Strikingly Low Prevalence of Atrial Fibrillation in Elderly Tanzanians

Matthew J. Dewhurst MD, Philip C. Adams MA, William K. Gray PhD, Felicity Dewhurst, Golda P. Orega, Paul Chaote MD, Richard W. Walker MD
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Objectives: To determine the prevalence of atrial fibrillation (AF) in individuals aged 70 and older in a rural African community.

Design: Community-based cross-sectional survey. Setting: A  demographic surveillance site (DSS) within the rural Hai district of northern Tanzania.

Participants: Approximately one-quarter (N = 2,232) of the population aged 70 and older of the DSS.

Measurements: Participants were screened for AF using 12-lead electrocardiography; demographic and 1-year mortality data were collected; and functional status, body mass index, and blood pressure were recorded. The sex-specific prevalence of AF in each 5-year age band was determined.

Results: Fifteen of 2,232 participants (12 women, 3 men) had AF, giving a crude prevalence rate of 0.67% (95% confidence interval (CI) = 0.33–1.01) and an age-adjusted prevalence of 0.64% (95% CI = 0.31–0.97). Prevalence was 0.96% (95% CI = 0.42–1.49) in women and 0.31% (95% CI = −0.04 to 1.24) in men. Prevalence increased with age, from 0.46% (95% CI = 0.01–0.90) in those aged 70–74–1.30% (95% CI = 0.17–2.42) in those aged 85 and older. One-year mortality was 50% in women and 66.6% in men.

Conclusions: This is the first published community-based AF prevalence study from sub-Saharan Africa. The prevalence rate of AF is strikingly lower than in other elderly populations studied, yet the 1-year mortality rate was exceedingly high.