Authors: Kim JB et al., J Am Coll Cardiol 2014 Jun 3; 63:2280
Overall mortality risk was 50% higher in patients who underwent off-pump versus on-pump coronary artery bypass grafting.
Compared with on-pump coronary artery bypass grafting (CABG), off-pump surgery offers potential advantages of reduced bleeding, reduced need for transfusion, and superior neurocognitive outcomes. However, few studies have compared long-term survival with each strategy.
In the current study, investigators compared all-cause mortality in 2333 patients who underwent off-pump CABG and 2570 patients who underwent on-pump surgery between 1989 and 2012 at a single center in Korea. Compared with the on-pump group, rates of diabetes, hypertension, and single-vessel coronary artery disease (CAD) were higher in the off-pump group. Mean ejection fraction was also slightly higher in the off-pump group, but age, sex, and prevalence of left-main CAD were similar between the two groups. More distal anastomoses were performed in the on-pump group (mean, 3.7 vs. 3.0), but more arterial grafts were used in the off-pump group.
All-cause mortality was similar between the two groups at 30 days and 1 year but increased more in the off-pump group during long-term follow-up (median, 6.4 years). Using propensity-matched adjustment, overall mortality risk was nearly 50% higher with off-pump versus on-pump CABG (mortality rates, 22% vs. 17%; hazard ratio, 1.48; 95% confidence interval, 1.14–1.90).
In this large, retrospective comparison, on-pump CABG was associated with better long-term survival compared with off-pump CABG. These findings are consistent with results of smaller studies and meta-analyses. Possible explanations for the better outcome with on-pump surgery include more-complete revascularization, superior graft patency for technical reasons (not assessed in this study), and the higher mortality observed in patients who crossed over from off-pump to on-pump surgery.