Leadless pacing in pre-adolescent patients weighing 30kg or less: case report and systematic review

Approach to pacing in patients with various septal defects

To evaluate the results of permanent epicardial pacing in children. All consecutive patients from one country (n = 119, period 1977-2009) undergoing permanent epicardial pacemaker implantation at <18 years of age (median 1.8 years, inter-quartile range 0.3-6.4 years) were studied retrospectively. Median patient follow up was 6.4 years (inter-quartile range 2.9-11.1 years); 207 generators, 89 atrial and 153 ventricular pacing leads were implanted. The probability of absence of any pacing system dysfunction was 70.1 and 47.2% at 5 and 10 years after implantation, respectively. Overall probability of continued epicardial pacing was 92.8 and 76.1% at 5 and 10 years, respectively, and increased in the recent implantation era (post-2000, P = 0.04). The use of steroid-eluting leads decreased the risk of exit block with a hazard ratio (HR) of 0.20 [95% confidence interval (CI) 0.09-0.44, P < 0.001)]. The use of bipolar Medtronic 4968 leads reduced the risk of surgical reintervention because of fracture, insulation break, outgrowth or exit block in comparison to the unipolar 4965 lead design (HR 0.12, 95% CI 0.04-0.40, P < 0.001). The AutoCapture™ feature (HR 0.08, 95% CI 0.02-0.36, P < 0.001) and steroid-eluting leads (HR 0.30, 95% CI 0.11-0.84, P = 0.021) decreased the risk of battery depletion. The probability of continued epicardial pacing in children was 76% at 10 years after implantation, increased for implantation in recent years, and allowed transvenous pacing to be deferred to a significantly greater age. The use of bipolar steroid-eluting leads and of a beat-to-beat capture tracking feature significantly increased pacing system longevity and decreased the need for surgical reinterventions.

Due to underlying cardiovascular anatomy and size, epicardial pacing may be the preferred method of pacing in small children. To assess long-term safety, we reviewed all epicardial pacemakers implanted in children between 1971 and 2001. We found that 122 patients, with a median age of 5.4 years, had a total of 181 pacemakers and 260 electrodes implanted over a total follow-up of 789 patient-years. Of the total, 12 patients died after the first implantation, with one death attributable to dysfunction of the pacemaker. Reintervention was required in 75 patients after 5.0 +/- 3.2 years, due to depletion of the battery in 45 patients (60%), fracture or dysfunction of electrodes in 27 patients (36%), and infection in 3 patients (4%). In univariate analyses, risk factors for reintervention were an approach via a median sternotomy, with a relative risk of 2.3 (p = 0.0087), and an indication for pacing other than atrioventricular block, with a relative risk of 1.7 (p = 0.0314). In multivariate analyses, the approach via the median sternotomy independently predicted the need for reintervention, with a relative risk of 2.1, and 95% confidence intervals from 1.1 to 4.1 (p = 0.0256). The longevity of the second pacemaker and/or its electrode, assessed in 26 patients, was 3.7 +/- 2.6 years, not shorter than the first implantation (p = 0.4037). We conclude that epicardial pacing is a reliable means of achieving permanent pacing in children, with low morbidity and mortality. A substantial proportion, nonetheless, requires reintervention within five years, warranting meticulous follow-up.

Pacing activity, patient and lead survival over 20 years of permanent epicardial pacing in children

Efficacy and safety of leadless pacemaker: A systematic review, pooled analysis and meta-analysis

Background Permanent cardiac pacing in paediatric patients remains a challenge. According to the European Paediatric and Congenital Society (AEPC) recommendations, below 20 kg epicardial implantation is preferred, while above 20 kg endocardial implantation is given priority unless specific contraindication. In the literature, a weight at 15 kg is also found to be the minimal weight above which an endovascular implantation is considered. However, endovascular systems have been reported to be associated with a high risk of complications. Recent improvements in epicardial leads technology have significantly improved pacing thresholds (1-3), battery life and reduced the risk of re-intervention for epicardial lead dysfunction (4,5). Purpose The aim of the study is to evaluate the long-term results and efficacy of epicardial pacing in children and to investigate risk factors for epicardial lead dysfunction. Method We performed a retrospective, single-centre analysis of consecutive patients aged ˂18 years implanted with an epicardial PM between 2004 and 2020. The data collection included initial pacing parameters, at 1 month, 1 year, 2 years, and at last follow-up, as well as occurrence of early and late complications. Results A total of 101 patients (93 atrial and 131 ventricular epicardial) were analysed. The mean follow-up time was 6.2 years (range 2 days to 16.9 years). Median age at implantation was 4.2 years (IQ 0.3-8.8 years), median weight was 15.2 kg (IQ 5.2-28.0 kg). Congenital heart disease (CHD) was recorded in 59,4% of patients. Reasons for implantation were postoperative complete atrioventricular block (AVB) (40.6%), congenital AVB (37.6%), sinus dysfunction (7.9%), complete AVB with heart disease without surgery (7.9%), others (4%). Four patients had a system infection resulting in device extraction and reimplantation. The mortality rate was 15.8%, but no deaths was directly related to PM implantation or dysfunction. Detection values, impedances were stable over time, and the and average pacing thresholds remained ˂0,98±0,81 volt in the atrium and ˂ 1.57±0,89 volt in the ventricle. Lead survival was 96,7%, 90,7%, 82,3%, 74,5% at 1, 5, 8 and 10 years. The presence of CHD, weight ˂15kg, dual chamber implantation, implantation for postoperative BAV were not significant risk factors for lead dysfunction. In the group of patients implanted above 15kg the presence of a CHD significantly increased the risk of lead dysfunction (p=0.037) and all-cause reimplantation (p=0.010). In the group implanted above 15kg without any cardiopathy, the survival rate without lead dysfunction at 5 and 10 years was 100% and 90.9% respectively. Conclusion Epicardial pacing in children with steroid-eluting leads shows good long-term results with stable pacing parameters and good survival from lead dysfunction. For children implanted at a weight above 15 kg and without cardiopathy results with epicardial stimulation were excellent.Epicardial lead survival

Percutaneous solution for a frequent complication after transcatheter aortic valve replacement: A case of atrioventricular leadless pacemaker implantation after transcatheter aortic valve replacement

Over the past decade, leadless pacing has undergone a rapid evolution, resulting in multiple leadless pacemaker (LPM) devices that offer advancements such as atrioventricular synchronized pacing in VDD mode, atrial stimulation, dual-chamber pacing, and longer battery longevity. Studies comparing LPMs with transvenous pacemakers (TVPMs) show a lower rate of device-related complications with LPMs. In the near future, LPMs could be combined with other devices such as non-transvenous implantable cardioverter-defibrillators to provide anti-tachycardia pacing or bradycardia pacing. Future prospectives for leadless cardiac resynchronization therapy and leadless conduction system pacing are being investigated. As LPMs continue to improve, their applications are anticipated to expand further improving patient outcome, promising a bright future for leadless pacing. In this review, the past, present, and future of leadless pacing are discussed with a focus on cutting-edge implantation techniques, clinical outcomes, and modern advancements of LPMs.

Permanent cardiac pacing in children and adolescents is rare and often occurs by means of epicardial pacing. Based on two decades of experience, operative and postoperative data of patients with epicardial and transvenous pacing were analyzed retrospectively. Between October 1979 and December 1998, 71 patients (mean age, 5.3+/-4.2, range, 1 day-16.2 years; mean body weight, 18+/-12; range, 8-56 kg) underwent permanent pacemaker implantation. Indications were sinus node dysfunction and atrio-ventricular block following surgery for congenital heart disease (69%), or congenital atrioventricular block (31%). Pacing was purely atrial (1.4%), purely ventricular (73%), ventricular with atrial synchronization (5. 6%), or atrioventricular synchronized (20%). Epicardial pacing was established in 49 (69%), transvenous in 22 (31%) patients. Follow-up was 3.4+/-3.8 years (epicardial) and 3.0+/-4.0 years (transvenous). Epicardial leads were implanted in younger patients (mean age: 4.5 vs. 7.0 years, P<0.05) and preferably after surgery induced atrioventricular block (78 vs. 46%, P<0.05). The youngest patient with transvenous pacing was 1.3 years old (weight, 8.5 kg). At implantation epicardial ventricular stimulation threshold at 1.0 ms was 1.07+/-0.46 vs. 0.53+/-0.31 V (transvenous) (P<0.05). The age-adjusted rate of lead-related reoperations was significantly higher in patients with epicardial leads (P<0.05), mainly due to increasing chronic stimulation thresholds resulting in early battery depletion. In three patients who received steroid-eluting epicardial leads initial low thresholds persisted after five month to one years. In two patients with recurrent epicardial threshold increase, steroid-eluting epicardial leads led to good acute and chronic thresholds after nine to 15 month. Two post-operative death (2.8%) were probably due to a dysfunction of the (epicardial) pacing system. Transvenous pacing in the pediatric population is associated with a lower acute stimulation threshold and a lower rate of lead-related complications. If epicardial pacing is necessary (e. g. small body weight, special intracardiac anatomy (e.g. Fontan), impossible access to superior caval vein), steroid-eluting leads may be considered.

This editorial refers to ‘Long-term outcome of cardiac pacing in octogenarians and nonagenarians’ by E. O. Udo et al ., on page 502 and ‘Permanent epicardial pacing in children: long-term results and factors modifying outcome’ by P. Kubus et al ., on page 509 The average age of patients with an indication for pacing is ∼75 years at the time of implantation. However, permanent pacemaker therapy can be necessary at all ages, from newborn to the nonagenarian. Particularly in these age groups, age matters: in small children, there are technical and anatomical considerations that render pacemaker implantation difficult; in very old patients, their relatives, in particular, but also physicians may have concerns about pacemaker implantation that is perceived as too invasive for such an old patient with significant comorbidity. Two publications in this issue of the journal address pacemaker therapy in these two age groups.1,2 Pacemaker therapy in children faces several challenges. Transvenous implantation may not be feasible due to lack of venous access to cardiac cavities, or may be difficult due to the small venous diameter that either prevents lead introduction or—if the lead can be introduced—obliterates soon after implantation. Lead dysfunction (lead fracture, exit block, and sensing failure) during growth can occur despite formation of loops of the lead at the time of implant. Therefore, epicardial pacing remains the preferred mode of implantation in small children. As an advantage, the epicardial approach allows dual-chamber pacing earlier than transvenous implantation and left ventricular pacing to prevent adverse haemodynamic long-term consequences of right ventricular pacing. Even though pacing is increasingly applied in paediatric patients, only few long-term data are available …

Leadless pacemakers (PMs) were recently introduced to address the complication rate of standard PMs with transvenous leads. A 34-year old male with a history of intravenous substance abuse and a chronic type C hepatitis developed a complete atrioventricular block after cardiac surgery for infective endocarditis. Repeatedly, endo- and epi-cardially implanted PMs had to be explanted due to infection. A leadless MICRA pacemaker was successfully implanted with a dislocation into pulmonary artery several days after implantation. The PM was successfully retrieved using a single-loop retrieval snare guided by a steerable sheath. Subsequently, another Micra PM was successfully implanted with no further issues. In the case of a Micra leadless pacemaker dislocation, a conventional gooseneck snare in combination with a steerable sheath can be used to retrieve the device, improving the overall safety of leadless pacemakers.

Low-energy epicardial pacing in children: the benefit of autocapture

Background Leadless pacemakers (LP) have emerged as an alternative to conventional transvenous single-lead ventricular pacemakers (SLP), with expanding indications beyond initially selected patients. This study evaluated the clinical and economic outcomes of LP compared with SLP in eligible patients from a real-world French hospital cohort. Methods We conducted a retrospective, propensity-weighted cost-effectiveness analysis from a hospital-based perspective, including all patients who underwent first LP or SLP implantation between 2016 and 2020 at our center. Patients with contraindications or high risk of device failure or infection were excluded. Four-year costs and life-years were used to estimate the incremental cost-effectiveness ratio (ICER). Cost-effectiveness acceptability curves (CEACs) were derived from the bootstrapped distribution of net monetary benefits. Sensitivity analyses explored cost drivers and robustness. Results A total of 352 patients were included (104 LP, 248 SLP). After weighting, LP was associated with shorter procedure duration (52 vs 80 min; p < 0.001) and hospital stay (3.6 vs 4.3 days; p = 0.007). Major clinical events occurred in 25.2% (LP) vs 33.8% (SLP; p = 0.17). Although implantation costs were higher for LP (€11,344 vs €9,326; p < 0.001), total 4-year costs were comparable (€12,925 vs €11,713; p = 0.13). The survival difference was 0.06 years (p = 0.67), yielding an ICER of €20,387 per life-year gained. Bootstrap analysis indicated a 70% probability of cost-effectiveness at a €35,000 per life-year threshold. Conclusions In both device eligible patients, leadless pacemakers showed favorable procedural and clinical outcomes with comparable long-term costs, supporting their cost-effective use in real-world French hospital practice.

Leadless pacemaker implantation under direct visualization during valve surgery

Transvenous pacing is nowadays the cornerstone of interventional management of bradyarrhythmias. It is still associated, however, with significant complications, mostly related to indwelling transvenous leads or device pocket. In order to reduce these complications, leadless pacemakers have been recently introduced into clinical practice, but no guidelines are yet available to indicate who are those patients that might benefit the most and whether leadless pacing should be preferred in the old or young population. This survey aims to describe the use of leadless pacemaker devices in a real-world setting. Eleven arrhythmia centers in the Lombardy region (out of a total of 17 participating centers) responded to the proposed questionnaire regarding patient characteristics and indications to leadless pacing. Out of a total of 411 patients undergoing leadless pacing during 4.2 ± 0.98 years, the median age was 77 years, with 0.18% of patients having less than 18 years, 29.9% 18-65 years, 34.3% 65-80 years and 35.6% >80 years. The most common indication was slow atrial fibrillation (49% of patients), followed by atrioventricular block and sinoatrial dysfunction. Two centers reported in-hospital complications. Leadless pacemakers proved to be a safe pacing strategy actually destined mostly to elderly patients.