Change of the pulmonary vein anatomy after cryoballoon ablation reflecting left atrial reverse remodeling

Background Cryoballoon ablation (CBA) is a widely used procedure for atrial fibrillation (AF). However, the anatomical change of pulmonary veins (PVs) and the risk factors of PV stenosis is less clear. We aimed to decipher the prevalence and the predictive factors for PV stenosis after CBA. Methods We analyzed the data of 320 PVs from 80 patients who underwent CBA for AF (age: 62±10 years, 59 males, 75 paroxysmal AF). All patients underwent pre- and post-procedural cardiac computed tomography (mean 6.7±3.3 months after ablation). We defined the PV stenosis when the cross sectional area of PV was less than 50% compared with that of PV before the CBA. Results The average cross sectional PV area decreased significantly after CBA (pre- vs. post-CBA; 2.4±1.0cm2 vs. 2.3±1.1cm2, P<0.001), whereas the volume of left atrium (LA) also decreased significantly (pre- vs. post-CBA; 75.0±23.2cm3 vs. 70.7±21.9cm3, P<0.001). There was a weak but significant correlation between the reduction rate of PV area and that of LA volume (Pearson's correlation coefficient 0.411, p<0.001). Only 6 PV stenosis were revealed, in which area reduction of more than 75% and 50–75% were observed in 2 PVs and 4 PVs, respectively. The incidence of PV stenosis was greater in female (male vs. female; 0.8% vs. 4.8%, P=0.043) and tend to be frequent in left PVs (left PVs vs. right PVs; 3.1% vs. 0.6%: P=0.107). Moreover, patients who developed PV stenosis tended to have lower weight and shorter height (PV stenosis group vs. non-PV stenosis group; 58.2±12.4kg vs. 67.7±13.0kg: P=0.078, 161.2±9.1cm vs. 167.2±8.8cm: P=0.094). There were no significant differences in the number of freezing, minimum temperature and total freezing time between PV stenosis group and non-PV stenosis group. Conclusions The ostial PV area decreased significantly but little after CBA, possibly due to LA reverse remodeling. The PV stenosis was more common in women and tend to be frequent in left PVs, lower weight, and shorter height patients, though severe stenosis after CBA was not observed in this study. Funding Acknowledgement Type of funding source: None