Pulmonary vein isolation (PVI) has become an established treatment option for symptomatic atrial fibrillation (AF). However, arrhythmia recurrence is common, with many patients needing repeat ablation procedures. A variety of ablation strategies have been developed to ensure durable isolation of the PV. Interestingly, in some patients, arrhythmia recurrence does not occur for several years after the initial ablation procedure. The mechanisms for these late recurrences are not yet fully understood. In this study, we investigated mechanisms of early and late arrhythmia recurrences after PVI.
Methods:
Consecutive patients who underwent radiofrequency-based PVI using a 3D mapping system, and who underwent repeat ablation procedure for symptomatic arrhythmia recurrence were analyzed retrospectively. All patients received intra-cardiac mapping during index- and repeat procedures including assessment of electrical PV reconnection. Depending on the timeframe between the index- and the repeat ablation procedure due to recurring symptomatic AF, patients were separated into 3 groups: Group 1 (repeat ablation for symptomatic arrhythmia recurrence after 3-24 months), group 2 (repeat ablation after 2-5 years) and group 3 (repeat ablation after > 5 years).
Analysis included mode of arrhythmia recurrence [AF or atrial tachycardia (AT)], PV reconnection (reconnected or fully isolated PVs) and baseline patient characteristics to develop a clearer understanding of the underlying mechanisms for late arrhythmia recurrences.
Results:
A total of 110 consecutive patients (79 male, 72%, mean age 61.3±8.9 years) who underwent first-time catheter ablation for paroxysmal (87 patients, 79%) or persistent AF (23 patients, 21%) were analyzed.
There were 47 patients with early repeat procedures (Group 1), 29 patients with mid-term arrhythmia recurrences (group 2), and 34 patients with repeat procedures for late arrhythmia recurrences (group 3).
Electrical PV reconnection was found in 46 patients (98%) in group 1, 21 patients (72%) in group 2, and 19 patients (56%) in group 3, respectively (p < 0.001, Figure 1).
When comparing the underlying arrhythmia mechanisms at the time of reablation in group 1 35 patients (75%) suffered from AF and 12 patients (25%) from AT. In group 2 21 patients (72%) presented with AF and 8 patients (28%) with AT. In group 3 repeat procedures were conducted for AF in 12 patients (35%) and for AT in 22 patients (65%) (p= 0.001).
We compared patients of all groups with reconnected PVs to patients with no PV reconnection. In patients with PV reconnection in 63 cases (73%) AF was the mode of arrhythmia recurrence whilst in 23 cases (27%) AT led to repeat ablation. When all PV were isolated at the time of repeat procedure AT was present in 19 cases (79%) and AF in 5 cases (21%). AF was significantly more often present in patients with reconnected PV, whilst AT was significantly more frequent when all PVs were isolated (p<0.001 for differences between patients with and without PV reconnection).
Conclusion:
PV reconnection was found in the majority of patients with early AF recurrence after PVI.
In patients with late arrhythmia recurrences, this mechanism seems to play an inferior role, with many patients presenting without PV reconnection. Additionally, either a late point in time of arrhythmia recurrence as well as absence of PV reconnection were associated with organized AT.
Figure 1
Electrical status of PV during repeat procedure
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