Sinus Rhythm During Cryoballoon Atrial Fibrillation Ablation Independently Predicts Improved Clinical Outcomes

Background: Catheter ablation with pulmonary venous isolation is performed for sinus rhythm maintenance in patients with atrial fibrillation. We aimed to identify clinical and procedural factors that influence outcome of cryoballoon pulmonary venous isolation.

Patients and methods: Consecutive 119 patients undergoing cryoballoon PVI in our institution were enrolled (age 37-81, mean 64.4 years, 37.8% female). The median follow up was 193 days.

Results: At follow up, 36.1% of patients experienced at least one clinical AF event, defined as the occurrence of symptomatic PAF that resolved spontaneously, cardioversion or hospitalization for AF or presence of AF at the follow up visit. There was no difference between them and patients without clinical AF event in age, sex, CHA₂DS₂VASc score and its individual components, LVEF, left atrial size, antiarrhythmic drug therapy before and after PVI, warming time, minimal temperature, operator experience, cardioversion before or during PVI or number of successfully isolated veins. Atrial fibrillation both at the start and at the end of the ablation was significantly associated with the occurrence of AF at the follow up (60.5% vs 27.4%, p=0.03 and 88.9% vs 31.8%, p=0.001, respectively). Multivariate analysis demonstrated that atrial fibrillation at the beginning of the ablation was independent predictor of the clinical AF events during the follow up (HR 3.08, CI 95% 1.17-8.13, p=0.023).

Conclusions:

Cryoballoon PVI is effective in maintaining sinus rhythm. Its efficacy is independent of patient’s demography, comorbidities, LV systolic function, left atrial size, antiarrhythmic therapy, operator experience, procedural parameters and number of successfully isolated veins. Atrial fibrillation at the start of the PVI independently predicts adverse outcome.