Cryoballoon Ablation for Atrial Fibrillation in a High-Volume Center: Seventeen Years of an All-Comer Strategy

Background: Atrial fibrillation (AF) is the most common arrhythmia, associated with increased risk of stroke and heart failure. Cryoballoon ablation (CBA) has emerged as a leading treatment for symptomatic AF, providing effective pulmonary vein isolation (PVI). While new technologies like pulsed field ablation are promising, long-term outcome data are limited. This study presents a 17-year longitudinal analysis of CBA outcomes at a high-volume center, assessing procedural success, complication rates, and long-term arrhythmia-free survival.

Methods: A prospective observational single-center all-comer study was conducted to evaluate long-term efficacy and safety of CBA as the initial ablation approach for AF. Over the study period, various CB systems and protocols were employed. The majority was guided by PV angiography, intracardiac echocardiography, and esophageal temperature monitoring, with cryo-dosing based on time-to-isolation (TTI). A standard freeze duration of 300, 240 or 180 seconds was applied, with an additional freeze if TTI was ³45 seconds or if TTI data were unavailable.

Results: From 2007 to 2024, 4,167 CBA procedures were performed, including 424 repeat ablations among 3,937 consecutive patients. Of these, 46.2% had persistent AF. Mean patient age was 65±11 years, with 38.5% female. Key baseline characteristics included a mean left atrial diameter of 42±7 mm, BMI of 26.2 kg/m² [5.8], and a median CHA₂DS₂-VASc score of 3 [3]. Comorbidities included hypertensive heart disease (22.9%), moderate to severe mitral regurgitation (3.6%), and prior myocardial infarction (1.5%).

Procedural data showed a median dose-area product of 1,313 cGy×cm² [1,802], median fluoroscopy time of 23 minutes [24], and procedural time of 95 minutes [30]. Various CB systems were used: first-generation ArcticFront™ (20.4%), second-generation ArcticFront Advance™ (31.8%), ArcticFront AdvanceST™ (6.4%), fourth-generation ArcticFront AdvancePro™ (33.7%), and POLARx/-Fit™ (7.6%). Acute PVI was achieved in all pulmonary veins.

Complications occurred in 4.1% of cases. Major adverse cardiovascular and cerebrovascular events were recorded in 5 patients (0.01%), including 5 strokes with no associated deaths or myocardial infarctions. Major complications included persistent phrenic nerve palsy (0.6%) and pericardial effusion treated by drainage (0.1%). Minor complications affected 3.4% of patients, with 0.5% experiencing vascular adverse events managed conservatively. During a mean follow-up of 45 months, 30.1% of patients experienced arrhythmia recurrence, with no independent risk factors for AF or atrial tachycardia recurrence identified in multivariate analysis.

Conclusion: This 17-year all-comer study of CBA as the initial ablation strategy for AF demonstrated effective long-term outcomes and a favourable safety profile. These results reinforce the role of CBA as a reliable approach for managing AF, highlighting its efficacy in optimizing patient outcomes amid evolving treatment technologies.