Off-pump vs. on-pump CABG: are we any closer to a resolution?

Abstract

This editorial refers to ‘Off-pump vs. on-pump coronary artery bypass surgery: an updated meta-analysis and meta-regression of randomized trials’, by J. Afilalo et al. , doi:10.1093/eurheartj/ehr307 Afilalo and colleagues have presented an updated meta-analysis and meta-regression of randomized trials of off-pump vs. on-pump coronary artery bypass grafting (CABG) surgery.1 Their two major findings are that while there was a reduction in mortality, myocardial infarction, and stroke in the off-pump group, this only reached significance for the latter, and that the effect of off-pump CABG was similar on all clinical outcomes regardless of age, gender, number of grafts, and trial publication date. The two key questions are: (i) Are these conclusions justifiable based on the data presented? (ii) How relevant are the findings to routine clinical practice? Before answering these questions it is worth addressing (i) the current situation with off-pump CABG and (ii) the appropriateness of the nature and conduct of the meta-analysis and the meta-regression analysis. Off-pump surgery was initially proposed almost three decades ago2 to allow CABG in developing countries without the need for cardiopulmonary bypass that was beyond the economic reality of vast numbers of potential patients. Despite initial scepticism about its technical feasibility, off-pump CABG was gradually adopted by some surgeons in developed countries who believed that the elimination of cardiopulmonary bypass could potentially and substantially eliminate the adverse clinical consequences of extracorporeal circulation. In developed countries this was particularly relevant in a progressively elderly population undergoing cardiac surgery in view of their greater burden of existing co-morbidities and their greater susceptibility to the potentially deleterious consequences of cardiopulmonary bypass. On the other hand, critics maintained that off-pump surgery led to inferior revascularization through a reduction in both the number and quality of bypass grafts and that no study appeared to demonstrate any substantial clinical …