Objective Supraventricular arrhythmias are common in adults with Ebstein anomaly (EA). However, there are limited data about prognostic implications of atrial fibrillation (AF) in this population. Accordingly, our aim was to assess the clinical profile and burden of AF in adults with EA, and the relationship between AF and outcomes.

Methods and results Six hundred eighty-two consecutive adults with a median age of 36 (24–49) years from Mayo Clinic, Minnesota, USA, between 2003 and 2020 were included. Sustained episodes of AF, clinical, echocardiographic, rhythm and surgical data were collected. Prevalence of AF at baseline was 18% (126 patients); the first episode occurred at a mean age of 43±17 years. Patients with AF were older, were more likely men, and had hypertension, renal dysfunction, cardiac devices, and more advanced right-sided and left-sided remodelling. During a median follow-up of 156 (81–240) months, 62 patients (11%) developed incident AF. At the last encounter, prevalence of AF was 28% (188 patients); of those, 63 (34%) had recurrent AF. Hospitalisation for heart failure (HF) occurred in 51 patients (7%). AF (HR 2.32, 95% CI 1.18 to 4.47; p=0.01) was independently associated with hospitalisation for HF. All-cause death occurred in 53 patients (8%); it was more frequent in those with AF in the univariable analysis, although it did not remain significant in the multivariable analysis.

Conclusions AF in EA develops at relatively young ages with one-third of the cohort exhibiting a recurrent pattern. Patients with AF had a higher prevalence of comorbidities and worse right-sided and left-sided cardiac remodelling. AF was independently associated with HF hospitalisation.