Anemia and 1-year outcomes in hospitalized patients with heart failure with preserved ejection fraction: Findings from the China Cardiovascular Association Database-Heart Failure Center Registry

Abstract

Abstract Background Little evidence exists regarding the association of anemia and clinical outcomes in patients with heart failure with preserved ejection fraction (HFpEF). Purpose To determine the associations of anemia and clinical outcomes in HFpEF. Methods Data were from 575 China Cardiovascular Association Database-HF Center certified secondary and tertiary hospitals across overall 31 provinces of mainland China. Between January 2017 and December 2021, 48,992 HFpEF patients with an left ejection fraction (LVEF) ≥50% and hemoglobin (Hb) data were included. According to the World Health Organization criterion (Hb <12g/dL for women and <13 g/dL for men), participants were categorized into two groups (with and without anemia). The primary outcome was a composite of hospitalization for HF and cardiovascular (CV) death, and the secondary outcomes were all-cause hospitalization and all-cause death. Results Among the overall patients, 50.0% were men, the mean age was 72.2 years, and 48.1% (n = 23,570) had anemia. Compared with individuals without anemia, participants with anemia were older and more symptomatic, more likely to have New York Heart Association class III/IV, and had greater comorbid burden. At 1-year’s follow-up, anemia was independently associated with an increased risk of primary outcome (hazard ratio [HR]: 1.08, 95% CI: 1.03-1.12), all-cause death (HR: 1.30, 9%% CI: 1.21-1.38), and all-cause hospitalization (HR: 1.06, 95% CI: 1.02-1.10). There was a trend toward increased risk of primary and secondary outcome with increasing severity of anemia (all P-trends were <0.05). The results were consistent in all the subgroups analyses (sex, age (≥75 and <75 years old), NYHA class (Ⅰ/Ⅱ and Ⅲ/Ⅳ), eGFR (≥60 and <60 ml/min/1.73m2)). The restricted cubic spline showed significant nonlinear relationships between primary outcome and hemoglobin as continuous variable, with a risk nadir around 13-15g/dL. Conclusion Anemia was common in Chinese HFpEF patients and was an independent risk factor for adverse clinical outcomes at 1 year’s follow-up. Further studies are needed to evaluate whether ameliorating anemia can improve outcome in HFpEF patients.Graphic Abstract