Background
Obesity is among the fastest growing global health threats. Among the management options for patients with obesity, bariatric surgery is a rapidly evolving field that has been shown to result in reliable weight loss. The association between obesity and atrial fibrillation has been well established; but the long-term impact of bariatric surgery on atrial fibrillation has not yet been explored. This study aims to assess the long-term incidence and resolution rates of atrial fibrillation in patients who undergo bariatric surgery in the United Kingdom.

Methods
The primary and secondary electronic healthcare records included in the Clinical Practice Research Datalink (CPRD) database were used to conduct a nation-wide cohort study. The 3,077 patients in the CPRD with no previous history of atrial fibrillation who had undergone bariatric surgery, were matched to 3,077 age, gender and BMI matched controls, also with no past history of atrial fibrillation. The primary endpoint was the incidence of any type of atrial fibrillation by clinical coded diagnosis. The secondary endpoint was a coded resolution of atrial fibrillation among the patients who received a diagnosis during follow-up.

Results
Patients were followed up for a median of 12.3 years; the median age was 50 years and median BMI was 43 kg/m2. Patients who had undergone bariatric surgery did not have a significantly lower occurrence of the primary outcome of incident AF (adjusted HR 0.720; 95% CI 0.492–1.054; p=0.091). However, secondary analysis among patients with AF identified higher rates of resolution among patients who had undergone bariatric surgery (p=0.049).

Conclusion
The results of this nationwide cohort study identify an association between bariatric surgery and higher rates of AF resolution; and describe a non-significant but biologically plausible trend towards lower rates of incident AF in patients who underwent bariatric surgery.