What is the success rate of ablation in patients with Wolff-Parkinson-White (WPW) syndrome?

Success Rate of Catheter Ablation for Wolff-Parkinson-White Syndrome

Catheter ablation for Wolff-Parkinson-White (WPW) syndrome has an excellent success rate of approximately 93-98.5%, making it the preferred first-line treatment for symptomatic patients. 1

Overall Success Rates

• Catheter ablation has a primary success rate of 88-95%, with final success rates reaching 93-98.5% after repeat procedures if needed 1, 2
• The European Heart Journal reports that catheter ablation has a success rate of >95% in experienced centers 3
• In the 2014 study by Pappone et al., ablation was reported to be successful in 98.5% of cases 1
• After successful ablation, no patients developed malignant atrial fibrillation or ventricular fibrillation over 8 years of follow-up 1

Success Rates by Pathway Location

Success rates vary depending on the location of the accessory pathway:

• Left free wall pathways: 91-94.5% success rate 4
• Right free wall pathways: approximately 100% success rate 4
• Septal pathways: 85-91.6% success rate 4
  • Anteroseptal: 83% success rate 4
  • Right posteroseptal: 76.5% success rate 4
  • Left posteroseptal: 92% success rate 4

Recurrence Rates

• The overall recurrence rate after initially successful ablation is approximately 9-11% 2, 5
• Prior use of antiarrhythmic medication is associated with higher recurrence rates (12.2% vs. 7.6%) 2
• In a Portuguese study with a mean follow-up period of 8 months, clinical recurrence occurred in 9% of patients 4

Complications of Ablation

• The overall complication rate is approximately 2.5-4% 2, 6
• Ablation-related complications occur in about 1.2% of cases 2
• Access-related complications occur in about 1.3% of cases 2
• Specific complications may include:
  • Right bundle-branch block: 0.9% 1
  • Left bundle-branch block: 0.3% (with anteroseptal accessory pathways) 1
  • Third-degree atrioventricular block: 0.1% 1
  • Small pericardial effusion: 0.2% 1
  • Pneumothorax: 0.2% 1
  • Femoral hematomas: 1% 1
  • Arteriovenous fistulas: 0.09% 1

Risk Factors for Complications and Recurrence

• Higher complication risk is associated with:
  • Repeat procedures (6.9% vs. 2.2%) 2
  • Septal pathway location (9.1% vs. 2.0% for left-sided pathways) 2
• Factors that may complicate ablation and lead to initial failure include:
  • Multiple or large accessory pathways 7
  • Epicardial pathways requiring irrigated-tip catheters 7
  • Posteroseptal pathways requiring bi-atrial and coronary sinus applications 7
  • Parahisian and midseptal pathways requiring careful power titration 7

Special Considerations

• The success rate for ablation of multiple accessory pathways (found in approximately 13.8% of WPW patients) is comparable to that of single accessory pathways (95%) 5
• Procedure duration (4.5 vs. 3.7 hours) and radiation exposure time (53 vs. 38 minutes) are longer in patients with multiple pathways 5
• The success rate of ablation improves significantly with operator experience, increasing from 53% to 96% over time in one study 6

Clinical Implications

• Catheter ablation is recommended as first-line therapy for symptomatic WPW patients, particularly those with syncope due to rapid heart rate or those with a short bypass tract refractory period 1, 3
• For patients with WPW in whom atrial fibrillation occurs with rapid ventricular response and hemodynamic instability, immediate electrical cardioversion is recommended before proceeding to ablation 1
• After ablation, monitoring is necessary as ablation of the accessory pathway does not always prevent atrial fibrillation, especially in older patients 1