Anatomical changes in the pulmonary veins and left atrium after cryoballoon ablation

Background: The anatomical changes in pulmonary veins (PVs) after cryoballoon ablation (CBA) are unclear. We aimed to determine the morphological changes in the PVs and left atrium (LA) along with the predictive factors for clinical PV stenosis. Methods: We analyzed data of 320 PVs from 80 patients who underwent CBA for atrial fibrillation (age: 62 ± 10 years, 59 males). All patients underwent pre- and post-procedural cardiac computed tomography. We defined clinical PV stenosis when the cross-sectional area decreased by more than 50%. Results: The average ostial PV area and LA volume decreased significantly after CBA (pre- vs post-CBA; 2.4 ± 1.0 cm² vs 2.3±1.1 cm², P <.001, 75.0 ± 23.2 cm³ vs 70.7 ± 21.9 cm³, P <.001, respectively). There was a significant correlation between the reduction rates of the PV area and those of LA volume (R = 0.411, P <.001). The larger preoperative PV area and greater reduction in LA volume were associated with advanced PV narrowing. Clinical PV stenosis was observed in six PVs, was more common in females (male vs female; 0.8% vs 4.8%, P =.043), and tended to be more frequent in left PVs (left PVs vs right PVs; 3.1% vs 0.6%: P =.107), irrespective of the LA volume reduction. Conclusions: The significant reduction of the ostial PV area occurred after CBA, which correlated with the reduction rate of LA volume. The narrowing of the PV was partly produced by the LA volume reduction. Clinical PV stenosis was more common in females and tended to be more frequent in left PVs.