P.099 Generator replacement with cardiac based VNS device in children with drug-resistant epilepsy

Background: We aimed to study the proportion of patients with DRE and pre-existing VNS device, who show improvement of at least one class in McHugh seizure outcome classification at last follow up after generator replacement with cardiac based VNS device. Methods: We retrospectively reviewed children with DRE with the older VNS model (102) who underwent battery replacement with the AspireSR®, model 106 since September 2016 at our institution. We assessed the seizure outcomes since the first VNS device insertion till the last follow up after AspireSR® (with cardiac-based seizure detection) using McHugh seizure outcome classification. Results: The study population was comprised of 15 patients. The mean age at seizure onset was 2.7 years old, with mean age of initial VNS1 placement being 10.1 years and mean age of replacement with VNS2 being 14.9 years of age. Three of the fifteen patients had reported status epilepticus prior to initial VNS insertion, and none reported episodes following insertion. Two patients showed at least one class improvement in McHugh seizure outcomes at last follow up after VNS2. Conclusions: Through our preliminary data at the present time, we note that the majority of our patients maintains their seizure control following replacement with VNS2 with a few showing improvement.

Comparison of Electrocautery Platforms for Pulse Generator Replacement Procedures

Introduction: Lead damage can occur during cardiovascular implantable electronic device (CIED) generator replacement procedures, resulting in additional procedures and added costs. PlasmaBlade (PL) and PhotonBlade (PH) are two commercially available insulated electrocautery devices designed to reduce this risk. Objective: This study compared complication rates of PL and PH in CIED generator replacement procedures. Methods: This retrospective study analyzed transvenous CIED generator replacements using PL or PH from 2017-2020. The primary endpoint was lead damage. Secondary endpoints included rate of pocket hematoma, superficial infection, and infections requiring device removal. Results: A total of 209 patients were included for analysis, including 86 procedures (188 leads) using PL and 123 procedures (266 leads) using PH. Lead insulation material consisted of 237 (52.2%) silicone, 66 (14.5%) polyurethane, and 151 (33.3%) copolymer leads, with no significant difference in frequency of insulation materials (p=0.91). The rate of lead damage was low for both PL and PH (0 vs. 0.4%, p=0.59). There was no significant difference in pocket hematoma (1.2% vs. 1.6%, p=0.43), superficial infection (1.2% vs. 0.8%, p=0.49), or infection requiring device removal (1.2% vs. 0%, p=0.41). The mean absolute change in lead impedance from pre- to post-procedure was similar between PL and PH (72.3 ± 126.1 ohms vs. 60.6 ± 72.3 ohms, p=0.10). Conclusions: There was a low rate of complications after CIED replacement procedures, with no significant difference between the PL and PH groups. A majority of leads with silicone insulation material may have contributed to the low rate of lead damage.

Defibrillation success after subcutaneous implantable cardioverter-defibrillator generator replacement is not affected by impedance increase

Funding Acknowledgements Type of funding sources: None. Background Routine defibrillation testing during implant and replacement of the subcutaneous implantable cardioverter-defibrillator (S-ICD) is recommended per current guidelines. Recently, concerns have been raised about an increase in shock impedance and consequent shock failure during defibrillation testing in S-ICD patients undergoing a generator replacement. Purpose We aim to describe the defibrillation success rate in relation to the shock impedance in patients undergoing S-ICD generator replacement in our large tertiary center. Methods In this retrospective analysis, data from replacement procedures were collected from all patients who underwent an S-ICD generator replacement in our center from June 2014 to December 2020. Defibrillation testing was performed with at least one shock of ≤65J, and a successful shock was defined as terminating the ventricular arrhythmia within 5 seconds after the shock. Results A total of 133 patients underwent an S-ICD generator replacement, 5.8 ± 0.9 years after initial implant. Reasons for replacement were: reaching of elective replacement indicator (n = 119), early battery depletion (n = 9), complaints of generator pocket (n = 3) and device malfunction (n = 2). Defibrillation testing was performed in 111 patients (86.5%) undergoing a replacement procedure. Shock impedance data from both the implant and replacement procedure were available in 101 patients. The median shock impedance of these patients during their replacement procedure was significantly higher than during their implant, 79Ω (IQR 66-94) and 66Ω (IQR 57.5-81) respectively (Z = -5.552, p < 0.001). Despite the higher shock impedance, first shock during defibrillation testing was successful in 105/111 patients (94.6%), with a success rate of 97.3% after two attempts. In the remaining three patients, the ventricular arrhythmia could only be terminated with a 80J shock. This was the case during both their initial implant and their replacement procedure. Shock impedance increase between implant and replacement was not significantly higher in patients with a successful first shock compared to patients with an unsuccessful first shock (Δ+11.1 ± 20.0Ω versus Δ+12.7 ± 27.6Ω, p = 0.86). Conclusion In this large retrospective analysis, we have shown a first shock success rate during S-ICD generator replacement of 94.6%, which is similar to the success rate of defibrillation testing after initial implant. After multiple attempts, defibrillation testing success rate was 100%. Even though the median shock impedance during replacement was significantly higher than during the initial implant, there was no difference in impedance increase in patients with a successful shock compared to patients with an unsuccessful shock. Abstract Figure. Defibrillation success

Incidence of Ventricular Arrhythmias and 1‐Year Predictors of Mortality in Patients Treated With Implantable Cardioverter‐Defibrillator Undergoing Generator Replacement

Background When implantable cardioverter defibrillator (ICD) battery is depleted most patients undergo generator replacement (GR) even in the absence of persistent ICD indication. The aim of this study was to assess the incidence of ventricular arrhythmias and the overall prognosis of patients with and without persistent ICD indication undergoing GR. Predictors of 1‐year mortality were also analyzed. Methods and Results Patients with structural heart disease implanted with primary prevention ICD undergoing GR were included. Patients were stratified based on the presence/absence of persistent ICD indication (left ventricular ejection fraction ≤35% at the time of GR and/or history of appropriate ICD therapies during the first generator's life). The study included 371 patients (82% male, 40% with ischemic heart disease). One third of patients (n=121) no longer met ICD indication at the time of GR. During a median follow‐up of 34 months after GR patients without persistent ICD indication showed a significantly lower incidence of appropriate ICD shocks (1.9% versus 16.2%, P <0.001) and ICD therapies. 1‐year mortality was also significantly lower in patients without persistent ICD indication (1% versus 8.3%, P =0.009). At multivariable analysis permanent atrial fibrillation, chronic advanced renal impairment, age >80, and persistent ICD indication were found to be significant predictors of 1‐year mortality. Conclusions Patients without persistent ICD indication at the time of GR show a low incidence of appropriate ICD therapies after GR. Persistent ICD indication, atrial fibrillation, advanced chronic renal disease, and age >80 are significant predictors of 1‐year mortality. Our findings enlighten the need of performing a comprehensive clinical reevaluation of ICD patients at the time of GR.

Abstract 14091: Outcomes of Patients With Recalled Defibrillator Leads: Results From the NCDR-ICD Registry

Introduction: Whether to reuse, abandon, or extract functioning, recalled ICD leads at the time of generator replacement is an area of uncertainty as lead failure is more common following generator replacement, and long term failure rates of recalled ICD leads are unknown. We sought to evaluate outcomes following various lead management strategies at the time of generator replacement. Hypothesis: Functional St. Jude Riata and Medtronic Sprint Fidelis leads at the time of elective generator replacement are more frequently reused than replaced, and extracting them poses significant procedural risk. Methods: We queried the NCDR ICD Registry for Medicare patients undergoing elective generator replacement with a normal Fidelis or Riata lead from 2010-2016 and categorized patients based on the fate of the recalled lead: reused, abandoned, or extracted. We report pre-discharge complications by group. Results: There were 9937 generator replacement patients between 2010-2016 with a functioning Riata or Fidelis lead in which lead management was reported. The lead was reused in 9806 (98%) patients, extracted in 55 (0.6%), and abandoned in 76 (0.8%). Compared with the reused group, extracted patients were >10 years younger, had less heart failure and fewer comorbidities. In-hospital death occurred in 4 (7.3%) patients in the extracted group and 7 (0.07%) in the reused group (P<0.0001). The combination of death or any pre-discharge event occurred in 11% of extracted patients compared with 0.3% and 0% in the reused and abandoned groups, respectively.(Table) Conclusions: At the time of generator replacement, a small percentage of functional Riata and Fidelis leads were extracted. Even in this highly selected extraction population, extraction posed significant risk of in-hospital mortality and severe complications. Future work will help clarify whether these peri-procedural risks may be justified by improved medium and long term outcomes.

Complications related to elective generator replacement of the subcutaneous implantable defibrillator

Aims To guarantee uninterrupted function of the subcutaneous implantable cardioverter-defibrillator (S-ICD), the pulse generator needs to be surgically replaced before the battery is depleted. The risks related to this replacement substantially impact long-term outcome for S-ICD recipients, as the majority will undergo one or several of these procedures in their lifetime. We aim to describe the procedural characteristics of the replacement procedure and to provide an insight in the complications associated with these replacements. Methods and results In this retrospective analysis, data from replacement procedures and follow-up visits were collected from all patients who underwent elective S-ICD generator replacement in our tertiary centre from June 2014 until November 2019. Original device position was assessed using the PRAETORIAN score. Complications were defined as those requiring surgical intervention, systemic antibiotic treatment, or device extraction. Seventy-two patients were included, with a median follow-up of 1.9 years (IQR 0.6–3.3 years) after replacement. Battery depletion occurred after 5.9 ± 0.7 years. The pulse generator was repositioned in patients with a PRAETORIAN score ≥90 to minimize the defibrillation threshold. Although there was an increase in impedance compared to the implant procedure, first shock conversion rate during defibrillation testing was 91.4% with a success rate of 100% after multiple attempts. Two patients developed a complication after, respectively, 9 and 21 months, resulting in a complication rate of 1.4% per year. Conclusion With a median follow-up of 1.9 years, this study shows a low complication rate after S-ICD replacement, with a first shock conversion rate of 91.4%.