Long-Term Outcomes of On- vs. Off-Pump CABG

Study Questions:

What are the long-term clinical outcomes of on-pump versus off-pump coronary artery bypass grafting (CABG)?


The investigators conducted systematic searches using various databases. The search strategy included the key concepts of “cardiopulmonary bypass” AND “off-pump” AND “long term” OR “5-year outcomes.” This was followed by a meta-analysis investigating mortality, incidence of myocardial infarction (MI), incidence of angina, need for revascularization, and incidence of stroke. This meta-analysis only included studies reporting long-term (>4 years) outcomes from randomized controlled trials of off-pump versus on-pump in patients undergoing CABG. A fixed-effects inverse variance model was used to calculate odds ratios.


Six studies totaling 8,145 participants were analyzed. In the on-pump group, mortality was 12.3% compared to 13.9% in the off-pump group. The odds ratio (OR) for this comparison was 1.16 (95% confidence interval [CI], 1.02-1.32; p = 0.03). In contrast, there were no differences in the incidence of MI: OR 1.06 (95% CI, 0.91-1.25; p = 0.45; 8.4 vs. 7.9%); incidence of angina: OR 1.09 (95% CI, 0.75-1.57; p = 0.65; 2.3 vs. 2.1%); need for revascularization: OR 1.15 (95% CI, 0.95-1.40; p = 0.16; 5.9 vs. 5.1%); and the incidence of stroke: OR 0.78 (95% CI, 0.56-1.1; p = 0.16; 2.2 vs. 2.8%).


The authors concluded that statistically, on-pump CABG appeared to offer superior long-term survival.


This study suggests that there is a significantly lower mortality incidence in the on-pump CABG group as compared to off-pump CABG, whereas the incidence of MI, angina, revascularization, and stroke were similar in both groups. Additional prospective studies are indicated to assess whether specific patient populations may benefit from off-pump CABG. For now, it is reasonable to consider on-pump CABG as standard of care except in rare individuals with extensively/severely 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: Angina Pectoris, Cardiac Surgical Procedures, Cardiopulmonary Bypass, Coronary Artery Bypass, Coronary Artery Bypass, Off-Pump, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Stroke, Treatment Outcome

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