac output syndrome (LCOS) in group I was significantly higher than group II (44% versus 26%, P = 0.04). At the end of 6 months follow-up, most of patients in group I had significant improvement of EF and NYHA class. On multivariate analysis the significant predictors of outcome in group I were insertion of IABP for early mortality, incomplete revascularization for LCOS, sternal wound infection and LCOS for prolonged hospital stay. Preoperative change in wall motion score following dobutamine stress echocardiography (DSE) had good predictive accuracy for early mortality. Conclusions Insertion of IABP, incomplete revascularization, wall motion scores on DSE, and postoperative LCOS are significant predictors of adverse outcome after CABG in patients with preoperative EF <50% and viable myocardium. A protocol approach should be established for such patients respecting perioperative risk factors.