Characteristics and outcomes among heart failure patients with anemia and renal insufficiency with and without blood transfusions (public discharge data from California 2000-2006)

Renal insufficiency and anemia are increasingly recognized as predictors of adverse events in heart failure. The impact of blood transfusion on mortality in patients with heart failure has not been previously characterized. We examined temporal changes in admissions and in-hospital mortality using public discharge data from California (2000 to 2006) and then evaluated the impact of renal insufficiency, anemia, and transfusion on in-hospital mortality in univariate and multivariate analyses. In total 596,456 unique patient admissions for heart failure were recorded. Renal insufficiency and anemia were common co-morbidities (27.4% and 27.1%, respectively) and 6.2% of patients received a transfusion of red blood cells. Renal insufficiency and anemia were associated with increased mortality (unadjusted odds ratio [OR] 2.45, 95% confidence interval [CI] 2.39 to 2.52, and 1.27, 95% CI 1.24 to 1.30, respectively). After adjustment, renal insufficiency (OR 2.54, 95% CI 2.46 to 2.62) and anemia (OR 1.12 95% CI 1.07 to 1.17) remained significant; however, transfusion emerged as the strongest single predictor (OR 3.81, 95% CI 3.51 to 4.13) of mortality. In conclusion, these data suggest that anemia and renal insufficiency are independently associated with mortality in an unselected heart failure population. This is the first study to demonstrate that transfusion magnifies this effect and is associated with a particularly poor prognosis.