Iron deficiency and risk of early readmission following a hospitalization for acute heart failure

Aims Early rehospitalization after an episode of acute heart failure (AHF) remains excessively high and its prediction a contemporary challenge. Iron deficiency (ID) is a frequent finding in AHF, but its prognostic implications remain unclear. We sought to evaluate the association between ID and risk of 30-day readmission in an unselected cohort of patients discharged for AHF. Methods and results Serum ferritin and transferrin saturation (TSAT) were measured before discharge in 626 consecutive patients with AHF in a single teaching centre. ID was defined as serum ferritin <100 mu g/L (absolute ID) or ferritin 100-299 mu g/L with a TSAT <20% (functional ID). Cox regression adapted for competing events was used to determine the association between ID and the risk of 30-day readmissions. Mean age was 73.4 +/- 10.4 years, 48% were females, and 52.1% showed an LVEF >50%. ID was identified in 463 patients (74%): 302 (48.2%) as absolute ID and 161 (25.7%) as functional ID. At 30-day post-discharge, 20 (3.2%) patients died and 103 (16.5%) were readmitted. Patients with absolute ID showed an increased rate of readmission compared with those with functional ID and no ID (19.9, 13, and 13.5%, respectively, P = 0.005). In a multivariate setting, absolute ID remained associated with higher risk of readmission [hazard ratio (HR) 1.72; 95% confidence interval (CI) 1.13-2.60, P = 0.011]. Compared with patients without ID, functional ID was not related to the risk of readmission (HR 0.87; 95% CI 0.46-1.62, P = 0.652). Conclusion In patients with AHF, absolute ID, but not functional ID, was associated with an increased risk of early readmission.