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.