SummaryThis study aimed to evaluate on-pump versus off-pump coronary artery bypass grafting (CABG) in patients with a high-risk operative profile.The pre-, intra-and post-operative data of high-risk patients with additive European system for cardiac operative risk evaluation (additive Euro-SCORE) over 6 undergoing isolated CABG from January 2008 to December 2011 in this center were investigated and retrospectively analyzed. Using the propensity score-matching method, those patients with similar pre-and intra-operative characteristics were selected and their early clinical outcomes were compared.From January 2008 to December 2011, 485 consecutive patients (398 males, with a mean age of 70.9 ± 9.0 years) whose additive Euro-SCORE was over 6 were entered into this study. Off-pump coronary bypass grafting (OPCAB) was performed in 58.1% (n = 282), and the remaining patients underwent conventional coronary artery bypass grafting (CCABG). After propensity score matching, the two groups of patients (90 OPCAB patients versus 90 CCABG patients) were similar with regard to pre-and intra-operative characteristics but not duration of surgical procedure. No significant differences in hospital mortality were found. Compared to CCABG, high-risk patients undergoing OPCAB had significantly lower prevalence of postoperative respiratory failure and postoperative renal failure (6.7% versus 17.8%, P = 0.0386, 5.6% versus 16.7%, P = 0.0307, respectively). Through multivariate logistic regression analysis, type of procedure (CCABG versus OPCAB), as an independent risk factor, had an impact on the postoperative respiratory failure (OR = 2.36, 95%CI 1.44-4.97, P = 0.0312) and postoperative renal failure (OR = 2.86, 95%CI 1.61-5.81, P = 0.0037).Compared with CCABG, OPCAB reduced postoperative respiratory and renal morbidity in high-risk patients. (Int Heart J 2014; 55: 484-488)