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.

Objective:To screen the risk factors for non-complete procedural success of transvenous lead extraction(TLE),and to establish a prediction model based on the results and evaluate its predictive efficacy.Methods:A total of 1 029 patients who underwent TLE in Peking University People's Hospital from January 2014 to December 2020 were enrolled and divided into training set(n=720)and validation set(n=309)using the random number method.There were no statistically significant differences among the variables in the training set and the validation set.The training set was divided into the complete procedural success(CPS)group(n=664)and the non-CPS group(n=56).Univariate analysis was employed to screen the relevant indicators of non-CPS,followed by binary logistic regression analysis to identify the independent risk factors of non-CPS.Subsequently,a predictive model and nomogram were constructed.The receiver operating characteristic(ROC)curve analysis was applied to evaluate the ability of the model to distinguish non-CPS from TLE patients in the training set and validation set.The Hosmer-Lemeshow goodness-of-fit test was used to assess the consistency between the predicted risk and the actual risk of the model.Results:Univariate analysis showed that the relevant variables with P<0.1 including the age at the first implantation of the lead,the number of leads extracted,the oldest dwell time of lead extracted,the presence of abandoned leads,non-manual traction for lead extracted,the number of extracted leads>3,bilateral lead implantation,and the indications for TLE.The binary logistic regression analysis revealed that the presence of abandoned leads(OR=2.252,95%CI:1.111-4.564,P=0.024),the oldest dwell time of the extracted leads(OR=1.009,95%CI:1.005-1.012,P<0.001),and the number of extracted leads>3(OR=3.177,95%CI:1.306-7.733,P=0.011)were independent risk factors for non-CPS of TLE.ROC curve analysis revealed that the area under the ROC curve(AUC)of the training set was 0.80(95%CI:0.75-0.85,P<0.001).The AUC of the validation set was 0.81(95%CI:0.72-0.90,P<0.001).The Hosmer-Lemeshow goodness-of-fit test indicated that the P values of both the training set(P=0.089)and the validation set(P=0.136)were greater than 0.05.Conclusions:The presence of abandoned leads,the oldest dwell time of lead extracted,and the number of extracted leads>3 are independent risk factors for non-CPS in patients undergoing TLE.The nomogram model based on the above factors has satisfactory predictive ability.

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 screen the risk factors for non-complete procedural success of transvenous lead extraction(TLE),and to establish a prediction model based on the results and evaluate its predictive efficacy.Methods:A total of 1 029 patients who underwent TLE in Peking University People's Hospital from January 2014 to December 2020 were enrolled and divided into training set(n=720)and validation set(n=309)using the random number method.There were no statistically significant differences among the variables in the training set and the validation set.The training set was divided into the complete procedural success(CPS)group(n=664)and the non-CPS group(n=56).Univariate analysis was employed to screen the relevant indicators of non-CPS,followed by binary logistic regression analysis to identify the independent risk factors of non-CPS.Subsequently,a predictive model and nomogram were constructed.The receiver operating characteristic(ROC)curve analysis was applied to evaluate the ability of the model to distinguish non-CPS from TLE patients in the training set and validation set.The Hosmer-Lemeshow goodness-of-fit test was used to assess the consistency between the predicted risk and the actual risk of the model.Results:Univariate analysis showed that the relevant variables with P<0.1 including the age at the first implantation of the lead,the number of leads extracted,the oldest dwell time of lead extracted,the presence of abandoned leads,non-manual traction for lead extracted,the number of extracted leads>3,bilateral lead implantation,and the indications for TLE.The binary logistic regression analysis revealed that the presence of abandoned leads(OR=2.252,95%CI:1.111-4.564,P=0.024),the oldest dwell time of the extracted leads(OR=1.009,95%CI:1.005-1.012,P<0.001),and the number of extracted leads>3(OR=3.177,95%CI:1.306-7.733,P=0.011)were independent risk factors for non-CPS of TLE.ROC curve analysis revealed that the area under the ROC curve(AUC)of the training set was 0.80(95%CI:0.75-0.85,P<0.001).The AUC of the validation set was 0.81(95%CI:0.72-0.90,P<0.001).The Hosmer-Lemeshow goodness-of-fit test indicated that the P values of both the training set(P=0.089)and the validation set(P=0.136)were greater than 0.05.Conclusions:The presence of abandoned leads,the oldest dwell time of lead extracted,and the number of extracted leads>3 are independent risk factors for non-CPS in patients undergoing TLE.The nomogram model based on the above factors has satisfactory predictive ability.

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 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 evaluate the strategy and clinical outcomes of reimplanting biventricular cardiac resynchronization therapy (Biv-CRT) devices after transvenous removal of coronary sinus left ventricular leads due to device-related infections. Methods:A retrospective analysis was conducted on the clinical data and surgical outcomes of all patients who underwent transvenous removal of infectious coronary sinus left ventricular leads and subsequent reimplantation of Biv-CRT devices at Peking University People's Hospital from January 2013 to December 2022.Follow-up was performed to assess the incidence of complications and all-cause mortality. Results:A total of 167 patients underwent coronary sinus left ventricular lead removal due to infection,removal was successful in 161 cases (96.4％) and failed in 6 cases (3.6％).Among the patients with successful removal,109 cases (67.7％) were scheduled for Biv-CRT device reimplantation.After a median time of 7 (5,7) days,6 cases (5.5％) of reimplantation failed,while 103 reimplantations (94.5％) were successful.Among these successful reimplantation cases,102 patients (99.0％) were through the right-side approach,and 1 case (1.0％) through the left-side approach due to bilateral pocket infections.Of the 161 patients with successful removal,58 cases (36.0％) did not undergo left ventricular lead reimplantation,including 39 cases (24.2％) where the initial indications for Biv-CRT were questionable or had resolved.During the one-year postoperative follow-up,among the 103 patients who had undergone Biv-CRT device reimplantation,7 patients (6.8％) died,1 patient (1.0％) experienced pocket infection,and 1 patient (1.0％) had right atrial lead dislodgment. Conclusions:Reimplantation of Biv-CRT devices after removal of coronary sinus left ventricular leads due to infections is feasible,with a high success rate,low complication rate,and low mortality rate for right-side approach implantation.Therefore,for patients re-evaluated to have indications for repeated Biv-CRT after lead removal,right-side reimplantation of the coronary sinus left ventricular lead should be recommended.

Objectives:To investigate the impact of reassessment and individualized reimplantation strategies on clinical outcomes in patients with cardiovascular implantable electronic device (CIED) infections following transvenous lead extraction (TLE).Methods:Patients who underwent TLE due to CIED infections at Peking University People's Hospital from January 2015 to January 2021 were included.Reimplantation decisions,including whether to reimplant and the type and location of the new device,were made based on patient history,infection type,and cardiac examination results.The reimplantation rate,device type,implantation site,and complications were recorded and analyzed.Results:A total of 993 patients were included in this study,of which 840 cases (84.6％) were pocket infections.Among the removed devices,827 cases (83.3％) were pacemakers.The clinical success rate of TLE was 98.3％ (976 cases),the perioperative mortality rate was 0.9％ (9 cases) .Excluding the perioperative death cases,out of 984 survived patients after reassessment,186 patients (18.9％) had no indication for reimplantation,69 patients (7.0％) refused reimplantation,and 729 patients (74.1％) opted for reimplantation.An individualized reimplantation strategy was developed according to their clinical situation.Devices were implanted in 703 patients (71.4％) on the contralateral side to reduce the risk of reinfection;leadless pacemakers (LP) were implanted in 24 patients (2.4％),and subcutaneous implantable cardioverter-defibrillators (S-ICD) were implanted in 2 patients (0.2％),based on specific indications.The rate of simultaneous reimplantation during TLE was 19.4％ (191/984),primarily among pacemaker-dependent patients with pocket infections.70 patients (7.1％) underwent device upgrade or downgrade.During a mean of (3.9±2.6) years follow-up,the all-cause mortality rate were 8.9％ (88 cases),and the pocket infection rate after reimplantation was 1.5％ (15 cases ) .Conclusions:Individualized reassessment after TLE for CIED infection patients can help optimize reimplantation decision-making and avoid unnecessary reimplantations and associated complications.The choice of reimplantation strategy should be strictly based on the clinical situations.Devices should preferably be re-implanted on the contralateral side to reduce reinfection risk.LP and S-ICD are suitable for patients with specific indications.Simultaneous reimplantation during TLE is feasible for some patients with pocket infections but further studies are required to evaluate the safety of this approach.

Objectives:To investigate the impact of reassessment and individualized reimplantation strategies on clinical outcomes in patients with cardiovascular implantable electronic device (CIED) infections following transvenous lead extraction (TLE).Methods:Patients who underwent TLE due to CIED infections at Peking University People's Hospital from January 2015 to January 2021 were included.Reimplantation decisions,including whether to reimplant and the type and location of the new device,were made based on patient history,infection type,and cardiac examination results.The reimplantation rate,device type,implantation site,and complications were recorded and analyzed.Results:A total of 993 patients were included in this study,of which 840 cases (84.6％) were pocket infections.Among the removed devices,827 cases (83.3％) were pacemakers.The clinical success rate of TLE was 98.3％ (976 cases),the perioperative mortality rate was 0.9％ (9 cases) .Excluding the perioperative death cases,out of 984 survived patients after reassessment,186 patients (18.9％) had no indication for reimplantation,69 patients (7.0％) refused reimplantation,and 729 patients (74.1％) opted for reimplantation.An individualized reimplantation strategy was developed according to their clinical situation.Devices were implanted in 703 patients (71.4％) on the contralateral side to reduce the risk of reinfection;leadless pacemakers (LP) were implanted in 24 patients (2.4％),and subcutaneous implantable cardioverter-defibrillators (S-ICD) were implanted in 2 patients (0.2％),based on specific indications.The rate of simultaneous reimplantation during TLE was 19.4％ (191/984),primarily among pacemaker-dependent patients with pocket infections.70 patients (7.1％) underwent device upgrade or downgrade.During a mean of (3.9±2.6) years follow-up,the all-cause mortality rate were 8.9％ (88 cases),and the pocket infection rate after reimplantation was 1.5％ (15 cases ) .Conclusions:Individualized reassessment after TLE for CIED infection patients can help optimize reimplantation decision-making and avoid unnecessary reimplantations and associated complications.The choice of reimplantation strategy should be strictly based on the clinical situations.Devices should preferably be re-implanted on the contralateral side to reduce reinfection risk.LP and S-ICD are suitable for patients with specific indications.Simultaneous reimplantation during TLE is feasible for some patients with pocket infections but further studies are required to evaluate the safety of this approach.