Discussion:
The main findings of the present analysis are that we observed no significant reduction in recurrence of any atrial arrhythmia >30s in duration after index ablation between patients undergoing RF ablation of NPAF with a contact-force sensing catheter using a stepwise linear ablation strategy vs. a LA PWI strategy, however there was a statistically significant reduction in recurrence of AT, recurrence of any persistent atrial arrhythmia, and need for repeat ablation in the LA PWI group. The divergence of these significant differences in outcomes is striking given the null result for the traditional primary endpoint for AF ablation trials (AF or AT >30s in duration). Furthermore, the present analysis provides no evidence that a more extensive initial ablation strategy provides a benefit related to outcomes following a repeat ablation procedure, and that the need for a third ablation procedure may in-fact be greater following a more extensive initial procedure.
A patient-centered evaluation of procedural success should place less emphasis on short episodes of asymptomatic atrial arrhythmia relative to more persistent and symptomatic arrhythmias that require intervention.13,14 The Circa-Dose study recently highlighted the shortcoming of considering arrhythmia recurrence as a binary condition since arrhythmia recurrence rates of 53% were associated with reduction of arrhythmia burden >99%. 15 A more meaningful representation of arrhythmia recurrence would better guide treatment choices. 16 In our study, the persistence of arrhythmia was an important determinant of need for repeat ablation, and more extensive ablation was strongly associated with an increased risk of persistent arrhythmia. The majority of recurrent ATs following stepwise linear ablation of AF have previously been shown to be macroreentrant ATs related to incomplete linear lesions,17 and the primary mode of recurrence remains AT despite utilization of CFS catheters.