On-pump versus off-pump coronary surgery outcomes in patients requiring dialysis: Perspectives from a single center and the United States experience

Objective: Coronary artery bypass graft surgery carries increased risk for patients requiring dialysis compared with other groups. Little data exist comparing outcomes of on-pump and off-pump techniques in dialysis patients. This study compares outcomes of bypass grafting in dialysis patients with these two techniques at a single institution and in the United States Renal Data System (USRDS) database. Methods: From March 1997 to April 2004, 37 patients requiring dialysis underwent bypass graft surgery at our institution. On-pump surgery was performed for 16 patients and off-pump surgery for 21. From January 1, 2001, to December 31, 2002, a total of 3922 patients in the USRDS underwent bypass graft surgery. On-pump surgery was performed for 3382 and off-pump surgery for 540. Comparisons were made between patients undergoing on-pump and off-pump bypass surgery with respect to demographics, risk factors, and outcomes. Univariate analysis, the Kaplan-Meier method, and a multivariate Cox model were used. Results: Institutional analysis revealed similar patient demographics, risk factors, use of thoracic artery grafts, and number of distal anastomoses. Outcome analysis was significant for less postoperative atrial fibrillation with the off-pump technique: 37.5% on-pump and 4.8% off-pump (P = .028). USRDS data revealed all-cause survivals at 1 and 18 months of 87.5% and 59.5% for on-pump versus 88.3% and 61.9% for off-pump procedures (P = .226). In a comorbidity-adjusted Cox model, off-pump bypass grafting was associated with a 16% reduction in all-cause mortality (P = .032). Conclusion: Off-pump bypass grafting is uncommon in patients in the United States who require dialysis. Off- pump bypass grafting provides a morbidity benefit and is associated with a lower risk of death.