Prevalence of anemia and their association with poor outcomes in acute heart failure patients in Northeastern Thailand

Background Anemia is a prevalent comorbidity in acute heart failure (AHF) patients and is linked to poorer clinical outcomes. Despite its significance, data on the impact of anemia in AHF patients in Asians remains scarce, especially its impact across different levels of severity in patients presenting to the emergency department (ED) remains underexplored. Objectives This study aimed to evaluate the prevalence and severity of anemia and its association with clinical outcomes in adult patients with AHF. Methods A retrospective analysis was conducted on 890 adult AHF patients extracted from 100,420 ED visits at Srinagarind Hospital between October 2021 and March 2023. Anemia was classified into three categories: mild (hemoglobin 11.0 g/dl to normal), moderate (hemoglobin 8.0–10.9 g/dl), and severe (hemoglobin < 8.0 g/dl). Patient characteristics, laboratory markers, and outcomes were compared among groups. Data were presented as n (%), and median (Q1, Q3). Statistical analyses included Pearson’s Chi-squared test, Fisher’s exact test, and Kruskal-Wallis rank sum test. Results Of the 890 patients, 71% were anemic, with 25% having mild, 51% moderate, and 24% severe anemia. Anemic patients, particularly those with moderate and severe anemia, were older (median age 74 and 71.5 years vs. 64 years for non-anemic, p-value < 0.001) and had higher rates of comorbidities, including chronic kidney disease and diabetes. Severe anemia was associated with worse kidney function (median eGFR 28.9 vs. 62.9 mL/min/1.73m² for non-anemic, p-value < 0.001) and higher initial cardiac troponin T levels (85.8 vs. 39.1 ng/dL, p-value < 0.001). Hospital admission rates increased with anemia severity, with 85% of severely anemic patients being admitted compared to 72% of non-anemic patients (p-value = 0.043). In-hospital mortality was highest in the severe anemia group (8.6%), though this was not statistically significant (p-value = 0.238). Conclusion Anemia is common in patients with AHF, with many exhibiting moderate or severe levels of anemia. Greater severity of anemia correlates with older age, more comorbidities, and higher hospital admission rates, along with a trend toward higher mortality. Clinical trial number: not applicable.