ABC | Volume 110, Nº5, May 2018

Original Article Pulmonary Vein Anatomy is Associated with Cryo Kinetics during Cryoballoon Ablation for Atrial Fibrillation Xiongbiao Chen, 1 Pihua Fang, 1 Zheng Liu, 1 Jia He, 1 Min Tang, 1 Jun Liu, 1 Bin Lu, 2 Shu Zhang 1 Department of Cardiac Arrhythmia - State Key Laboratory of Cardiovascular Disease - Fuwai Hospital - National Center for Cardiovascular Diseases - Chinese Academy of Medical Sciences and Peking Union Medical College, 1 Beijing - China Department of Radiology - State Key Laboratory of Cardiovascular Disease - Fuwai Hospital - National Center for Cardiovascular Disease - Chinese Academy of Medical Sciences and Peking Union Medical College, 2 Beijing - China Mailing Address: Pihua Fang • 167 Beilishi Road, Xicheng District. 100037, Beijing – China E-mail: pihua_fang@yahoo.com Manuscript received June 30, 2017, revised manuscript October 15, 2017, accepted November 09, 2017 DOI: 10.5935/abc.20180071 Abstract Background: The influence of pulmonary vein (PV) anatomy on cryo kinetics during cryoballoon (CB) ablation is unclear. Objective: To investigate the relationship between PV anatomy and cryo kinetics during CB ablation for atrial fibrillation (AF). Methods: Sixty consecutive patients were enrolled. PV anatomy, including ostial diameters (long, short and corrected), ratio between short and long diameters, ostium shape (round, oval, triangular, and narrow), and drainage pattern (typical, with common trunk, common antrum, ostial branch and supernumerary PV) were evaluated on multi-detector computed tomography (MDCT) images pre-procedure. Cryo kinetics parameters [balloon freeze time from 0 to -30°C (BFT), balloon nadir temperature (BNT) and balloon warming time from -30 to +15°C (BWT)] were recorded during procedure. All p values are two-sided, with values of p < 0.05 considered to be statistically significant. Results: 606 times of freezing cycle were accomplished. Moderate negative correlation was documented between BNT and corrected PV diameter (r = -0.51, p < 0.001) when using 23-mm CBs, and mild negative correlation (r = - 0.32, p = 0.001) was found when using 28-mm CBs. Multivariate logistic regression analysis revealed that PV corrected ostial diameter (OR, 1.4; p = 0.004) predicted a BNT < -51°C when using 23-mm CBs, while PV ostium oval shape (OR, 0.3; p = 0.033) and PV locations (left inferior PV: OR, 0.04; p = 0.005; right superior PV: OR, 4.3; p = 0.025) predicted BNT < -51°C when using 28-mm CBs. Conclusions: MDCT can provide PV anatomy accurate evaluation prior CB ablation. PV anatomy is associated with cryo kinetics during ablation. (Arq Bras Cardiol. 2018; 110(5):440-448) Keywords: PulmonaryVeins / anatomy&histology; Atrial Fibrillation; Catheter Ablation;Multidetector ComputedTomography; Cost-Benefit Analysis. Introduction CB ablation has an increasing clinical application worldwide, it has been proved a comparable technique to radiofrequency (RF) ablation in safety and efficacy for the AF treatment, 1 and maybe more cost-effective. 2 By achieving appropriate occlusion in targeted PVs with the balloon and getting good balloon – PV ostium contact, it can simplify the procedure with a “single-shot” approach to get circumferential PV isolation. 3 It is reported that some parameters of cryo kinetics, such as balloon temperature, 4 balloon warming time, 5 can predict acute PV isolation or late PVs reconnection. Some parameters of PV anatomy have been used to predict occlusion, 6 or acute, mid- and long-term success of CB ablation. 7-9 It is reasonable to imaging that PV anatomy plays a role in cryo kinetics, thus exerting an influence on ablation efficacy. However, limited data exist regarding the association between PV anatomy and cryo kinetics during CB ablation. We aimed to investigate the relationship between PV anatomy parameters and cryo kinetic parameters in patients undergoing CB ablation using either 23- or 28-mm CB for AF. Methods Patients Between January and October 2014, a prospective study was carried out at our institution. Sixty consecutive patients with symptomatic and drug-refractory AF underwent CB ablation. In these patients, pre-procedural MDCT images and complete recordings of cryoballoon temperature during each CB ablation were available. All patients provided written informed consent. The study followed the ethical standards of the Declaration of Helsinki of 1975, revised in 2008 and was approved by the local institutional ethics committee. 440