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.