The cardiorenal anaemia syndrome in systolic heart failure: prevalence, clinical correlates, and long‐term survival

Abstract

We sought to assess the prevalence and clinical correlates of cardiorenal anaemia (CRA) syndrome in systolic heart failure and the relationship between renal dysfunction and anaemia on hard clinical outcomes. We studied 951 patients with chronic heart failure (CHF) and systolic dysfunction. The primary outcome was all-cause mortality and urgent heart transplantation (UHT). Cox's regression analyses were used to assess the relation of the variables to the primary outcome. Hazard ratios (HRs) with 95% confidence intervals (CI) were calculated. The prevalence of CRA syndrome was 21.1%. Age (P < 0.001), body mass index (P< 0.001), diabetes (P =< 0.001), ischaemic aetiology (P< 0.006), left ventricular ejection fraction (P= 0.018), and treatment with renin-angiotensin system inhibitors (P< 0.001) were independently related to CRA syndrome. During a median follow-up of 3.7 years, the primary outcome occurred in 404 patients (42.5%). Compared with patients with preserved renal function and normal haemoglobin (Hb) levels, those with CRA syndrome had a significantly increased risk for the primary outcome; the univariate and multivariate-adjusted HRs were 4.04 (CI: 3.11-5.24; P< 0.0001) and 2.22 (CI: 1.64-2.98; P< 0.0001), respectively. Three-year UHT-free survival was 86 and 47%, respectively. Among patients with renal dysfunction, the adjusted HR for the primary outcome increased by 17% (CI: 8-26; P= 0.0001) for each 1g/dL decrease below an Hb value of 13.0 g/dL. Heart failure, renal dysfunction, and anaemia are a fatal combination. Despite a relatively low prevalence, the CRA syndrome contributes to considerable mortality due to CHF.