Prevalence, clinical characteristics, and associated factors of atrial fibrillation among adults 60 years and older attending noncardiac outpatient clinics at a tertiary hospital in Tanzania: A cross-sectional study

Background Atrial fibrillation (AF) is the most common cardiac arrhythmia globally and is associated with an increased risk of adverse outcomes. Age is an important risk factor for AF with a sharp rise in prevalence after 60 years. Despite a rising share of older adults in Africa, there is paucity of data regarding AF burden in this demographic. Objective To determine the prevalence, clinical characteristics and associated factors of AF among adults 60 years and older attending non-cardiac outpatient clinics at a tertiary hospital in Tanzania. Methodology We conducted a cross-sectional study among consenting adults 60 years and older at non-cardiac outpatient clinics of Muhimbili National Hospital from June 2021 to February 2022. A structured questionnaire was used to collect socio-demographic and clinical characteristics of participants. They were screened for AF using a smartphone-connected single-lead electrocardiography device (KardiaMobile (AliveCor, USA)). Probable AF was confirmed by 12-lead ECG. Multivariable logistic regression was used to determine factors associated with AF. Data analysis was performed using STATA version 13 (StataCorp LLC, USA). Results A total of 1055 patients were enrolled with a median age of 67 years (IQR:62-72). AF was detected in 44 participants (4.2%). Only 1 participant with AF was previously diagnosed. Most patients with AF had high CHA 2 DS 2 -VASc stroke risk scores with a median of 4.0 (IQR:3-5) and 3.0 (IQR:2-3) in females and males respectively. Age above 75 years (aOR=3.12, CI:1.31-7.40, p=0.01), being underweight (aOR=8.46, CI:1.44-49.76, p=0.018), hypertension (aOR=5.35, CI:2.46-11.62, p<0.001) and obstructive sleep apnea (aOR=11.90, CI:4.74-29.88, p<0.001) were independently associated with AF. Conclusion Atrial fibrillation is common, underdiagnosed and carries high stroke risk among elderly outpatients in Tanzania. Opportunistic screening of the elderly for AF in low-resource countries with 1L-ECG is feasible and has the potential to reduce the burden of stroke.