Incidence of atrial fibrillation and its association with long-term outcome in patients with an accessory pathway.

Objective: This study aimed to examine the incidence of atrial fibrillation in patients with an accessory pathway (AP) and its association with transient ischemic attack (TIA)/stroke as well as mortality over long-term follow-up. Methods: A total of 1,302 consecutive patients who underwent first-time ablation AP between 2005 and 2018 were included from the Karolinska Ablation Registry and followed up through the National Patient Registry and Cause of Death Registry. Results: Patients were 41.7 ± 15.7 years old and 60.9% were men. New-onset or recurrence of atrial fibrillation occurred in 111 patients (8.5%) after a follow-up of up to 10 years (median 6.8 years; interquartile range 3.9-9.9 years). Multivariable analysis revealed that a history of atrial fibrillation, hyperlipidemia, a higher BMI, and older age were independently associated with new-onset or recurrence of atrial fibrillation during follow-up. All-cause mortality and TIA/stroke occurred in 35 patients (2.7%) and 28 patients (2.2%) after a follow-up of 10 years, respectively. Multivariable analysis revealed that the occurrence of atrial fibrillation during follow-up was independently associated with both outcomes. Conclusion: In this large patient cohort with ablated APs, long-term follow-up revealed a high incidence of atrial fibrillation with 8.5%. Occurrence of atrial fibrillation during follow-up was independently associated with both all-cause mortality and TIA/stroke. Hence, closer monitoring for atrial fibrillation is advisable in patients with ablated APs, especially in those with a prior history of atrial fibrillation.