Clinical characteristics of challenging catheter ablation procedures in patients with WPW syndrome: A 10 year single-center experience.

Background: Catheter ablation is the established treatment for patients with symptomatic Wolff-Parkinson-White syndrome (WPW). However, some patients undergo a challenging ablation or have recurrences during the early post-ablation phase. The aim of this study was to evaluate the clinical factors associated with an unsuccessful ablation outcome or repeated sessions.

Methods: Four hundred seventy-five symptomatic consecutive WPW patients (38.2±16.2 years old, 61% men, 69% with pre-excitation) who underwent an accessory pathway (AP) ablation from August 2005 to December 2015 were enrolled. When APs recurred, a redo ablation procedure was performed according to the patients' desire.

Results: Four hundred thirty-nine patients (92.4%) were cured by ablation, but it failed in 36 (7.6%) after the first procedure. Seventeen patients had AP recurrences during the acute phase within 36h post-ablation. On the other hand, 4 were identified after more than one year. In a multivariate logistic regression analysis, multiple, parahisian, and broad APs were significant independent predictors of recurrences after the 1st procedure, with odds ratios of 14.88 (p<0.001), 10.14 (p<0.001), and 6.88 (p<0.001), respectively. Finally, 468 patients (98.5%) received a successful ablation during a mean follow-up of 8.3±3.0 years. However, after the final procedure no significant predictors were recognized. Out of 508 total procedures, three major (0.6%) complications occurred.

Conclusions: Symptomatic WPW patients with multiple, parahisian, and broad APs had a significantly higher risk of recurrence. In half of the recurrence patients, AP recurrences were confirmed during the acute phase, but were rarely recorded in the very late phase.