Relationship of anemia and clinical outcome in heart failure patients with preserved versus reduced ejection fraction in a rural area of Thailand.

Background: Heart failure (HF) has become a significant health burden in developing countries where anemia is highly prevalent. Limited data exists on the effects of anemia on HF in these population.

Methods: A retrospective observational study was conducted in all adult patients hospitalized due to HF at Buriram Hospital in Thailand, during July 2010 to June 2015. Survival analysis was performed to evaluate the impact of anemia on 1- year all-cause mortality for the overall cohort, patients with HF with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF).

Results: A total of 414 HF patients including 287 HFpEF patients (69.3%) and 127 HFrEF patients (30.7%) were included in our analysis. Mean age was 62.51 ± 14.89 years, with 55% female. Overall prevalence of anemia in HF was 62.6% (259 patients). One-year all-cause mortality was significantly higher in patients with anemia than in non-anemia groups (20.08% vs 12.26%, p = 0.041). When analyzed based on types of HF, anemia significantly increased mortality risk in HFpEF group [adjusted hazard ratio (HR) 2.667, 95%CI, 1.216-5.853, p = 0.014] but not with HFrEF group (adjusted HR 0.901, 95%CI, 0.376-2.155, p = 0.804). The mortality of anemic patients who were left untreated was significantly higher than those who were treated (adjusted HR 2.13, 95%CI, 1.13-3.99, p = 0.027).

Conclusion: Anemia significantly increased mortality in HF patients, especially among HFpEF. Attempts to identify, diagnose and manage anemia should be integrated in HF care plan in developing countries with high prevalence of anemia.