Atrial Fibrillation Diagnosis using ECG Records and Self-Report in the Community: Cross-Sectional Analysis from ELSA-Brasil

Atrial fibrillation or flutter (AFF) is the most common sustained cardiac arrhythmia. Limited data can be found on AFF epidemiology in South America. The present study sought to describe the clinical epidemiology of AFF and the use of stroke prevention medication in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline assessment. This study analyzed data from 13,260 ELSA-Brasil participants. AFF was defined according to ECG recording or by self-report. Logistic regression models were built to analyze factors associated with AFF. This study also analyzed if age and sex were associated with anticoagulant use for stroke prevention. Significance level was set at 5%. Median age was 51 years and 7,213 (54.4%) participants were women. AFF was present in 333 (2.5%) participants. Increasing age (odds ratio [OR]:1.05; 95% confidence interval [95%CI]: 1.04-1.07), hypertension (OR:1.44; 95%CI: 1.14-1.81), coronary heart disease (OR: 5.11; 95%CI: 3.85-6.79), heart failure (OR:7.37; 95%CI: 5.00-10.87), and rheumatic fever (OR:3.38; 95%CI: 2.28-5.02) were associated with AFF. From 185 participants with AFF and a CHA2DS2-VASc score ≥2, only 20 (10.8%) used anticoagulants (50.0% among those with AFF in the baseline ECG). Stroke prevention in this group was associated with a higher age (1.8% vs 17.7% in those aged ≤ 54 and ≥ 65 years, respectively; p=0.013). A trend towards a reduced anticoagulant use was observed in women (7.1% vs. 16.4% in women and men, respectively; p=0.055). At the ELSA-Brasil baseline, 2.5% of the participants had AFF. The lack of stroke prevention was common, which is an especially challenging point for healthcare in this setting.