Does coronary artery bypass graft surgery improve survival among patients with end-stage renal disease?

BACKGROUND: Cardiovascular disease remains the most frequent cause of death for patients with end-stage renal disease. To determine the long-term benefit of surgical revascularization in this high-risk population, we studied our patients with ESRD having coronary artery bypass graft surgery (CABG), comparing the results of off-pump to on-pump revascularization. As a baseline reference group, we used dialysis patients with a diagnosis of coronary artery disease who did not have surgical revascularization or percutaneous coronary interventions. The control group data set was obtained from the United States Renal Data System.

METHODS: From January 1995 through July 2003, 158 patients with end-stage renal disease who were on hemodialysis (excluding those in cardiogenic shock, needing resuscitation, and with emergent or salvage status) underwent CABG. Fifty-nine patients (37.3%) had off-pump revascularization, and 99 patients (62.7%) had bypass grafting utilizing extracorporeal circulation. Preoperative risk factors and operative results were analyzed, and longitudinal survival data obtained.

RESULTS: The mean follow-up time was 39.1 months (median, 33.1) for the on-pump patients and 18.3 months (median, 14.7) for off-pump. The total number of anastomoses per off-pump patient was 2.4 +/- 1.0, and with cardiopulmonary bypass (CPB), it was 3.3 +/- 0.9 (p < 0.001). Patients revascularized off-pump had an operative mortality rate of 1.7%, whereas patients grafted using CPB had an operative mortality of 17.2% (p = 0.003). The predicted risk of mortality for the off-pump group (9.3% +/- 7.4%) was not statistically different from the on-pump cohort (9.1% +/- 7.7%, p = not significant). Logistic regression analysis indicates that CPB use was an independent risk factor for early death (p = 0.01, odds ratio = 13.6, 95% confidence interval: 1.7 to 110). Long-term follow-up demonstrated that the patients revascularized using CPB had improved survival compared with the off-pump patients and the control population.

CONCLUSIONS: Off-pump CABG improves early mortality rate when compared with conventional revascularization. Despite a greater operative mortality, however, long-term survival is improved in the patients revascularized with CPB as compared with the off-pump cohort, suggesting possible advantages from a more complete revascularization in this population.