For diabetic patients who require coronary artery bypass graft (CABG) operation, controversy persists whether an off-pump or an on-pump approach may be advantageous. This US-based, multicenter, randomized, controlled trial, Department of Veterans Affairs Randomization On versus Off Bypass Follow-up Study, compared diabetic patients’ 5-year clinical outcomes for off-pump versus on-pump procedures.
From 2002 to 2008, 835 medically treated (ie, oral hypoglycemic agent or insulin) diabetic patients underwent either off-pump (n = 402) or on-pump (n = 433) CABG. Five-year primary end points included all-cause death and major adverse cardiovascular events (MACE; composite included all-cause death, myocardial infarction, or repeat revascularization). Secondary 5-year end points included cardiac death and MACE-related components. With baseline risk factors balanced, outcomes were evaluated by using a p value less than or equal to 0.01; nonsignificant trends were reported for p values greater than 0.01 and less than or equal to 0.15.
Five-year all-cause death rates were 20.2% off pump versus 14.1% on pump (p = 0.0198). No differences were seen in MACE (32.6% off-pump approach versus 28.6% on-pump approach, p = 0.216), repeat revascularization (12.4% off-pump approach versus 11.8% on-pump approach, p = 0.770), and nonfatal myocardial infarction (12.7% off-pump approach versus 10.4% on-pump approach, p = 0.299). Cardiac death trended worse with off-pump CABG (9.0%) than with on-pump CABG (6.25%, p = 0.137). Sensitivity analyses that removed conversions confirmed these findings.
With a 6.1% absolute difference, a strong trend toward improved 5-year survival was observed with on-pump CABG for medically treated diabetic patients. No off-pump advantage was found for any 5-year end points. A future clinical trial now appears warranted to rigorously compare off-pump versus on-pump longer term outcomes for diabetic patients.