Abstract 9002: Off-pump Rather than On-pump Coronary Artery Bypass Grafting Increases Late Mortality: A Meta-analysis of Randomized controlled Trials

Abstract

Background: A recent meta-analysis incorporating 59 randomized controlled trials (RCTs) of off-pump versus on-pump (conventional) coronary artery bypass grafting (CABG) suggests that there appears to be a beneficial effect of off-pump CABG on post-operative (30-day or in-hospital) stroke but neither all-cause mortality nor myocardial infarction. To determine whether off-pump CABG reduces late all-cause mortality, we performed a meta-analysis of RCTs of off-pump versus on-pump CABG. Methods: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through January 2012. Eligible studies were RCTs of off-pump versus on-pump CABG and reporting late (≥1-year) all-cause mortality as an outcome. For each RCT, data regarding mortality in both the off-pump and on-pump CABG groups were used to generate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Eighteen RCTs enrolling 5358 patients were identified. Pooled analysis suggested a significant increase in late total mortality among patients randomized to off-pump versus on-pump CABG in the fixed-effects model (OR, 1.35; 95% CI, 1.07-1.70; P =0.01; Figure). There was minimal trial heterogeneity ( P =0.87) and accordingly little difference in the pooled result from the random-effects modeling. Mortality increase remained significant even after elimination of the largest and highest-weight RCT (Randomized On/Off Bypass [ROOBY] study) (OR, 1.32; 95% CI, 1.01-1.72; P =0.04). In general, exclusion of any single RCT from the analysis did not substantively alter the overall result of our analysis. There was no evidence of significant publication bias. Conclusions: Off-pump rather than on-pump CABG appears to significantly increase late (≥1-year) mortality