Durability of Thermal Pulmonary Vein Isolation in Persistent Atrial Fibrillation Assessed by Mandated Repeat Invasive Study.

BACKGROUND: No study has assessed durability of pulmonary vein isolation (PVI) with radiofrequency (RF) and Cryoballoon (CB) in patients with persistent AF. These data are especially lacking for those with significantly diseased left atria (LA).

OBJECTIVE: To assess PVI durability in patients with significant LA disease and compare reconnection rates between RF and CB.

METHODS: 44 Patients (mean age 63, 77% male, median time since AF diagnosis 22.5 months, median indexed LA volume 36 ml/m2 ) were randomised 1:1 to RF (StablePoint catheter, Boston Scientific) or CB (Arctic Front Advance, Medtronic) PVI. A redo procedure using ultra high-density electroanatomic mapping (Rhythmia, Boston Scientific) was mandated at 2 months, where PV reconnections were identified and re-isolated.

RESULTS: 38 patients underwent both procedures (n=17 CB, n=21 RF). Index RF procedures were longer (median 158 vs 97min; p<0.001) but required less fluoroscopy (9.5 vs 23min; p<0.001). At the index RF procedure, median 47% of LA myocardium had voltage <0.5mV, suggesting half of the mapped LA comprised scar. PV reconnection was observed in 73/152 (48.0%) PVs and was more frequent with CB (58.8%) vs RF (39.3%), p=0.022. Reconnection of at least 1 PV was detected in >75% of patients. Significantly more ablation was required at redo to reisolate PVs in the CB arm (median 10.8 vs 1.2min; p<0.001).

CONCLUSION: PVI durability may be poor in those with significant LA scarring and dilatation, even with modern thermal ablation technologies. RF resulted in significantly better PVI durability than CB in this complex population.

CLINICAL TRIAL REGISTRATION: NCT04111731.