Anemia is associated with worse symptoms, greater impairment in functional capacity and a significant increase in mortality in patients with advanced heart failure

Abstract

This study aimed to evaluate the relationship between anemia and heart failure (HF) prognosis. Although it is known that chronic diseases, including HF, may be associated with anemia, the impact of hemoglobin (Hb) level on symptoms and survival in HF has not been fully defined. We analyzed a cohort of 1,061 patients with advanced HF (New York Heart Association [NYHA] functional class III or IV and left ventricular ejection fraction [LVEF] <40%) referred to a single center for evaluation and management. The Hb level was drawn at time of initial evaluation. Patients were divided into quartiles of Hb: Hb <12.3; Hb 12.3 to 13.6; Hb 13.7 to 14.8; Hb >14.8 g/dl. Mean Hb was 13.6, and values ranged from 7.1 to 19.0 g/dl. The Hb groups were similar in age, medication profile, LVEF, hypertension, diabetes, smoking status and serum sodium. Lower Hb was associated with an impaired hemodynamic profile, higher blood urea nitrogen and creatinine, and lower albumin, total cholesterol and body mass index. Patients in the lower Hb quartiles were more likely to be NYHA functional class IV (p < 0.0001) and have lower peak oxygen consumption (PKVO(2)) (p < 0.0001). Survival at one year was higher with increased Hb quartile (55.6%, 63.9%, 71.4% and 74.4% for quartiles 1, 2, 3 and 4, respectively). On multivariate analysis adjusting for known HF prognostic factors, low Hb proved to be an independent predictor of mortality (relative risk 1.131, confidence interval 1.045 to 1.224 for each decrease of 1 g/dl). In chronic HF, relatively mild degrees of anemia are associated with worsened symptoms, functional status and survival.