Five-Year Outcomes After On- and Off-Pump CABG

Study Questions:

What are the 5-year outcomes between off-pump coronary artery bypass grafting (CABG) and on-pump CABG?


The ROOBY-FS investigators randomly assigned 2,203 patients at 18 medical centers from February 2002 through June 2007, to undergo either on-pump or off-pump CABG, with 1-year assessments completed by May 2008. The two primary 5-year outcomes were death from any cause and a composite outcome of major adverse cardiovascular events (MACE), defined as death from any cause, repeat revascularization (CABG or percutaneous coronary intervention), or nonfatal myocardial infarction. Secondary 5-year outcomes included death from cardiac causes, repeat revascularization, and nonfatal myocardial infarction. Primary outcomes were assessed at a p value of ≤0.05, and secondary outcomes at a p value of ≤0.01. For the time-to-event analyses, log-rank tests and Kaplan-Meier curves were used.


The rate of death at 5 years was 15.2% in the off-pump group versus 11.9% in the on-pump group (relative risk [RR], 1.28; 95% confidence interval [CI], 1.03-1.58; p = 0.02). The rate of MACE at 5 years was 31.0% in the off-pump group versus 27.1% in the on-pump group (RR, 1.14; 95% CI, 1.00-1.30; p = 0.046). For the 5-year secondary outcomes, no significant differences were observed: for nonfatal myocardial infarction, the rate was 12.1% in the off-pump group and 9.6% in the on-pump group (p = 0.05); for death from cardiac causes, the rate was 6.3% and 5.3%, respectively (p = 0.29); for repeat revascularization, the rate was 13.1% and 11.9%, respectively (p = 0.39); and for repeat CABG, the rate was 1.4% and 0.5%, respectively (p = 0.02).


The authors concluded that off-pump CABG led to lower rates of 5-year survival and event-free survival than on-pump CABG.


This large-scale multicenter trial reports that at 5 years, on-pump CABG was superior to off-pump CABG with regard to death from any cause and the primary composite MACE outcome. Furthermore, at all 5-year clinical outcomes that were evaluated, the off-pump approach did not confer any advantage over on-pump CABG procedures. These results suggest that innovative surgical approaches such as the more technically demanding off-pump procedure may not necessarily provide superior clinical outcomes. Additional long-term follow-up, evaluating these same outcomes rigorously at 10 years after CABG, is indicated. For now, on-pump CABG should be considered standard of care except in rare individuals with extensively calcified (porcelain) aorta where off-pump technique may result in less manipulation of the aorta, potentially decreasing the risk of aortic emboli or stroke.

Keywords: Cardiac Surgical Procedures, Coronary Artery Bypass, Coronary Artery Bypass, Off-Pump, Myocardial Infarction, Percutaneous Coronary Intervention, Myocardial Revascularization, Outcome Assessment, Health Care, Risk, Survival

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