The absence of real-time pulmonary vein isolation during cryoballoon ablation is associated with atrial fibrillation recurrence and pulmonary vein reconnection : Insights from the Middelheim-PVI Registry 2.

BACKGROUND

Absence of real-time pulmonary vein (PV) isolation (PVI) occurring in 15-40% of PVs during cryoballoon ablation (CBA) of atrial fibrillation (AF) raises doubt about adequate PVI. Aim of the present study is to determine whether real-time PVI during CBA is predictive of long-term clinical outcome and durability of PVI.

METHODS

Eight hundred three AF patients (64 ± 10 years, 68% males) undergoing CBA were studied. The cohort was divided in 4 groups according to the number of PVs without real-time PVI: none (N = 252 [31.4%]), 1 (N = 255 [31.8%]), 2 (N = 159 [19.8%]), and 3-4 (N = 137 [17.1]).

RESULTS

At 3 years, 279 (34.7%) patients had recurrence of AF of which 188 underwent repeat ablation. A vein without real-time PVI was associated with AF recurrence (HR = 1.275; 95% CI 1.134-1.433; p < 0.01), independent of persistent AF type (HR = 2.075; 95% CI 1.584-2.738; p < 0.01), left atrial diameter (HR = 1.050; 95% CI 1.028-1.072; p < 0.01), and diagnosis-to-ablation time (HR = 1.002; 95% CI 1.000-1.005; p = 0.04). Highest success was achieved with present real-time PVI in all veins (77.4%), gradually decreasing per increasing number of absent real-time PVI: 66.3% for 1 vein, 58.5% for 2, and 48.9% for 3-4 veins (p < 0.001). At repeat ablation (N = 188), PV reconnection was seen in 99/430 (23.0%) versus 83/288 (28.8%) veins with and without real-time PVI, respectively (p = 0.08). Right inferior PVs (RIPVs) with real-time PVI were less reconnected than RIPVs without real-time PVI: 29.7% versus 43.7% (p = 0.047).

CONCLUSION

The absence of real-time PVI during CBA independently predicts AF recurrence with a 30% gradual decrease in outcome per increase in veins without real-time PVI. Real-time PVI is particularly important for the RIPV to achieve durable PVI.