Use Of Subcutaneous Implantable Cardioverter Defibrillator Research Articles

Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: data from a multicenter experience

Abstract Background Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF).Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs, with a lower risk of short- and long-term of device-related complications and infections. Purpose:The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation. Methods:The study population included patients with an S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy. Results:The study population included 30 patients (25 male;median age 45 [38-52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1-20).There were no reports of inability to interrogate S-ICD systems in this population.Electromagnetic interference (EMI) occurred in 21 (70%) patients.The primary sensing vector was the one most significantly involved in determining EMI.Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector.The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks due to EMI. Six patients (20%) experienced appropriate shocks.No S-ICD extraction because of need for antitachycardia pacing,ineffective therapy or infection was reported. Conclusions: Concomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS,and undersensing in the post-operative period following LVAD implantation should be considered.Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.

Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: Data from a multicenter experience

BackgroundLeft ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF). Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs with a lower risk of short- and long-term of device-related complications and infections.The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation. MethodsThe study population included patients with a preexisting S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy. ResultsThe study population included 30 patients (25 male; median age 45 [38–52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1–20).There were no reports of inability to interrogate S-ICD systems in this population. Electromagnetic interference (EMI) occurred in 21 (70%) patients. The primary sensing vector was the one most significantly involved in determining EMI. Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector. The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks (IS) due to EMI. Six patients (20%) experienced appropriate shocks. No S-ICD extraction because of need for antitachycardia pacing, ineffective therapy or infection was reported. ConclusionsConcomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS and undersensing in the post-operative period following LVAD implantation should be considered. Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.

Inappropriate shock incidence in patients with subcutaneous implantable cardioverter-defibrillators with concomitant cardiac implantable electronic devices: A single-center cohort study.

Subcutaneous implantable cardioverter defibrillators (S-ICDs) are occasionally used in combination with other cardiac implantable electronic devices (CIEDs). However, whether the incidence of inappropriate shock increases in patients with S-ICDs and concomitant CIEDs remains unclear. This study aimed to investigate the association between the concomitant use of CIEDs and the incidence of inappropriate shock in patients with current-generation S-ICDs. A total of 127 consecutive patients received an S-ICD. Patients were assigned to two groups depending on concomitant use of CIEDs at the time of S-ICD implantation: patients without other CIEDs (non-combined group, 106 patients) and patients with other CIEDs (combined group, 21 patients). CIEDs included pacemakers, implantable cardioverter defibrillators, cardiac resynchronization therapy pacemakers, and cardiac resynchronization therapy defibrillators. The primary outcome was inappropriate shock, defined as a shock other than ventricular arrhythmia. Hazard ratios and 95% confidence intervals were calculated using a time-varying Cox proportional hazards model which was adjusted for age because age differed between the groups and could be a confounder. During a median follow-up period of 2.2 years (interquartile range, 1.0-3.4 years), inappropriate shock events occurred in 17 (16%) and five (19%) patients of the non-combined and combined groups, respectively. While the age-adjusted hazard ratio for inappropriate shock was 24% higher in the combined than in the non-combined group (hazard ratio=1.24, 95% confidence interval, 0.39-3.97), this difference was insignificant (p=.71). The incidence of inappropriate shock did not differ between patients with and without concomitant use of CIEDs, suggesting that S-ICDs could potentially be combined with other CIEDs without increasing the number of inappropriate shocks. Further studies are warranted to confirm the safety and feasibility of concomitant use of S-ICDs and CIEDs.

Complications and inappropriate shocks in pediatric patients receiving a subcutaneous implantable cardioverter defibrilator

Introduction and objectivesThere is limited evidence regarding the use of subcutaneous implantable cardioverter-defibrillators (S-ICD) in pediatric patients. The aim of this study was to determine the incidence of complications in these patients at our center, according to the type of ICD and patient size. MethodsWe included all patients aged<18 years who received an S-ICD since 2016 at our center. As a control group, we also included contemporary patients (since 2014) who received a transvenous ICD (TV-ICD). The primary endpoint was a composite of complications and inappropriate shocks. ResultsA total of 26 patients received an S-ICD (median age, 14 [5-17] years; body mass index [BMI], 20.2 kg/m2). Implantation was intermuscular in 23 patients (88%) and subserratus in the remainder. Two incisions were used in 24 patients (92%). In all patients, 2 zones were programmed: a conditional zone set at 230 (220-230) bpm, and a shock zone set at 250 bpm. Nineteen patients received a TV-ICD (median age, 11 [range, 5-16] years; BMI, 19.2 kg/m2, 79% single-chamber). Survival free from the primary endpoint at 5 years was 80% in the S-ICD group and 63% in the TV-ICD group (P=.54). Survival free from inappropriate shocks was similar (85% vs 89%, P=.86), while survival free from complications was higher in the S-ICD group (96% vs 57%, cloglog P=.016). There were no therapy failures in the S-ICD group, and no increased complication rates were observed in patients with BMI ≤20 kg/m2. ConclusionsWith contemporary implantation techniques and programming, S-ICD is a safe and effective therapy in pediatric patients. The number of inappropriate shocks is similar to TV-ICD, with fewer short- and mid-term complications.

Temporal trends in baseline characteristics of implantable cardioverter defibrillator recipients for primary prevention of sudden cardiac death- The DAIPP program

Abstract Introduction Since expanding the indication for implantable cardioverter defibrillators (ICD) to primary prevention, the patient population of ICD carriers continues to evolve over time. In pursuit of progressively decreasing the burden of sudden cardiac death, improved patient selection and risk-benefit assessment demand, among others, awareness of these temporal changes in clinical baseline characteristics of the ICD population. Purpose The aim was to explore the temporal differences in baseline characteristics of ICD recipients implanted for primary prevention of sudden cardiac death (SCD), and perioperative complications, to improve understanding of ICD population selection over the last two decades in a real-world setting. Methods The Primary Prevention ICD French Registry (DAI-PP program) was initiated in 2002 with an overall aim to assess the risk-benefit ratio of the introduction of ICD for primary prevention over a 20-year period, including a pilot evaluation that finished in 2012. The pilot study laid ground for the ongoing prospective DAIPP Consortium that started in 2018 and is aiming to follow 10000 patients under remote monitoring, using a specific integrational research platform. The two cohorts are in this study compared with regards to baseline characteristics as well as perioperative outcomes, i.e., early mortality and procedural complications. Results This study included 8432 participants, 5521 from the pilot study and 2211 from the prospective trial, with a median follow up of 2.36 (IQR 1.25-3.75) years. Median age was 64 (IQR 56-71) years, 17% female and 61% had ischemic heart disease. Baseline characteristics that remained stable over time were age, cancer burden. Compared to the 2002-2012 period, recent findings found a significant increase in the proportion of females (15 vs 20%, p &amp;lt;0.001), pauci-symptomatic patients (New York Heart Association Functional class-NYHA II, 41 vs. 57%, p &amp;lt;0.001), narrow QRS patients (31 vs. 43%, p&amp;lt;0.001), use of subcutaneous ICD (0 vs. 14%, P&amp;lt;0.001) and more comorbidities including an increase in diabetes, and slight increase in stroke. Regarding pharmacological treatment, there was an increase in use of 2 or 3 medications (2: 6.5% to 16% p&amp;lt;0.001; 3: 20% to 33%, p&amp;lt;0.001) where more received beta blockers and amiodarone in the contemporary study. Perioperative complications decreased over time (13% to 7.9% p&amp;lt;0.001) with a decrease in early reinterventions (1.3% to 0.1% p&amp;lt;0.001) and discrete fall in number of infections (0.7% to 0.1%, p&amp;lt;0.001) and pocket hematoma (4.4% to 3.0% p&amp;lt;0.001). A slight upward trend in number of lead dislodgements was seen over time (1.3% to 1.7% p&amp;lt;0.001). See Table 1 for perioperative complications. Conclusion The primary prevention ICD population has significantly changed over time. An increase in women, comorbidities, and use of 2-3 medications was seen, coupled with more participants receiving a subcutaneous ICD. Perioperative complications decreased over time.

Combined subcutaneous implantable cardioverter defibrillator and pacemaker devices in complex congenital heart disease: a single-center experienced based study.

Subcutaneous implantable cardioverter defibrillators (S-ICD) are widely accepted therapy in congenital heart disease (CHD) patients at risk of life-threatening ventricular arrhythmias or sudden cardiac death (SCD) when pacing is not required. Occasionally, pacemaker (PM)-dependent CHD patients will subsequently develop an indication for a cardioverter defibrillator. The use of S-ICD in complex CHD patients who have had already PM devices implanted implies some specific considerations, as the safety for these patients in unknown and recommendations among physicians may vary widely. We review the data and studied the indications for S-ICD in complex CHD with previous PM and discuss its usefulness in clinical practice. From a large cohort of 345 patients enrolled in the S-ICD Monaldi care registry, which encompass all the patients implanted in the Monaldi Hospital of Naples, we considered 11 consecutive complex CHD patients (10M/1F aged 40.4 ±18.4 years) who underwent S-ICD implant after a previous PM implant, from February 2015 to October 2022. Mean follow-up was 25.5 ± 22 months. All the patients showed a good compliance to the device system with no complications (infections or skin erosions). In complex CHD with already implanted PM devices, S-ICD implant appears to be a safe alternative to PM upgrading to transvenous ICD system, avoiding abandoned leads or life-threatening lead extraction. However, there are important issues with regard to testing and programming that need to be addressed at the time of implantation.

Complicaciones y descargas inapropiadas tras el implante de un desfibrilador subcutáneo en pacientes pediátricos

Introduction and objectivesThere is limited evidence regarding the use of subcutaneous implantable cardioverter-defibrillators (S-ICD) in pediatric patients. The aim of this study was to determine the incidence of complications in these patients at our center, according to the type of ICD and patient size. MethodsWe included all patients aged<18 years who received an S-ICD since 2016 at our center. As a control group, we also included contemporary patients (since 2014) who received a transvenous ICD (TV-ICD). The primary endpoint was a composite of complications and inappropriate shocks. ResultsA total of 26 patients received an S-ICD (median age, 14 [5-17] years; body mass index [BMI], 20.2 kg/m2). Implantation was intermuscular in 23 patients (88%) and subserratus in the remainder. Two incisions were used in 24 patients (92%). In all patients, 2 zones were programmed: a conditional zone set at 230 (220-230) bpm, and a shock zone set at 250 bpm. Nineteen patients received a TV-ICD (median age, 11 [range, 5-16] years; BMI, 19.2 kg/m2, 79% single-chamber). Survival free from the primary endpoint at 5 years was 80% in the S-ICD group and 63% in the TV-ICD group (P=.54). Survival free from inappropriate shocks was similar (85% vs 89%, P=.86), while survival free from complications was higher in the S-ICD group (96% vs 57%, cloglogP=.016). There were no therapy failures in the S-ICD group, and no increased complication rates were observed in patients with BMI ≤ 20 kg/m2. ConclusionsWith contemporary implantation techniques and programming, S-ICD is a safe and effective therapy in pediatric patients. The number of inappropriate shocks is similar to TV-ICD, with fewer short- and mid-term complications.Full English text available from:www.revespcardiol.org/en

Real-world evidence for the use of subcutaneous implantable cardioverter-defibrillators in China: Asingle-center experience.

Subcutaneous implantable cardioverter-defibrillators (S-ICDs) have been shown to be non-inferior to transvenous ICDs in the prevention of sudden cardiac death (SCD), but there is still alack of evidence from clinical trials in China. We investigated whether S‑ICD implantation in the Chinese population is safe and feasible and should be promoted in the future. Consecutive patients undergoing S‑ICD implantation at our center were enrolled in this retrospective study. Data were collected within the median follow-up period of 554days. Data concerning patient selection, implantation procedures, complications, and episodes of shock were analyzed. In total, 70.2% of all 47patients (median age = 39years) were included for secondary prevention of SCD with different etiologies. Vector screening showed that 98% of patients were with > 1 appropriate vector in all postures. An intraoperative defibrillation test was not performed on six patients because of the high risk of disease deterioration, while all episodes of ventricular fibrillation induced post implantation were terminated by one shock. As expected, no severe complications (e.g., infection and device-related complications) were observed, except for one case of delayed healing of the incision. Overall, 15patients (31.9%) experienced appropriate shocks (AS) with all episodes terminated by one shock. Two patients (4.3%) experienced inappropriate shocks (IAS) due to noise oversensing, resulting in ahigh Kaplan-Meier IAS-free rate of 95.7%. Based on appropriate patient selection and standardized implantation procedures, this real-world study confirmed the safety and efficacy of S‑ICD in Chinese patients, indicating that it may help to promote the prevention of SCD in China.

Subcutaneous Implantable Cardioverter-Defibrillators in Patients With Congenital Heart Disease

BackgroundVery few data have been published on the use of subcutaneous implantable cardioverter-defibrillators (S-ICDs) in patients with congenital heart disease (CHD). ObjectivesThe aim of this study was to analyze outcomes associated with S-ICDs in patients with CHD. MethodsThis nationwide French cohort including all patients with an S-ICD was initiated in 2020 by the French Institute of Health and Medical Research. Characteristics at implantation and outcomes were analyzed in patients with CHD. ResultsFrom October 12, 2012, to December 31, 2019, among 4,924 patients receiving an S-ICD implant in 150 centers, 101 (2.1%) had CHD. Tetralogy of Fallot, univentricular heart, and dextro-transposition of the great arteries represented almost one-half of the population. Patients with CHD were significantly younger (age 37.1 ± 15.4 years vs 50.1 ± 14.9 years; P < 0.001), more frequently female (37.6% vs 23.0%; P < 0.001), more likely to receive an S-ICD for secondary prevention (72.3% vs 35.9%; P < 0.001), and less likely to have severe systolic dysfunction of the systemic ventricle (28.1% vs 53.1%; P < 0.001). Over a mean follow-up period of 1.9 years, 16 (15.8%) patients with CHD received at least 1 appropriate shock, with all shocks successfully terminating the ventricular arrhythmia. The crude risk of appropriate S-ICD shock was twice as high in patients with CHD compared with non-CHD patients (annual incidences of 9.0% vs 4.4%; HR: 2.1; 95% CI: 1.3-3.4); however, this association was no longer significant after propensity matching (especially considering S-ICD indication, P = 0.12). The burden of all complications (HR: 1.2; 95% CI: 0.7-2.1; P = 0.4) and inappropriate shocks (HR: 0.9; 95% CI: 0.4-2.0; P = 0.9) was comparable in both groups. ConclusionsIn this nationwide study, patients with CHD represented 2% of all S-ICD implantations. Our findings emphasize the effectiveness and safety of S-ICD in this particularly high-risk population. (S-ICD French Cohort Study [HONEST]; NCT05302115)

A survey study of the use of a subcutaneous implantable cardioverter-defibrillator in various clinical scenarios by expert electrophysiologists in Poland.

A subcutaneous implantable cardioverter-defibrillator (S-ICD) has become a recognized alternative to a traditional transvenous implantable cardioverter-defibrillator (T-ICD). Despite the growing evidence of non-inferiority of S-ICD, there are no clear clinical guidelines for selection of either of the two available systems. The aim of the study was to analyze the decisions made in predefined typical clinical scenarios by Polish cardiologists experienced in the use of both S-ICDs and T-ICDs. A group of 30 experts of cardiac electrotherapy experienced in the use of S-ICDs was recruited and invited to participate in a web-based anonymous survey. The survey questions regarded the proposed therapy in various but typical clinical scenarios. From the invited 30 experts representing 18 clinical centers, 25 completed the survey. 72% of them declared that the number of S-ICDs implanted at their center during the preceding 12 months exceeded 10, and 40% - that it was over 20. Rates of responders preferring S-ICD or T-ICD in various clinical scenarios are reported and discussed in detail. Significant divergence of opinion exists among Polish experts regarding the use of a subcutaneous cardioverter-defibrillator. It is especially pronounced on the issue of the use of the system in middle-age patients, in case of complications of the hitherto ICD therapy, or the need of upgrading the existing cardiac implantable electronic device.

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.

Experience of using the of subcutaneous cardioverter-defibrillators in the world practice: review

The article provides a review of international clinical studies on the use of a subcutaneous implantable cardioverter-defibrillator (ICD) in comparison with classical intravenous defibrillation systems. Subcutaneous ICDs have shown themselves to be a worthy alternative to intravenous defibrillating systems for the primary prevention of sudden cardiac death, when the patient is not indicated for anti-tachy stimulation and anti-brady stimulation. World experience on the use of subcutaneous ICDs proves the safety and effectiveness of the functioning of the subcutaneous ICD system, excluding from the patient’s life the formidable risks associated with the implantation procedure and further functioning of the classical intravenous ICD system.

Safety and Tolerability of Implanted Subcutaneous Cardioverter-Defibrillator Systems

Aim. To study the safety and tolerability of the subcutaneous implantable cardioverter defibrillator (S-ICD) after implantation.Material and methods. The results of 33 patients with implanted S-ICD 6 months follow-up. The criteria for inclusion in the observational study were: age over 18 years, indications for primary or secondary prevention of sudden cardiac death. The exclusion criteria were indications for implantation of transvenous ICD (patients with sustained monomorphic ventricular tachycardia, the need for anti-bradycardia or resynchronization therapy), as well as patients with a QRS complex of more than 130 msec. All patients underwent a standard preoperative examination (routine blood tests, chest X-ray, transthoracic echocardiography), quality-of-life questionnaires and transesophageal echocardiography. At follow-up, patients were examined after 6 months after implantation, the device was interrogated and a quality-of-life questionnaire was completed. All episodes of shock therapy and complications were documented.Results. Male patients predominated (84%), with a mean age of 57 [43;62] years. Left ventricular ejection fraction was 30% [26;34]. The mean QRS duration was 100 [94;108] msec. According to the of 24-hour Holter ECG monitoring, episodes of unstable VT were recorded in 42.4% of patients. The most common indications for S-ICD implantation were dilated (33%) and ischemic cardiomyopathy (42%). Primary prevention was indicated in 97% of patients. At the end of the implantation of the S-ICD, the patients underwent a defibrillation test and device configuration. In 63.6% of cases, during automatic tuning, the device selected the primary perception vector. In 27.2% of patients, optimal recognition of the subcutaneous signal was observed in the secondary vector, and in 9.2% of patients, the alternative vector was favorable. All patients underwent two-zone programming. The conditional shock zone was programmed at an average rate of 192 beats/min (range 180-210 beats/min) and the shock zone was programmed at an average rate of 222 beats/min (range 220-240 beats/min). Perioperative complications occurred in two patients. During the follow-up period, no shocks were recorded in 27 patients. Adequate shocks for 6 months were recorded in two patients. During 6 months of observation, one lethal outcome was noted due to complications of viral pneumonia. During the observation period, there were no rehospitalizations for cardiovascular diseases.Conclusion. The use of S-ICD, even in patients with structural myocardial disease who do not require antibradycardia pacing, is effective in preventing SCD. The number of inadequate discharges and the number of complications in clinical practice is comparable to the data of multicenter studies. S-ICD implantation was not accompanied by a decrease in quality of life. Careful selection of candidates, along with state-of-the-art device programming, is an important parameter for the selection and success of S-ICD application.

Process mapping strategies to prevent subcutaneous implantablecardioverter-defibrillator infections.

BackgroundInfection remains a major complication of cardiac implantable electronic devices and can lead to significant morbidity and mortality. Implantable devices that avoid transvenous leads, such as the subcutaneous implantable cardioverter‐defibrillator (S‐ICD), can reduce the risk of serious infection‐related complications, such as bloodstream infection and infective endocarditis. While the 2017 AHA/ACC/HRS guidelines include recommendations for S‐ICD use for patients at high risk of infection, currently, there are no clinical trial data that address best practices for the prevention of S‐ICD infections. Therefore, an expert panel was convened to develop a consensus on these topics.MethodsAn expert process mapping methodology was used to achieve consensus on the appropriate steps to minimize or prevent S‐ICD infections. Two face‐to‐face meetings of high‐volume S‐ICD implanters and an infectious diseases specialist, with expertise in cardiovascular implantable electronic device infections, were conducted to develop consensus on useful strategies pre‐, peri‐, and postimplant to reduce S‐ICD infection risk.ResultsExpert panel consensus on recommended steps for patient preparation, S‐ICD implantation, and postoperative management was developed to provide guidance in individual patient management.ConclusionAchieving expert panel consensus by process mapping methodology for S‐ICD infection prevention was attainable, and the results should be helpful to clinicians in adopting interventions to minimize risks of S‐ICD infection.

Temporal trend of QRS voltage amplitude on surface sensing in patients with arrhythmogenic cardiomyopathy implanted with a subcutaneous ICD

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Previous studies have reported a significant decrease in ventricular sensing amplitude during follow-up in patients with arrhythmogenic cardiomyopathy (ACM) implanted with trans-venous implantable cardioverter defibrillator (ICD). No data are yet available on sensing amplitudes values over time for subcutaneous ICD (S-ICD). Low QRS voltage on surface ECG is one of the diagnostic clues in ACM. This, together with the progressive nature of the disease and the not-negligible incidence of inappropriate shocks due to oversensing, raise safety concerns on the use of S-ICD in this population. Aim The aim of this study was to evaluate the trend of QRS amplitude on subcutaneous ECG (S-ECG) over time in patients with ACM implanted with S-ICD. Methods We conducted a retrospective analysis on a cohort of consecutive patients with ACM implanted with S-ICD in two tertiary centers, prospectively enrolled in the home-monitoring program. The S-ECGs recorded by the S-ICD at the time of first and last data transmission were analyzed. The voltage amplitude was estimated for each QRS complex available, and the values obtained were compared between the two time points (i.e. baseline and last follow-up available). The primary endpoint of our study was the proportion of patients in which the decrease of QRS amplitude during follow-up was statistically significant. Results Eleven patients (1 female, 9%) were enrolled in this study. The mean age was 43±10 years. An exclusive right ventricular involvement was reported in 5 patients (46%), 2 patients (18%) had an exclusive left ventricular, and 4 (36%) a biventricular involvement. Three patients (27%) were implanted in secondary prevention. During a median follow-up of 9 months (IQR 6-17), 6 patients (55%, 95%CI 24-84%) experienced a statistically significant reduction in the S-ECG QRS amplitude (Figure A). Considering these 6 patients, the mean absolute reduction was -0.46±0.32 mV corresponding to a relative reduction of -19%±11%. Moreover, we found a statistically significant correlation between follow-up duration and QRS amplitude relative reduction (r=-0.89, p=0.018, Figure B). No patients experienced inappropriate shocks. Conclusions In a cohort of ACM patients implanted with S-ICD the majority of patients experienced a significant reduction in the amplitude of QRS voltage during follow-up, confirming a potential safety concern on the use of S-ICD in this population. Further studies are needed to investigate this issue.

Abstract 9977: Concerns Raised Around Adverse Event Reporting Associated with the Subcutaneous Implantable Cardioverter Defibrillator Device

Objective: To review adverse events reports for the subcutaneous implantable cardioverter defibrillator (S-ICD) device and understand challenges in its application. Background: The S-ICD is an increasingly popular alternative to transvenous ICD (TV-ICD) devices since FDA approval in 2012. Although we have the benefit of professional guidelines, there are no high-quality trials showing mortality benefit. There are concerns about higher rates of inappropriate shocks with use of S-ICD, which prompted a ‘Smartpass’ firmware upgrade in 2016. The impact of this upgrade on rates of inappropriate shocks remains ill-defined. Methods: Narrative reports of adverse events associated with the S-ICD reported to the FDA MAUDE database were reviewed for reason for reporting and outcomes. These were compared with the total number of devices found on shareholder reports as of October 2020. Results: Of 35,000 S-ICD devices in the US, 9,349 adverse events and 2,521 inappropriate shocks were reported in MAUDE. There were 108 deaths, 21 of which were due to a failure to convert a ventricular arrhythmia. Rates of inappropriate shocks comprised an increasing proportion of adverse events year over year with no decline following the ‘Smartpass’ upgrade. Conclusion: The multiple instances of death following S-ICD failure are alarming as these fatal events are thought to be rare for TV-ICDs. Additionally, even with the introduction of Smartpass, inappropriate shocks have not declined. These findings, taken in conjunction with the lack of data for mortality benefit of the S-ICD and safety concerns surrounding the recent lead recall, should be considered by clinicians in future decisions about S-ICD use.

Subcutaneous implantable cardioverter defibrillator in children and adolescents: results from the S-ICD "Monaldi care" registry.

Implantable cardioverter defibrillators (ICD) are widely accepted therapy in children and adolescents who are survivors of cardiac arrest or for high-risk patients with inheritable channelopathies, cardiomyopathies, or congenital heart disease. Initial experience with subcutaneous ICD (S-ICD) systems has shown a high efficacy in adults. However, the use of S-ICD in children and adolescents implies some specific considerations, as the safety for these patients is unknown and recommendations among physicians may vary widely. We reviewed the data and studied the indications for S-ICD in children and adolescents and discuss the preliminary clinical experience. From a cohort of 297 patients enrolled in the S-ICD "Monaldi care" registry that encompass all the patients implanted in the Monaldi Hospital of Naples, we considered 21 consecutive children and adolescents (mean age 13.9 years, range 8-18 years, mean body weight 59.3 kg, range 38-100 kg) who underwent S-ICD implant from April 2014 to June 2020. Mean follow-up was 41.9±21.9 months. Only one patient presented, 6 weeks after implantation, skin erosion at the inferior parasternal incision that resolved after antibiotic therapy, without the necessity of any system revision. Two patients experienced appropriate shocks and four inappropriate shocks, due to T wave oversensing or atrial arrhythmia. Only one patient, with arrhythmogenic right ventricular dysplasia, required a system revision after 36 months of the first implantation and then a reintervention with a replacement of the S-ICD by a conventional ICD system. Our experience suggests that the S-ICD device can be used in some children over the age of 8 as well as adults, with a similar rate of unwanted side effects, and early evidence of apparent efficacy.

Abstract 15562: Incidence and Risk Factors of Device-related Infection in De Novo Transvenous Implantable Cardiac Defibrillator Medicare Patients

Introduction: Practice guidelines recommend use of subcutaneous implantable cardioverter-defibrillators (ICD) in patients (pts) at risk of sudden cardiac death and high risk for infection. This has prompted a need to better identify pts at high risk of infection to assist in de novo device selection. The objective of this study is to estimate infection incidence in de novo transvenous (TV) ICD implants and assess risk factors associated with infection in a large Medicare population. Methods: A retrospective cohort study was conducted using 100% Medicare administrative and claims data to identify pts who underwent de novo TV-ICD implantation between 7/2016 and 1/2018. Device-related infection within 2 years of implantation was identified using ICD-10 diagnosis and procedure codes. Baseline pt factors associated with infection were identified by univariable logistic regression analysis of all variables of interest, including factors in Charlson and Elixhauser comorbidity indices, followed by stepwise selection criteria with a p≤0.25 for inclusion in a multivariable model and a backwards, stepwise elimination process with p≤0.1 to remain in the model. A time-to-event analysis was also conducted. Results: Among 26,742 pts with de novo TV-ICD, 519 (1.9%) had a device-related infection over 2 years. The mean pt age with and without infection was 68 and 71 years, respectively. While more than half (54%) of infections occurred within 90 days post implant, infections continued to be diagnosed with 16% of infections occurring between years 1 and 2. Multivariable analysis revealed several significant predictors of infection (Figure) including age &lt;70 years, end stage renal disease with chronic dialysis and diabetes with complications. Conclusion: The rate of de novo TV-ICD infection in a large real-world Medicare population is clinically significant. The factors associated with increased infection risk identified here can be used to help determine device selection.

Increased risk of hematoma with uninterrupted warfarin in patients undergoing implantation of subcutaneous implantable cardioverter defibrillator.

The perioperative management of anticoagulation with the use of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation is still evolving. The purpose of this study was to assess whether it is safe to perform S-ICD implantation with uninterrupted warfarin. This is a multi-center retrospective review of patients undergoing S-ICD implantation between October 1, 2012 and June 30, 2017. Forty-eight patients underwent successful S-ICD implantation during the study period. The most common indication for implantation was primary prevention of sudden cardiac death. In 23 (47.9%) patients, warfarin was continued without any interruption. In 25 (52.1%) patients, warfarin was interrupted prior to implantation. The incidence of clinically significant lateral pocket hematoma was compared in the two groups. The mean international normalized ratio was 2.0±0.4 in the uninterrupted group and 1.4±0.4 for the interrupted group. A total of seven patients developed a hematoma at the lateral pocket. No patient developed a hematoma at the parasternal pockets. Six patients in the uninterrupted group (26.1%) and one patient in the interrupted group (0.04%) developed a significant lateral pocket hematoma (P=.04). The concomitant use of dual antiplatelet therapy did not increase the risk of hematoma. There was no significant difference between HASBLED and CHA2 DS2 VASc scores between the groups. None of the patients with a hematoma developed infection or required hematoma evacuation. The uninterrupted use of warfarin in the perioperative period of S-ICD implantation is associated with an increased risk of lateral pocket hematoma.

Subcutaneous implantable cardioverter defibrillators in patients with left ventricular assist devices: case report and comprehensive review.

BackgroundLeft ventricular assist devices (LVAD) are increasingly used in patients with advanced heart failure, many of whom have been or will be implanted with an implantable cardioverter defibrillator (ICD). Interaction between both devices is a matter of concern. Subcutaneous ICD (S-ICD) obtains its signals through subcutaneous vectors, which poses special challenges with regards to adequate performance following LVAD implantation.Case summaryWe describe the case of a 24-year-old man implanted with an S-ICD because of idiopathic dilated cardiomyopathy, severe biventricular dysfunction, and self-limiting sustained ventricular tachycardias. After the implantation of a HeartMate 3™ (Left Ventricular Assist System, Abbott) several months later, the S-ICD became useless because of inappropriate sensing due to electromagnetic interference and attenuation of QRS voltage.DiscussionWe reviewed the reported cases in PubMed about the concomitant use of S-ICD and LVAD. Seven case reports about the performance of S-ICD in patients with an LVAD were identified, with discordant results. From these articles, we analyse the potential causes for these differing results. Pump location and operating rates in LVAD, as well as changes in the subcutaneous-electrocardiogram detected by the S-ICD after LVAD implantation are related to sensing disturbances when used in the same patient.