A Systematic Review and Meta-Analysis of Catheter Ablation Versus Anti-arrhythmic Drugs for Treatment of Ventricular Arrhythmia.

Catheter ablation (CA) and anti-arrhythmic drugs (AADs) minimize implanted cardioverter-defibrillator (ICD) shocks in individuals with ischemic cardiomyopathy and an ICD, while the best strategy is still unknown. CA has been proposed as a potentially effective means of reducing the occurrence of ICD events in a number of studies; however, there were insufficient relevant dates from randomized controlled trials. A meta-analysis and systematic review of randomized controlled trials were carried out to evaluate the efficacy of CA for the prevention of VA in patients with ischemic heart disease. Cardiovascular mortality, an unscheduled hospitalization due to increasing heart failure, appropriate ICD shock, or serious treatment-related consequences comprised the composite primary outcome. AADs were examined in six trials (n = 1564; follow-up = 15 ± 8 months), while CA was evaluated in four trials (n = 682; follow-up = 12 ± 6 months). Both CA (odds ratio (OR) 0.65, 95% confidence interval (CI) 0.47-0.82, p = 0.001) and AADs (OR 0.76, 95% CI 0.32-0.84, p = 0.034) significantly reduced the number of suitable ICD interventions, with no discernible difference between the two treatment approaches. AADs were observed to reduce incorrect ICD interventions (OR 0.38, p = 0.001), but CA did not. During follow-up, there was no correlation seen between reduced mortality and either CA or AAD. When compared to AAD, CA decreased the composite endpoint of cardiovascular death, adequate ICD shock, heart failure-related hospitalization, or severe treatment-related consequences in ICD patients with ischemic cardiomyopathy and symptomatic VT.

Incidence of Staphylococcus aureus Bacteremia in Patients Following Implantation of Cardiac Implantable Electronic Devices: A Danish Nationwide Cohort Study.

Background: Staphylococcus aureus bacteremia (SAB) is a high-risk condition associated with high morbidity and mortality. In the presence of cardiac implantable electronic devices (CIEDs), SAB may cause or clinically indicate device infection. We aimed to estimate the 10-year absolute risk of SAB in adult Danish first-time CIED carriers. Secondary aims included identification of risk factors associated with SAB. Methods: A registry-based study utilizing Danish nationwide registers and including consecutive Danish patients undergoing first CIED implantation between 2000 and 2020 was conducted. The primary outcome was first-time SAB after CIED implantation. Results: A total of 87 257 patients with first CIED implantation in the study period were identified (median age, 75 years; 62.6% were male; median follow-up, 3.8 years). Patients with pacemakers (PMs) were older and with more noncardiovascular comorbidities compared to patients with implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy devices with or without defibrillator capacity (CRTs). In total, 1366 patients (1.6%) developed SAB. The 10-year absolute risk (95% confidence interval) of SAB was 2.0% (1.9%-2.1%) for PM, 2.6% (2.2%-3.1%) for ICD, and 3.7% (3.0%-4.5%) for CRT. A multivariable Cox analysis identified hemodialysis (hazard ratio [HR], 8.51), SAB before CIED (HR, 2.76), liver disease (HR, 2.35), and carrying a CRT device (HR, 1.68) among the covariates associated with increased risk of SAB. Conclusions: The absolute risk of SAB in Danish CIED carriers increased with more advanced CIED systems. The risk was highest within the first 3 months after CIED implantation and increased with the presence of certain covariates including renal dialysis, SAB before CIED, male sex, and advancing age.

[(LV)EF is a poor predictor of sudden cardiac death : Pro/Contra]. / Die (LV)EF ist ein schlechter Prädiktor für den plötzlichen Herztod : Pro/Contra.

For more than two decades the left ventricular ejection fraction (LVEF) has been utilized with practically uncritical absolutism for the risk stratification of patients with ischemic and, historically, also nonischemic cardiomyopathy, in order to identify patients who could be threatened by sudden cardiac death. Based on historical data and in the absence of other better predictive parameters, the LVEF continues to appear in the guidelines unchanged, with cut-off values that lie in the region of the measurement accuracy of LVEF as determined by echocardiography. The basic identification of high-risk patients who then really benefit from an implantable cardioverter defibrillator (ICD) must be re-evaluated under the aspect of a meaningfully altered interventional and pharmaceutical treatment of heart failure.

Predictors of Mortality in Patients with Cardiac Device-Related Infective Endocarditis.

Infective endocarditis (IE) associated with implantable cardiac devices (ICD) is a serious disease with high mortality rates. The increased number of ICD implants has led to increased ICD infection rates. The aim of this study was to characterize clinical, laboratory profiles and the prognosis of cardiac-device-related endocarditis (CDIE), as well as to identify predictors of in-hospital death. A total of 274 patients with IE were included in a prospective cohort (2007-2019). From these, 82 patients (30%) had CDIE (46 pacemakers, 23 cardioverter defibrillators, and 13 cardiac resynchronization therapy devices). Predisposed conditions; clinical, laboratory and echocardiographic parameters; etiologic agents; and in-hospital outcomes were evaluated. The mean age was 55.8 ± 16.4 years, where 64.6% were male. Among the clinical manifestations at diagnosis, the most prevalent were heart failure (67.9%), fever (60.5%), anorexia/hyporexia (44.4%), and heart murmur (37.5%). The median serum C-reactive protein (CRP) level at diagnosis was 63 mg/L (interquartile range [IQR] 20-161). Etiological agents were identified through positive blood cultures in 55% of cases. The main etiologic agents were negative-coagulase staphylococci (19.5%) and Staphylococcus aureus (18.3%). Vegetation was identified in 74 patients (90.1%). In-hospital mortality was 28%. CRP concentrations at diagnosis were identified as markers of disease severity (odds ratio [OR] 1.006; 95%CI 1.001-1.011; p = 0.016), and the worsening of heart failure was associated with unfavorable outcomes (OR 3.105; 95%CI 1.397-6.902; p = 0.005). Unlike what is traditionally accepted, CDIE does not have a better prognosis.

Long-term adherence to a wearable for continuous behavioural activity measuring in the SafeHeart implantable cardioverter defibrillator population.

Aims: Wearable health technologies are increasingly popular. Yet, wearable monitoring only works when devices are worn as intended, and adherence reporting lacks standardization. In this study, we aimed to explore the long-term adherence to a wrist-worn activity tracker in the prospective SafeHeart study and identify patient characteristics associated with adherence. Methods and results: This study enrolled 303 participants, instructed to wear a wrist-worn accelerometer day and night for 6 months. Long-term adherence was defined as valid days (≥22 h of wear time) divided by expected days, and daily adherence as mean hours of wear time per 24 h period. Optimal, moderate, and low long-term and daily adherence groups were defined as long-term adherence above or below 95 and 75% and daily adherence above or below 90 and 75%. Regression models were used to identify patient characteristics associated with long-term adherence. In total, 296 participants [median age 64 years; interquartile range (IQR) 57-72; 19% female] were found eligible, yielding 44 003 days for analysis. The median long-term adherence was 88.2% (IQR 74.6-96.5%). A total of 83 (28%), 127 (42.9%), and 86 (29.1%) participants had optimal, moderate, and low long-term adherence, and 163 (55.1%), 87 (29.4%), and 46 (15.5%) had optimal, moderate, and low daily adherence, respectively. Age and smoking habits differed significantly between adherence levels, and increasing changeover intervals improved the degree of long-term adherence. Conclusion: Long-term adherence to a wearable activity tracker was 88.2% over a 6-month period. Older age and longer changeover interval were positively associated with long-term adherence. This serves as a benchmark for future studies that rely on wearable devices. Trial registration number: The National Trial Registration number: NL9218 (https://onderzoekmetmensen.nl/).

Extraction and Reimplantation of a Subcutaneous Implantable Cardioverter Defibrillator: Two Cases and a Review of the Literature.

For several years, implantable cardioverter defibrillators (ICDs) have been the cornerstone for the prevention of sudden cardiac death. However, the weakness of traditional transvenous ICD systems lies in the intravascular lead, which is prone to issues such as conductor fracture, insulation abrasion, risk of dislodgement, and infection. With the new generation of subcutaneous defibrillators, these risks are far less common. To date, the frequency of lead fracture is very low, and infection is much rarer. The management of these complications requires complete lead extraction. Traction is the reference procedure, sometimes necessitating the use of a dilating sheath. These techniques remain straightforward to perform without significant risk of procedural complications. Nevertheless, they must be carried out by an expert in cardiac pacing. We report here two cases with indications for lead extraction: one for lead dysfunction and the other for an infection related to a replacement procedure. The management approaches will be described, followed by a review of the literature.

Spanish implantable cardioverter-defibrillator registry. 20th official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2023).

INTRODUCTION: This article presents data on implantable cardioverter-defibrillator implants in Spain in 2023. METHODS: The registry is based on information provided by centers following device implantation, which is submitted to the Heart Rhythm Association of the Spanish Society of Cardiology via the national online registry platform (Cardiodispositivos). Additional information sources include: a) data transfer from the manufacturing and marketing industry; and b) local databases sent from the implanting centers. Population data from the National Institute of Statistics for the first quarter of 2024 was used to calculate implant rates. RESULTS: In 2023, 180 hospitals participated in the registry. Data were reported for 8219 units, compared with 8523 reported by Eucomed (European Confederation of Medical Suppliers Associations). The total implant rate was 172 implants per million inhabitants (177 according to Eucomed), representing an increase compared with previous years. However, differences among autonomous communities persisted, and Spain continues to have the lowest implant rate among the European countries participating in Eucomed. CONCLUSIONS: The data from the 2023 registry reflects 96.4% of the implants performed in Spain. Despite the improvement observed in the implantation rate, Spain's position in Europe remains unchanged, with wide disparities among autonomous communities. Full English text available from: www.revespcardiol.org/en.

Tricuspid valve surgery following septal myectomy in patients with a cardiac implantable electronic device.

Background: Patients with hypertrophic cardiomyopathy (HCM) are at increased risk of developing cardiac arrhythmias and have a high prevalence of cardiac implantable electronic device (CIED) use. Tricuspid regurgitation (TR) is a potential complication of device leads and can be severe enough to prompt surgical intervention. Methods: We identified 21 consecutive patients who underwent tricuspid valve (TV) surgery for device lead-induced TR late following septal myectomy (SM) for obstructive HCM. The primary endpoint was long-term all-cause mortality. Results: The median patient age was 63 years (range, 55-71 years), 19 patients (91%) had New York Heart Association class III or IV limitation, and all patients were receiving diuretics for right heart failure. The median interval between device implantation and TV surgery was 4 years (range, 1.5-8.5 years). Eight patients (38%) underwent pacemaker implantation due to complete heart block following SM. Preoperatively, TR was severe in 81% of the patients. The primary mechanism of lead-induced TR was leaflet impingement without adherence (n = 15; 75%). Nine patients (43%) underwent TV replacement, and 12 patients (57%) underwent repair. Only 1 patient died early postoperatively. Patients with lead-induced TR had markedly reduced long-term survival compared to the overall population of patients undergoing SM; 5-year survival was 58%, compared to 96% for the contemporary SM group. Conclusions: Late lead-induced TR is a potential complication of CIEDs in patients with HCM who have undergone SM. Although TV repair and replacement can be done with acceptable early mortality, late patient survival is poor.

Benefit of implantable cardioverter defibrillator use in Japanese patients based on modified MADIT-ICD benefit score.

AIMS: The MADIT-ICD benefit score is used to stratify the risk of life-threatening arrhythmia and non-arrhythmic mortality. We sought to develop an implantable cardioverter defibrillator (ICD) benefit-prediction score for Japanese patients with ICDs. METHODS: Patients who underwent ICD implantation as primary prophylaxis were retrospectively enrolled. Based on their MADIT-ICD benefit scores, we developed a modified MADIT-ICD benefit score adapted to the Japanese population. The primary endpoints were appropriate ICD therapy and all-cause death without appropriate ICD therapy (non-arrhythmic death). We used the Fine and Gray multivariate model and Cox proportional hazard regression to identify factors for adjusting the MADIT-ICD benefit-risk score specifically for the Japanese population. The scoring points for the original MADIT-ICD benefit score were adjusted to optimal points based on the multivariate analysis results in the population. RESULTS: The study enrolled 167 patients [age, 61.9 ± 12.3 years; male individuals, 138 (82.6%); cardiac resynchronization therapy, 73 (43.7%); ischaemic cardiomyopathy, 53 (31.7%)]. Fourteen patients received anti-tachycardia pacing (ATP) therapy, and 23 received shock therapy as the initial appropriate ICD therapy. Non-arrhythmic deaths occurred in 37 patients. The original MADIT-ICD benefit score could not stratify non-arrhythmic mortality in the Japanese population. The patients were reclassified into three groups according to the modified MADIT-ICD benefit score. The modified MADIT-ICD benefit score could effectively stratify the incidence of appropriate ICD therapy and non-arrhythmic mortality. In the highest-benefit group, the 10 year cumulative rates of appropriate ICD therapy and non-arrhythmic mortality were 56.8% and 12.9%, respectively (P < 0.01). In the intermediate-benefit group, these rates were 20.2% and 40.2% (P = 0.01). In the lowest-benefit group, the incidence of non-arrhythmic deaths was 68.1%, and no patient received appropriate ICD therapy. CONCLUSIONS: The modified MADIT-ICD benefit score may be useful for stratifying ICD candidates in the Japanese population.

Relationship between activity and sleep, as measured through a wearable accelerometer, and appropriate cardioverter-defibrillator interventions: a prospective SafeHeart substudy.

INTRODUCTION: Physical activity has shown association with ventricular arrhythmia, however, the role of specific behavioral patterns over a 24-hour cycle remains unknown. Therefore, we aimed to explore associations between physical behavior and appropriate implantable cardioverter-defibrillator (ICD) therapy. METHODS: We included patients with an ICD at two European sites, who wore wrist-based accelerometers capturing 24-hour movement and sleep behaviors for 28 days. Behavioral measures included activity volume, duration and intensity, sleep duration and efficiency. Patients were followed for 12 months for the outcome of appropriate ICD therapy. Cox proportional hazard models with restricted cubic splines were used for the analysis. Lastly, the predictive capacity was tested. RESULTS: : A total of 253 ICD patients were included (mean age 63.8 (±10.2), 50 (19.8%) female). During follow-up, 40 patients (15.8%) received appropriate ICD therapy; 32 ATP only (12.6%), 5 shock only (2.0%) and 3 combined ATP and shock (1.2%). In the adjusted model, high inactive duration (HR 1.40 (95% 1.10-1.78), peak walking cadence (HR 1.07 (95% 1.03-1.12) and total sleep duration (HR 1.50 (1.02-2.22) were associated with the outcome. The dose-response relationship was U-shaped for inactive duration with a cutoff at 16 hours, and linear for peak cadence and sleep. The prediction model reached an AUROC of 0.70 ±0.03, with highest accuracy in the first months. CONCLUSION: Wearable-derived 24-hour movement and sleep behaviors collected over 28 days were associated with later appropriate ICD therapy risk. Testing of the predictive value of digital biomarkers for enhanced risk stratification of ventricular arrhythmia warrants larger prospective studies. TRIAL REGISTRATION: National Trial Registration (NL9218, http://onderzoekmetmensen.nl/).

Validation of the German Purpose in Life Questionnaire (PLQ) in a healthy population and patients with cardiovascular disease.

In this cross-sectional study, a German translation of the subscale "Purpose in Life" (PLQ) from the Scales of Psychological Well-being (SPWB) was validated in a representative sample of participants from healthy and cardiovascular populations. The main objectives were to assess the reliability, convergent, and discriminant validity using a large and representative sample (N = 466 healthy sample, N = 247 patients with an implanted cardioverter-defibrillator (ICD), N = 70 patients with a cardiovascular disease (CVD)). The findings indicated that the German PLQ is a reliable and valid measure of positive psychological well-being, showing a positive correlation with health-related quality of life, optimism, and positive affect. In turn, the PLQ score was significantly and negatively correlated with depressive symptom severity, anxiety, pessimism, and negative affect, while being distinct from these constructs. The comparability of the measurement properties of the German PLQ with the original English version further supports the validity of the translation. Additionally, the unidimensional structure of the German version mirrored that of the English PLQ. As this study used a large and representative sample, it provides the most up-to-date normative population value for the subscale of the SPWB. Moreover, this study represents the first known exploration of the questionnaire in a cardiovascular sample, revealing relationships between health-related quality of life, optimism, positive affect, and the German PLQ. However, in patients with ICD, the positive correlation between the PLQ and the physical component of the SF-12 did not reach significance. Despite these valuable findings, future research to enhance the understanding of the PLQ and its implications is warranted.

Prediction of sudden cardiac death using artificial intelligence: Current status and future directions.

Sudden cardiac death (SCD) remains a pressing health issue, affecting hundreds of thousands each year globally. The heterogeneity among SCD victims, ranging from individuals with severe heart failure to seemingly healthy individuals, poses a significant challenge for effective risk assessment. Conventional risk stratification, which primarily relies on left ventricular ejection fraction, has resulted in only modest efficacy of implantable cardioverter-defibrillators (ICD) for SCD prevention. In response, artificial intelligence (AI) holds promise for personalised SCD risk prediction and tailoring preventive strategies to the unique profiles of individual patients. Machine and deep learning algorithms have the capability to learn intricate non-linear patterns between complex data and defined endpoints, and leverage these to identify subtle indicators and predictors of SCD that may not be apparent through traditional statistical analysis. However, despite the potential of AI to improve SCD risk stratification, there are important limitations that need to be addressed. We aim to provide an overview of the current state-of-the-art of AI prediction models for SCD, highlight the opportunities for these models in clinical practice, and identify the key challenges hindering widespread adoption.

Body Image Concerns in patients with an Implantable Cardioverter Defibrillator: Association with other PRO measures.

AIM: To investigate associations between Body Image concerns (BICs) measured by the ICD Body Image Concerns Questionnaire (ICD-BICQ) and other Patient-Reported-Outcomes (PROs), in a cohort of patients with an Implantable Cardioverter Defibrillator (ICD). METHODS AND RESULTS: In a cross-sectional survey, we included patients >18 years implanted with a first-time ICD (VVI, DDD and CRT-D) who had lived with their ICD from 3-24 months. They completed the 39-item ICD-BICQ together with the Generalized Anxiety Disorder-scale, Patient Health-Questionnaire, Type D-Scale, Health Status-Questionnaire and the Florida Patient Acceptance-Survey. Data were analyzed using linear regression to compare personality constructs between patients with and without BICs. Logistic repression and receiver operating characteristic curves were used to predict patients with BICs based on other PROs.A total of 330 patients completed the survey. Five patients were excluded due to re-operations leaving 325 patients in the analyses. A total of 20% reported BICs at the recommended cut-off at 36-points. Patients with BICs reported higher anxiety and depression levels, lower device acceptance and health status, had a Type D personality as compared to patients without BICs. FPAS was moderately able to predict BICs, while other PROs only had limited ability to predict BICs. CONCLUSION: Patients with BICs reported poorer PROs. The PRO instruments were not able to predict patients with BICs, indicating that the ICD-BICQ provides independent relevant clinical information. In clinical practice, healthcare professionals can use the ICD-BICQ to identify and obtain information on possible BICs. The ICD-BICQ can also be used to evaluate new operation techniques.

Cardiovascular Implantable Electronic Device Infections: A Contemporary Review.

Infections associated with cardiac implantable electronic devices (CIEDs) are increasing and are a cause of significant morbidity and mortality. This article summarizes the latest updates with respect to the epidemiology, microbiology, and risk factors for CIED-related infections. It also covers important considerations regarding the diagnosis, management, and prevention of these infections. Newer technologies such as leadless pacemakers and subcutaneous implantable cardioverters and defibrillators are discussed.

Standard Defibrillator Leads for Left Bundle Branch Area Pacing: First-in-Man Experience and Short-Term Follow-Up.

The authors report for the first time to their knowledge, implantation of a standard implantable cardioverter-defibrillator lead for permanent delivery of left bundle branch area pacing. Implantation was successful and safe in 11 of 12 patients, with adequate defibrillation testing, good electrical and electrocardiographic parameters, and uneventful device-related short-term follow-up.

Implantable Cardioverter-Defibrillators Among Older Survivors of Out-of-Hospital Cardiac Arrest.

BACKGROUND: Although current guidelines recommend implantable cardioverter-defibrillator (ICD) placement in survivors of out-of-hospital cardiac arrest, contemporary data on secondary-prevention ICDs in survivors of out-of-hospital cardiac arrest remain limited. METHODS AND RESULTS: Using 2013 to 2019 CARES (Cardiac Arrest Registry to Enhance Survival) linked to Medicare, we identified 3226 patients aged ≥65 years with an initial shockable rhythm who survived to discharge without severe neurological disability. Multivariable hierarchical regression models were used to examine the association between patient variables and ICD placement and quantify hospital variation in ICD implantation. The mean age was 72.2 years, 23.5% were women, 10% were Black individuals, and 4% were Hispanic individuals. Overall, 997 (30.9%) patients received an ICD before discharge, 1266 (39.2%) at 90 days, and 1287 (39.9%) within 6 months. Older age (≥85 years), female sex, history of diabetes, calendar year, and presentation with acute myocardial infarction were associated with lower odds of ICD implantation, but race or ethnicity was not associated with ICD implantation. Among 297 hospitals, the median proportion of survivors receiving ICD at discharge was 28.6% (interquartile range, 20%-50%). The relative odds of ICD implantation varied by 62% across hospitals (median odds ratio, 1.62 [95% CI, 1.38-1.82]) after adjusting for case mix. CONCLUSIONS: Fewer than 1 in 3 survivors of out-of-hospital cardiac arrest due to a shockable rhythm received a secondary-prevention ICD before discharge. Although patient variables were associated with ICD implantation, there was no difference by race or ethnicity. Even after adjusting for patient case mix, ICD implantation varied markedly across hospitals.

Validation of Novel Risk Prediction Models in Patients with Brugada Syndrome: A Multicenter Study in Japan.

BACKGROUND: Risk stratification in patients with Brugada syndrome (BrS) is challenging, especially in those at intermediate risk. The Predicting Arrhythmic evenT (PAT) score has recently been demonstrated to be excellent for predicting future arrhythmic events in patients without prior ventricular fibrillation (VF). However, validation studies are lacking. OBJECTIVE: This study aimed to assess the performance of a novel risk stratification model in predicting future VF events in patients with BrS in a Japanese multicenter cohort. METHODS: The PAT score was calculated for 413 patients with BrS (mean age, 50.9±13.6 years; 395 men) from 59 hospitals in Japan, including 314 patients without prior VF. The incidence of developing VF during the follow-up period was investigated. RESULTS: During the 106.8-month follow-up period, 54 patients (13.1%) experienced VF events. Of the 314 patients without prior VF at enrollment, 14 (4.5%) experienced VF events. The incidence of VF events during the follow-up period was significantly higher in patients with PAT scores ≥10 than in those with scores <10 (41/173 [23.7%] vs. 13/240 [5.4%], p<0.0001) in the total cohort. No difference was observed in the incidence of VF events between patients with PAT scores ≥10 and <10 among the 314 patients without prior VF (6/86 [7.0%] vs. 8/228 [3.5%], p=0.22). PAT scores ≥10 predicted future VF events with a sensitivity and specificity of 42.9% and 73.3%, respectively. CONCLUSION: This Japanese multicenter registry demonstrated that the novel risk stratification model could not accurately predict future VF events in patients with BrS, but without prior VF.

Implantable cardioverter defibrillator therapy in paediatric patients for primary vs. secondary prevention.

AIMS: The decisions about placing an ICD in a child are more difficult than in an adult due to longer expected lifespan and the complication risk. Young patients gain the most years from ICDs, despite higher risk of device-related complications. The secondary prevention ICD indication is clear, and device is implanted regardless of potential complications. For primary prevention, risk of sudden cardiac death and complications need to be evaluated. We aimed to compare outcomes for primary and secondary prevention ICDs. METHODS AND RESULTS: Retrospective nationwide cohort study including paediatric patients identified from the Danish ICD registry with ICD implanted at an age ≤ 15 from 1982-21. Demographics, complications (composite of device-related infections or lead-failure requiring re-operation, mortality because of arrhythmia, or unknown cause), and mortality were retrieved from medical charts. Endpoint was appropriate therapy (shock or anti-tachycardia pacing for ventricular tachycardia or fibrillation). Of 72 receiving an ICD, the majority had channelopathies (n = 34) or structural heart diseases (n = 28). ICDs were implanted in 23 patients for primary prevention and 49 for secondary prevention, at median ages of 13.8 and 11.6 years (P-value 0.01), respectively. Median follow-up was 9.0 (interquartile ranges: 4.7-13.5) years. The 10-year cumulative incidence of first appropriate therapy was 70%, with complication and inappropriate therapy rates at 41% and 15%, respectively. No difference was observed between prevention groups for all outcomes. Six patients died during follow-up. CONCLUSION: In children, two-thirds are secondary prevention ICDs. Children have higher appropriate therapy and complication rates than adults, while the inappropriate therapy rate was low.