Comparing off-pump and on-pump clinical outcomes and costs for diabetic cardiac surgery patients

Observational studies have documented an off-pump over on-pump advantage for high-risk patients, including diabetic patients. Randomized trials have not confirmed this advantage. The VA Randomization On Versus Off Bypass (ROOBY) trial randomly assigned 2,203 coronary artery bypass graft surgery (CABG) patients at 18 sites to either on-pump (n=1,099) or off-pump (n=1,104) procedures. An a priori ROOBY aim was to evaluate treatment impact on diabetic patients.

Actively treated diabetic patients (n=835, receiving oral hypoglycemic or insulin medications) received off-pump CABG (n=402) or on-pump CABG (n=433). The primary ROOBY trial endpoints were a short-term composite (30-day operative death or major complications) and a 1-year composite (death, nonfatal acute myocardial infarction, or repeat revascularization). Secondary ROOBY endpoints included 1-year all-cause death, 1-year graft patency, 1-year changes from baseline in neurocognitive status and health-related quality of life, and costs.

Diabetic patients' risk factors at baseline were balanced across treatments. For diabetic patients, the primary short-term composite outcome rate showed a worse trend for off-pump (8.0%) than on-pump (3.9%, p=0.013), with no difference in the 1-year primary composite outcome or 1-year death rate. One-year patency was 83.1% off-pump versus 88.4% on-pump (p=0.004). No differences were found in neurocognitive, health-related quality of life, discharge cost, and 1-year cumulative cost.

Concordant with the ROOBY trial's overall findings, off-pump CABG yielded no advantage over on-pump CABG for actively treated diabetic patients. The 1-year graft patency was lower and the short-term composite trended higher for off-pump CABG, with no other significant outcome or cost differences.