First-Pass Isolation as an Independent Predictor of Atrial Fibrillation Recurrence After Cryoballoon Ablation in Patients with Persistent Atrial Fibrillation.

Background/Objectives: Data on predictors of atrial fibrillation (AF) recurrence after cryoballoon pulmonary vein isolation (PVI) in persistent AF (PeAF) remain limited. We evaluated clinical, echocardiographic, and procedural parameters associated with recurrence. Methods: We retrospectively studied 192 PeAF patients who underwent cryoballoon PVI and had ≥6 months of follow-up. Recurrence was any atrial tachyarrhythmia > 30 s beyond a 3-month blanking period. Cox models assessed predictors, including number of veins with first-pass isolation (FPI), left atrial volume index (LAVI), hemoglobin, and prespecified covariates. Results: During a median follow-up of 670 days (interquartile range 425-944), recurrence occurred in 75 patients (39.1%). On multivariable analysis, reduced extent of FPI (<3 veins) independently predicted recurrence (HR 2.48, 95% CI 1.48-4.16; p = 0.001). In continuous analysis, each one-vein decrement in FPI was associated with a 58% higher hazard. Lower hemoglobin was also independently associated; each 1 g/dL decrease corresponded to a 29% higher hazard (HR 1.29, 95% CI 1.05-1.58; p = 0.015). Male sex showed approximately a twofold higher recurrence risk than female sex (HR 2.23, 95% CI 1.06-4.68; p = 0.034). In PeAF patients treated with cryoballoon PVI, intraprocedural FPI extent was a strong independent predictor, outperforming anatomical remodeling after adjustment. Achieving FPI in fewer than three pulmonary veins predicted higher recurrence. Hemoglobin provides an accessible systemic risk marker, while male sex identifies a higher-risk subgroup. Conclusions: In PeAF patients, the extent of FPI in cryoballoon PVI is a strong independent predictor of outcome, and maximizing the number of veins with FPI could be a pragmatic procedural goal.