Cardiac surgery in moderate to end-stage renal failure: analysis of risk factors.

Background: The incremental surgical risk caused by different categories of renal failure is not well defined.
Methods: Data from 159 patients with moderate to end-stage renal dysfunction, who had consecutive operations using cardiopulmonary bypass, were included in a multivariate analysis of morbidity and survival. Ninety-nine patients had preoperative serum creatinine levels (PSCL) of 1.9 to 2.5 mg/dL (moderate), 36 had PSCL higher than 2.5 mg/dL and were not dialysis dependent (severe), and 24 required chronic dialysis (end-stage dysfunction).
Results: Operative mortality was 4% with moderate dysfunction and compared favorably with 16.7% in severe and 8% in end-stage dysfunction (p < 0.05). Independent predictors of death were severe non-dialysis-dependent renal dysfunction (p < 0.05), diabetes (p < 0.05), and cardiopulmonary bypass time (p < 0.01). Severe renal dysfunction (p < 0.01) and diabetes (p < 0.01) also predicted pulmonary and neurologic morbidity. Freedom from late death at 4 years was 82% +/- 5% with moderate, 49% +/- 10% with severe, and 60% +/- 10% with end-stage dysfunction (p < 0.01). Time to late death was adversely affected by severe (p < 0.05) and end-stage dysfunction (p < 0.01). Persistent improvement of symptoms was observed in all subgroups.
Conclusions: Satisfactory early and late surgical outcomes may be expected in patients with moderate renal failure, but outcomes are often poor with severe non-dialysis-dependent and end-stage renal dysfunction.