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

Abstract

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. 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 µg/L (absolute ID) or ferritin 100-299 µg/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). In patients with AHF, absolute ID, but not functional ID, was associated with an increased risk of early readmission.