Off-pump versus on-pump coronary artery bypass grafting: comparative effectiveness

摘要

Background: Historically, coronary artery bypass grafting (CABG) with the use of cardiopulmonary bypass (CPB), referred to as on-pump CABG, has been regarded as the “gold standard”. However, in recent years, it has been increasingly recognized that the systemic inflammatory response associated with using CPB contributes substantially to postoperative organ dysfunction. Intuitively, performance of CABG without CPB, referred to as off-pump CABG, should translate into improved clinical outcomes. Interestingly, no single randomized trial has been able to prove the superiority of off-pump CABG over on-pump CABG for all hard outcomes, and off-pump CABG remains the subject of intense scrutiny as well as controversy. The purpose of the review is to summarize the current best available evidence, comparing the effectiveness of off- and on-pump CABG. Methods: The English language scientific literature was reviewed primarily by searching MEDLINE from January 2010 to December 2014 using PubMed interface to identify meta-analyses and systematic reviews of randomized controlled trials as well as observational studies using propensity score matching, comparing the effectiveness of off- and on-pump CABG. Results: Current best available evidence from meta-analyses and systematic reviews of randomized controlled trials as well as propensity score analyses suggests that off-pump CABG is associated with fewer distal anastomoses, increased repeat revascularization rates, and poor saphenous vein graft patency compared with on-pump CABG. No significant differences were observed for other hard outcomes including mortality, myocardial infarction, and stroke. Conclusion: Off-pump CABG compared to on-pump CABG is associated with similar short-, mid-, and long-term mortality, comparable organ protection, and fewer distal anastomoses. The concerns about the safety and efficacy of off-pump CABG are not substantiated by the current best available evidence. However, the impact of learning curve on outcomes remains a valid issue.