Off-Pump vs. On-Pump Coronary Artery Bypass Surgery: An Updated Meta-Analysis and Meta-Regression of Randomized Trials

Study Questions:

What is the contemporary evidence for off-pump coronary artery bypass (OPCAB) versus conventional coronary artery bypass (CCAB)?


The investigators systematically reviewed MEDLINE, EMBASE, and the Cochrane database for published and unpublished randomized trials of OPCAB versus CCAB in which 30-day or in-hospital clinical outcomes were reported. The outcomes of interest were: all-cause mortality, stroke, and myocardial infarction. In addition to measuring the pooled treatment effects using a random-effects meta-analysis model, the authors measured the effect of selected trial-level factors on the effects observed using the meta-regression technique.


Fifty-nine trials were included, encompassing 8,961 patients, with a mean age of 63.4 and 16% females. There was a significant 30% reduction in the occurrence of postoperative stroke with OPCAB (risk ratio [RR], 0.70; 95% confidence interval [CI], 0.49-0.99). There was no significant difference in mortality (RR, 0.90; 95% CI, 0.63-1.30) or myocardial infarction (pooled RR, 0.89; 95% CI, 0.69-1.13). In the meta-regression analysis, the effect of OPCAB on all of the clinical outcomes was similar regardless of mean age, proportion of females in the trial, number of grafts per patient, and trial publication date.


The authors concluded that there appears to be a beneficial effect of OPCAB on stroke.


This large meta-analysis of randomized data performed to date suggests that OPCAB reduces the incidence of postoperative stroke compared with CCAB. However, OPCAB does not significantly reduce the incidence of short-term all-cause mortality and postoperative myocardial infarction. Given the apparent reduction in stroke, the use of OPCAB may be suitable, especially in patients at higher risk of this complication. Factors such as aortic atheroma appear promising to predict which patients will derive the greatest benefit from OPCAB for stroke reduction, and may need to be incorporated in the decision process if validated in future studies.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention

Keywords: Incidence, Postoperative Complications, Risk, Myocardial Infarction, Stroke, Plaque, Atherosclerotic, Coronary Artery Bypass, Off-Pump, Cardiovascular Diseases, Cardiopulmonary Bypass

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