The impact of impaired renal function on mortality in patients with acutely decompensated chronic heart failure

Acute heart failure syndromes, commonly recognized as de novo heart failure or acute decompensated chronic heart failure (ADHF), are characterized by a rapid onset or change in signs and symptoms of heart failure requiring urgent treatment. Coexisting renal dysfunction is associated with poor prognosis in these patients. We sought to determine whether renal impairment in particular and other admission factors in general predict long-term mortality after hospitalization for ADHF.

We studied 128 patients (age 63 + or - 12 years, 76% male) in NYHA class 2.6 + or - 0.7 with a left ventricular ejection fraction (LVEF) < or = 39%, hospitalized due to ADHF. Mortality rates (per 100 person-years) were 21.9 at 12 months and 12.0 at 60 months. We found that admission serum creatinine level was the best predictor of mortality after 1 (P < 0.001, log-transformed due to skewed distribution) and 5 years (P = 0.001), followed by creatinine clearance, the use of loop diuretics, and digoxin. Moreover, higher NYHA class, decreased body mass index (BMI) and increased levels of urea predicted 1 and 5 years mortality on univariate analysis. In the multivariate analysis, creatinine, NYHA class, and LVEF emerged as independent predictors of mortality after 1 year, whereas BMI and the use of diuretics did not reach significance (joint chi(2) = 29.40, P < 0.001). After 5 years, creatinine and NYHA class independently predicted all-cause mortality (joint chi(2) = 22.71, P < 0.001), but BMI and age did not remain significant.

Admission creatinine level strongly predicts medium- and long-term mortality after hospitalization in patients with ADHF, and serves as a cheap and fast clinical marker to identify patients at risk of death.