Limitations
The retrospective study design limits statistical power of our analysis
and its multicenter nature introduces heterogeneity in both ablation
performance and patient outcomes. Furthermore, our investigation
explored a wide variety of ablation strategies in this patient
population. Detailed information regarding the ablation procedures,
including ablation settings and operator preferences, was not available.
Therefore, we are likely be underpowered to detect true difference
between AF ablation strategies and this analysis should be considered
hypothesis-generating. Additionally, while the efficacy of ablation
strategies was assessed, confirmation of lesion durability for each
strategy (e.g., posterior wall isolation or mitral line block) was not
systematically verified, which may have influenced the observed
recurrence rates.
It should be emphasized that identification of these patients is only
possible during repeat procedures, making the inclusion of large numbers
of patients challenging. Nonetheless, despite the retrospective design,
through the NHR we were still able to identify one of the largest series
of patients with durably isolated PVs. Lastly, detection of AF
recurrences was not standardized, possibly leading to under-detection of
AF recurrence. Despite this, we still observed a high recurrence rate
suggesting that AF recurrence is very common in this subset of patients.