Early and late outcomes of cardiac surgery in patients with moderate to severe preoperative renal dysfunction without dialysis

It is well known that end-stage renal failure requiring dialysis negatively impacts early and late outcome of cardiac surgery. However, data with respect to non-dialysis-dependent renal failure patients (NDRF) are limited. We retrospectively analyzed 6940 consecutive patients undergoing cardiac surgery from January 1998 to September 2006. Patients undergoing cardiac transplantation and ventricular assist device implantation (n=246) and dialysis dependent patients (n=245) were excluded. NDRF was present in 135 (2.1%) patients (mean age 64+/-14, 38% female). NRDF patients were more likely to present with cardiac related risk factors including ejection fraction <30% (P<0.001), prior myocardial infarction (P<0.001), congestive heart failure (P<0.001), active endocarditis (P<0.001) and hemodynamic instability (P<0.001). The estimated odds (OR) of hospital mortality in NDRF patients was 6.6 (P<0.001). Multivariate analysis retained NDRF as an independent factor for increasing the risk of hospital mortality among patients undergoing cardiac surgery (OR=5.1, P<0.001). Patients with NDRF were more likely to experience major postoperative complications when compared to the control group. One- and 5-year survival in NDRF patients was 82+/-4% and 63+/-6%, respectively, and significantly reduced compared to the control group. NDRF is a strong independent predictor of hospital mortality and morbidity in patients undergoing cardiac surgery. Preoperative renal dysfunction also adversely affects long-term survival in these patients.