King's College London

Objective This study aimed to determine the risk of atrial fibrillation in patients with objectively confirmed GERD. Methods This was a nationwide population-based cohort study between 2005 and 2018, including the majority (n = 8 421 115) of all Swedish adult residents (≥18 years). Within this cohort, the exposed group were all individuals with a diagnosis of esophagitis or Barrett's esophagus, and the unexposed group was made up of five times as many individuals without any GERD, matched by age, sex, and calendar year. The outcome was the first diagnosis of atrial fibrillation. Cox regression provided hazard ratios (HRs) with 95% confidence intervals (CIs), adjusted for confounders. Results Among 118 013 individuals with esophagitis or Barrett's esophagus and 590 065 without GERD, 7042 (6.0%) and 40 962 (6.9%) developed atrial fibrillation, respectively. The risk of atrial fibrillation among patients with GERD was 13% increased within the first year of diagnosis (HR, 1.13; 95% CI, 1.06-1.20), but was not increased after that. Among individuals aged less than 60 years, the HR of atrial fibrillation was 55% increased within the first year of diagnosis (HR, 1.55; 95% CI, 1.27-1.88), and this association remained increased after the first year (HR, 1.14; 95% CI, 1.06-1.22). No association was found in older participants (≥60 years). Results were similar in men and women. Conclusion This large population-based cohort study indicates that objectively determined GERD increases the risk of atrial fibrillation shortly after diagnosis in men and women younger than 60 years.