Impact of congestive heart failure, chronic kidney disease, and anemia on survival in the Medicare population

Abstract

Background: Congestive heart failure (CHF) is a common clinical problem in the elderly, yet few studies have focused on this population. In addition, information on mortality rates conferred by chronic kidney disease (CKD) and anemia in elderly patients with CHF is lacking.

Methods and results: A cohort of 1,136,201 patients in the 5% Medicare database, excluding those with end-stage renal disease (ESRD), was identified for a 2-year period (1996-1997). Subgroups with CHF, CKD, and anemia were identified. The effect of each disease as an independent predictor of mortality was examined in a comorbidity-adjusted Cox model, with patients followed for 2 years and censored for death or ESRD. In the study population, 61% were women; 89% were white and 7% were black. Mean +/- SD age was 76.5 +/- 6.9 years. The annual mortality rate for patients with no CHF, CKD, or anemia was 4%. Anemia was associated with an annual mortality of 8%, which was the same as CKD (8%). The annual mortality for CHF was 13%. The highest annual mortality was found in patients with all 3 comorbid conditions; mortality in these patients was 23%.

Conclusions: Elderly CHF patients are at high risk of death; this risk is magnified in the presence of CKD and anemia.