Characterization of “Super-Responders” to Cryoballoon Ablation

Background: Pulmonary Veins Isolation (PVI) is the cornerstone in the treatment of atrial fibrillation. Recurrence rate is common in the long-term followup (FU); nevertheless, some patients maintain Sinus Rhythm (SR) for more than 5 years after the index ablation. The aim of this study is characterize this kind of patients so called “super-responders”. Methods: This is a retrospective single-center study including all patients summited for cryo-balloon ablation in our hospital from January 2011 to September 2020. We investigated clinical, electrocardiographic, echocardiographic variables and those linked to the ablation procedure. A univariate and multivariate logistic regression was performed. Results: During this period, 422 patients underwent PVI; however, 193 were excluded: 21 lost in the FU, 30 got radiofrequency ablation and 142 did not reach a minimum 5 years FU. Of the 229 finally included, 85 (group 1) did not have any recurrence during the follow-up, in front of 144 (group 2) with AF recurrences. In the multivariate analysis the p wave duration: OR: 0.92; 95% CI (0.89-0.94); p <0.001, BMI kg/m²: OR: 0.74; 95% CI (0.65-0.85); p <0.001, a temperature <-40°C in all the targeted veins: OR: 3.52; 95% CI (1.45-8.54); p=0.005 and SR on the ablation index day OR: 7.29; 95% CI (1.53-34.71); p=0.012, maintained statistical significance. Conclusions: In our series the p wave duration, BMI, the presence of SR the ablation index day and achieving a temperature <-40°C in all the targeted veins, resulted as protective factors to maintain SR in the long term follow-up. An adequate selection of patients probably could improve results and optimize resources.