Mid-long Term Clinical Outcome Of Second-generation Cryoballoon Ablation For Paroxysmal Atrial Fibrillation

Objective: As a standard method for pulmonary vein isolation(PVI),the cryoballoon ablation(CBA)has been widely used in treating paroxysmal atrial fibrillation(AF).Our country has used the second-generation cryoballoon(CB-2)for over 2 years,but currently there are limited datas for mid-long-term clinical outcome for CB-2.This study aims to assess the mid-long-term clinical outcome of paroxysmal AF by using CB-2 and investigate the predictive factors of baseline and intraoperative datas of patients that may affect postoperative recurrence.Methods: It was a retrospective study that enrolled 211 paroxysmal AF patients who underwent CBA in Shanghai Ruijin Hospital from 15 August 2016 to 30 June 2018,7 of these patients were out of contact and therefore the actual inclusion was 204(mean age 61.2±10.5 years,57.8%males).All routine preoperative examinations were performed and during the operation we use 28 mm cryoballoon for priority and intraoperative datas were recorded.All the patients were completed follow-up for a mean follow-up 17.4±6.1 months.They have routinely evaluated by Holter at 1?3?6?12?24 months after ablation to evaluate the presence or absence of AF recurrence.The primary endpoint was the documented AF events after the blanking period(90 days after the operation).We divided the patients with non-recurrence group and recurrence group and compared the baseline and intraoperative datas between two groups.Survival curves were performed and we used multivariate logistic regression analysis to observe the factors that relate to the recurrence of AF.Results: All 204 patients have achieved complete PVI by using CB-2,successful rate was 100%.Mean operation time 88.7±37.1 minutes,mean follow-up time 17.4±6.1 months.The AF non recurrence rate was80.9%.168 patients have followed up for over 1 year,the AF non recurrence rate at one year is 86.9%.71 patients have documented AF recurrence during the acute period(3 days after operation)and 26 of which have documented AF recurrence after blanking period(36.6%).133 patients have not documented AF recurrence during the acute period and13 of which have documented AF recurrence after blanking period(9.8%).There was significant difference between them.Compared with non recurrence group,the recurrence group had more females(P=0.018),longer AF duration(P=0.047),higher systolic blood pressure(P=0.036),more operation time(P=0.007),more operation time in left atrium(P=0.036),more time using radiography(P=0.032),higher temperature in left superior pulmonary vein(LSPV)and left inferior pulmonary vein(RSPV)(P=0.032 and P=0.037),more time of time to isolation(TTI),higher temperature at the TTI in right superior pulmonary vein(RSPV)and right inferior pulmonary vein(RIPV)(P=0.049 and P=0.048).During the perioperation and follow-up,there were 4complications.3 patients had phrenic nerve pulsy(PNP)and 1 patient had pericardial tamponade.No patients died during this study.The overall rate of complications was 1.96%.Multivariate Logistic regression analysis showed that high blood pressure(P=0.049),AF duration(P=0.022),left atrium diameter(P=0.046),LSPV TTI(P=0.037)and RSPV TTI(P=0.029)were risk factors that related to late AF recurrence.Conclusion: This study shows that CB-2 is an efficient and safety method for treating paroxysmal AF.Females,longer AF duration,higher systolic blood pressure,higher temperature and more time of TTI in LSPV and RSPV,higher temperature at TTI in RSPV and RIPV seems more likely to the AF recurrence.High blood pressure,AF duration,left atrium diameter,LSPV TTI and RSPV TTI are risk factors that related to late AF recurrence.