Background and objective: Patients with heart failure and overt kidney failure (KF) have poor prognosis. Even mild degrees of kidney dysfunction might have prognostic value. The aim was to assess whether creatinine clearance values estimated with Cockroft formula correlated with survival at 2 years of follow-up in an outpatient heart failure unit population.
Patients and method: 423 patients (72% men), with a mean (standard deviation) age of 65.5 (11) years, were studied. Etiology of heart failure was mainly ischemic heart disease (59.6%). Mean left ventricle ejection fraction was 32.3% (13.3%). Patients were grouped according to stages of chronic kidney disease: $ 90 ml/min; 89-60 ml/min; 59-30 ml/min; 29-15 ml/min, and < 15 ml/min or on dialysis. KF was defined as creatinine clearance < 60 ml/min.
Results: Prevalence of KF was 52%. Mortality at 2 years was 3.2% in patients with creatinine clearance >or= 90 ml/min; 13.7% between 89-60 ml/min; 23.7% between 59-30 ml/min; 51% between 29-15 ml/min and 80% in patients with creatinine clearance < 15 ml/min or on dialysis (p < 0.001). Mortality was 30.4% in patients with KF and 10.3% in those without it (p < 0.001).
Conclusions: Creatinine clearance values estimated by Cockroft formula had a highly predictive prognostic value in patients with heart failure. Even mild degrees of kidney function impairment showed higher mortality than normal kidney function values.