[Prognostic significance of creatinine clearance rate in patients with heart failure and normal serum creatinine].

Kidney failure is an important prognostic factor in patients with heart failure. Renal function is usually evaluated by measuring the serum creatinine level. However, a normal creatinine level can mask established kidney failure. We investigated the prognostic significance of the estimated creatinine clearance rate (Cockcroft formula) in 235 patients with heart failure and a normal serum creatinine level. The two-year mortality rate was significantly higher in patients who had established kidney disease (i.e., a creatinine clearance rate <60 mL/min) than in those who did not (35.1% vs. 10.1%, P<.001). Even when only patients without established kidney failure were analyzed, the creatinine clearance rate had prognostic significance (rate > or = 90 mL/min, mortality 3.2%; rate 89-60 mL/min, mortality 13.9%; P=.02). On Cox regression analysis, which included age, sex, heart failure etiology, left ventricular ejection fraction, diabetes and hypertension, the creatinine clearance rate remained an independent predictor of mortality.