Evaluation of the in vivo chemical reactivity of a novel copolymer insulation on cardiac leads in a single-center study.

BACKGROUND: Human in vivo data on the chemical stability of different transvenous lead materials, particularly OptimTM leads, are lacking. OBJECTIVES: The purpose of this study was to determine the chemical reactivity of insulation materials by analyzing the molar mass of extracted pacing and defibrillator leads METHODS: We collected extracted leads at Emory University Hospitals and sent the leads with thermoplastic outer insulation material for molar mass analysis, a material characteristic that informs biostability. Leads were separated based on the chemical identity of the outer insulation material, and the molar mass was measured by an independent party. The extent of chemical reaction was compared across leads having different materials: poly(ether)urethane 55D, poly(ether)urethane 80A, and Optim. RESULTS: A total of 70 leads were extracted. The subset of extracted leads having outer insulation materials composed of PEU or Optim were analyzed for molar mass, where implant times ranged from 0.12 to 16.26 years. The rate of chemical degradation was compared by plotting the extent of reaction [Mn(t = 0)/Mn(t)] as a function of implant time. The Optim molar mass decreased to 40% of its initial value at 10 years of implant. No change in the molar mass of the PEU insulations could be resolved over the same 10-year implant time. CONCLUSION: Because the molar mass of a polymer is directly related to its mechanical integrity, the observed decrease in molar mass of Optim likely translates into premature insulation defects and is consistent with the observed increased rate of electrical malfunction/noise in this subset of cardiac leads.

Implantable cardioverter-defibrillator lead failure and revision following transcutaneous bicaval valve (TricValve®) implantation.

INTRODUCTION: Tricuspid regurgitation is associated with significant morbidity and mortality, and occurs at a higher rate in patients with cardiovascular implantable electronic devices. Percutaneous strategies for managing tricuspid regurgitation are evolving, including the development of bicaval valve implantation which has been successfully used in patients with pacing leads. METHODS AND RESULTS: We present the first documented case of lead failure following TricValve® implantation, a dedicated self-expanding system for bicaval valve implantation, and the first successful lead revision procedure in this setting. CONCLUSION: The case illustrates important considerations in undertaking percutaneous intervention in patients with cardiovascular implantable electronic devices, and their ongoing management.

Single-Chamber and Dual-Chamber Pacemaker Devices in Adults with Moderate and Complex Congenital Heart Disease: A Single Tertiary Referral Center Experience.

The number of device implantation procedures has increased in adult patients with congenital heart disease (ACHD). Despite significant improvements in materials and implantation techniques, these patients are exposed to higher risk of device related complications than general population. Herein, we describe our single tertiary referral center experience on transvenous pacemaker (PM) implantation and follow-up in adult patients with moderate and complex congenital heart disease (CHD) as limited data are available on long-term outcome. We considered all adults with moderate and complex CHD aged more than 16 years who underwent transvenous single-chamber and dual-chamber PM implant for sinus node dysfunction or atrioventricular block between January 2013 to December 2022 at our Unit. Seventy-one ACHD patients were included in the study (mean age 38.6 ± 15.2 years, 64% with moderate CHD, 36% with complex CHD). Among 32 patients implanted with a dual chamber PM (DDD PM), 4 devices were reprogrammed in VDD mode, 3 in VVI and 2 in AAI mode during follow-up because of lead dysfunction or permanent atrial arrhythmia. In addition, 26 patients had a single chamber PM (AAI or VVI PM) and 13 patients had single-lead pacing system with a free-floating atrial electrode pair (VDD PM). Just one of 13 single-lead VDD PM was reprogrammed in VVI mode due to a low atrial sensing. In DDD PM group, 10 re-interventions were needed due to lead dysfunction (8 cases) and lead-related infective endocarditis (2 cases). Only 3 patients in the single-lead PM group developed lead dysfunction with 2 re-interventions needed, but no infective endocarditis was reported. The rate of long-term complications is high in moderate and complex ACHD with transvenous PM devices, and it is mainly lead-related. In our experience, the less leads implanted, the less complications will occur. Considering the heterogeneity of the ACHD population, transvenous single-chamber or dual-chamber PM device implantation should always be tailored on the single patient, balancing risks and benefits in this complex population.

Long-term performance of single-connector (DF4) implantable defibrillator leads.

AIMS: Single-connector (DF4) defibrillator leads have become the predominantly implanted transvenous implantable cardioverter-defibrillator lead. However, data on their long-term performance are derived predominantly from manufacturer product performance reports. METHODS AND RESULTS: We reviewed medical records in 5289 patients with DF4 leads between 2011 and 2023 to determine the frequency of lead-related abnormalities. We defined malfunction as any single or combination of electrical abnormalities requiring revision including a sudden increase (≥2×) in stimulation threshold, a discrete jump in high-voltage impedance, or sensing of non-physiologic intervals or noise. We documented time to failure, predictors of failure, and management strategies. Mean follow-up after implant was 4.15 ± 3.6 years (median = 3.63), with 37% of leads followed for >5 years. A total of 80 (1.5%) leads demonstrated electrical abnormalities requiring revision with an average time to failure of 4 ± 2.8 years (median = 3.5). Of the leads that malfunctioned, 62/80 (78%) were extracted and replaced with a new lead and in the other 18 cases, malfunctioned DF4 leads were abandoned, and a new lead implanted. In multivariable models, younger age at implant (OR 1.03 per year; P < 0.001) and the presence of Abbott/St. Jude leads increased the risk of malfunction. CONCLUSION: DF4 defibrillator leads demonstrate excellent longevity with >98.3% of leads followed for at least 5 years still functioning normally. Younger age at implant and lead manufacturer are associated with an increased risk of DF4 lead malfunction. The differences in lead survival between manufacturers require further investigation.

Long-term follow-up of patients undergoing add-on pacing/sensing lead vs. ICD lead implantation for failed IS-1/DF-1 ICD leads: a single centre experience.

BACKGROUND: Intracardiac defibrillator/cardioverter (ICD) is a cornerstone device for prevention of sudden cardiac death. Lead failure (LF) is one of the most important long-term complications. In this study, we sought to investigate mid-to-long term clinical, device and lead characteristics of patients who have undergone pacing sensing lead (PSL) implantation for an ICD LF and compare them to the patients who have undergone a new ICD lead implantation. METHODS: In this retrospective, single centre, case-control study, we have screened all ICD patients presenting with LF. Patients with IS-1/DF-1 ICD leads with intact high-voltage conductor were included in the study group, while other patients were included in the control arm. Study group patients underwent PSL implantation, control group patients underwent ICD lead implantation. RESULTS: Thirty patients were included in each arm of the study. The mean duration of follow-up after intervention was similar in both groups (47.6 months ± 20.4 vs. 46.1 months ± 25.7, p = .808). The total failure rate was not different between two groups (p = .640). Rate of high-voltage conductor disfunction was also similar between two arms: 1 (3.3%) in PSL arm and 0 in control arm (p = .303). CONCLUSIONS: Addition of a PSL for IS-1/DF-1 ICD LF with normal high-voltage conductor measurements is a viable treatment option with similar long-term results to addition of a new ICD lead. This approach is potentially less costly, technically less demanding, and, in case of concomitant extraction procedure, associated with less acute complication risk.

Prevalence and management of electrical lead abnormalities in cardiac implantable electronic device leads.

Background: Electrical lead abnormalities (ELAs) can result in device malfunction, leading to significant morbidity in patients with cardiac implantable electronic devices (CIEDs). Objective: We sought to determine the prevalence and management of ELAs in patients with CIEDs. Methods: This was a retrospective cohort study of patients implanted with a CIED between 2012 and 2019 at a tertiary care center. The primary outcome was ELA defined as increased capture threshold (≥2× implantation value), decreased sensing (≤0.5 implantation value), change in impedance (>50% over 3 months), or nonphysiologic potentials. A secondary outcome of device clinic utilization was also collected. Results: There were 2996 unique patients (35% female) included with 4600 leads (57% Abbott, 43% Medtronic). ELAs were observed in 135 (3%) leads, including 124 (92%) Abbott and 10 (7%) Medtronic leads (hazard ratio 9.25, P < .001). Mean follow-up was 4.5 ± 2.2 years. ELAs were associated smaller lead French size, atrial location, and Abbott leads. Lead revision was required in 28% of cases. Patients with lead abnormalities had 38% more in-clinic visits per patient year of follow-up compared with those without (P < .001). Conclusion: ELAs were more frequent in certain models, which increased rates of revision and follow-up. Identification of factors that mitigate these abnormalities to improve lead performance are required to improve care for these devices and provide efficient healthcare.

Impact of fracture-prone implantable cardioverter defibrillator leads on long-term patient mortality.

Background: The long-term relationship between fracture-prone implantable cardioverter-defibrillator (ICD) leads and poor prognosis remains unclear in Japanese patients. Methods: We conducted a retrospective review of the records of 445 patients who underwent implantation of advisory/Linox leads (Sprint Fidelis, 118; Riata, nine; Isoline, 10; Linox S/SD, 45) and non-advisory leads (Endotak Reliance, 33; Durata, 199; Sprint non-Fidelis, 31) between January 2005 and June 2012 at our hospital. The primary outcomes were all-cause mortality and ICD lead failure. The secondary outcomes were cardiovascular mortality, heart failure (HF) hospitalization, and the composite outcome of cardiovascular mortality and HF hospitalization. Results: During the follow-up period (median, 8.6 [4.1-12.0] years), there were 152 deaths: 61 (34%) in patients with advisory/Linox leads and 91 (35%) in those with non-advisory leads. There were 32 ICD lead failures: 27 (15%) in patients with advisory/Linox leads and five (2%) in those with non-advisory leads. Multivariate analysis for ICD lead failure demonstrated that the advisory/Linox leads had a 6.65-fold significantly greater risk of ICD lead failure than non-advisory leads. Congenital heart disease (hazard ratio 2.51; 95% confidence interval 1.08-5.83; p = .03) could also independently predict ICD lead failure. Multivariate analysis for all-cause mortality demonstrated no significant association between advisory/Linox leads and all-cause mortality. Conclusions: Patients who have implanted fracture-prone ICD leads should be carefully followed up for ICD lead failure. However, these patients have a long-term survival rate comparable with that of patients with non-advisory ICD leads in Japanese patients.

Transcatheter Leadless Pacing in Children: A PACES Collaborative Study in the Real-World Setting.

BACKGROUND: Transcatheter Leadless Pacemakers (TLP) are a safe and effective option for adults with pacing indications. These devices may be an alternative in pediatric patients and patients with congenital heart disease for whom repeated sternotomies, thoracotomies, or transvenous systems are unfavorable. However, exemption of children from clinical trials has created uncertainty over the indications, efficacy, and safety of TLP in the pediatric population. The objectives of this study are to evaluate clinical indications, procedural characteristics, electrical performance, and outcomes of TLP implantation in children. METHODS: Retrospective data were collected from patients enrolled in the Pediatric and Congenital Electrophysiology Society TLP registry involving 15 centers. Patients ≤21 years of age who underwent Micra (Medtronic Inc, Minneapolis, MN) TLP implantation and had follow-up of ≥1 week were included in the study. RESULTS: The device was successfully implanted in 62 of 63 registry patients (98%) at a mean age of 15±4.1 years and included 20 (32%) patients with congenital heart disease. The mean body weight at TLP implantation was 55±19 kg and included 8 patients ≤8 years of age and ≤30 kg in weight. TLP was implanted by femoral (n=55, 87%) and internal jugular (n=8, 12.6%) venous approaches. During a mean follow-up period of 9.5±5.3 months, there were 10 (16%) complications including one cardiac perforation/pericardial effusion, one nonocclusive femoral venous thrombus, and one retrieval and replacement of TLP due to high thresholds. There were no deaths, TLP infections, or device embolizations. Electrical parameters, including capture thresholds, R wave sensing, and pacing impedances, remained stable. CONCLUSIONS: Initial results from the Pediatric and Congenital Electrophysiology Society TLP registry demonstrated a high level of successful Micra device implants via femoral and internal venous jugular approaches with stable electrical parameters and infrequent major complications. Long-term prospective data are needed to confirm the reproducibility of these initial findings.

Performance of an implantable cardioverter-defibrillator lead family.

BACKGROUND: Lead failure is the major limitation in implantable cardioverter-defibrillator (ICD) therapy. Long-term follow-up data for Biotronik Linox ICD leads are limited. Therefore, we analyzed the performance of all these leads implanted at our institution. MATERIALS AND METHODS: All Linox and Linox Smart ICD leads implanted between 2006 and 2015 were identified. Lead failure was defined as electrical dysfunction (oversensing, abnormal impedance, exit block). Lead survival was described, according to Kaplan-Meier. Associations between lead failure and specific variables were examined. p < .05 was considered significant. RESULTS: We included 417 ICD leads. The median follow-up time for Linox (n = 205) was 81 months and for Linox Smart (n = 212) 75 months. During that follow-up time, 30 Linox (14.6%) and 16 Linox Smart leads (7.6%) showed a malfunction. The 5-year lead survival probability was 97.4% for Linox and 95.2% for Linox Smart (log-rank test, p = .19). The 6- and 8-year lead survival probability for Linox was 93.6% and 84.6%, and for Linox Smart 93% and 91.9%. The only factor significantly associated with lead failure was younger patient age at implantation (hazard ratio/year: 0.97, 95% CI: 0.94-0.99, p = .002). CONCLUSION: This relatively large study with a long follow-up period highlights a relevant failure rate of Biotronik Linox leads. The performance of Linox versus Linox Smart ICD leads was comparable. Although we show an acceptable 5-year lead survival probability, we observed a marked drop after just 1 more year of follow-up. In an era of improving heart failure survival probability, a prolonged follow-up of ICD leads is increasingly clinically relevant.

Synchronous atrioventricular sequential pacing utilizing conventional and leadless pacemakers in an elderly patient: a case report.

Background: Leadless pacemakers present a viable alternative to conventional transvenous devices to mitigate the risk of lead- and/or pocket-related complications. In elderly patients who have encountered ventricular lead failures with transvenous pacemakers, this option may enable the delivery of atrioventricular synchronous pacing therapy, while obviating the requirement for lead extraction and lead-based pacemaker re-implantation. Case summary: This case report describes the successful implantation of a leadless pacemaker in a 90-year-old who had undergone two dual-chamber permanent pacemaker implantation procedures with a failure of three of four previously implanted leads. Atrioventricular synchronous pacing was achieved, as the leadless device was able to track the atrial-paced rhythm from the pre-existing right-sided device. Discussion: In elderly patients who have encountered issues with transvenous pacemakers, alternative approaches should be considered to mitigate the risk of future complications. Leadless pacemakers may offer a low-risk solution, enabling the delivery of atrioventricular synchronous pacing therapy in such patient groups. Future studies should be designed to delineate whether these devices could be utilized as a first-line approach in certain situations.

Rationale for and use of the lumenless 3830 pacing lead.

Most currently available pacing and defibrillation leads utilize a stylet-based design that facilitates implantation. This has advantages, but also increases the lead diameter and adds the potential for metal fatigued-based conductor failure. A systematic literature search was conducted, and the authors add their twenty-year experience with this lead design. The global experience with lumenless leads was reviewed both for "standard" positioning and with conduction system pacing. Methods for both placement and system modification are reviewed. Lumenless leads have the potential to improve the durability of endocardial pacing and facilitate conduction system pacing.

Cardiovascular implantable electronic device lead safety: Harnessing real-world remote monitoring data for medical device evaluation.

BACKGROUND: Current methods to identify cardiovascular implantable electronic device lead failure include postapproval studies, which may be limited in scope, participant numbers, and attrition; studies relying on administrative codes, which lack specificity; and voluntary adverse event reporting, which cannot determine incidence or attribution to the lead. OBJECTIVE: The purpose of this study was to determine whether adjudicated remote monitoring (RM) data can address these limitations and augment lead safety evaluation. METHODS: Among 48,191 actively monitored patients with a cardiovascular implantable electronic device, we identified RM transmissions signifying incident lead abnormalities and, separately, identified all leads abandoned or extracted between April 1, 2019, and April 1, 2021. We queried electronic health record and Medicare fee-for-service claims data to determine whether patients had administrative codes for lead failure. We verified lead failure through manual electronic health record review. RESULTS: Of the 48,191 patients, 1170 (2.4%) had incident lead abnormalities detected by RM. Of these, 409 patients had administrative codes for lead failure, and 233 of these 409 patients (57.0%) had structural lead failure verified through chart review. Of the 761 patients without administrative codes, 167 (21.9%) had structural lead failure verified through chart review. Thus, 400 patients with RM transmissions suggestive of lead abnormalities (34.2%) had structural lead failure. In addition, 200 patients without preceding abnormal RM transmissions had leads abandoned or extracted for structural failure, making the total lead failure cohort 600 patients (66.7% with RM abnormalities, 33.3% without). Patients with isolated right atrial or left ventricular lead failure were less likely to have lead replacement and administrative codes reflective of lead failure. CONCLUSION: RM may strengthen real-world assessment of lead failure, particularly for leads where patients do not undergo replacement.

Early Experience with the Biotronik Protego ICD Lead.

Background: In the last decade, newer generation ICD leads have been developed based on mechanistic insides of priorly failing leads. The aim of our study was to assess the long-term performance and mechanisms of failure of the 2013-introduced Biotronik Protego ICD lead in a real-world population. Methods: All patients, who underwent implantation of a Protego ICD lead at the Heart Centre Lucerne (Lucerne, Switzerland) between November 2013 and March 2017, were followed up with semi-annual device-controls. The primary endpoint was defined as lead failure, secondary endpoints compromised all-cause death, (in)appropriate shocks and the need for reintervention. Results: A total of 64 patients (mean age 66.7 ± 8.7 years, 30% female) underwent implantation of a Protego ICD lead: 78% for primary prevention, 53% had underlying ischemic heart disease, and 40.6% had a dilated cardiomyopathy (DCM). Mean left ventricular ejection fraction (LVEF) was 32.6 ± 10.5%. A total of 24 patients were treated with cardiac resynchronization therapy (CRT), and their baseline LVEF improved from 27.8 ± 7.3% before to 39.8 ± 12.5 after implantation (p < 0.001). Mean time to follow-up was 5.5 ± 0.9 years. Overall, 14 patients (26.6%) suffered from at least one episode of sustained ventricular tachycardia; in total 10 patients (15.6%) died. Two patients experienced lead failure due to lead fracture after 5.5 and 5.7 years, which was clinically apparent by an abrupt rise in lead impedance (>2000 Ω) and by repetitive inappropriate shocks, respectively. Conclusions: In this retrospective observational study, the calculated annual lead failure rate of the Biotronik Protego ICD lead was 0.59% per patient­thus, the durability and long-term performance seem to be promising.

Different venous approaches for implantation of cardiac electronic devices. A network meta-analysis.

OBJECTIVES: Many of the complications arising from cardiac device implantation are associated to the venous access used for lead placement. Previous analyses reported that cephalic vein cutdown (CVC) is safer but less effective than subclavian vein puncture (SVP). However, comparisons between these techniques and axillary vein puncture (AVP) - guided either by ultrasound or fluoroscopy - are lacking. Thus, we aimed to compare safety and efficacy of these approaches. METHODS: We searched for articles assessing at least two different approaches regarding the incidence of pneumothorax and/or lead failure (LF). When available, bleeding and infectious complications as well as procedural success were analyzed. A frequentist random effects network meta-analysis model was adopted. RESULTS: Thirty-six studies were analyzed. Most articles assessed SVP versus CVC. Compared to SVP, both CVC and AVP were associated with reduced odds of pneumothorax (OR: 0.193, 95%CI: 0.136-0.275 and OR: 0.128, 95%CI: 0.050-0.329; respectively) and LF (OR: 0.63, 95%CI: 0.406-0.976 and OR: 0.425, 95%CI: 0.286-0.632; respectively). No significant differences between AVP and CVC were demonstrated. Limited data suggests no major impact of different approaches on infectious and bleeding complications. Initial CVC approach required significantly more often an alternate/additional venous access for lead placement, compared to both AVP and SVP. No differences between these two were identified. CONCLUSION: Both AVP and CVC seem to decrease incident pneumothorax and LF, compared to SVP. Initial AVP approach seems to decrease the need of alternate venous access, compared to CVC. These results suggest that AVP should be further clinically tested.