Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Clinical Trials / Outcomes D-PO03 - Poster Session III (ID 48) Poster

D-PO03-133 - Durability Of Pulmonary Vein Isolation And Reduction In Atrial Fibrillation Burden Assessed With Implantable Loop-recorder And Mandatory Re-procedure (ID 335)

 S.K. Sørensen: Nothing relevant to disclose.


Background: Pulmonary vein isolation (PVI) is the main ablation strategy for paroxysmal atrial fibrillation (AF), and recurrence after ablation is ascribed to failure to achieve durable PVI. However, the effect of PVI durability on AF-burden has not been tested directly.
Objective: To determine the effect of PVI durability on AF burden assessed by an implantable loop recorder (ILR).
Methods: In the prospective RACE-AF trial (NCT03805555), 98 patients (pts) with paroxysmal AF had an ILR implanted ≥ 1 month prior to PVI (by radiofrequency or cryoballoon ablation pr randomization), and had PVI durability assessed by mandatory re-procedure after 4-6 months. AF-burden before PVI was compared to AF-burden before the re-procedure (excl. a 3-month blanking period), and reductions were analyzed according to PVI status, regardless of ablation method used in the initial procedure.
Results: Median AF-burden was 5.4% (IQR: 0.6-18.0%) before PVI and 0.0% (0.0-0.3%) after PVI (p < 0.001), corresponding to an overall AF-burden reduction of 100% (89.7-100%). AF-burden reduction significantly correlated to the number of isolated pulmonary veins (PVs) as illustrated in Figure 1 (p = 0.03). In pts with all PVs isolated, 5/40 (13%) failed to achieve an AF-burden reduction ≥ 60%; and conversely, in pts with only 1-2 isolated PVs, 5/19 (26%) still achieved an AF-burden reduction ≥ 99%.
Conclusion: In pts with paroxysmal AF, catheter based PVI produced a marked reduction in AF burden which was strongly associated to PVI durability. However, durable isolation of all veins was neither necessary nor sufficient to achieve this in all pts, indicating a place for more individualized ablation strategies.