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Catheter Ablation for Asymptomatic Ventricular Preexcitation: Not Yet

Why aren't we ready for widespread clinical use of catheter ablation for this condition?

The Wolff-Parkinson-White (WPW) electrocardiographic pattern results from accessory pathways (APs) that connect the atrium to the ventricle. These APs can allow atrial fibrillation (AF) to be conducted rapidly to the ventricle, with some rare occurrences of ventricular fibrillation and possible sudden death. For symptomatic patients with WPW syndrome, catheter ablation is recommended for eliminating APs. Prophylactic ablation of APs in asymptomatic WPW patients seems promising, but the potential benefit must be weighed against the risk for major complications.

Researchers in Italy randomized, in unblinded fashion, 72 patients with asymptomatic ventricular preexcitation (documented by 12-lead ECG) to radiofrequency catheter ablation of APs (37) or to no ablation (35). From an initial group of 224 patients, the randomized 72 were those deemed at high risk for arrhythmias -- i.e., they had inducible arrhythmias on electrophysiologic (EP) testing and were younger than age 36 (range, 13-35).

Catheter ablation was successful in all 37 patients. During follow-up (median, 27 months), 2 patients (5%) experienced arrhythmic events. Repeat EP testing revealed that these patients had atrioventricular-node reentrant tachycardia, which was ablated in both cases. Of the 35 controls, 21 (60%) experienced arrhythmic events during follow-up (median, 21 months): 15 had supraventricular tachycardia, 5 had AF, and 1 had a cardiac arrest.

Comment: These results from an unblinded, randomized trial challenge the current approach of not recommending EP testing and, if necessary, catheter ablation for patients with asymptomatic ventricular preexcitation. The difference in arrhythmia incidence during about 2 years of follow-up (60% of controls vs. 5% of ablated patients) is striking indeed. However, only 1 arrhythmia was life threatening, so nearly every patient could have been safely referred for catheter ablation after the index event. Furthermore, the risk for major complications associated with catheter ablation, though small, is real. Therefore, it seems that prophylactic catheter ablation is not yet ready for widespread clinical use in asymptomatic patients with the WPW ECG pattern.

— Hugh Calkins, MD

Published in Journal Watch Cardiology January 23, 2004

Citation(s):

Pappone C et al. A randomized study of prophylactic catheter ablation in asymptomatic patients with the Wolff-Parkinson-White syndrome. N Engl J Med 2003 Nov 6; 349:1803-11.

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• Medline abstract (Free)

Lerman BB and Basson CT. High-risk patients with ventricular preexcitation -- A pendulum in motion. N Engl J Med 2003 Nov 6; 349:1787-9.

• Original article (Subscription may be required)
• Medline abstract (Free)