Atrial fibrillation among inpatients with acute heart failure or acute ischemic stroke at Mbarara Regional Referral Hospital

Sampling and recruitment This study involved adults admitted to MRRH with a diagnosis of acute heart failure or new ischemic stroke. We recruited patients in conjunction with the hospital staff, who used admission registries to purposively identify potential participants with a similar ratio of men and women and a balanced distribution among participants with heart failure and stroke. Inclusion criteria included an established physician-made diagnosis of heart failure or ischemic stroke found on computed tomography scan, being 18 years or older, and able to speak either English or one of the local languages (Runyankole or Rukiga). Exclusion criteria included being pregnant (as pregnancy-related disease was considered beyond the scope of the current study), end-stage liver or kidney disease (as they could complicate heart failure diagnosis in a resource limited setting), and an inability to provide informed consent, including impairment from intoxication or psychosis. Based on a population proportion of 20% in the THESUS-EF trial (as the largest trial done in SSA), we calculated a sample size of 246 would provide prevalence estimates with a confidence level of 95% and a margin of error of 5%. Data collection Upon enrollment, a research assistant administered a survey collecting socio-demographics (i.e., age, sex, district of residence, occupation, level of education, tobacco and alcohol use) and co-morbid conditions (i.e., history of cardiovascular, renal, and lung diseases, stroke, heart failure, malignancy, human immunodeficiency virus [HIV]); performed a 12-lead ECG; and collected clinical data from the patient’s medical chart. A trained phlebotomist from MRRH took blood samples from all patient participants for basic metabolic panels and complete blood counts, which were subsequently analyzed at the MRRH clinical laboratory. Additional clinically ordered labs that resulted within 1 month of recruitment were extracted from the patient’s chart, including thyroid stimulating hormone (TSH), lipid panel, aminotransferases, and CD4 cell count. A physician (author PT) performed a focused cardiovascular and neurological physical exam and transthoracic echocardiogram (TTE) on all participants. Finally, hospital outcomes and medications administered during hospital admission were recorded. A research assistant equipped patients with a 24-hour Holter monitor (Norav Medical, Delray Beach, FL), placing three leads on participants using disposable foam electrodes. The research assistant collected the Holter monitor after 24 hours and uploaded the collected data to an encrypted server. Results were evaluated by a physician (author AF).