Catheter Ablation in Asymptomatic Pediatric WPW Patients: Results from a Large Multicenter Study

Objectives: There is limited data on catheter ablation of accessory pathways in asymptomatic children and adolescents with a Wolff-Parkinson-White ECG pattern. We therefore performed a multicenter (n = 193) retrospective study (“CASPED”).

Methods: Patients with asymptomatic preexcitation < 18 years without structural abnormalities who underwent catheter ablation of the accessory pathway (AP) at the participating centers from January 2004 to December 2014 were included. Study endpoints were acute success, safety and recurrence rate.

Results: In 193 children and adolescents (mean age: 12.5 ± 3.1 years; 65% male), a total of 211 APs were targeted (multiple APs in 16 patients). APs were right-sided (63%) or left- sided (37%). The most common right-sided location was the posteroseptal region (35%). RF ablation was performed in 176 patients (91%), cryoablation in 9 patients (5%) and RF + cryo in 8 patients (4%). A 3D mapping system was used in 60/193 patients (31%). Catheter ablation was acutely successful in 194/211 APs (91.9%) in 176/193 patients (91.2%). Acute failure occurred most often in right septal APs (12/17). Mean procedure time was 138.4 ± 64.2 with a mean fluoroscopy time of 15.6 ± 13.6 minute. Overall mortality was 0%. There were no major periprocedural complications. Transient second-degree AV block was seen in four patients and right bundle branch block in two patients. Minor vascular complications were observed only in 1 patient (0.5%). During a median follow-up time of 19.8 months, AP recurrence occurred in 18/176 patients (10.2%). Recurrence rates were highest in right anteroseptal APs (27.8%), right midseptal APs (20%) and right posteroseptal APs (10.6%). For the whole group, pre-excitation was still present after the first ablation in 35/193 patients (18.1%) including 17 patients with failed primary ablation and 18 patients with AP recurrence. In 20 of 23 patients, a second ablation attempt was performed successfully. Overall, success rate was 92.2% after two ablations.

Conclusion: Catheter ablation in asymptomatic children and adolescents with a preexcitation pattern is an effective treatment strategy with a high acute success rate, very low complication rate and acceptable recurrence rate. The most common AP localization (63%) was right-sided, especially in the right posteroseptal region. Right septal APs had the highest recurrence rate (16.7%). In summary, catheter ablation showed to be effective and safe in this patient population.