Long-term survival of dialysis patients after coronary bypass grafting

Abstract

Background: Dialysis patients are undergoing coronary artery bypass grafting (CABG) with increasing frequency. The long-term effect of preoperative dialysis-dependent renal failure on mortality after CABG has not been well studied.

Methods: We conducted a prospective regional cohort study of 15,574 consecutive patients undergoing isolated CABG in northern New England from 1992 to 1997. Patient records were linked to the National Death Index to assess mortality. Five-year survival and adjusted hazard ratios were calculated.

Results: During 32,589 person-years of follow-up 1298 deaths were recorded. Renal failure was present in 283 patients (1.8%), and 67.8% of patients with renal failure also had diabetes or peripheral vascular disease (PVD). The annual death rate was 3.8% for nonrenal failure patients, 16.9% for all renal failure patients, 7.7% for renal failure patients without diabetes or PVD, and 23.0% for renal failure patients with diabetes or PVD. Five-year survival was 83.5% for nonrenal failure patients, 55.8% for all renal failure patients, 78.5% for renal failure patients without diabetes or PVD, and 42.2% for renal failure patients with diabetes or PVD. After adjustment for differences in base line patient and disease characteristics, renal failure patients without diabetes or PVD had a statistically nonsignificant 57% increase rate of death compared with those without renal failure; renal failure patients with diabetes or PVD had more than a fourfold increased risk of death.

Conclusions: After adjustment for other risk factors, renal failure remains a highly significant predictor of decreased long-term survival in CABG patients. Patients with renal failure plus diabetes or PVD are at especially high risk of death.