A meta-analysis of adjusted risk estimates for survival from observational studies of complete versus incomplete revascularization in patients with multivessel disease undergoing coronary artery bypass grafting

Abstract

To determine whether coronary artery bypass grafting (CABG) with complete revascularization improves survival in patients with multivessel disease (MVD) over CABG with incomplete revascularization, we performed a meta-analysis of adjusted (but not unadjusted) risk estimates from observational studies. Databases including MEDLINE and EMBASE were searched through October 2013 using Web-based search engines (PubMed, OVID). Eligible studies were observational studies of complete- versus incomplete-revascularization CABG enrolling ≥ 100 patients with MVD in each treatment arm and reporting an adjusted hazard ratio for follow-up mortality. Mixed-effects meta-regression analyses were performed to determine whether the effects of complete-revascularization CABG on survival were modulated by the prespecified factors. Fourteen observational studies enrolling 30 389 patients were identified and included. A pooled analysis demonstrated a statistically significant 37% reduction in follow-up mortality with complete- relative to incomplete-revascularization CABG (hazard ratio, 0.63; 95% confidence interval, 0.53-0.75; P < 0.00001). Although meta-regression coefficients were not statistically significant for mean follow-up duration and age and proportion of men and patients undergoing off-pump CABG, that for proportion of patients with diabetes was significantly negative (P = 0.03), which would indicate that as patients with diabetes increase, complete-revascularization CABG is more beneficial for survival. In conclusion, complete-revascularization CABG appears to improve survival over incomplete-revascularization CABG in patients with MVD.

Keywords: Complete revascularization; Coronary artery bypass grafting; Incomplete revascularization; Meta-analysis.