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.