Incidence, Risk Factors, and Outcomes of Atrial Arrhythmias in Patients With Ebstein Anomaly

Specific incidences of the different atrial arrhythmias remain poorly described in Ebstein anomaly (EA).

This study aimed to assess their incidence, identify risk factors, and evaluate associated outcomes in adults with EA.

This retrospective observational study included all patients diagnosed with EA between 2001 and 2024 at a large tertiary referral center. Lifetime incidences of atrial arrhythmias were analyzed. Time-dependent Cox regression models were used to identify risk factors.

A total of 200 patients with EA were included (55.5% women; mean age at the last follow-up: 40.4 ± 17.8 years). Overall, 79 (39.5%) patients experienced at least 1 episode of atrial arrhythmia. Focal atrial tachycardia/intra-atrial re-entrant tachycardia were documented in 54 (27.0%) patients, atrial fibrillation in 37 (18.5%), and 12 (6.0%) patients experienced both arrhythmias. The estimated lifetime risks at ages 20, 40, and 60 years were 5.7% (2.3%-9.0%), 25.0% (18.1%-31.9%), and 54.2% (44.1%-64.3%), respectively. Cardiac surgery (HR: 3.10; 95% CI: 1.80-5.32), moderate-to-severe tricuspid regurgitation (HR: 2.44; 95% CI: 1.47-4.06), severe right ventricular dysfunction (HR: 2.40; 95% CI: 1.21-4.78), and age (HR: 1.18, 95% CI: 1.09-1.28, by 5-year increment) were independently associated with atrial arrhythmias. Atrial arrhythmia occurred in 46.2% of patients who underwent at least 1 cardiac surgery vs 21.8% of nonoperated patients (HR: 3.10; 95% CI: 1.80-5.32; P < 0.001).

The lifetime burden of arrhythmic events in patients with EA is considerable, with more than half developing atrial arrhythmias by the age of 60 years. Intra-atrial re-entrant tachycardia/focal atrial tachycardia is the predominant arrhythmia, although the cumulative incidence of atrial fibrillation is also substantial. The significantly higher incidence of atrial arrhythmia observed in patients who underwent cardiac surgery is driven by a more advanced disease severity.