Off-pump coronary artery bypass is associated with improved risk-adjusted outcomes

Background. The impact of off-pump median sternotomy coronary artery bypass grafting procedures on risk-adjusted mortality and morbidity was evaluated versus on-pump procedures. Methods. Using the Department of Veterans Affairs Continuous Improvement in Cardiac Surgery Program records from October 1997 through March 1999, nine centers were designated as having experience (with at least 8% coronary artery bypass grafting procedures performed off-pump). Using all other 34 Veterans Affairs cardiac surgery programs, baseline logistic regression models were built to predict risk of 30-day operative mortality and morbidity. These models were then used to predict outcomes for patients at the nine study centers. A final model evaluated the impact of the off-pump approach within these nine centers adjusting for preoperative risk. Results. Patients treated off-pump (n = 680) versus on-pump (n = 1,733) had lower complication rates (8.8% versus 14.0%) and lower mortality (2.7% versus 4.0%). Risk-adjusted morbidity and mortality were also improved for these patients (0.52 and 0.56 multivariable odds ratios for off-pump versus on-pump, respectively, p < 0.05). Conclusions. An off-pump approach for coronary artery bypass grafting procedures is associated with lower risk-adjusted morbidity and mortality.