Safety and efficacy of miniaturized extracorporeal circulation when compared with off-pump and conventional coronary artery bypass grafting: evidence synthesis from a comprehensive Bayesian-framework network meta-analysis of 134 randomized controlled trials involving 22 778 patients

OBJECTIVES: Coronary artery bypass grafting (CABG) remains the standard of care in patients with extensive coronary artery disease. Yet the use of cardiopulmonary bypass (CPB) is believed to be a major determinant of perioperative morbidity. Novel techniques are sought to tackle the shortcomings of CPB, among them off-pump coronary artery bypass (OPCAB) and miniaturized extracorporeal circulation (MECC) systems have been extensively tested in randomized controlled trials (RCTs). To assess perioperative safety and efficacy of MECC and OPCAB when compared with conventional extracorporeal circulation (CECC). METHODS: Published literature and major congress proceedings were screened for RCTs evaluating the safety and efficacy of MECC, OPCAB and CECC. Selected end-points such as 30-day all-cause mortality, myocardial infarction (MI), cerebral stroke, postoperative atrial fibrillation (POAF) and renal dysfunction were assessed in a Bayesian-framework network meta-analysis. RESULTS: A total of 134 studies with 22 778 patients were included. When compared with CECC, both OPCAB and MECC significantly reduced 30-day all-cause mortality odds ratios (95% credible intervals): 0.75 (0.51-0.99) and 0.46 (0.22-0.91), respectively. No differences in respect to MI were demonstrated with either strategy. OPCAB, when compared with CECC, reduced the odds of cerebral stroke 0.57 (0.34-0.80); 60% reduction was observed with MECC when compared with CECC 0.40 (0.19-0.78). Both OPCAB and MECC reduced the odds of POAF 0.66 (0.48-0.90) and 0.62 (0.35-0.98), respectively when compared with CECC. OPCAB conferred over 30% reduction of renal dysfunction when compared with CECC 0.69 (0.46-0.92). MECC reduced these odds by more than 50% 0.47 (0.24-0.89). Ranking of treatments emerging from the probability analysis (highest to lowest SUCRA values) was MECC followed by OPCAB and CECC. CONCLUSIONS: MECC and OPCAB both improve perioperative outcomes following coronary bypass surgery when compared with conventional CABG performed with extracorporeal circulation. MECC may represent an attractive compromise between OPCAB and CECC.