Veins without real-time pulmonary vein isolation during cryoballoon ablation strongly predict long-term atrial fibrillation recurrence

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Absence of real-time PV isolation (PVI) by the Achieve catheter occurring in 15 to 40% of the veins during cryoballoon ablation (CBA) of atrial fibrillation (AF) raises doubt about adequate PVI. PURPOSE: To determine whether veins without real-time PVI are predictive of long-term clinical outcome. METHODS AND RESULTS: 803 of 1000 consecutive AF patients (mean age 64±10 years, 68% males) treated with CBA were followed for 3 years. Clinical success defined as freedom of documented AF at 3 years was achieved in 65.3% of the patients. The cohort was divided in 4 groups according to the number of PVs with real-time PVI: all veins (N=252(31,4%)), 3 (N=255(31,8%)), 2 (N=159(19,8%)) and 0-1 vein (N=137(17,1)). 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 established predictors as 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). The highest clinical success was achieved in patients with real-time PVI in all veins (77.4%), gradually decreasing per increasing number of veins without 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), 83 out of 288 (28.8%) veins without real-time PVI were reconnected versus 99 out of the 430 (23.0%) veins with real-time PVI (p=0.08). CONCLUSION: Veins without real-time PVI during CBA independently predict long-term AF recurrence with increasing AF recurrence per increase in veins without real-time PVI. A trend towards a higher reconnection rate in veins without real-time PVI suggest incomplete PVI or a less efficacious freeze resulting in less durable PVI.