WPW Syndrome in the Era of Catheter Ablation: Insights from a Registry Study of 2169 Patients
Background—The management of Wolff-Parkinson-White (WPW) is based on the distinction between "asymptomatic" and "symptomatic" presentations but evidence is limited in the asymptomatic population.
Methods and Results—WPW registry was an 8-year prospective study of either symptomatic or asymptomatic WPW patients referred to our Arrhythmology Department for evaluation and/or ablation. Inclusion criteria were a baseline electrophysiological testing with or without catheter ablation (RFA). Primary endpoints were the percentage of patients who experienced ventricular fibrillation (VF) or potentially malignant arrhythmias (MA) and risk factors. Among 2169 enrolled patients, 1001 (550 asymptomatic) did not undergo RFA (no-RFA group) and 1168 (206 asymptomatic) underwent ablation (RFA group). There was no difference in clinical and electrophysiological characteristics between the 2 groups except for symptoms. In no-RFA group VF occurred in 1.5% of patients, virtually exclusively (13 of 15) in children (median age 11 years), and was associated with a short AP antegrade refractory period (P<0.001), and AVRT initiating AF (P<0.001), but not symptoms. In RFA group, ablation was successful in 98.5% and, after RFA no patients developed MA or VF over 8-year follow-up. Untreated patients were more likely to experience MA and VF (log-rank, P<0.001). Time-dependent ROC curves for predicting VF identified an optimal AP-AERP cut-off at 240ms.
Conclusions—Prognosis of WPW syndrome essentially depends on intrinsic electrophysiological properties of AP rather than on symptoms and RFA performed during the same procedure after EPT is of benefit in improving the long-term outcomes.
- Received May 13, 2014.
- Revision received June 16, 2014.
- Accepted June 20, 2014.