Contemporary Results Show Repeat Coronary Artery Bypass Grafting Remains a Risk Factor for Operative Mortality

Background. Reoperative coronary artery bypass grafting (redo CABG) shows improving outcomes, but with varying degrees of improvement. We assessed contemporary outcomes after redo CABG to determine if redo status is still a risk factor for early postoperative complications and midterm survival. Methods. Isolated CABG procedures (June 1, 2001 to May 31, 2008) within the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database were included. Redo status as a predictor for early outcomes was assessed with logistic regression analysis. Midterm survival was determined from the National Death Index. Effect of redo status on midterm survival was assessed using a Cox proportional hazards model. Results. Inclusion criteria were met by 13,436 patients, and 458 (3.4%) underwent redo CABG. Operative mortality was 4.8% for redo CABG and 1.8% for first-time CABG (p < 0.001). After adjustment, redo status remained a predictor for operative mortality (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.3 to 3.6), myocardial infarction (OR, 2.8; 95% CI, 1.6 to 6.0), and prolonged ventilation (OR, 1.5; 95% CI, 1.1 to 2.0). Unadjusted survival was lower for the redo CABG group vs the first-time CABG group at up to 6 years (p = 0.01, log-rank test. After adjusting for differences in patient variables, redo status was not a predictor of midterm survival (OR, 1.03; 95% CI, 0.78 to 1.35; p = 0.85). Conclusions. Early postoperative outcomes of redo CABG are encouraging. Midterm survival is excellent; however, redo remains a significant risk factor for operative mortality in contemporary practice.