Managing Implanted Cardiac Electronic Devices in Patients With Severe Tricuspid Regurgitation: JACC State-of-the-Art Review.

Orthotopic transcatheter tricuspid valve replacement (TTVR) devices have been shown to be highly effective in reducing tricuspid regurgitation (TR), and interest in this therapy is growing with the recent commercial approval of the first orthotopic TTVR. Recent TTVR studies report preexisting cardiac implantable electronic device (CIED) transvalvular leads in ∼35% of patients, with entrapment during valve implantation. Concerns have been raised regarding the safety of entrapping leads and counterbalanced against the risks of transvenous lead extraction (TLE) when indicated. This Heart Valve Collaboratory consensus document attempts to define the patient population with CIED lead-associated or lead-induced TR, describe the risks of lead entrapment during TTVR, delineate the risks and benefits of TLE in this setting, and develop a management algorithm for patients considered for TTVR. An electrophysiologist experienced in CIED management should be part of the multidisciplinary heart team and involved in shared decision making.

Transvenous Lead Extraction in the Left Ventricular Assist Device Patient.

The population of patients with advanced heart failure continues to increase steadily as does the need for mechanical circulatory support. Combination therapy with left ventricular assist devices (LVADs) and cardiovascular implantable electronic devices (CIEDs) is unavoidable. CIED complications in patients with LVADs are common and often necessitate device system revision and transvenous lead extraction. Despite this, management recommendations are limited, and guidelines are lacking.

Open Chest Approach Lead Extraction in a Patient with a Large Vegetation: The Importance of Multidisciplinary Approach, Advanced Imaging, and Procedural Planning.

We present a complex case of cardiac implantable electronic device infection and extraction in the setting of bacteremia, large lead vegetation, and patent foramen ovale. Following a comprehensive preprocedural workup including transesophageal echocardiogram and computed tomography lead extraction protocol, in addition to the involvement of multiple subspecialties, an open chest approach to extraction was deemed a safer option for eradication of the patient's infection. Despite percutaneous techniques having evolved as the preferred extraction method during the last few decades, this case demonstrates the importance of a thorough evaluation at an experienced center to determine the need for open chest extraction.

Case Series and Review of Literature for Superior Vena Cava Injury During Laser Lead Extraction.

Transvenous laser lead extraction poses a risk of major complications (0.19%-1.8%), notably injury to the superior vena cava (SVC) in 0.19% to 0.96% of cases. Various factors contribute to SVC injury, which can be categorized as patient-related (such as female gender, low body mass index, diabetes, renal problems, anemia, and reduced ejection fraction), device-related (including the number, dwell time, and type of leads), or procedural-related (such as reason for extraction, venous obstructions, and bilateral lead placements).

The axillary vein puncture for implantable cardiac defibrillator implantation: 14 years of experience. Analysis of the results.

BACKGROUND: Axillary vein puncture (AVP) is a valid alternative to Subclavan vein puncture for leads insertion in cardiac implantable electronic device implantation, that may reduce acute and delayed complications. Very few data are available about ICD recipients. A simplified AVP technique is described. METHODS: All the patients who consecutively underwent "de novo" ICD implantation, from March 2006 to December 2020 at the University of Verona, were considered. Leads insertion was routinely performed through an AVP, according to a simplified technique. Outcome and complications have been retrospectively analyzed. RESULTS: The study population consisted of 1711 consecutive patients. Out of 1711 patients, 38 (2.2%) were excluded because they were implanted with Medtronic Sprint Fidelis lead. Out of 1673 ICD implantations, 963 (57.6%) were ICD plus cardiac resynchronization therapy, 434 (25.9%) were dual-chamber defibrillators, and 276 (16.5%) were single-chamber defibrillators, for a total of 3879 implanted leads. The AVP success rate was 99.4%. Acute complications occurred in 7/1673 (0.42%) patients. Lead failure (LF) occurred in 20/1673 (1.19%) patients. Comparing the group of patients with lead failure with the group without LF, the presence of three leads inside the vein was significantly associated with LF, and the multivariate analysis confirmed three leads in place as an independent predictor of LF. CONCLUSION: AVP, according to our simplified technique, is safe, effective, has a high success rate, and a very low complication rate. The incidence of LF was exceptionally low. The advantages of AVP are maintained over time in a population of ICD recipients.

Factors of mortality in patients with cardiac implantable electronic device: 5-year experience.

OBJECTIVE: The use of cardiac implantable electronic devices has increased in recent years. It has also brought some issues. Among these, the complications of cardiac implantable electronic devices infection and pocket hematoma are difficult to manage. It can be fatal with the contribution of patient-related risk factors. In this study, we aimed to find mortality rates in patients who developed cardiac implantable electronic devices infection and pocket hematoma over 5 years. We also investigated the risk factors affecting mortality in patients with cardiac implantable electronic devices. METHODS: A total of 288 cardiac implantable electronic devices patients were evaluated. Demographic details, history, and clinical data of all patients were recorded. Cardiac implantable electronic devices infection was defined according to the modified Duke criteria. The national registry was used to ascertain the mortality status of the patients. The patients were divided into two groups (exitus and survival groups). In addition, the pocket hematoma was defined as significant bleeding at the pocket site after cardiac implantable electronic devices placement. RESULTS: The cardiac implantable electronic devices infection was similar in both groups (p=0.919), and the pocket hematoma was higher in the exitus group (p=0.019). The exitus group had higher usage of P2Y12 inhibitors (p≤0.001) and novel oral anticoagulants (p=0.031). The Cox regression analysis, including mortality-related factors, revealed that renal failure is the most significant risk factor for mortality. Renal failure was linked to a 2.78-fold higher risk of death. CONCLUSION: No correlation was observed between cardiac implantable electronic devices infection and mortality, whereas pocket hematoma was associated with mortality. Furthermore, renal failure was the cause of the highest mortality rate in patients with cardiac implantable electronic devices.

Complicaciones y descargas inapropiadas tras el implante de un desfibrilador subcutáneo en pacientes pediátricos / Complications and inappropriate shocks in pediatric patients receiving a subcutaneous implantable cardioverter defibrilator

Introducción y objetivos: La experiencia con el desfibrilador automático implantable subcutáneo (DAI-SC) en pacientes pediátricos aún es reducida. El objetivo de este estudio es determinar la incidencia de complicaciones en pacientes pediátricos de nuestro centro en función del tipo de DAI y del tamaño del paciente.MétodosSe incluyó a pacientes menores de 18 años que recibieron un DAI-SC desde 2016 y pacientes contemporáneos (desde 2014) que recibieron un DAI transvenoso (DAI-TV). El evento principal fue el combinado de complicaciones y descargas inapropiadas.ResultadosSe implantó un DAI-SC a 26 pacientes (edad, 14 [intervalo, 5-17] años; índice de masa corporal [IMC], 20,2). De ellos, 23 (88%) fueron implantes intermusculares y el resto, en subserrato, 24 (92%) con 2 incisiones. Se programaron 2 zonas en todos los pacientes: condicional a 230 (220-230) lpm y de choque a 250 lpm. El grupo de DAI-TV incluyó a 19 pacientes (edad, 11 [5-16] años; IMC, 19,2; el 79% monocamerales). La supervivencia libre del evento principal a 5 años fue el 80% de los pacientes con DAI-SC y el 63% del grupo con DAI-TV (p=0,54); la de descargas inapropiadas fue similar (el 85 frente al 89%; p=0,86), mientras que la de complicaciones fue mayor en el grupo de DAI-SC (el 96 frente al 57%; cloglog p=0.016). En el grupo de DAI-SC no hubo fallo de la terapia ni mayores complicaciones con un IMC ≤ 20.ConclusionesCon las técnicas de implante y programación actuales, el DAI-SC es eficaz y seguro en pacientes pediátricos, con similares descargas inapropiadas y menos complicaciones a corto y medio plazo que el DAI-TV. (AU)

Introduction and objectives: There 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. (AU)

Infective Endocarditis Involving Implanted Cardiac Electronic Devices: JACC Focus Seminar 1/4.

Cardiac implantable electronic device-related infective endocarditis (CIED-IE) encompasses a range of clinical syndromes, including valvular, device lead, and bloodstream infections. However, accurately diagnosing CIED-IE remains challenging owing in part to diverse clinical presentations, lack of standardized definition, and variations in guideline recommendations. Furthermore, current diagnostic modalities, such as transesophageal echocardiography and [18F]-fluorodeoxyglucose positron emission tomography-computed tomography have limited sensitivity and specificity, further contributing to diagnostic uncertainty. This can potentially result in complications and unnecessary costs associated with inappropriate device extraction. Six hypothetical clinical cases that exemplify the diverse manifestations of CIED-IE are addressed herein. Through these cases, we highlight the importance of optimizing diagnostic accuracy and stewardship, understanding different pathogen-specific risks for bloodstream infections, guiding appropriate device extraction, and preventing CIED-IE, all while addressing key knowledge gaps. This review both informs clinicians and underscores crucial areas for future investigation, thereby shedding light on this complex and challenging syndrome.

Impact of a Chronic Total Coronary Occlusion on the Incidence of Appropriate Implantable Cardioverter-Defibrillator Shocks and Mortality: A Substudy of the Dutch Outcome in ICD Therapy (DO-IT)) Registry.

BACKGROUND: Chronic total coronary occlusions (CTO) substantially increase the risk for sudden cardiac death. Among patients with chronic ischemic heart disease at risk for sudden cardiac death, an implantable cardioverter defibrillator (ICD) is the favored therapy for primary prevention of sudden cardiac death. This study sought to investigate the impact of CTOs on the risk for appropriate ICD shocks and mortality within a nationwide prospective cohort. METHODS AND RESULTS: This is a subanalysis of the nationwide Dutch-Outcome in ICD Therapy (DO-IT) registry of primary prevention ICD recipients in The Netherlands between September 2014 and June 2016 (n=1442). We identified patients with chronic ischemic heart disease (n=663) and assessed available coronary angiograms for CTO presence (n=415). Patients with revascularized CTOs were excluded (n=79). The primary end point was the composite of all-cause mortality and appropriate ICD shocks. Clinical follow-up was conducted for at least 2 years. A total of 336 patients were included, with an average age of 67±9 years, and 20.5% was female (n=69). An unrevascularized CTO was identified in 110 patients (32.7%). During a median follow-up period of 27 months (interquartile range, 24-32), the primary end point occurred in 21.1% of patients with CTO (n=23) compared with 11.9% in patients without CTO (n=27; P=0.034). Corrected for baseline characteristics including left ventricular ejection fraction, and the presence of a CTO was an independent predictor for the primary end point (hazard ratio, 1.82 [95% CI, 1.03-3.22]; P=0.038). CONCLUSIONS: Within this nationwide prospective registry of primary prevention ICD recipients, the presence of an unrevascularized CTO was an independent predictor for the composite outcome of all-cause mortality and appropriate ICD shocks.

Subcutaneous air entrapment after subcutaneous implantable cardioverter defibrillator implantation evaluated by computed tomography.

BACKGROUND: Inappropriate shock (IAS) caused by subcutaneous air entrapment (AE) in an early period after subcutaneous implantable cardioverter defibrillator (S-ICD) implantation has been reported, however, no detailed data on air volume are available. We evaluated the subcutaneous air volume after implantation and its absorption rate one week after implantation. METHODS: Patients who underwent S-ICD implantation in our hospital received chest CT scans immediately after implantation and followed up 1 week later. The total subcutaneous air volume, air around the generator, the distal electrode, and the proximal electrode within 3 cm were calculated using a three-dimensional workstation. Fat areas at the level of the lower edge of the generator were also analyzed. RESULT: Fifteen patients received CT immediately after implantation. The mean age was 45.6 ± 17.9 (66.7% of men), and the mean body mass index was 24.3 ± 3.3. The three-incision technique was applied in seven patients and two-incision technique was in the latter eight patients. The mean total subcutaneous air volume was 18.54 ± 7.50 mL. Air volume around the generator, the distal electrode, and the proximal electrode were 11.05 ± 5.12, 0.72 ± 0.72, and 0.88 ± 0.87 mL, respectively. Twelve patients received a follow-up CT 1 week later. The mean total subcutaneous air was 0.25 ± 0.45 mL, showing a 98.7% absorption rate. CONCLUSION: Although subcutaneous air was observed in all patients after S-ICD implantation, most of the air was absorbed within 1 week, suggesting a low occurrence of AE-related IAS after a week postoperation.

First implantable cardiac defibrillator insertions in New South Wales, 2005-2020: an analysis of linked administrative data.

OBJECTIVES: To determine the annual numbers of first ICD insertions in New South Wales during 2005-2020; to examine health outcomes for people who first received ICDs during this period. STUDY DESIGN: Retrospective cohort study; analysis of linked administrative health data. SETTING, PARTICIPANTS: All first insertions of ICDs in NSW, 2005-2020. MAIN OUTCOME MEASURES: Annual numbers of first ICD insertions, and of emergency department presentations and hospital re-admissions 30 days, 90 days, 365 days after first ICD insertions; all-cause and disease-specific mortality (to ten years after ICD insertion). RESULTS: During 2005-2020, ICDs were first inserted into 16 867 people (18.5 per 100 000 population); their mean age was 65.7 years (standard deviation, 13.5 years; 7376 aged 70 years or older, 43.7%), 13 214 were men (78.3%). The annual number of insertions increased from 791 in 2005 to 1256 in 2016; the first ICD insertion rate increased from 15.5 in 2005 to 18.9 per 100 000 population in 2010, after which the rate was stable until 2019 (19.8 per 100 000 population). Of the 16 778 people discharged alive from hospital after first ICD insertions, 54.4% presented to emergency departments within twelve months, including 1236 with cardiac arrhythmias (7.4%) and 434 with device-related problems (2.6%); 56% were re-admitted to hospital, including 1944 with cardiac arrhythmias (11.5%) and 2045 with device-related problems (12.1%). A total of 5624 people who received first ICDs during 2005-2020 (33.3%) died during follow-up (6.7 deaths per 100 person-years); the survival rate was 94.4% at one year, 76.5% at five years, and 54.2% at ten years. CONCLUSIONS: The annual number of new ICDs inserted in NSW has increased since 2005. A substantial proportion of recipients experience device-related problems that require re-admission to hospital. The potential harms of ICD insertion should be considered when assessing the likelihood of preventing fatal ventricular arrhythmia.

Cardiac implantable electronic device-induced tricuspid regurgitation: Implications and management.

Tricuspid regurgitation (TR) secondary to cardiac implantable electronic devices (CIEDs) has been well documented and is associated with worse cardiovascular outcomes. A variety of mechanisms have been proposed including lead-induced mechanical disruption of the tricuspid valvular or subvalvular apparatus and pacing-induced electrical dyssynchrony. Patient characteristics such as age, sex, baseline atrial fibrillation, and pre-existing TR have not been consistent predictors of CIED-induced TR. While two-dimensional echocardiography is helpful in assessing the severity of TR, three-dimensional echocardiography has significantly improved accuracy in identifying the etiology of TR and whether lead position contributes to TR. Three-dimensional echocardiography may therefore play a future role in optimizing lead positioning during implant to reduce the risk of CIED-induced TR. Optimal lead management strategies in addition to percutaneous interventions and surgery in alleviating TR are very important.

Relationship of Mild to Moderate Impairment of Left Ventricular Ejection Fraction With Fatal Ventricular Arrhythmic Events in Cardiac Sarcoidosis.

BACKGROUND: Current guidelines recommend placing an implantable cardiac defibrillator for patients with cardiac sarcoidosis and a severely impaired left ventricular ejection fraction (LVEF) of ≤35%. In this study, we determined the association between mild or moderate LVEF impairment and fatal ventricular arrhythmic event (FVAE). METHODS AND RESULTS: We retrospectively analyzed 401 patients with cardiac sarcoidosis without sustained ventricular arrhythmia at diagnosis. The primary end point was an FVAE, defined as the combined endpoint of documented ventricular tachycardia or ventricular fibrillation and sudden cardiac death. Two cutoff points for LVEF were used: a sex-specific lower threshold of normal range of LVEF (52% for men and 54% for women) and an LVEF of 35%, which is used in the current guidelines. During a median follow-up of 3.2 years, 58 FVAEs were observed, and the 5- and 10-year estimated incidences of FVAEs were 16.8% and 23.0%, respectively. All patients were classified into 3 groups according to LVEF: impaired LVEF group, mild to moderate impairment of LVEF group, and maintained LVEF group. Multivariable competing risk analysis showed that both the impaired LVEF group (hazard ratio [HR], 3.24 [95% CI, 1.49-7.04]) and the mild to moderate impairment of LVEF group (HR, 2.16 [95% CI, 1.04-4.46]) were associated with a higher incidence of FVAEs than the maintained LVEF group after adjustment for covariates. CONCLUSIONS: Patients with cardiac sarcoidosis are at a high risk of FVAEs, regardless of documented ventricular arrhythmia at the time of diagnosis. In patients with cardiac sarcoidosis, mild to moderate impairment of LVEF is associated with FVAEs.

Cardiac implantable electronic devices and bloodstream infections: management and outcomes.

BACKGROUND AND AIMS: Bloodstream infection (BSI) of any cause may lead to device infection in cardiac implantable electronic device (CIED) patients. Aiming for a better understanding of the diagnostic approach, treatment, and outcome, patients with an implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy and defibrillator (CRT-D) hospitalized with BSI were investigated. METHODS: This is a single-centre, retrospective, cohort analysis including consecutive ICD/CRT-D patients implanted between 2012 and 2021. These patients were screened against a list of all hospitalized patients having positive blood cultures consistent with diagnosed infection in any department of a local public hospital. RESULTS: The total cohort consisted of 515 patients. Over a median follow-up of 59 months (interquartile range 31-87 months), there were 47 BSI episodes in 36 patients. The majority of patients with BSI (92%) was admitted to non-cardiology units, and in 25 episodes (53%), no cardiac imaging was performed. Nearly all patients (85%) were treated with short-term antibiotics, whereas chronic antibiotic suppression therapy (n = 4) and system extraction (n = 3) were less frequent. Patients with BSI had a nearly seven-fold higher rate (hazard ratio 6.7, 95% confidence interval 3.9-11.2; P < .001) of all-cause mortality. CONCLUSIONS: Diagnostic workup of defibrillator patients with BSI admitted to a non-cardiology unit is often insufficient to characterize lead-related endocarditis. The high mortality rate in these patients with BSI may relate to underdiagnosis and consequently late/absence of system removal. Efforts to increase an interdisciplinary approach and greater use of cardiac imaging are necessary for timely diagnosis and adequate treatment.

The Importance of Nitric Oxide and Oxidative Stress in Atrial High-Rate Episodes in Patients with Cardiac Devices.

OBJECTIVE: Atrial High Rate Episodes (AHRE) are subclinical atrial tachyarrhythmias detectable by cardiac implantable electronic devices (CIEDs). AHREs have been associated with an increased risk of developing atrial fibrillation (AF), thromboembolism, cardiovascular and cerebrovascular events, and mortality. Although recent studies have assessed the value of oxidative stress markers in patients with AF, the relationships between AHRE and oxidative stress markers, including nitric oxide, has not yet been elucidated. This study aims to investigate the relationship between these markers and AHRE. METHOD: This prospective, cross-sectional study comprised 180 patients with CIEDs. The study population was divided into two groups based on the presence (n = 78) and absense (n = 102) of AHRE to analyze its association with biomarkers. RESULTS: The AHRE (+) group was significantly older, had a higher prevalence of hypertension, higher NT-proBNP (508.8 ± 249 pg/mL vs. 415.3 ± 292.1; P = 0.037), MDA levels (20.9 ± 4.1 µmol/L vs. 19.1 ± 3.1 µmol/L; P = 0.006), and iNOS activity (1,935.9 ± 326.1 pg/mL vs. 1,677.4 ± 363.2 pg/mL; P < 0.001). Logistic regression analysis identified age, hypertension, MDA (odds ratio [OR]: 1.131, 95%CI: 1.009 - 1.268, P = 0.035), inducible nitric oxide synthase (iNOS) activity (OR = 1.002, 95% CI = 1.001 - 1.003, P < 0.001), and endothelial nitric oxide synthase (eNOS) activity (OR = 0.990, 95% CI = 0.986 - 0.984, P < 0.001) as independent predictors of AHRE. CONCLUSION: The study findings indicated that plasma levels of NT-proBNP, MDA, nitric oxide, and the expression of iNOS and eNOS were significantly associated with AHRE. Moreover, elevated plasma MDA concentrations, increased iNOS activity, and decreased eNOS activity were identified as independent predictors of AHRE.

[Whether to implant a defibrillator or not? The Possibility of Using the MADIT-ICD Benefit Score Calculator in Real Practice].

AIM: To study the predictive capabilities of the MADIT-ICD Benefit Score calculator in assessing the benefit of implantable cardioverter defibrillator (ICD) placement for the primary prevention of sudden cardiac death (SCD). MATERIAL AND METHODS: This study included 388 patients with NYHA II-IV functional class chronic heart failure (CHF) with a left ventricular ejection fraction (LVEF) ≤35 % who underwent ICD placement for the primary prevention of SCD. Patients were followed up for two years to record the endpoints of first-time paroxysmal sustained ventricular tachyarrhythmia (VT) or non-arrhythmic death. RESULTS: According to the results of calculation with the MADIT-ICD Benefit Score calculator, 276 (71 %) patients had a high risk of VT (score ≥7) and 150 (39 %) had a high risk of non-arrhythmic death (score ≥3). 336 (94%) patients would benefit from an ICD: 148 (38 %) with a high level of probability and 218 (56 %) with a medium level of probability. According to the incidence of endpoints, VT episodes predominated in the low-ICD benefit group (36%), while the high-ICD benefit group had a relatively high incidence of non-arrhythmic death (12%). CONCLUSION: The results obtained for a cohort of Russian patients with CHF and reduced LVEF indicated that the use of the MADIT-ICD Benefit Score in routine clinical practice does not improve the stratification of SCD risk compared to the traditional approach to selecting patients with CHF for ICD based on the LVEF value.

Evaluation of patients with implantable cardioverter-defibrillator in a Latin American tertiary center.

INTRODUCTION: Despite advancements in implantable cardioverter-defibrillator (ICD) technology, sudden cardiac death (SCD) remains a persistent public health concern. Chagas disease (ChD), prevalent in Brazil, is associated with increased ventricular tachycardia (VT) and ventricular fibrillation (VF) events and SCD compared to other cardiomyopathies. METHODS: This retrospective observational study included patients who received ICDs between October 2007 and December 2018. The study aims to assess whether mortality and VT/VF events decreased in patients who received ICDs during different time periods (2007-2010, 2011-2014, and 2015-2018). Additionally, it seeks to compare the prognosis of ChD patients with non-ChD patients. Time periods were chosen based on the establishment of the Arrhythmia Service in 2011. The primary outcome was overall mortality, assessed across the entire sample and the three periods. Secondary outcomes included VT/VF events and the combined outcome of death or VT/VF. RESULTS: Of the 885 patients included, 31% had ChD. Among them, 28% died, 14% had VT/VF events, and 37% experienced death and/or VT/VF. Analysis revealed that period 3 (2015-2018) was associated with better death-free survival (p = .007). ChD was the only variable associated with a higher rate of VT/VF events (p < .001) and the combined outcome (p = .009). CONCLUSION: Mortality and combined outcome rates decreased gradually for ICD patients during the periods 2011-2014 and 2015-2018 compared to the initial period (2007-2010). ChD was associated with higher VT/VF events in ICD patients, only in the first two periods.