Cardio-renal interaction: impact of renal function and anemia on the outcome of chronic heart failure

The purpose of this study is to investigate the effects of renal function and anemia on the outcome of chronic heart failure (CHF). We targeted 711 consecutive patients who were hospitalized at the Division of Cardiology of Fujita Health University Hospital during a 5-year period. The subjects were divided into four groups according to their estimated glomerular filtration rate (e-GFR) calculated using the Modification of Diet in Renal Disease (MDRD) formula. Intergroup comparisons were conducted for underlying heart diseases, clinical findings at the time of hospitalization, treatment, and outcome. Moreover, the patients were divided into two groups according to their serum hemoglobin concentration at the time of hospitalization, using 12.0 g/dl as the dividing point, to study the effects of anemia on the outcome. In the group with decreased renal function, the average age was higher, and ischemic heart disease and associated conditions such as hypertension and diabetes mellitus were observed in most of the patients. In addition, the rate of anemia development and the plasma B-type natriuretic peptide concentration were also high. The greater the deterioration in renal function, the poorer the outcome became (P < 0.0001). Chronic heart failure complicated by anemia showed an especially poor outcome (P < 0.0001). As this study showed that renal function and anemia significantly affected the outcome of CHF, it is clear that the preservation of renal function and the management of anemia are important in addition to the conventional treatments for CHF.