Anemia and its relationship to clinical outcome in heart failure

Background - Anemia is often observed in patients with chronic heart failure (CHF), but its implications for patient outcomes are not well understood. The goal of this study was to investigate the relationship between anemia, severity of CHF, and clinical outcomes. Methods and Results - Hemoglobin concentration (Hb) was measured in 912 subjects with CHF enrolled in the Randomized Etanercept North American Strategy to Study Antagonism of Cytokines (RENAISSANCE) trial. In a subgroup of 69 subjects, cardiac MRI was performed at randomization and 24 weeks later. Anemia (Hb ≤ 12.0 g/dL) was present in 12% of subjects. Cox regression analysis indicated that for every 1-g/dL-higher baseline Hb, the risk of mortality was 15.8% lower (P=0.0009) and the risk of mortality or hospitalization for heart failure was 1.4.2% lower (P<0.0001). Greater CHF severity was associated with significantly lower Hb concentrations. An increase in Hb over time was associated with a decrease in left ventricular mass and lower mortality, whereas a decrease in Hb over time was associated with an increase in left ventricular mass and higher mortality. In multivariate analysis, anemia remained a significant, independent predictor of death or hospitalization for heart failure, with both outcomes being significantly higher in all NYHA classes. Conclusions - Anemia is frequently present in patients with CHF. Lower Hb is associated with greater disease severity, a greater left ventricular mass index, and higher hospitalization and mortality rates.