The growing heart failure epidemic imposes a substantial burden on the US health care system. The ability to accurately assess prognosis would allow clinicians to triage patients to appropriate therapy and to plan the intensity of care following hospital discharge.
A cohort of 282 elderly (mean ± SD age, 79.2 ± 6.1 years) patients with heart failure were followed for up to 14 years after enrollment in a prospective randomized multidisciplinary disease management trial conducted from 1990 through 1994. Kaplan-Meier survival curves were constructed to assess the probability of survival during the follow-up period. A Cox proportional hazards model was developed to identify independent predictors of long-term survival. C statistics were calculated to assess the utility of the model for predicting mortality at 6 months, 1 year, and 5 years.
During the 14-year follow-up period, 269 patients (95%) died and the median survival was 894 days. Cox analysis identified 7 variables that were independent predictors of shorter survival time: older age (hazard ratio [HR], 1.14 per 5 years; 95% confidence interval [CI], 1.03-1.26), serum sodium level less than 135 mEq/L (HR, 1.67; 95% CI, 1.19-2.32), coronary artery disease (HR 1.51; 95% CI, 1.16-1.95), dementia (HR, 2.02; 95% CI, 1.13-3.61), peripheral vascular disease (HR, 1.74; 95% CI, 1.20-2.52), systolic blood pressure (HR, 0.95 per 10 mm Hg; 95% CI, 0.92-0.98), and serum urea nitrogen level (HR, 1.20 per 10 mg/dL [3.57 mmol/L]; 95% CI, 1.12-1.29). C statistics for the model were 0.84, 0.79, and 0.75 at 6 months, 1 year, and 5 years, respectively. A risk score for mortality was developed using the 7 independent predictor variables. One-year mortality rates among patients with 0 to 1 (n = 89), 2 to 3 (n = 153), and 4 or more (n = 37) risk factors were 9.0%, 22.2%, and 73.0%, respectively (P<.001).
Among elderly patients hospitalized with heart failure, median survival is about 2.5 years. However, there is considerable heterogeneity in survival, with 25% of patients dying within 1 year and 25% surviving for more than 5 years. A simple 7-item risk score, based on data readily available at the time of admission, provides a reliable estimate of prognosis.