Subcutaneous Implantable Cardioverter-defibrillator Patients Research Articles

EFFICACY AND SAFETY OF THE SUBCUTANEOUS IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR IN PATIENTS WITH AND WITHOUT OBESITY: A META-ANALYSIS

The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as an alternative to transvenous systems for preventing sudden cardiac death. However, concerns have been raised regarding its efficacy and safety in obese individuals. This meta-analysis aims to evaluate the efficacy and safety of the S-ICD in patients with obesity by assessing the relationship between body mass index (BMI) and clinical outcomes. A comprehensive search of multiple databases was conducted for English-language peer-reviewed studies reporting clinical outcomes in S-ICD recipients with (BMI ≥30 kg/m2) and without obesity (BMI <30 kg/m2). Data on pre-implantation screening failure, defibrillation testing, complications, appropriate and inappropriate shocks, and survival were analysed using standard random-effect meta-analytical techniques. Twenty-nine studies involving 20,486 patients were included. There was no statistically significant difference in the mean BMI values of patients with failed or successful preimplantation screening (mean difference -0.60 kg/m2, 95% CI -2.06 to 0.86). Obesity was associated with higher rates of failed defibrillation testing at ≤65J (OR 2.16, 95% CI 1.39-3.35), and mal-/suboptimal positioning occurred more frequently in obese compared to non-obese patients (OR 3.37, 95% CI 1.76-6.44). Increased BMI as a continuous variable (per increase in 1 kg/m2 BMI) was associated with elevated defibrillation thresholds (OR 1.05, 95% CI 1.03-1.08), a higher risk of complications (HR 1.04, 95% CI 1.02-1.05), a trend towards increased number of appropriate shocks (HR 1.02, 95% CI 1.00-1.04), and no significant increase in the risk for inappropriate shocks (HR 1.01, 95% CI 0.99-1.03). This meta-analysis underscores the importance of considering obesity in S-ICD implantation decisions. While S-ICD remains effective in obese patients, attention to potential technical challenges and higher complication rates is warranted.

Device programming and SMART pass algorithm activation in subcutaneous implantable defibrillator patients: data from a remote monitoring database

Abstract Background In subcutaneous implantable cardioverter-defibrillator (S-ICD) recipients, a previous study demonstrated very low rates of delivered shocks and inappropriate shocks on programming a conditional zone between 200 and 250 bpm and a shock zone for arrhythmias &amp;gt;250 bpm. The extent to which this programming approach is adopted in clinical practice has been little studied, as the activation status of the SMART Pass filter, that was implemented to reduce inappropriate shocks and enhanced over time. Purpose We assessed device programming during follow-up and the rate of detected arrhythmias in a cohort of consecutive S-ICD recipients. Methods We analyzed data from 670 S-ICD patients followed on the remote network at 17 Italian centers for a median of 31 months (25th-75th percentile: 16-51). The enhanced SMART Pass version was available for all patients after October 2022. It makes the deactivation monitor less sensitive to premature ventricular contractions or other transient amplitude changes while maintaining arrhythmia sensitivity and specificity, and it was expected to reduce unintentional deactivation rate. Results At the last remote data transmission, the median programmed conditional zone cut-off was set to 210 bpm (25th-75th percentile: 200-220), the shock zone cut-off was 250 bpm (25th-75th percentile: 240-250), and the SMART Pass was enabled in 586 (87%) patients. During follow-up, 194 automatic deactivation events (0.10/patient-year) were reported in 118 (18%) patients. The SMART Pass-disabled time was 13% of the total observation period. Shocks were delivered in 129 (19%) patients (rate: 0.13/patient-year), and untreated arrhythmias were recorded in 136 (20%) patients (rate: 0.14/patient-year). The rate of shocks was lower when SMART Pass was enabled – 0.12/patient-year (95% CI: 0.10-0.14) versus 0.20 (95%CI: 0.15-0.26) (p=0.002), as it was the rate of untreated arrhythmias – 0.12/patient-year (95% CI: 0.11-0.14) versus 0.23 (95%CI: 0.18-0.30) (p=0.001). The enhanced SMART Pass version was associated with a lower rate of deactivations – 0.04/patient-year (95%CI: 0.02-0.05) versus 0.14 (95% CI: 0.12-0.16) (p&amp;lt;0.001), and with a reduction in treated and untreated arrhythmias (Incidence rate ratios: 0.40 (95%CI: 0.28-0.53) and 0.40 (95%CI: 0.30-0.55), respectively (p&amp;lt;0.001)). Conclusions In current clinical practice, S-ICD implantation centers often program high cut-off rates for arrhythmia detection. Most patients have SMART Pass consistently enabled during follow-up. This is associated with significantly lower rates of detected and treated arrhythmias. The enhanced SMART Pass version seems associated with lower deactivation rate, and with further decrease in treated and untreated detected arrhythmias.

Sex-based outcomes of subcutaneous implantable cardioverter-defibrillator and impact of surgical technique.

Because of differences in chest wall anatomy, female patients may have higher rates of subcutaneous implantable cardioverter-defibrillator (S-ICD) pocket-related complications. We sought to evaluate sex-based outcomes after S-ICD implantation. Patients implanted with an S-ICD at Emory Healthcare between 2010 and 2023 were included in the analysis. Patients' clinical characteristics and post-S-ICD implantation complications were collected. There were 429 male patients (68%) and 199 female patients (32%) observed for a median duration of 2.3 years (0.6-4.4 years). Male and female patients had comparable rates of diabetes (28%), end-stage renal disease (29.5%), ejection fraction (30.2% ± 13.4%), and body mass index (29.1 ± 6.6 kg/m2). There was no statistical difference in the incidence of shocks between men and women (26.3% vs 20.1%; P = .09), including appropriate shocks (14.7% vs 12%; P = .98) and inappropriate shocks (11.7% vs 9.5%; P = .98). Pocket-related complications occurred in 21 patients; these included pocket infection (n = 12), wound dehiscence (n = 7), and hematoma requiring drainage (n = 2). Female patients had a significantly higher pocket-related complication rate compared with male patients (7.2% vs 2.5%; P = .016). In controlling for age, body mass index, diabetes, and end-stage renal disease, female patients had higher odds of pocket-related complications compared with male patients (odds ratio, 3.15; 95% confidence interval, 1.27-7.75). Pocket-related complications decreased after 2018 compared with before 2018 (6% vs 2.6%, P=.052), mainly driven by reduction in complications in women (12.3% vs 3.2%; P = .034) but not in men (2.8% vs 2.4%; P=1). In this cohort of S-ICD patients, women had a higher rate of post-S-ICD pocket-related complications that could be explained by sex-based differences in anatomy.

Validation of the PRAETORIAN score in a large subcutaneous implantable cardioverter-defibrillator collective: Usefulness in clinical routine

BackgroundTo assess the risk of unsuccessful conversion of ventricular fibrillation during defibrillation testing (DFT) with the subcutaneous implantable cardioverter-defibrillator (S-ICD), the PRAETORIAN score has been proposed. ObjectiveThe purpose of this study was to validate the PRAETORIAN score in a large S-ICD collective. MethodsA retrospective single-center analysis of S-ICD patients receiving intraoperative DFT was performed. DFT was performed using a stepwise protocol with 65-J standard polarity, change of polarity, increase to 80 J, and repositioning if necessary. If all DFTs failed, we switched to a transvenous ICD. ResultsOverall, 398 patients were analyzed (268 male [67.3%]; mean age 42.4 ± 15.9 years; mean body mass index [BMI] 25.9 ± 4.8 kg/m2). Successful DFT with the first ICD shock was observed in 264 patients (66.3%). One hundred fourteen patients were defibrillated with the second (n = 104) or third (n = 10) DFT after changing shock polarity and/or shock energy. Overall, 20 patients needed at least 3 DFT (ie, 80 J and/or re-positioning). The majority (n = 88 [65.7%]) of DFT failures occurred before 2015 with the first-generation S-ICD. PRAETORIAN score was an independent predictor of DFT failure (odds ratio [OR] 1.007; 95% confidence interval [CI] 1.003–1.011 P ≤.001), while whereas BMI alone was not (P = .31). Presence of hypertrophic cardiomyopathy (HCM) (OR 2.6; 95% CI 1.3–4.4; P = .004) was predictive for at least 1 unsuccessful DFT in our multivariate regression analysis. ConclusionPRAETORIAN score proved to be a useful and valid predictive tool for successful DFT, whereas BMI only had a limited role. Patients with HCM were at increased risk for DFT failure or needed higher DFT energy.

Clinical course of hypertrophic cardiomyopathy patients implanted with a transvenous or subcutaneous defibrillator.

The implantable cardioverter-defibrillator (ICD) is a life-saving therapy in patients with hypertrophic cardiomyopathy (HCM) at risk of sudden cardiac death. Implantable cardioverter-defibrillator complications are of concern. The subcutaneous ICD (S-ICD) does not use transvenous leads and is expected to reduce complications. However, it does not provide bradycardia and anti-tachycardia pacing (ATP). The aim of this study was to compare appropriate and inappropriate ICD interventions, complications, disease-related adverse events and mortality between HCM patients implanted with a S- or transvenous (TV)-ICD. Consecutive HCM patients implanted with a S- (n = 216) or TV-ICD (n = 211) were enrolled. Propensity-adjusted cumulative Kaplan-Meier curves and multivariate Cox proportional hazard ratios were used to compare 5-year event-free survival and the risk of events. The S-ICD patients had lower 5-year risk of appropriate (HR: 0.32; 95%CI: 0.15-0.65; P = 0.002) and inappropriate (HR: 0.44; 95%CI: 0.20-0.95; P = 0.038) ICD interventions, driven by a high incidence of ATP therapy in the TV-ICD group. The S- and TV-ICD patients experienced similar 5-year rate of device-related complications, albeit the risk of major lead-related complications was lower in S-ICD patients (HR: 0.17; 95%CI: 0.038-0.79; P = 0.023). The TV- and S-ICD patients displayed similar risk of disease-related complications (HR: 0.64; 95%CI: 0.27-1.52; P = 0.309) and mortality (HR: 0.74; 95%CI: 0.29-1.87; P = 0.521). Hypertrophic cardiomyopathy patients implanted with a S-ICD had lower 5-year risk of appropriate and inappropriate ICD therapies as well as of major lead-related complications as compared to those implanted with a TV-ICD. Long-term comparative follow-up studies will clarify whether the lower incidence of major lead-related complications will translate into a morbidity or survival benefit.

A 25-year single-center experience with transvenous and subcutaneous ICD patients under thirty years of age

Abstract Funding Acknowledgements Type of funding sources: None. Background Young implantable cardioverter-defibrillator (ICD) recipients present high rate of inappropriate shocks and complications. Some of them seem to be underestimated. The subcutaneous ICD(S-ICD) system was developed to eliminate lead-related complications and was proved to be effective, avoiding intracardiac and endovascular adhesions. Aims To report on our clinical experience with transvenous (TV-ICD) and S-ICD therapy in patients under thirty years of age. Methods We reviewed database of ICD recipients in our institution between 1996 and 2022(25 years) and have chosen 125 pts consecutively implanted up to and including the age of 30 years. We retrospectively analyzed the rate of appropriate(AI) and inappropriate interventions(IS), lead complications rate, infection rate, mortality and treatment options. Results The study group: 84 TV-ICD(age: 6-30, BMI: 16,3-22,2) and 41 S-ICD( age: 15-30, BMI; 15,6-31,1) patients. The mean follow-up in analyzed groups was 159±48 and 40± 2 months respectively. Abnormal ventricular function: EF≤30 occurred in compared groups: 12/84(14%) and 5/41(12%) respectively, p=0,3. 24/84pts(28%) received ≥1 AI for VT/VF(ATP or shock) in TV-ICD and 4/40pts(10%) in S-ICD groups. 25/84 pts(30%) received one or multiple (IS) and 1/40pts(2,5%) in compared groups respectively, p=0,02. There were 18/84 (21.5%) ventricular lead dysfunctions(reimplantation of a new system) in TV-ICD and 0% in S-ICD groups, p=0,025. An infection rate (endocarditis or device pocket )was 8/84 (10%) in TV-ICD group with complete system removal and 1 pts (2,5%) wound infection(staphylococcus aureus) in S-ICD group successfully treated with antibiotics. 1 left ventricular assist device was implanted in end-stage heart failure S-ICD patient with good result. There were 2 S-ICD implantations as a concomitant device i.e. conversion of TV-ICD(with therapy OFF) to S-ICD due to ventricular lead dysfunction. 4(10%) pts required generator elective replacement due to early battery depletion in S-ICD group. In 2(5%)pts right sternal lead location was chosen due to better sensing results. Mortality rate was 6/84 pts (7%), caused by ventricular lead dysfunction, end-stage heart failure or heart transplantation fatal result in TV-ICD group. There was no death in S-ICD group. Conclusions TV- ICD implantation in children and young adults is a feasible and effective procedure in a 25-year follow-up but the rate of complications is high in this population. S-ICD recipients did not experienced lead failures or systematic infections. S-ICD appears to be a good therapy option and an alternative to TV-ICD in pediatric and young patients population, preventing from some serious lead complications and tricuspid valve regurgitation. The method and follow-up period effect is present between the TV-ICD and S-ICD in analyzed groups.

Comparison of defibrillation modalities in the paediatric population: IChildren registry, a French observational and multicentric study

The presence of an implantable cardioverter-defibrillator (ICD) in the paediatric population is marked by the occurrence of more frequent complications compared to the adult population, such as lead failure, infections and inappropriate shocks. The objectives of the iChildren study is to carry out an inventory of French practices and to compare the three available defibrillation methods (endovascular, surgical, subcutaneous S-ICD) in terms of effectiveness and safety. We retrospectively included 274 children aged 16 years or younger at the time of the first implantation of an ICD, from most of the major French implanting centres since 2005. Data were collected in an eCRF. The primary composite outcome (PCO) associates the occurrence of lead failure or device infection. We also analyse the rate of appropriate and inappropriate shocks. An endovascular ICD was implanted in 103 patients (38%), a subcutaneous ICD (S-ICD) in 55 patients (20%), a surgical ICD in 116 patients (42%). During a mean follow-up time of 5.7 years, the occurrence of PCO was found in 21% of patients, 5% of the S-ICD patients, 19% of the endovascular patients, 29% of the surgical patients. In univariate analysis, the factors associated with PCO were: young age group, type of ICD. In multivariate analysis, after adjustment, the surgical ICD was associated with the highest risk of PCO (P < 0.05). In the total population, the rate of appropriate shocks was 30%, the rate of inappropriate shocks was 11%, with no statistically significant difference between ICD types at implantation. Surgical implantation of an ICD is associated with more long-term complications, such as lead failure and device infection. There was no statistically significant difference in the occurrence of inappropriate shocks between the 3 defibrillation approaches.

Eligibility of patients with temporary paced rhythm for a subcutaneous implantable cardioverter-defibrillator.

A concomitant use of a pacemaker and a subcutaneous implantable cardioverter-de-fibrillator (S-ICD) may be required in some patients. Our study aimed to evaluate the influence of permanent cardiac pacing on the morphology of the QRS complex in the context of S-ICD screening. One hundred patients with cardiac electronic implantable devices (CIEDs) were included in whom S-ICD screening could be performed both during intrinsic and paced rhythm. The positive result of screening during spontaneous rhythm for at least one vector (in both supine and standing positions) was obtained in 80% and for 2 vectors in 59% of patients. Positive screening during paced rhythm for at least one vector was recorded in 36% of patients (78% right ventricular and 22% biventricular pacing) and for 2 vectors in 15% of patients (93% right ventricular and 7% biventricular pacing). At least one vector acceptable during both types of rhythm and in both positions was recorded in 23% of patients and at least 2 vectors in 8% of patients. The use of S-ICD in patients with paced ventricular rhythm is associated with a serious risk of inappropriate sensing due to different QRS morphology during intrinsic and paced rhythm, and it is particularly high in patients in whom periods of spontaneous rhythm interchange with periods of ventricular pacing. That risk has been hardly acknowledged in available reports, but according to our data, it is significant, and therefore it should be considered during S-ICD screening.

Feasibility and image quality of myocardial perfusion imaging by CMR in patients with conditional and non-conditional cardiac devices

Abstract Purpose First, to determine image quality using different cardiovascular magnetic resonance (CMR) perfusion protocols in patients with all available active device types in a real-world setting, including non-conditional devices. Second, to demonstrate feasibility of high-quality perfusion imaging using spoiled gradient echo (sGE) protocols for non-invasive stress-testing. Methods From August 2020 to March 2022, N=222 patients with active cardiac implantable electronic devices (CIED) were scanned on a 1.5-T MR scanner (Philips Ingenia and Ambition). Our CMR scanning protocol was tailored to the clinical indication, and whenever myocardial perfusion imaging was possible, both a conventional steady-state-free-precession (SSFP)-based and a modified sGE-perfusion protocol were applied. Such a tailored perfusion protocol was performed in N=119 patients (70% men) with exclusively left-sided devices (pacemaker (PM), n=45; implantable cardioverter-defibrillator (ICD), n=46; subcutaneous ICD (S-ICD), n=15 and cardiac resynchronization therapy-pacemaker (CRT-P, n=5) or -defibrillator (CRT-D, n=8) with a percentage of 10% non-conditional devices. For assessment of image quality, a semi-quantitative 4-point grading scale was used based on a standard 16-segment model. Results A total of N=33 stress-tests with either regadenosone, adenosine or dobutamine and N=86 rest perfusion protocols were performed. Asynchronous pacing was required in 34% of the patients due to a heart rate of &amp;lt;40bpm. Device interrogation before and after CMR scanning showed no significant changes. Image quality was substantially better in sGE-based perfusion protocols compared to conventional SSFP-based perfusion in ICD, CRT-D and S-ICD patients (p&amp;lt;0.001). In patients with PM/ CRT-P image quality was neither significantly impaired in SSFP- nor in sGE-based protocols. Most device artefacts were located primarily in the anterior myocardial segments (1, 7, 13) in transvenous implanted devices and lateral in SICD-patients. A significant relationship between the extent of device artefacts and the parameters LVEDV (p=0.03), LVESV (p=0.005) and non-conditional devices (p=0.029) in SSFP-perfusion protocols were found in patients with PM/CRT-P. In contrast, there was no correlation between clinical and CMR-parameters in patients with ICD/ CRT-D. In S-ICD-patients, there was an inverse relationship between the extent of device artefact and age (p=0.006), BMI (p=0.001) in sGE-perfusion. Conclusion Myocardial perfusion imaging by CMR is safe and feasible with high image-quality in patients with all kinds of CIEDs – including MR-conditional as well as non-conditional devices. When performing CMR-based myocardial perfusion imaging in patients with left-sided ICD/CRT-D/S-ICD, a sGE-based perfusion-protocol should be preferred compared to conventional SSFP-based perfusion protocols in order to achieve artefact-free and well interpretable images. Funding Acknowledgement Type of funding sources: None.

Age-related differences and associated mid-term outcomes of subcutaneous implantable cardioverter-defibrillators: A propensity-matched analysis from a multicenter European registry.

A few limited case series have shown that the subcutaneous implantable cardioverter-defibrillator (S-ICD) system is safe for teenagers and young adults, but a large-scale analysis currently is lacking. The purpose of this study was to compare mid-term device-associated outcomes in a large real-world cohort of S-ICD patients,stratified by age at implantation. Two propensity-matched cohorts of teenagers + young adults (≤30 years old) and adults (>30 years old) were retrieved from the ELISIR Registry. The primary outcome was the comparison of inappropriate shock rate. Complications, freedom from sustained ventricular arrhythmias, and overall and cardiovascular mortality were deemed secondary outcomes. Teenagers + young adults represented 11.0% of the entire cohort. Two propensity-matched groups of 161 patients each were used for the analysis. Median follow-up was 23.1 (13.2-40.5) months. In total, 15.2% patients experienced inappropriate shocks, and 9.3% device-related complications were observed, with no age-related differences in inappropriate shocks (16.1% vs 14.3%; P = .642) and complication rates (9.9% vs 8.7%; P = .701). At univariate analysis, young age was not associated with increased rates of inappropriate shocks (hazard ratio [HR] 1.204 [0.675-2.148]: P = .529). At multivariate analysis, use of the SMART Pass algorithm was associated with a strong reduction in inappropriate shocks (adjusted HR 0.292 [0.161-0.525]; P <.001), whereas arrhythmogenic right ventricular cardiomyopathy (ARVC) was associated with higher rates of inappropriate shocks (adjusted HR 2.380 [1.205-4.697]; P = .012). In a large multicenter registry of propensity-matched patients, use of the S-ICD in teenagers/young adults was safe and effective. The rates of inappropriate shocks and complications between cohorts were not significantly different. The only predictor of increased inappropriate shocks was a diagnosis of ARVC.

Pooled Analysis of Complications with Transvenous ICD Compared to Subcutaneous ICD in Patients with Catecholaminergic Polymorphic Ventricular Arrhythmia.

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is associated with arrhythmic events which may lead to sudden cardiac death (SCD). A leading therapy for CPVT besides medical treatment with beta-blockers is the use of an implantable cardioverter-defibrillator (ICD). For this paper we compared data from a pooled analysis to get further evidence about the complications of transvenous and subcutaneous ICDs. Methods: We gathered data from a search of PubMed, Web of Science, Cochrane Library and Cinahl. For our analysis, we chose 30 studies with a total number of 784 patients. We compared the data regarding complications caused by different ICD device types. Results: During a mean follow up of 38.9 months for the patients with ICD implantation (n = 337), data showed a complication rate of 101 (30%). A total of 330 (98%) of them received a transvenous-ICD (T-ICD) and 7 (2%) a subcutaneous-ICD (S-ICD). A total of 97 (29.4%) of the T-ICD patients and 4 (57.1%) of the S-ICD patients had at least one complication. Of the 234 complications that occurred in T-ICD patients 152 (65%) were inappropriate shocks due to supraventricular arrhythmias, T/R-wave oversensing or electrode defect, 26 (11.1%) lead fracture/failure, 1 (0.4%) electrode defect, 46 were (19.7%) events of electrical storms, 1 (0.4%) thromboembolic event, 2 (0.8%) cases of endocarditis and 6 (2.6%) infections of the ICD-pocket. Ten (100%) of the complications for the four patients with the S-ICD were an event of an inappropriate shock due to supraventricular arrhythmias, T/R-wave oversensing or electrode defect. Conclusion: Subcutaneous ICDs (S-ICD) show a certain advantage over T-ICDs regarding lead-related complications. Nevertheless, they still show problems with inappropriate shocks and other ICD related complications. Therefore, a case-by-case decision is advised, but the continuous improvement of S-ICD might make it an overall advantageous therapy option in the future.

Comparative Study between Subcutaneous and Endovascular Defibrillator Recipients Regarding Tolerance to the Implant Procedure and Perception of Quality of Life.

ResumoFundamentoO cardioversor-desfibrilador implantável subcutâneo (S-CDI) é uma alternativa segura ao sistema convencional do CDI transvenoso (TV-CDI) para evitar morte súbita.ObjetivoComparar o impacto do tipo de sistema de CDI e técnica cirúrgica na qualidade de vida dos pacientes, bem como a gravidade do desconforto e da dor, entre receptores de S-CDI e TV-CDI.MétodosPacientes consecutivamente implantados com um sistema S-CDI foram pareados com pacientes com um sistema TV-CDI. Além disso, foram incluídos os pacientes submetidos ao implante de S-CDI após a remoção de um TV-CDI, devido a complicações. Foram avaliadas a qualidade de vida (medida com o questionário de saúde de 12 itens) e a gravidade da dor e desconforto. Significância estatística foi definida como p < 0,05.ResultadosForam analisados 64 pacientes implantados com S-CDI ou TV-CDI sob anestesia local e sedação consciente. Pacientes com sistemas S-CDI e TV-CDI não diferiram significativamente nos escores de qualidade de vida. Os pacientes com S-CDI apresentaram maior nível de dor peri-operatória; nenhuma diferença foi encontrada em relação à gravidade da dor intra-operatória. A magnitude do desconforto estético e dos distúrbios do sono não diferiu entre os grupos.O S-CDI foi implantado em 7 pacientes adicionais após a remoção de um TV-CDI. Todos exceto um desses pacientes recomendaram o sistema S-CDI.ConclusõesO tipo de sistema de CDI e a técnica cirúrgica têm impacto insignificante na qualidade de vida dos pacientes. Estes resultados sugerem que a sedação consciente, fornecida por uma equipe experiente de eletrofisiologia, pode ser considerada uma alternativa à anestesia geral para o manejo de pacientes submetidos ao implante de S-CDI.

Long-Term clinical outcomes of subcutaneous implantable defibrillator therapy in patients with heart failure and reduced ejection fraction: a single center experience

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): P. JACON consultant: Boston Scientific France Introduction The implantable cardioverter defibrillator (ICD) is the most effective therapy for prevention of sudden cardiac death in high-risk patients with heart failure and reduced ejection fraction (HFrEF). The subcutaneous implantable cardioverter defibrillator (S-ICD) has been considered as a comparable and relatively safer alternative to transvenous ICD in patients (pts) without pacing indication. Purpose Our aim was to assess the clinical "real-life" outcomes of S-ICD in patients with HFrEF and primary or secondary prevention, over a long-term follow-up (FU) period after S-ICD implantation. Methods All pts with HFrEF (left ventricular ejection fraction ≤35%) implanted with a S-ICD and a FU above 6 months were included in a cross-sectional monocentric study. Pts were followed by remote monitoring. Results 88 pts were included (52 ± 12.8 years old, male 87.5%). Indications were: primary 92% and secondary 8% prevention (ischemic cardiopathy 46%; dilated 46%; hypertrophic 5%; congenital 2%; valvular 1%). The mean left ventricular ejection fraction was 27%. 9 pts had a previous transvenous ICD implanted, but required revision because of infection or lead defects. The mean FU period was 33 ± 18 months with a mortality rate of 10% (S-ICD-related death secondary to inappropriate (inap) shocks for one patient). 5 pts underwent S-ICD system extraction after a mean FU period of 30 ± 21 months. Reasons were infectious complication (1 pt), pacing indication (2 pts) and S-ICD lead dysfunction (2 pts). Extraction after heart transplant was performed in 4 pts. During FU, 18 pts (20.5%) experienced at least one therapy: 8 pts (9%) with appropriate (ap) (3.3% per year) and 11 pts (12%) with inap shocks (4.36% per year). A total number of 24 ap shocks have been observed (3 ± 4 ap shocks per patient, several shocks for 3 pts), the first shock occurred after a mean FU period of 24 ± 14 months. 2 pts were referred to VT ablation and no recurrence of events was observed after medical therapy modification for the other pts. For the 11 pts with inap shocks, time to the first event was 19 ± 20 months. Reasons were: supraventricular arrhythmias (18%), T wave (36%) and noise (54%) oversensing. There was 1.8 ± 1.6 shock per patient with several shocks for 4 pts. Among pts with inap shocks, 2 pts required S-ICD system extraction, 1 pt died, while reprogramming and medical therapy options were efficient in other pts. Conclusion In pts with HFrEF at high risk of sudden cardiac death, S-ICD has proven to be effective in treating ventricular arrhythmias. However, more investigations must be conducted to explain the real-life high rate of inappropriate therapies. Abstract Figure. Survival-free from therapies curve

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

Abstract 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 &amp;lt; 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

Rate and impact on patient outcome and healthcare utilization of complications requiring surgical revision: Subcutaneous versus transvenous implantable defibrillator therapy

Comparison data on management of device-related complications and their impact on patient outcome and healthcare utilization between subcutaneous implantable cardioverter-defibrillator (S-ICD) and transvenous ICD (TV-ICD) are lacking. We designed this prospective, multicentre, observational registry to compare the rate, nature, and impact of long-term device-related complications requiring surgical revision on patient outcome and healthcare utilization between patients undergoing S-ICD or TV-ICD implantation. A total of 1099 consecutive patients who underwent S-ICD or TV-ICD implantation were enrolled. Propensity matching for baseline characteristics yielded 169 matched pairs. Rate, nature, management, and impact on patient outcome of device-related complications were analyzed and compared between two groups. During a mean follow-up of 30 months, device-related complications requiring surgical revision were observed in 20 patients: 3 in S-ICD group (1.8%) and 17 in TV-ICD group (10.1%; p = .002). Compared with TV-ICD patients, S-ICD patients showed a significantly lower risk of lead-related complications (0% vs. 5.9%; p = .002) and a similar risk of pocket-related complications (0.6 vs. 2.4; p = .215) and device infection (0.6% vs. 1.2%; p = 1.000). Complications observed in S-ICD patients resulted in a significantly lower number of complications-related rehospitalizations (median 0 vs. 1; p = .013) and additional hospital treatment days (1.0 ± 1.0 vs. 6.5 ± 4.4 days; p = .048) compared with TV-ICD patients. Compared with TV-ICD, S-ICD is associated with a lower risk of complications, mainly due to a lower risk of lead-related complications. The management of S-ICD complications requires fewer and shorter rehospitalizations.

Acute shock efficacy of the subcutaneous implantable cardioverter-defibrillator according to the implantation technique.

The traditional technique for subcutaneous implantable cardioverter defibrillator (S-ICD) implantation involves three incisions and a subcutaneous (SC) pocket. An intermuscular (IM) 2-incision technique has been recently adopted. We assessed acute defibrillation efficacy (DE) of S-ICD (DE ≤65 J) according to the implantation technique. We analyzed consecutive patients who underwent S-ICD implantation and DE testing at 53 Italian centers. Regression analysis was used to determine the association between DFT and implantation technique. A total of 805 patients were enrolled. Four groups were assessed: IM + 2 incisions (n = 546), SC + 2 incisions (n = 133), SC + 3 incisions (n = 111), and IM + 3 incisions (n = 15). DE was ≤65 J in 782 (97.1%) patients. Patients with DE ≤65 J showed a trend towards lower body mass index (25.1 vs. 26.5; p = .12), were less frequently on antiarrhythmic drugs (13% vs. 26%; p = .06) and more commonly underwent implantation with the 2-incision technique (85% vs. 70%; p = .04). The IM + 2-incision technique showed the lowest defibrillation failure rate (2.2%) and shock impedance (66 Ohm, interquartile range: 57-77). On multivariate analysis, the 2-incision technique was associated with a lower incidence of shock failure (hazard ratio: 0.305; 95% confidence interval: 0.102-0.907; p = .033). Shock impedance was lower with the IM than with the SC approach (66 vs. 70 Ohm p = .002) and with the 2-incision than the 3-incision technique (67 vs. 72 Ohm; p = .006). In a large population of S-ICD patients, we observed a high defibrillation success rate. The IM + 2-incision technique provides lower shock impedance and a higher likelihood of successful defibrillation.

Implantation of a subcutaneous implantable cardioverter-defibrillator in a patient with epicardial defibrillation patches

The subcutaneous implantable cardioverter-defibrillator (S-ICD) was developed to provide an alternative to the transvenous implantable cardioverter-defibrillator (TV-ICD), because it is implanted without any transvenous or epicardial leads. Studies demonstrating the safety and effectiveness of the S-ICD have been published, indicating that it is a good alternative for a variety of patients eligible for a TV-ICD system.1 However, the implantation of an S-ICD in patients with epicardial defibrillation patches is not well documented and remains unclear. Herein, we describe the implantation of S-ICD in a patient with epicardial defibrillation patches and a conductor breakage in the ICD shock circuit.

Evaluation of subcutaneous implantable cardioverter-defibrillator performance in patients with ion channelopathies from the EFFORTLESS cohort and comparison with a meta-analysis of transvenous ICD outcomes.

BackgroundThe subcutaneous implantable cardioverter-defibrillator (S-ICD) is an alternative to conventional transvenous ICD (TV-ICD) therapy to reduce lead complications.ObjectiveTo evaluate outcomes in channelopathy vs patients with structural heart disease in the EFFORTLESS-SICD Registry and with a previously reported TV-ICD meta-analysis in channnelopathies.MethodsThe EFFORTLESS registry includes 199 patients with channelopathies (Brugada syndrome 83, long QT syndrome 24, idiopathic ventricular fibrillation 78, others 14) and 786 patients with structural heart disease.ResultsChannelopathy patients were younger (39 ± 14 years vs 51 ± 17 years; P < .001) with left ventricular ejection fraction 59% ± 9% vs 41% ± 18% (P < .001). The complication rate (follow-up: 3.2 ± 1.5 years vs 3.0 ± 1.5 years) was similar: 13.6% vs 11.2% (P = .42). Appropriate shocks rates were 9.5% vs 10.8% (P = .70), with shocks for monomorphic ventricular tachycardia being 2.0% vs 6.9% (P < .02) and for polymorphic ventricular tachycardia/ventricular fibrillation (VT/VF) 8.0% vs 5.7% (P = .30). Conversion effectiveness of VT/VF episodes was similar: 36 of 37 (97.3%) vs 151 of 155 (97.4%, P = .59). VT/VF storm event (2% vs 0.9%, P = .33) and lower inappropriate shock (IAS) (8.5% vs 12.5%, P = .12) rates were statistically similar between channelopathy and non-channelopathy patients, with 45.5% channelopathy vs 31.4% non-channelopathy patients managed with a conditional zone > 200 beats per minute (P = .0002). Annualized appropriate shock, IAS, and complication rates appear to be lower for the S-ICD vs meta-analysis TV-ICD patients, particularly lead complications.ConclusionEFFORTLESS demonstrates similar S-ICD efficacy and a nonsignificant, lower rate of IAS in channelopathy patients as compared to structural heart disease. Comparable IAS rates were achieved with the device programmed to higher rates for channelopathy patients.

Eligibility for subcutaneous implantable cardioverter-defibrillator in patients with left ventricular assist device

PurposeThe subcutaneous implantable cardioverter-defibrillator (S-ICD) could be a promising alternative to the conventional transvenous ICD in patients with LVAD due to its reduced risk of infection. However, surface ECG is altered following LVAD implantation and, since S-ICD detection is based on surface ECG, S-ICD could be potentially affected. The aim of the present study was to analyze S-ICD eligibility in patients with LVAD.MethodsSeventy-five patients implanted with an LVAD were included in this prospective single-center study. The ECG-based screening test and the automated screening test were performed in all patients.ResultsFifty-five (73.3%) patients had either a positive ECG-based or automated screening test. Out of these, 28 (37.3%) patients were found eligible for S-ICD implantation with both screening tests performed. ECG-based screening test was positive in 50 (66.6%) patients; automated screening test was positive in 33 (44.0%) patients. Three ECG-based screening tests could not be evaluated due to artifacts. With the automated screening test, in 9 (12.0%) patients, the test yielded no result.ConclusionsPatients implanted with an LVAD showed lower S-ICD eligibility rates compared with patients without LVAD. With an S-ICD eligibility rate of maximal 73.3%, S-ICD therapy may be a feasible option in these patients. Nevertheless, S-ICD implantation should be carefully weighed against potential device-device interference. Prospective studies regarding S-ICD eligibility before and after LVAD implantation are required to further elucidate the role of S-ICD therapy in this population.

Improving the care for female subcutaneous ICD patients: A qualitative study of gender-specific issues

BackgroundThe subcutaneous implantable cardioverter-defibrillator (S-ICD) consists of a large generator and is implanted near the left breast. This might lead to discomfort and problems with self-perception and sexuality, especially in the female population. We aimed to assess the issues that female S-ICD patients experience and to provide practical guidance for cardiologists and implanters on minimizing these issues. MethodsFor this retrospective single-center study, we conducted semi-structured interviews with four female S-ICD patients and processed their experiences into a questionnaire. This consisted of three open questions and 17 statements that participants could answer through a five-point Likert scale. The questionnaire was subsequently sent to all female adult patients who received an S-ICD between February 2009 and November 2018 in our tertiary centre in Amsterdam, the Netherlands. ResultsThe response rate of the questionnaire was 73%, with 52 female respondents (mean age 47.4 ± 12.5 years, mean time since implant 4.6 ± 3.1 years). Postoperative pain exceeded the expectation of 54% of the respondents. Furthermore, 14 out of 49 respondents (29%) expressed an unpleasant feeling during intimate contact with their sexual partner since the implant. Many women (44%) reported daily discomfort caused by their bra and preferred a more cranial and posterior position of the S-ICD generator. Finally, a smaller design of the generator is desired by a great majority (63%) of female S-ICD patients ConclusionFemale S-ICD patients experience a variety of issues with a substantial impact on their daily life. Most issues that we identified would benefit from adequate counseling and implanter awareness.