The Prevalence of Atrial Fibrillation and its Treatment Vary Globally

23 Jun, 21

Introduction

The current understanding on the global variation in the community prevalence of atrial fibrillation (AF) can be improved by directly comparing the AF prevalence across regions of the world having a similar demographic profile and by using similar methods of AF assessment.

Aim

To compare the prevalence of electrocardiogram (ECG)-documented AF (or flutter) across eight regions of the world
To determine antithrombotic use as indicated in patients and the variation in the associated clinical outcomes

Patient Profile

Participants from two, large prospective population-based cohort studies:
- The Prospective Urban Rural Epidemiology (PURE) study (participants from 20 countries; n=131,104)
- The Canadian Longitudinal Study of Aging (CLSA) (participants from 7 provinces in Canada; n=22,048)
All participants were in the age group 35-70 years and had a baseline ECG performed

Methods

Study Design

Cross-sectional analysis of 2 prospective studies

Assessments

Baseline ECG data were collected to document the prevalence of AF in 153,152 study participants

Results

Data on medication use and clinical outcomes was available for one cohort (mean follow up of 7.4 years)
Mean age of the study participants was 52.1 years, and 57.7% of them were females.
There was a 12-fold variation in age and gender-standardized prevalence of AF between regions. The prevalence was highest in North America, Europe, China and Southeast Asia (270-360 cases per 100,000 persons); and lowest in the Middle East, Africa, and South Asia (30-60 cases per 100,000 persons) (p<0.001).
The prevalence of AF in middle-income countries (MICs) was 7-fold higher as compared with low-income countries (LICs) and 11-fold higher as compared with high income countries (HICs) (p<0.001).
Differences in AF prevalence remained significant even after adjusting for the traditional AF risk factors.
Higher proportion of patients in HICs rather than those in LICs/MICs had a CHADS2 score >1 and received anti-thrombotic therapy (85% vs. 24%).
AF was associated with an increased risk of stroke [hazard ratio (HR): 2.29; 95% confidence interval (CI) 1.49-3.52] and death (HR: 2.97; 95% CI 2.25-3.93); the rates being similar in countries with various income categories.

Conclusions

Globally, the prevalence of AF varies widely across different regions and in countries with varied income settings. Traditional AF risk factors, could only partially explain these differences.
Use of anti-thrombotic therapy was less common in poorer countries, despite the high risk of stroke associated with AF.

Cardiovasc Res. 2021 May 25;117(6):1523-1531.