Invited Commentary

Abstract

Off-pump coronary artery bypass graft (OPCABG) surgery has been a controversial topic for many years, with a growing number of randomized controlled trials demonstrating that early and 1-year survival are no different whether the heart-lung machine is used or not. Two observational studies [1Bakaeen F.G. Chu D. Kelly R.F. et al.Performing coronary artery bypass grafting off-pump may compromise long-term survival in a veteran population.Ann Thorac Surg. 2013; 95: 1952-1958Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar, 2Filardo G. Grayburn P.A. Hamilton C. Hebeler R.F. Cooksey W.B. Hamman B. Comparing long-term survival between patients undergoing off-pump and on-pump coronary artery bypass graft operations.Ann Thorac Surg. 2011; 92: 571-577Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar] have recently suggested that long-term survival could actually be worse after OPCABG than after conventional coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass. Greater technical difficulty, fewer number of grafts with possible incomplete revascularization, and lower quality of the anastomoses in OPCABG surgery have been hypothesized as possible causes of such reduced survival. The study by Dalén and colleagues [3Dalén M. Ivert T. Holzmann M.J. Sartipy U. Long-term survival after off-pump coronary artery bypass surgery: a Swedish nationwide cohort study.Ann Thorac Surg. 2013; 96: 2054-2060Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar] demonstrates once again that performing CABG off-pump does not improve early operative survival in a large population of unselected coronary patients, but distinguishing this study is the length of follow-up—a mean of 7.1 years with survival assessment at 10 years. Remarkably, in this extensive and meticulous retrospective observational study, on more than 50,000 consecutive patients, late survival was not at all diminished in off-pump patients, even though the percentage of OPCABG was very low and became lower as time went on (16% in the year 2000, progressing to 1% in 2008, with a variance of 3% to 11% of all isolated coronary operations in the different participating centers). Actually, both curves describing survival and freedom from major events seem to begin to diverge in favor of OPCABG after 9 to 10 years [3Dalén M. Ivert T. Holzmann M.J. Sartipy U. Long-term survival after off-pump coronary artery bypass surgery: a Swedish nationwide cohort study.Ann Thorac Surg. 2013; 96: 2054-2060Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar]. There are probably several different reasons, besides avoidance of cardiopulmonary bypass, for such an excellent outcome of OPCABG in this study: one reason may be the more extensive use of arterial grafts, with the radial artery utilized twice as frequently in off-pump patients. Possibly, a liberal use of intraoperative graft validation with transit-time flow measurement, very popular in Scandinavia in the past decade, might also have played a role in improving the outcome of OPCABG patients, (Unfortunately, though, we do not know the transit-time flow measurement utilization in the study group.) Incongruous in this study is the higher incidence of perioperative complications such as stroke, reexploration for sternal wound problems, reoperation for bleeding (each occurring twice as frequently after OPCABG), and acute renal failure recorded in the off-pump group. In fact, while some aspects of off-pump coronary surgery are still debated, randomized controlled trials have shown that OPCABG reduces bleeding, stroke, and acute kidney injury, especially in high-risk patients. This noteworthy study on a remarkably large series of patients, in a “real-world” setting, shows that OPCABG can be performed with excellent results despite infrequent performance. Further investigation of survival and freedom from major adverse events at a longer follow-up on the same series of patients would be particularly appealing. Long-Term Survival After Off-Pump Coronary Artery Bypass Surgery: A Swedish Nationwide Cohort StudyThe Annals of Thoracic SurgeryVol. 96Issue 6PreviewThe aim of this study was to analyze long-term survival after primary isolated off-pump coronary artery bypass grafting (CABG) compared with on-pump CABG in a nationwide patient cohort. Full-Text PDF