Off-Pump or On-Pump Coronary-Artery Bypass Grafting at 30 Days

Study Questions:

What are the relative benefits and risks of performing coronary artery bypass grafting (CABG) with the use of a beating-heart technique (off-pump CABG), as compared with the use of cardiopulmonary bypass (on-pump CABG)?

Methods:

At 79 centers in 19 countries, the investigators randomly assigned 4,752 patients in whom CABG was planned to undergo the procedure off-pump or on-pump. The first coprimary outcome was a composite of death, nonfatal stroke, nonfatal myocardial infarction, or nonfatal new renal failure requiring dialysis at 30 days after randomization.

Results:

There was no significant difference in the rate of the primary composite outcome between off-pump and on-pump CABG (9.8% vs. 10.3%; hazard ratio for the off-pump group, 0.95; 95% confidence interval [CI], 0.79-1.14; p = 0.59) or in any of its individual components. The use of off-pump CABG, as compared with on-pump CABG, significantly reduced the rates of blood-product transfusion (50.7% vs. 63.3%; relative risk [RR], 0.80; 95% CI, 0.75-0.85; p < 0.001), reoperation for perioperative bleeding (1.4% vs. 2.4%; RR, 0.61; 95% CI, 0.40-0.93; p = 0.02), acute kidney injury (28.0% vs. 32.1%; RR, 0.87; 95% CI, 0.80-0.96; p = 0.01), and respiratory complications (5.9% vs. 7.5%; RR, 0.79; 95% CI, 0.63-0.98; p = 0.03), but increased the rate of early repeat revascularizations (0.7% vs. 0.2%; hazard ratio, 4.01; 95% CI, 1.34-12.0; p = 0.01).

Conclusions:

The authors concluded that there was no significant difference between off-pump and on-pump CABG with respect to the 30-day rate of death, myocardial infarction, stroke, or renal failure requiring dialysis.

Perspective:

This study suggests that there was no significant difference between off-pump and on-pump CABG with respect to the 30-day rate of death, myocardial infarction, stroke, or renal failure requiring dialysis. However, the use of off-pump CABG resulted in reduced rates of transfusion, reoperation for perioperative bleeding, respiratory complications, and acute kidney injury, but also resulted in an increased risk of early revascularization. Essentially, the off-pump group would benefit in the short-term from fewer deleterious effects of blood transfusions, respiratory complications, and renal dysfunction, which may be counterbalanced by the risk of lower rates of long-term graft patency. Additional data on long-term results of the primary outcomes and neurocognitive outcomes are needed, and may have a determinant influence on the final interpretation of this trial. For now, a patient-centered individualized approach offering patients full disclosure on risks/benefits would be the best strategy.

Keywords: Stroke, Myocardial Infarction, Acute Kidney Injury, Blood Transfusion, Renal Dialysis, Renal Insufficiency, Reoperation, Research Personnel, Cardiopulmonary Bypass, Confidence Intervals, Risk Assessment, Coronary Artery Bypass


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