Antagonist: It is not appropriate at this time to recommend pulmonary vein ablation for all patients with paroxysmal atrial fibrillation. The procedure is associated with risk of potentially severe adverse events including stroke, cardiac tamponade, and pulmonary vein stenosis. Proper selection and administration of antiarrhythmic drug therapy can treat these patients with equivalent efficacy and better safety.

Protagonist: There are many problems associated with antiarrhythmic drug therapy for atrial fibrillation. The simple fact is, drugs don't work very well: many common drugs such as amiodarone, propafenone, sotalol, are associated with a 60% probability of recurrence within a year. The recurrence rate with amiodarone is lower, but few patients are likely to take amiodarone for as long as 2 to 3 years. In fact, when we do clinical trials to evaluate efficacy of antiarrhythmic drugs, we measure average time between recurrences rather than cure rates, because there are no cures. In addition, these drugs tend to have high rates of side effects, which can dramatically reduce the patients' quality of life. Also, many antiarrhythmics have a significant pro-arrhythmic potential. Finally, these drugs tend to be expensive. All of these factors have an adverse impact on the patient's compliance with the prescribed medication regimen.

Atrial fibrillation is initiated by premature atrial events that most typically occur in the pulmonary veins. Ablation techniques have, therefore, focused on ablation of tissue in the pulmonary veins. There are 2 general types of techniques: focal ablation of the sites of abnormal activity, and a more empiric general approach in which the pulmonary vein is broadly separated, in terms of electrophysiology, from the atrium, essentially blocking potential arrhythmogenic activity from reaching the atrium.

With either the older focal approach or the more recent pulmonary vein isolation procedure, cure rates for patients with paroxysmal atrial fibrillation are very good: about 70% with the older focal procedure, and about 80% with the newer approach. Even for patients with chronic or persistent atrial fibrillation, cure rates with these approaches range from 20% to 60%, and typically reach the 50% to 60% range.

Interestingly, those patients who are not cured by the ablation procedures tend to have excellent responses to subsequent pharmacologic therapy. Therefore, the overall success rate of these procedures is really in the 90% range.

Antagonist: It is very difficult for me to agree with a recommendation for the use of pulmonary vein ablation for all patients with paroxysmal atrial fibrillation. First, not all patients have similar pathophysiology - we don't necessarily know the underlying cause of atrial fibrillation in patients with congestive heart failure or other underlying cardiovascular diseases. Second, the ablation procedure carries significant risks. And third, when properly used, drug therapy can provide equivalent efficacy and safety.

Most of the published data on the pulmonary vein ablation procedure are from series of patients with an average age below 65, and with cardiac ejection fractions well in the normal range. We have to be careful about extrapolating these data to typical atrial fibrillation patients who are 75 years old or have congestive heart failure.

While cure rates generally in the 65% to 75% range, and even as high as 92%, are being seen with pulmonary vein ablation in electrophysiology labs around the world, these procedures are associated with significant adverse events rates of 2% to 3%. The adverse events include cerebrovascular events, pericardial effusion and tamponade, and pulmonary vein stenosis. In fact, a new clinical syndrome has been defined recently: pulmonary vein stenosis following pulmonary vein ablation.

I have recently analyzed data from patients I have treated for atrial fibrillation with antiarrhythmic drug therapy during the last 15 years. By using an algorithmic approach to drug selection, I have produced a success rate of 66% at 3.2 years of follow-up. This is comparable to success rates reported with pulmonary vein ablation, but such reports include follow-up times ranging from 4 months to 13 months, and no longer. The mean time to failure for my patients was 6.5 years, and cumulative success rates with patients being under good control were 89% at 1 year and 70% at 5 years. Among these patients there were no cases of stroke, tamponade, or pulmonary vein stenosis. Therefore, I cannot at this time recommend pulmonary vein ablation for all patients with paroxysmal atrial fibrillation.