Characteristics and 12-month outcome of patients with atrial fibrillation at a tertiary hospital in Botswana

Abstract

Background: Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia associated with high morbidity and mortality rates. Notwithstanding the scale of the problem, there are sparse data on the characteristics and outcomes of both valvular and non-valvular AF patients in sub-Saharan Africa (SSA). Objective: This study aimed at describing the clinical features and outcome of AF patients at a tertiary hospital in Botswana. Methods: This prospective study was carried out in the Princess Marina Hospital in Gaborone, Botswana between August 2016 and July 2018. We consecutively enrolled 138 (97.8% black Africans) adult patients with electrocardiographically documented AF. Their baseline clinical and biomedical data were documented, and each patient was followed up for 12 months. The primary study outcome was 12-month all-cause mortality. Results: The mean [standard deviation (SD)] age of enrolled patients was 66.7 (17.2) years, and 63.8% were females. Common co-morbidities were hypertension (59.4%), rheumatic heart disease (37.7%) and heart failure (35.5%). Stroke/ transient ischaemic attack (TIA) (21.7%) and obesity (34.8%) were also prevalent. Compared to patients with non-valvular AF, those with valvular AF were more likely to be female (82 vs 55%, p = 0.003), younger (60 vs 75 years, p < 0.001), on anticoagulation (88.6 vs 66%, p = 0.005), or have a dilated left atrium (5.3 vs 4.5 cm, p < 0.001). They were also less likely to present with hypertension (33 vs 72%, p < 0.001), stroke/TIA (nine vs 27%, p < 0.017), chronic kidney disease (five vs 20%, p < 0.02), or history of cigarette smoking (two vs 13%, p = 0.049) than non-valvular AF patients. The mean (SD) CHA 2 DS 2-VASc score in non-valvular AF patients was 3.6 (1.5), and the median HAS-BLED score was 2.0 [interquartile range (IQR) 1.0-3.0]. During the 12-month follow up, 20 (14.5%) patients died. Despite differences in baseline characteristics, there was no difference in mortality rate in patients with valvular compared to those with non-valvular AF (13.8 vs 15.9%; p = 0.746). Conclusion: In this study, hypertension, rheumatic heart disease and heart failure were the most prevalent co-morbidities. AF presented in young people and conferred high mortality rates in both valvular and non-valvular AF patients. Prevention and optimal management of AF and associated co-morbidities are of critical importance.

A review of the epidemiology of atrial fibrillation in sub‐Saharan Africa

“…In a study in Cameroon, during a mean follow‐up was 318 ± 124 days, 29.5% of patients with AF died, with the death being from cardiovascular origin in 55.7% of cases . Mortality rates of 6.5% and 15.9% over 6 months and 14.5% over a year follow‐up were reported in the multinational THESUS‐HF registry and from studies in Kenya and Botswana, respectively. In the THESUS‐HF registry, the 6‐month mortality was significantly higher in patients with valvular AF compared to those with nonvalvular AF (24.8% vs 13.2%; P = .032) .…”

“…Heart failure was very frequent in patients with AF (Figure and Table S3). In more than half of studies about two thirds of patients with AF were in heart failure .…”

“…In more than half of studies about two thirds of patients with AF were in heart failure . Stroke was a common complication in patients with AF; most studies reported that 10% to 15% of patients with AF had a current or a past history of stroke, with rates varying between 2.4% and 33.8% (Figure and Table S3). Peripheral embolism was much less common with prevalence rates of less than 5% .…”

“…Few studies reported primary mortality data in patients with AF, most of them lacking information on the time of follow‐up. In a study in Cameroon, during a mean follow‐up was 318 ± 124 days, 29.5% of patients with AF died, with the death being from cardiovascular origin in 55.7% of cases .…”

“…In all studies presenting data on thromboembolic risk and antithrombotic therapy use, at least 80% of patients had an indication of anticoagulation based on the CHADS 2 or CHA 2 DS 2 VASC scores. However, in most of those studies, a large number of patients were not on antithrombotic therapy, especially oral anticoagulation (Figure and Table ). Data from the ROCKET AF trial showed that participants from South Africa had suboptimal warfarin anticoagulation, with their mean time in therapeutic INR being only 54.8% .…”