Cardiorenal Anemia Syndrome as a Prognosticator for Death in Heart Failure

Anemia and chronic kidney disease are common in patients with heart failure (HF) and are associated with adverse outcomes. We analyzed the effect of cardiorenal anemia (CRA) syndrome, defined as anemia (hemoglobin <130 g/L for men, <120 g/L for women) and stage 3 or greater chronic kidney disease (estimated glomerular filtration rate <60 ml/min/1.73 m2), in outpatients with HF. Consecutive patients with HF were prospectively enrolled from 2000 to 2005 (n = 748). The baseline clinical characteristics, pathology test results, and medication use were compared between those with and without CRA syndrome. The primary end point was all-cause mortality. The mean follow-up was 2.5 ± 1.6 years, with a left ventricular ejection fraction <45% present in 70% of patients. Angiotensin-converting enzyme inhibitors, β blockers, and spironolactone were used in 87%, 67%, and 37%, respectively. CRA syndrome was present in 224 patients (30%). These patients had greater all-cause mortality (51% vs 26%, p <0.001), older age (mean 77 ± 8 vs 67 ± 14 years, p <0.001), and greater rates of diabetes mellitus (35% vs 23%, p <0.001) and ischemic heart disease (50% vs 35%, p <0.001). The independent predictors of mortality were CRA syndrome (hazard ratio 2.0, 95% confidence interval 1.4 to 2.8, p <0.001), left ventricular systolic dysfunction per grade (hazard ratio 1.5, 95% confidence interval 1.3 to 1.8, p <0.001), the absence of a β blocker (hazard ratio 1.6, 95% confidence interval 1.1 to 2.2, p = 0.005), New York Heart Association class per class (hazard ratio 1.5, 95% confidence interval 1.2 to 1.9, p <0.01), and age per decade (hazard ratio 1.6, 95% confidence interval 1.4 to 2.0, p <0.001). In conclusion, CRA syndrome was common in patients with HF and was an independent predictor of all-cause mortality. Consideration should be given to identifying CRA syndrome and modifying reversible factors.