| Part ⅠComparison of using second-generation cryoballoon and radiofrequency catheter for atrial fibrillation ablation in patients with common ostium of inferior pulmonary veinsObjective:The common ostium of inferior pulmonary vein(COIPV)is an unusual variation of pulmonary venous drainage.For catheter ablation in atrial fibrillation(AF)patients with COIPV,few studies comparing radiofrequency ablation(RFA)and cryoballoon ablation(CBA)exists.This study was to compare the procedural outcomes of CBA and RFA in AF patients with COIPV,and to explore the effect of COIPV on CBA performance through the assessment of anatomical factors.Methods:From October 2013 to October 2019,a total of 18 patients with COIPV who underwent catheter ablation for AF were included.Pulmonary vein isolation(PVI)was performed with second-generation CBA and RFA.The procedural data and post-ablation outcomes were retrospectively analyzed.Through the three-dimensional anatomical reconstruction image of left atrium and pulmonary veins(PVs),the anatomical characteristics of COIPV and its impact on CBA performance were evaluated.Results:A total of 18 AF patients with COIPV were enrolled and the prevalence of COIPV was 0.82%in enrolled population.Among them,10 patients underwent second-generation CBA,and the remaining 8 underwent RAF.All PVs were successfully isolated.Comparing with RFA,CBA had shorter procedural time(53.0 min.vs.78.0 min.,P<0.001)and longer fluoroscopy time(13.5 min.vs.6.0 min.,P<0.001).There was no statistical difference in recording rate of pulmonary vein potential(PVP),reconnection rate of PVP,perioperative complications and anatomical parameters of the inferior pulmonary vein(IPV).In the comparison of the two subgroups of CBA,subgroup B had more freezing(more than 3 times)in IPVs,and higher ovality index of IPV ostium than subgroup A(0.95 vs.0.49,P=0.038).There was no statistical difference in other anatomical parameters between the two subgroups.During a median of 23.5 months of follow-up,three patients(16.7%)had recurrence of atrial arrhythmias(AAs).The CBA and RFA groups had no significant difference in AAs-free survival rate during follow-up period(P=0.729),as well as at 12 and 18 months after ablation(p=0.083 and 0.541,respectively).There were 2 patients with AA recurrence undergoing redo-procedure.The reconnection sites of PVP was found in the anterior part of left superior pulmonary vein.All the electrically reconnected PVs were successfully isolated in the redoprocedure.Conclusions:The COIPV is a rare anatomical variation.Though CBA for AF patients with COIPV has longer fluoroscopy time,it may shorten procedural time and have the similar long-term prognosis as RFA.In CBA,the cryoablation can be performed separately in each of IPVs,and the segmental cryoablation approach may bring great efficacy to the procedure.Part ⅡAnatomical accuracy of a novel three-dimensional imaging system in measurement of pulmonary veinsObjective:A novel three-dimensional imaging system(KODEX-EPD)based on the dielectric technology has been applied in cryoablation for atrial fibrillation(AF).There is still a lack of evaluation in accuracy of this system.This study retrospectively analyzed the measurement of KODEX-EPD and X-ray fluoroscopy for pulmonary vein(PV)ostium,and verified the accuracy and reliability of this novel system in reflecting the anatomical characteristics of PVs.Methods:Patients who underwent cryoablation for AF under the guidance of KODEX-EPD were retrospectively included.The three-dimensional images of left atrium(LA)and PVs reconstructed by KODEX-EPD and the corresponding pulmonary venography were collected.The agreement in diameter of the PV ostium measured by KODEX-EPD and X-ray fluoroscopy was analyzed.Results:A total of 65 AF patients who underwent cryoballoon ablation under the guidance of KODEX-EPD were included in this study,with a median age of 63.0 years.All PVs(270 in total)were successfully reconstructed by KODEX-EPD.The diameters of each PV ostium measured by KODEX-EPD were significantly lower than those measured by pulmonary venography(all P values were less than 0.05).The Pearson correlation test showed that the two modalities had strong correlation in measurement of each PV ostium(all correlation coefficients>0.8),and the correlation coefficient of all PV measurements by the two modalities was 0.94(P<0.001).Bland-Altman analysis showed that KODEX-EPD underestimated fluoroscopy measurements by 0.8 mm(95%limits of agreement of-3.5 mm to 1.9 mm).Conclusions:The novel three-dimensional imaging system(KODEX-EPD)has feasibility and safety in guiding cryoablation for AF.This system has great accuracy and reliability in evaluating the anatomical characteristics of LA and PVs.Part ⅢApplication of segmental cryoablation approach in second-generation cryoballoon ablation for inferior pulmonary veinsObjective:Pulmonary vein isolation(PVI)is the basis of catheter ablation for atrial fibrillation(AF),and the durable PVI is a key factor to ensure the long-term efficacy of cryoablation.The inferior pulmonary vein(IPV)is the most likely part to restore electrical connections after cryoablation.The segmental cryoablation for IPVs,which means freezing in each branch of the IPVs to achieve PVI,can be expected to further improve the efficacy of cryoablation.The purpose of this study was to explore the efficacy and safety of segmental cryoablation for IPVs,and to further explore the feasibility and advantages of the novel three-dimensional imaging system(KODEX-EPD)used in segmental cryoablation for IPVs.Methods:From August 2020 to January 2022,a total of 219 AF patients who underwent second-generation cryoballoon(CB)ablation in Arrhythmia Center Ward 2 were retrospectively included.Patients were assigned to two groups by cryoablation approach in IPVs:conventional occlusion group(COG,N=44)and segmental cryoablation group(SCG,N=175).The procedural characteristics and post-ablation outcomes were compared between the two groups.Additionally,SCG can be further divided into KODEX subgroup(N=65)and X-ray subgroup(N=110).The procedural characteristics and follow-up outcomes of the two subgroups were also compared.Results:All PVs were successfully isolated in the procedure.The SCG patients had more freezing applications and longer freezing time in IPVs than COG patients,while they had no significant difference in procedural time,X-ray exposure dose,cryoablation parameters and the incidence of complication.During the follow-up period,there was no statistical difference in the recurrence of atrial arrhythmia between the two groups.To further compare the two subgroups of SCG patients,the X-ray exposure time of KODEX subgroup was less than that of the fluoroscopy subgroup(23.0 min vs.27.0 min,P<0.001),but the two subgroups had no significant difference in procedural time,X-ray exposure dose and usage of contrast agent.There was no statistical difference in the incidence of complications and post-ablation outcome between the two subgroups.Conclusions:While the segmental cryoablation approach increases freezing applications in IPVs,it can still achieve PVI with efficiency and safety,and has the same post-ablation efficacy compared with conventional occlusion.The application of KODEX-EPD system in segmental cryoablation of IPVs can reduce the use of X-ray fluoroscopy. |
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