High Rates of Atrial Fibrillation among Inpatients with Heart Failure or Ischemic Stroke in Southwestern Uganda

Abstract

Background: Atrial fibrillation (AF) affects over 37 million people worldwide, and its prevalence is projected to increase by 60% by 2050. Addressing AF is critical in Uganda and elsewhere in sub-Saharan Africa, where data are lacking despite the high prevalence of AF risk factors, comorbidities, and sequelae. Objectives: To evaluate AF prevalence among inpatients with acute heart failure or acute ischemic stroke in Uganda. Methods: Between November 4, 2024 and November 30, 2025, we recruited a cohort of inpatients at the Regional Referral Hospital in Mbarara, Uganda with either acute heart failure or acute ischemic stroke. We collected baseline clinical data and hospital outcomes, performed a transthoracic echocardiogram, and equipped participants with a 24-hour Holter monitor. A multivariable logistic regression model was fitted for a primary outcome of AF detection. Results: Among 250 individuals, mean age was 61.7 years (SD 20.5), of whom 175 (70.0%) were women. 123 (49.2%) had acute heart failure; 127 (50.8%) had acute ischemic stroke. Holter monitors detected AF in 105 (42.0%), with a mean AF duration of 11.0 hours (IQR 1.0–21.9) with a bimodal distribution. Mean stroke risk (CHA2 DS2 VA) was 3.5 (SD 1.6). Factors associated with AF included increasing age in years (OR 1.04, 95% CI 1.02–1.06) and left atrial volume index (mL/m2) (OR 1.02, 95% CI 1.01–1.03). Conclusions: We found high rates of AF among inpatients with acute heart failure or acute ischemic stroke, comparable to studies from the United States and Europe. These findings highlight the need to address AF in Uganda, with improved screening using long-term monitors, updated treatment protocols, and broadened access to cardiac care.