Five-Year Outcomes after On-Pump and Off-Pump Coronary-Artery Bypass

To the Editor: Shroyer et al. (Aug 17 issue) 1 report the 5-year outcomes of the Randomized On/Off Bypass (ROOBY) trial. They conclude that off-pump coronary-artery bypass grafting (CABG) led to lower rates of 5-year survival and event-free survival than on-pump CABG. Although the authors allude to criticism of the trial design that allowed inexperienced surgeons to participate in the off-pump part of the trial, this Achilles’ heel is inadequately explored. The sensitivity analysis, excluding numerous off-pump–to–on-pump conversions (12.4%, vs. a 2.2% national average; the higher rate is a surrogate marker of inexperience) obviated the risk from off-pump CABG. The authors . . .