Objectives:To evaluate the performance of AVEIR VR single chamber leadless pacemaker(AVEIR VR)in the real world in China and the predictive factors of pacing threshold to assess the feasibility of AVEIRTM VR implantation in the domestic population.Methods:All patients who underwent AVEIR VR implantation by experienced operators from Peking University People's Hospital in multiple domestic hospitals from June 2024 to October 2024 were consecutively included,and their baseline characteristics,procedural data(including pacemaker electrical measurements at various stages),and follow-up results were observed,recorded,and statistically analyzed.Results:This study included 20 patients who met the indication for pacemaker implantation and underwent AVEIR VR implantation.Their mean age was(71.40±13.37)years,body mass index(BMI)was(23.05±3.71)kg/m2,body surface area(BSA)was(1.70±0.16)m2,all 20 patients were successfully implanted with pacemakers,there were no major complications(newly occurred pericardial effusion during the perioperative period,cardiac tamponade,poor pacemaker function,pacemaker dislocation/perforation,tricuspid valve injury,myocardial infarction,stroke,pulmonary embolism,and clinical death).One patient developed new frequent ventricular premature contractions after pacemaker release.The pacing threshold(PCT)at one week after implantation was correlated with PCT in tether mode(r=0.650,P=0.009)and PCT in release phase(r=0.596,P=0.019),but not with the sensing and impedance in each phase.Conclusions:This preliminary exploration study show that AVEIRTM VR implantation demonstrates satisfactory performance among real world patients in China,especially in elderly and low weight populations,confirming its safety.

Objective:To evaluate the clinical feasibility of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation following transvenous lead extraction (TLE).Methods:This was a retrospective study. Consecutive patients who underwent S-ICD implantation at Peking University People′s Hospital between June 2015 and October 2023 were enrolled. Patients were divided into the TLE group and the newly implanted group based on whether they received TLE prior to S-ICD implantation. Baseline characteristics, S-ICD indication, defibrillation threshold test results, complications, and postoperative follow-up data were collected and compared between the two groups.Results:A total of 27 patients were included, aged (49.2±14.2) years, including 19 males. There were 12 patients in the TLE group and 15 in the newly implanted group. Compared with the TLE group, patients in the newly implanted group were younger ((43.3±13.7) years vs. (55.6±12.0) years, P=0.013). The main S-ICD indication in the TLE group was high infection risk (9/12), whereas in the newly implanted group it was younger age (11/15). All patients underwent successful S-ICD implantation, with 18 patients completing defibrillation threshold testing (all successful). Additionally, the TLE group had longer follow-up duration than the newly implanted group (42 (19, 60) months vs. 12 (3, 28) months, P=0.001). No complications or deaths occurred during follow-up, with normal device function in both groups. A total of 17 ventricular tachycardia or fibrillation events were recorded, of which 7 met defibrillation criteria and all received effective therapy. Conclusion:S-ICD demonstrates safety and efficacy as a therapeutic option for patients after TLE, with comparable device functionality and follow-up outcomes to patients with newly implanted S-ICD.

Objective:To evaluate the incidence and frequency of inappropriate shocks caused by defibrillation lead failure in patients with implantable cardioverter-defibrillators (ICD), and to explore methods for reducing the incidence and frequency of such inappropriate shocks.Methods:This was a single-center retrospective study involving patients treated for defibrillation lead failures at Peking University People′s Hospital between March 2015 and May 2024. Patients were divided into an alarm function group and a non-alarm function group based on whether their ICDs were equipped with lead alarm functions. Clinical data, lead data, and the incidence and frequency of inappropriate shocks were collected and compared between the two groups. A multivariate logistic regression model was used to analyze factors influencing the incidence and frequency of inappropriate ICD shocks. Kaplan-Meier survival curves were plotted to compare the trends in the incidence and frequency of inappropriate shocks over time since ICD implantation between the two groups.Results:A total of 59 patients were enrolled, with a age of (56.7±15.2) years, including 42 males (71%). The lifespan of the failed leads in the entire cohort was 64.0 (36.0, 96.0) months. There were 26 patients in the alarm function group and 33 in the non-alarm function group. The most common manifestations of lead failure were oversensing (85%, 50/59) and abnormal pacing impedance (42%, 25/59). A total of 33 patients (56%, 33/59) experienced inappropriate shock therapy, with an average of 27.3 shocks per patient. The frequency of inappropriate ICD shocks in the non-alarm function group was higher than that in the alarm function group (25.0 (10.0, 60.0) times/year vs. 5.0 (2.8, 7.8) times/year, P=0.001). Multivariate logistic regression analysis showed that oversensing ( OR=2.057, 95% CI 1.125-6.763, P=0.019) was an influencing factor for incidence of inappropriate shocks, while the lead alert function ( OR=0.062, 95% CI 0.005-0.719, P=0.001) was a factor influencing the frequency of inappropriate shocks. Kaplan-Meier survival analysis revealed that the incidence and frequency of inappropriate shocks increased with the duration of ICD implantation in both groups, but the differences were not statistically significant (incidence: log-rank P=0.908; frequency: log-rank P=0.767). Conclusion:The lead alert function can reduce the frequency of inappropriate shocks caused by lead failure.

Objectives:To analyze the clinical characteristics,strategies,success and complication rates of lead extraction and re-implantation during the upgrade of cardiovascular implantable electronic devices(CIED)in non-infectious patients.Methods:This retrospective study collected and analyzed the baseline clinical data and surgical data of 66 non-infected patients who had their existing CIEDs(including cardiac pacemaker,implantable cardioverter defibrillator[ICD],cardiac resynchronization therapy pacemaker[CRT-P])upgraded to ICD or CRT-P or cardiac resynchronization therapy defibrillator(CRT-D)or subcutaneous implantable cardioverter defibrillator(S-ICD)in Peking University People's Hospital from March 2018 to March 2024.We analyzed the strategies of lead extraction and reimplantation as well as the operation success rate and complication rate.Results:Among the 66 patients,preoperative imaging revealed that 12 patients(18.2%)had severe stenosis/occlusion of the venous access route,with lead wear/perforation in 26 patients(39.4%).32 patients(48.5%)underwent transvenous lead extraction(TLE),of which all leads were removed in 27 patients(84.4%),and only non-functional leads were removed in 5 patients(15.6%).The success rate of the TLE procedure was 100%and no complication occurred.Among the 66 patients,functional leads retained and new leads were implanted on the same side in 28 patients(42.4%),all leads were removed and new leads were reimplanted on the opposite side in 22 patients(33.3%),only non-functional leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),all leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),and 6 patients(9.1%)had the leads abandoned and then were re-implanled.The success rate of the upgrade surgery was 100%,no complications were reported.Conclusions:When the existing CIEDs(including cardiac pacemaker,ICD,CRT-P)of non-infected patients are upgraded to ICD,CRT-P,CRT-D or S-ICD,lead extraction and reimplantation are safe and feasible,and reimplantation can be performed on the ipsilateral or contralateral side.

Objectives:To evaluate the performance of AVEIR VR single chamber leadless pacemaker(AVEIR VR)in the real world in China and the predictive factors of pacing threshold to assess the feasibility of AVEIRTM VR implantation in the domestic population.Methods:All patients who underwent AVEIR VR implantation by experienced operators from Peking University People's Hospital in multiple domestic hospitals from June 2024 to October 2024 were consecutively included,and their baseline characteristics,procedural data(including pacemaker electrical measurements at various stages),and follow-up results were observed,recorded,and statistically analyzed.Results:This study included 20 patients who met the indication for pacemaker implantation and underwent AVEIR VR implantation.Their mean age was(71.40±13.37)years,body mass index(BMI)was(23.05±3.71)kg/m2,body surface area(BSA)was(1.70±0.16)m2,all 20 patients were successfully implanted with pacemakers,there were no major complications(newly occurred pericardial effusion during the perioperative period,cardiac tamponade,poor pacemaker function,pacemaker dislocation/perforation,tricuspid valve injury,myocardial infarction,stroke,pulmonary embolism,and clinical death).One patient developed new frequent ventricular premature contractions after pacemaker release.The pacing threshold(PCT)at one week after implantation was correlated with PCT in tether mode(r=0.650,P=0.009)and PCT in release phase(r=0.596,P=0.019),but not with the sensing and impedance in each phase.Conclusions:This preliminary exploration study show that AVEIRTM VR implantation demonstrates satisfactory performance among real world patients in China,especially in elderly and low weight populations,confirming its safety.

Objectives:To analyze the clinical characteristics,strategies,success and complication rates of lead extraction and re-implantation during the upgrade of cardiovascular implantable electronic devices(CIED)in non-infectious patients.Methods:This retrospective study collected and analyzed the baseline clinical data and surgical data of 66 non-infected patients who had their existing CIEDs(including cardiac pacemaker,implantable cardioverter defibrillator[ICD],cardiac resynchronization therapy pacemaker[CRT-P])upgraded to ICD or CRT-P or cardiac resynchronization therapy defibrillator(CRT-D)or subcutaneous implantable cardioverter defibrillator(S-ICD)in Peking University People's Hospital from March 2018 to March 2024.We analyzed the strategies of lead extraction and reimplantation as well as the operation success rate and complication rate.Results:Among the 66 patients,preoperative imaging revealed that 12 patients(18.2%)had severe stenosis/occlusion of the venous access route,with lead wear/perforation in 26 patients(39.4%).32 patients(48.5%)underwent transvenous lead extraction(TLE),of which all leads were removed in 27 patients(84.4%),and only non-functional leads were removed in 5 patients(15.6%).The success rate of the TLE procedure was 100%and no complication occurred.Among the 66 patients,functional leads retained and new leads were implanted on the same side in 28 patients(42.4%),all leads were removed and new leads were reimplanted on the opposite side in 22 patients(33.3%),only non-functional leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),all leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),and 6 patients(9.1%)had the leads abandoned and then were re-implanled.The success rate of the upgrade surgery was 100%,no complications were reported.Conclusions:When the existing CIEDs(including cardiac pacemaker,ICD,CRT-P)of non-infected patients are upgraded to ICD,CRT-P,CRT-D or S-ICD,lead extraction and reimplantation are safe and feasible,and reimplantation can be performed on the ipsilateral or contralateral side.

Objective:To evaluate the clinical feasibility of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation following transvenous lead extraction (TLE).Methods:This was a retrospective study. Consecutive patients who underwent S-ICD implantation at Peking University People′s Hospital between June 2015 and October 2023 were enrolled. Patients were divided into the TLE group and the newly implanted group based on whether they received TLE prior to S-ICD implantation. Baseline characteristics, S-ICD indication, defibrillation threshold test results, complications, and postoperative follow-up data were collected and compared between the two groups.Results:A total of 27 patients were included, aged (49.2±14.2) years, including 19 males. There were 12 patients in the TLE group and 15 in the newly implanted group. Compared with the TLE group, patients in the newly implanted group were younger ((43.3±13.7) years vs. (55.6±12.0) years, P=0.013). The main S-ICD indication in the TLE group was high infection risk (9/12), whereas in the newly implanted group it was younger age (11/15). All patients underwent successful S-ICD implantation, with 18 patients completing defibrillation threshold testing (all successful). Additionally, the TLE group had longer follow-up duration than the newly implanted group (42 (19, 60) months vs. 12 (3, 28) months, P=0.001). No complications or deaths occurred during follow-up, with normal device function in both groups. A total of 17 ventricular tachycardia or fibrillation events were recorded, of which 7 met defibrillation criteria and all received effective therapy. Conclusion:S-ICD demonstrates safety and efficacy as a therapeutic option for patients after TLE, with comparable device functionality and follow-up outcomes to patients with newly implanted S-ICD.

Objective:To evaluate the incidence and frequency of inappropriate shocks caused by defibrillation lead failure in patients with implantable cardioverter-defibrillators (ICD), and to explore methods for reducing the incidence and frequency of such inappropriate shocks.Methods:This was a single-center retrospective study involving patients treated for defibrillation lead failures at Peking University People′s Hospital between March 2015 and May 2024. Patients were divided into an alarm function group and a non-alarm function group based on whether their ICDs were equipped with lead alarm functions. Clinical data, lead data, and the incidence and frequency of inappropriate shocks were collected and compared between the two groups. A multivariate logistic regression model was used to analyze factors influencing the incidence and frequency of inappropriate ICD shocks. Kaplan-Meier survival curves were plotted to compare the trends in the incidence and frequency of inappropriate shocks over time since ICD implantation between the two groups.Results:A total of 59 patients were enrolled, with a age of (56.7±15.2) years, including 42 males (71%). The lifespan of the failed leads in the entire cohort was 64.0 (36.0, 96.0) months. There were 26 patients in the alarm function group and 33 in the non-alarm function group. The most common manifestations of lead failure were oversensing (85%, 50/59) and abnormal pacing impedance (42%, 25/59). A total of 33 patients (56%, 33/59) experienced inappropriate shock therapy, with an average of 27.3 shocks per patient. The frequency of inappropriate ICD shocks in the non-alarm function group was higher than that in the alarm function group (25.0 (10.0, 60.0) times/year vs. 5.0 (2.8, 7.8) times/year, P=0.001). Multivariate logistic regression analysis showed that oversensing ( OR=2.057, 95% CI 1.125-6.763, P=0.019) was an influencing factor for incidence of inappropriate shocks, while the lead alert function ( OR=0.062, 95% CI 0.005-0.719, P=0.001) was a factor influencing the frequency of inappropriate shocks. Kaplan-Meier survival analysis revealed that the incidence and frequency of inappropriate shocks increased with the duration of ICD implantation in both groups, but the differences were not statistically significant (incidence: log-rank P=0.908; frequency: log-rank P=0.767). Conclusion:The lead alert function can reduce the frequency of inappropriate shocks caused by lead failure.

Objectives:To evaluate the safety and efficacy of implantation of subcutaneous implantable cardioverter defibrillator(S-ICD)after transvenous lead extraction(TLE)in ICD patients without pacing indications. Methods:All patients who underwent TLE at Peking University People's Hospital from June 2018 to October 2023 were consecutively included.TLE indication,S-ICD implantation indication,defibrillation threshold(DFT)test,complications and postoperative follow-up were collected and analyzed. Results:A total of 11 patients with TV-ICD underwent S-ICD implantation after TLE,eight patients were males and median age were 56(44,65)years.The indications for TLE were infection and lead dysfunction.Nine patients were implanted with S-ICD for secondary prevention,and the most common cause of implantation was ion channelopathies(5 cases).The operative time for S-ICD was 51(48,58)minutes and no perioperative complications were noted.Eight patients underwent DFT testing,and 100%were successful.During a median follow up of 30(9,39)months,a total of six appropriate treatments occurred in two patients,and no complications occurred,including inappropriate treatment,ineffective treatment,infection,lead malfunction and death. Conclusions:Our study provides evidence for S-ICD implantation as a replacement after TV-ICD removal.The S-ICD implantation after TLE is safe and effective.

Objectives:To assess the clinical characteristics and lead extraction in patients with venous occlusion related to infection of cardiovascular implantable electronic devices. Methods:Clinical data of 405 patients(147 men,mean age[62.4±13.2]years)who underwent lead extraction from January 2020 to January 2024 in Peking University People's Hospital were reviewed.Contrast venography of the access vein was retrospectively analyzed.The patients were divided into venous occlusion group(n=119)and non-venous occlusion group(n=286)according to the presence or absence of venous occlusion.The clinical characteristics and lead extraction of patients in two groups were analyzed. Results:Occlusion of the access vein occurred in 119 patients(29.4%).The subclavian vein was occluded in 48 cases(40.3%),brachiocephalic vein was occluded in 37 cases(31.1%),axillary vein was occluded in 30 cases(25.2%),superior vena cava was occluded in 4 cases(3.4%).There were no significant differences between venous occlusion group and non-venous occlusion group in terms of age,sex,device type,number of leads,or anticoagulation therapy(all P>0.05).Time from implant of the initial leads was significantly longer in the venous occlusion group than in the non-venous occlusion group([10.4±3.8]years vs.[5.9±4.1]years,P=0.042).Clinical extraction success rate and complications were similar between the venous occlusion group and the non-venous occlusion group(both P>0.05).Procedural duration and fluoroscopy exposure time were significantly lower in non-venous occlusion group than in the venous occlusion group(both P<0.05).Patients in the venous occlusion group required more advanced tools(such as laser sheaths,evolution sheaths,and needle's eye snares)for lead extraction compared to patients in the non-venous occlusion group(84.0%vs.67.1%,P=0.001). Conclusions:The incidence of venous occlusion related to infection of cardiovascular implantable electronic devices is 29.4%.Time from implant of the initial leads is significantly longer and lead extraction is more difficult in patients with venous occlusion,and requires more advanced tools and more time to achieve the successful lead extraction.