Prophylactic catheter ablation reduces frequency of arrhythmic events in asymptomatic patients

Prophylactic catheter ablation markedly reduces the frequency of arrhythmic events in asymptomatic patients with Wolff-Parkinson-White (WPW) syndrome, according to a randomized study published in the latest issue of the New England Journal of Medicine.Young age and inducibility of atrioventricular reciprocating tachycardia or atrial fibrillation during invasive electrophysiological testing identify asymptomatic patients with a Wolff-Parkinson-White pattern on the electrocardiogram as being at high risk for arrhythmic events. The researchers tested the hypothesis that prophylactic catheter ablation of accessory pathways would provide meaningful and durable benefits as compared with no treatment in such patients. From 1997 to 2002, among 224 eligible asymptomatic patients with the Wolff-Parkinson-White syndrome, patients at high risk for arrhythmias were randomly assigned to radio-frequency catheter ablation of accessory pathways (37 patients) or no treatment (35 patients). The end point was the occurrence of arrhythmic events over a five-year follow-up period. Patients assigned to ablation had base-line characteristics that were similar to those of the controls. Two patients in the ablation group (5%) and 21 in the control group (60%) had arrhythmic events. One control patient had ventricular fibrillation as the presenting arrhythmia. The five-year Kaplan-Meier estimates of the incidence of arrhythmic events were 7% among patients who underwent ablation and 77% among the controls. Prophylactic radio-frequency catheter ablation of accessory pathways in asymptomatic patients with a Wolff-Parkinson-White pattern at high risk for arrhythmias resulted in a risk reduction of 92% over a five-year follow-up period," state Pappone and colleagues.They conclude that prophylactic accessory-pathway ablation markedly reduces the frequency of arrhythmic events in asymptomatic patients with the Wolff-Parkinson-White syndrome who are at high risk for such events. In an accompanying editorial, Dr. Craig Basson comments that it remains unclear exactly when catheter ablation should be performed."In the past, there has been some controversy regarding the optimal management for asymptomatic WPW patients," he said. In recent years, however, "many people thought the controversy was settled" in light of several population-based studies that supported a non-aggressive approach after showing that the risk of sudden death was very low."I think the new findings open this controversy again," Dr. Basson noted.The crux of the problem is that asymptomatic patients tend to do very well, so we don't like to perform risky, invasive procedures on them," Dr. Basson said. Counterbalancing this, however, is the fact that sudden death is such a terrible complication that even if it is exceedingly rare it drives clinicians to prevent it, he added.This study is important and it needed to be done, but it is really putting the cart before the horse," Dr. Basson said. "The study shows that ablation is a good therapy for high-risk patients, if only we could identify such patients.""Ultimately, I think that the best way to identify such patients will be through a better understanding of the genetic factors involved in the disorder," Dr. Basson added.Reference...