Impact of cardiorenal anemia syndrome on short- and long-term clinical outcomes in patients hospitalized with heart failure

Background: Dysfunctional interplay between the heart and kidneys may lead to the development of anemia. The aim of this study was to evaluate the impact of cardiorenal anemia syndrome (CRAS) on short- and long-term outcomes among patients hospitalized with heart failure (HF). Methods: We enrolled 303 patients hospitalized with HF. We divided the patients into two groups: a CRAS group (n = 64) and a non-CRAS group (n = 239). We defined CRAS as HF accompanied by (1) an estimated glomerular filtration rate <60 ml/min/1.73 m² calculated by the Modification of Diet in Renal Disease at admission and (2) a hemoglobin level <12 g/dl for females and <13 g/dl for males at admission. The primary outcome was a composite of cardiac death, non-fatal myocardial infarction and rehospitalization for HF. Results: During a median follow-up period of 25.6 months (range 0.1-35.3 months), the patients with CRAS had a significantly increased risk for the primary outcome (27.5 vs. 10.7%, p < 0.001) compared with the patients in the non-CRAS group. Using Cox proportional hazard analyses, the hazard ratio (HR) for the presence of CRAS was found to be 1.874 (95% confidence interval [CI] 1.011-3.475, p = 0.046); HRs were also computed for the presence of diabetes mellitus (HR = 2.241, 95% CI 1.221-4.112, p = 0.009), New York Heart Association class III or IV HF (HR = 2.948, 95% CI 1.206-7.205, p = 0.018) and the use of intravenous loop diuretics (HR = 2.286, 95% CI 0.926-5.641, p = 0.073). Conclusions: Renal dysfunction and anemia are a fatal combination and are associated with poor prognosis in patients with HF.