| Objective:The second-generation version of cryoballoon(CB2)has been proven to be a safe and effective tool in procedural and clinical outcomes.Electrical reconnections after pulmonary vein(PV)isolation have been considered the main responsible mechanism of recurrent atrial fibrillation(AF).However,data on the characteristics of repeat ablation for recurrent AF after CB2 is limited.The study aims to summarize the characteristics of repeat ablation for recurrent AF after CB2 and to investigate parameters predicting durable PV isolation.Methods:From January 2017 to September 2020,a total of 43 consecutive recurrent AF patients with prior successful CB2 ablation were retrospectively enrolled.All patients underwent pulmonary vein re-isolation and other inducible tachycardia by radiofrequency irrigation catheter.Number and location of reconnected PVs,reconnection sites,procedural characteristics were collected and the correlation between CB2 parameters and durable PV isolation was analyzed.Results:All PVs were successfully isolated during previous CB2 ablation.37 patients with 61 PVs exhibited PV-left atrium reconnection in the redo procedure,which include 22(52.4%)left superior PVs(LSPV),1(100%)left middle PV(LMPV),1(100%)left common PV(LCPV),11(26.2%)left inferior PV(LIPV),12(27.9%)right superior PVs(RSPV),and 14(32.6%)right inferior PVs(RIPV).The common reconnection sites were from top of LSPV(21.9%),bottom of RIPV(10.9%),posteroinferior part of right PV(9.4%),anterio-superior part of Left PV(9.4%),bottom of LIPV(7.8%),and posteroinferior part of left PV(7.8%).Compared to the PVs with durable isolation,more cryoballon application(2.2±1.2vs.1.6±0.7,P<0.001),longer time to isolation(TTI)(59.2±27.7s vs.40.4±22.2s,P<0.001),higher nadir temperature(-46.5±6.0?vs.-49.8±5.8?,P=0.001)were observed in PVs with electrical reconnection.TTI<50s predicted durable PV isolation with 75.5%sensitivity and 75%specificity.However,some parameters differed among the 4 individual PVs.For the LSPV,TTI<74s predicts predicted durable PV isolation with 88%sensitivity and 57%specificity.For the LIPV,the nadir temperature?-45? predicted higher PV isolation durability with 91%sensitivity and 57%specificity.For the RIPV,TTI?37s predicts predicted durable PV isolation with 100%sensitivity and 72%specificity and the nadir temperature?-45?predicted higher PV isolation durability with 50%sensitivity and 96%specificity.All PVs with electrical reconnection were successfully re-isolated.Additional radiofrequency ablation was applied in 19(44.2%)patients with other types of tachycardia including typical atrial flutter and atrial tachycardia from non-PV foci.Conclusions:The common reconnection sites after CB2 ablation were more frequent in the top and anteriosuperior part of Left PV,the bottom and posteroinferior part of both inferior PV.TTI<50s predicted absence of durable PV isolation.In the repeat ablation,additional ablation of non-PV foci and atrial flutter should be addressed.Objective:The second-generation version of cryoballoon(CB2)has showed significant improvement in the efficacy of cryoablation.However,whether elderly patients with atrial fibrillation(AF)can withstand the CB2 ablation procedure remains to be explored.In this study,we aim to evaluate the efficacy and safety in elderly patients over 75 years old.Methods:Our study divided the symptomatic AF patients undergoing CB2 ablation into two groups by the age of submission:elderly group with 75 years and older,younger group with 65 years old below.The patients of both groups were matched according to propensity score method(107 patients for each).The cryoablation procedure and follow-up data were retrospectively analyzed,and the long-term AF recurrence rate and incidence of perioperative period complications were compared between the elderly group and younger group.Results:The mean age in the elderly group was 76.8±2.2years and 57.6±9.2 in the younger group.All PVs were successfully isolated in the procedure.Compared to the younger group,less cryoballon applications in right supper pulmonary vein(RSPV)and right inferior pulmonary vein(RIPV)(RSPV:1.5±0.6vs.2.0±1.0,P<0.0001;RIPV:1.9±1.1vs.2.3±1.1,P<0.05),shorter procedure time(52.0±16.6minvs.57.7±16.5min,P<0.05)were observed in elderly group and time to isolation(TTI),nadir temperature,rate of need for touch-up ablation,X-ray fluoroscopy time were comparable between two groups.After average 19.3±9.2 months follow-up,there was no significant difference in the total success rate between the elderly group and the younger group(71.0%VS.72.9%,Log-Rank test,95%CI,P=O.729).In subgroup analyses,the success rate of persistent AF was significantly lower than paroxysmal AF(61.2%vs.76.9%,P=0.028).The incidence of perioperative complications was 26.2%and 24.3%(P=0.753)in the elderly and younger groups respectively.Conclusions:CB2 is a safe and effective tool in elderly patients over 75 years,with similar success and perioperative complications rate when compared with younger patients.Objective:The complete occlusion of inferior pulmonary vein(PV)is always the main difficulty in cryoballoon ablation.It is reported than less than half inferior pulmonary vein can achieve complete occlusion in one shot and quite a few inferior pulmonary veins ultimately need touch-up ablation.Electrical reconnections after PV isolation have been considered the main responsible mechanism of recurrent atrial fibrillation(AF)and inferior pulmonary vein is lower in PV isolation durability than superior pulmonary vein.The second-generation version of cryoballoon(CB2)have not shown significant improvement in the cryoablation of inferior pulmonary veins.Segmental ablation approach is to separately ablate the superior branch and inferior branch of inferior PV for PV isolation.In this study,we aim to investigate the efficacy and safety of segmental ablation approach by second generation cryoballoon for the inferior PV.Methods:From June 2019 to June 2020,a total of 124 consecutive symptomatic atrial fibrillation(AF)patients were enrolled in this study.Patients were assigned two groups by the different ablation strategy in inferior PV:complete occlusion group and segmental ablation group.The comparsion of cryoablation parameters and complication rates were analyzed between complete occlusion group and segmental ablation group.Results:124 patients were involved in this study,40 in the segmental ablation group and 80 in the complete occlusion group.All PVs were successfully isolated in the procedure.Compared to the complete occlusion group,the segmental ablation group had less cryoballon applications in inferior PV(4.0±1.4vs.4.6±0.7,P=0.027),higher nadir temperature(-49.4±6.2?vs.-47.5±6.1?,P<0.005),and the total cryoballon applications,time to isolation(TTI),nadir temperature,procedure time,X-ray fluoroscopy time were comparable between two groups.In subgroup analyses,while no touch-up ablation needs was required in segmental ablation group,the rate of touch-up ablation in complete occlusion group is 2.4%,however,without achieving statistical difference(P=0.161).Compared to the complete occlusion group,the segmental ablation group had higher nadir temperature in both left inferior PV(LIPV)and right inferior PV(RIPV)(LIPV:-45.3±5.1°Cvs.-42.6±5.7?,P<0.01;RIPV:-48.7±5.5?vs.-46.2±5.9,P=0.029),less cryoballon applications in LIPV(1.8±0.7vs.2.1±0.4,P<0.05),higher proportion of PV isolation within two cryoablation.The incidence of perioperative complication was comparable between two groups and there was no occurrence of phrenic nerve paralysis in segmental ablation group.Conclusions:Segmental ablation approach by CB2 is a safe and effective strategy for the inferior PVs with a slight increase in cryoballon applications in inferior PV. |
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