Trends in adoption of extravascular cardiac implantable electronic devices: the Dutch cohort.

INTRODUCTION: Conventional implantable cardioverter-defibrillators (ICDs) and pacemakers carry a risk of pocket- and lead-related complications in particular. To avoid these complications, extravascular devices (EVDs) have been developed, such as the subcutaneous ICD (S-ICD) and leadless pacemaker (LP). However, data on patient or centre characteristics related to the actual adoption of EVDs are lacking. OBJECTIVE: To assess real-world nationwide trends in EVD adoption in the Netherlands. METHODS: Using the Netherlands Heart Registration, all consecutive patients with a de novo S­ICD or conventional single-chamber ICD implantation between 2012-2020, or de novo LP or conventional single-chamber pacemaker implantation between 2014-2020 were included. Trends in adoption are described for various patient and centre characteristics. RESULT: From 2012-2020, 2190 S­ICDs and 10,683 conventional ICDs were implanted; from 2014-2020, 712 LPs and 11,103 conventional pacemakers were implanted. The general use has increased (S-ICDs 8 to 21%; LPs 1 to 8%), but this increase seems to have reached a plateau. S­ICD recipients were younger than conventional ICD recipients (p < 0.001) and more often female (p < 0.001); LP recipients were younger than conventional pacemaker recipients (p < 0.001) and more often male (p = 0.03). Both S­ICDs and LPs were mainly implanted in high-volume centres with cardiothoracic surgery on-site, although over time S­ICDs were increasingly implanted in centres without cardiothoracic surgery (p < 0.001). CONCLUSION: This nationwide study demonstrated a relatively quick adoption of innovative EVDs with a plateau after approximately 4 years. S­ICD use is especially high in younger patients. EVDs are mainly implanted in high-volume centres with cardiothoracic surgery back-up, but S­ICD use is expanding beyond those centres.

Assessment of ICD eligibility in non-ischaemic cardiomyopathy patients: a position statement by the Task Force of the Dutch Society of Cardiology.

International guidelines recommend implantation of an implantable cardioverter-defibrillator (ICD) in non-ischaemic cardiomyopathy (NICM) patients with a left ventricular ejection fraction (LVEF) below 35% despite optimal medical therapy and a life expectancy of more than 1 year with good functional status. We propose refinement of these recommendations in patients with NICM, with careful consideration of additional risk parameters for both arrhythmic and non-arrhythmic death. These additional parameters include late gadolinium enhancement on cardiac magnetic resonance imaging and genetic testing for high-risk genetic variants to further assess arrhythmic risk, and age, comorbidities and sex for assessment of non-arrhythmic mortality risk. Moreover, several risk modifiers should be taken into account, such as concomitant arrhythmias that may affect LVEF (atrial fibrillation, premature ventricular beats) and resynchronisation therapy. Even though currently no valid cut-off values have been established, the proposed approach provides a more careful consideration of risks that may result in withholding ICD implantation in patients with low arrhythmic risk and substantial non-arrhythmic mortality risk.

One-Year Mortality in Patients Undergoing an Implantable Cardioverter Defibrillator or Cardiac Resynchronization Therapy Pulse Generator Replacement: Identifying Patients at Risk.

Implantable cardioverter defibrillators (ICDs) significantly contribute to the prevention of sudden cardiac death in selected patients. However, it is essential to identify those who are likely to not have benefit from an ICD and to defer a pulse generator exchange. Easily implementable guidelines for individual risk stratification and decision making are lacking. This study investigates the 1-year mortality of patients who underwent an ICD or cardiac resynchronization therapy with defibrillator function (CRT-D) pulse generator replacement in a contemporary real-world tertiary hospital setting. The cause of death and patient- and procedure-related factors are stratified, and predictive values for 1-year mortality are evaluated. Patients with a follow-up of ≥365 days (or prior mortality) after an ICD or CRT-D exchange at the Leiden University Medical Center from 1 January 2018 until 31 December 2021 were eligible. In total, 588 patients were included (77% male, 69 [60-76] years old, 59% primary prevention, 46% ischemic cardiomyopathy and 37% mildly reduced left ventricular ejection fraction (LVEF)). Patients undergoing a CRT-D replacement or upgrade had a significantly higher 1-year all-cause mortality (10.7% and 11.9%, respectively) compared to patients undergoing ICD (2.8%) exchange (p = 0.002). LVEF ≤ 30%, New York Heart Association class ≥ 3, estimated glomerular filtration rate ≤ 30 mL/min/m2 and haemoglobin ≤ 7 mmol/L were independently associated with mortality within 1 year after pulse generator replacement. There is a growing need for prospectively validated risk scores to weight individualized risk of mortality with the expected ICD therapy benefit and to support a well-informed, shared decision-making process.

Five-year safety and efficacy of leadless pacemakers in a Dutch cohort.

BACKGROUND: Adequate real-world safety and efficacy of leadless pacemakers (LPs) have been demonstrated up to 3 years after implantation. Longer-term data are warranted to assess the net clinical benefit of leadless pacing. OBJECTIVE: The purpose of this study was to evaluate the long-term safety and efficacy of LP therapy in a real-world cohort. METHODS: In this retrospective cohort study, all consecutive patients with a first LP implantation from December 21, 2012, to December 13, 2016, in 6 Dutch high-volume centers were included. The primary safety endpoint was the rate of major procedure- or device-related complications (ie, requiring surgery) at 5-year follow-up. Analyses were performed with and without Nanostim battery advisory-related complications. The primary efficacy endpoint was the percentage of patients with a pacing capture threshold ≤2.0 V at implantation and without ≥1.5-V increase at the last follow-up visit. RESULTS: A total of 179 patients were included (mean age 79 ± 9 years), 93 (52%) with a Nanostim and 86 (48%) with a Micra VR LP. Mean follow-up duration was 44 ± 26 months. Forty-one major complications occurred, of which 7 were not advisory related. The 5-year major complication rate was 4% without advisory-related complications and 27% including advisory-related complications. No advisory-related major complications occurred a median 10 days (range 0-88 days) postimplantation. The pacing capture threshold was low in 163 of 167 patients (98%) and stable in 157 of 160 (98%). CONCLUSION: The long-term major complication rate without advisory-related complications was low with LPs. No complications occurred after the acute phase and no infections occurred, which may be a specific benefit of LPs. The performance was adequate with a stable pacing capture threshold.

NL-EVDR: Netherlands-ExtraVascular Device Registry.

Cardiac implantable electronic device (CIED) therapy is an essential element in treating cardiac arrhythmias. Despite their benefits, conventional transvenous CIEDs are associated with a significant risk of mainly pocket- and lead-related complications. To overcome these complications, extravascular devices (EVDs), such as the subcutaneous implantable cardioverter-defibrillator and intracardiac leadless pacemaker, have been developed. In the near future, several other innovative EVDs will become available. However, it is difficult to evaluate EVDs in large studies because of high costs, lack of long-term follow-up, imprecise data or selected patient populations. To improve evaluation of these technologies, real-world, large-scale, long-term data are of utmost importance. A Dutch registry-based study seems to be a unique possibility for this goal due to early involvement of Dutch hospitals in novel CIEDs and an existing quality control infrastructure, the Netherlands Heart Registration (NHR). Therefore, we will soon start the Netherlands-ExtraVascular Device Registry (NL-EVDR), a Dutch nationwide registry with long-term follow-up of EVDs. The NL-EVDR will be incorporated in NHR's device registry. Additional EVD-specific variables will be collected both retrospectively and prospectively. Hence, combining Dutch EVD data will provide highly relevant information on safety and efficacy. As a first step, a pilot project has started in selected centres in October 2022 to optimise data collection.

The development of a decision aid for shared decision making in the Dutch implantable cardioverter defibrillator patient population: A novel approach to patient education.

Background: Counseling of Implantable Cardioverter-defibrillator (ICD) patients with regard to individual risks and benefits is challenging. An evidence-based decision aid tailored to the needs of Dutch ICD patients is not yet available. The objective of this pilot project was to structurally evaluate the current clinical practice in The Netherlands and the ICD patient experience, in order to develop an online decision aid to facilitate shared decision making in ICD procedures. Methods: Between June 2016 and December 2017, a Dutch web-based decision aid was developed according to the Patient Decision Aid Standards (IPDAS) using the RAND-UCLA/multi-stepped Delphi model. Development process consisted of 5 stages in which the Dutch clinical practice was reviewed (stage 1), patients' needs and their history of decision making was structurally assessed (stages 2A and B) and a modified Delphi consensus process was performed with an expert panel consisting of representatives from different medical fields (stage 3). Results from stages 1-3 were used to design and structure the content of an online-based decision aid (stage 4) which was finally evaluated in a usability testing by patients in stage 5. Results and conclusion: This study describes the evidence-based approach to the development of the Dutch ICD decision aid. In our population, levels of shared decision-making experience were low. The ICD decision aid was structurally developed for the Dutch ICD patient population. Our upcoming multicenter stepped wedge clustered randomized trial will further evaluate the ICD decision aid in clinical practice.

Development of Central Venous Stenosis Upon ICD Implantation in Dialysis Patients: A Non-Negligible Issue.

Background: In hemodialysis patients, implantable cardioverter-defibrillator (ICD) implantation may result in central venous stenosis (CVS) with associated symptoms, such as pain, edema of the ipsilateral arm, facial edema, and loss of dialysis access. However, literature concerning CVS in dialysis patients with a cardiac implantable electronic device is scarce. Methods: We conducted a prospective cohort study in which we investigated the incidence of CVS in end-stage renal disease patients on chronic dialysis who received an ICD as part of participation in the randomized ICD2 trial. A venography was performed before ICD implantation and at 1 year follow-up. Results: Between 2007 and 2017, 80 patients on dialysis received an ICD according to ICD2 trial protocol. Our population mainly consisted of males (76.3%), and had a median age of 67 years. Hemodialysis was the predominant dialysis modality (71.3%). The ICD was implanted in the right pectoral region in 58 patients (72.5%). A minority of the patients (27.5%) had a history of central venous catheters use, ipsilateral to ICD implantation site. Median follow-up was 16 months (IQR 13-35). Prospective assessment of central vein patency was possible in 56 patients (70.0%). Partial obstruction of central vein at follow-up was present in 19 out of 56 patients (33.9%) and complete occlusion in 4 patients (7.1%). With a complete clinical follow-up of all patients with a median duration of 3.5 years (IQR 2.7 - 6.3), 3 patients developed clinically significant symptoms of CVS. Conclusions: Development of CVS in patients on chronic dialysis who received an ICD is a cause of concern. Prevention of such complications deserves attention and further research. Trial Registration: ISRCTN20479861.

Implantable cardioverter-defibrillators and the older patient: the Dutch clinical practice.

BACKGROUND AND OBJECTIVE: Balance between benefit and burden of implantable cardioverter-defibrillator (ICD) therapy is more debatable in older patients, compared to younger patients. Of around 6000 yearly implanted ICDs in the Netherlands, 1:4 is received by patients ≥75 years. We aimed to evaluate the current clinical practice in the Netherlands for ICD implants and generator replacements, with a special focus on the older ICD patients. RESEARCH DESIGN AND METHODS: Cardiologists from all Dutch ICD implanting centres (n = 28) were interviewed. Questions aimed to evaluate outpatient care, pre-operative patient assessment, end-of-life-care counselling, evaluation of social and cognitive wellbeing, clinical evaluation of all patients prior to ICD replacement, and the consideration of the option to downgrade or not replace a device. RESULTS: Implanting cardiologists from all 28 implanting centres were approached for an interview. Response rate was 86%. Management appeared diverse. An age ≥80 years was consistently reported as incentive for more extensive patient evaluation. Patients were invited for counselling prior to device replacements in only the minority (46%) of hospitals. Downgrade or non-replacement was performed in rare cases. End-of-life care discussions were not standard procedure in 67% of the hospitals. Evaluation of social and cognitive wellbeing of patients was based solely on the general clinical impression of the physician in 83%, or not at all assessed in 8% of the centres. DISCUSSION AND IMPLICATION: A structured framework for care and evaluation of cognitive and/or physical limitations is currently absent in most hospitals. At time of ICD (re-)evaluation, several factors may be considered before deciding on (continuation of) ICD therapy: patient preferences and comorbidity, the need for pacemaker therapy, primary vs. secondary prevention, procedural risks, and patient preferences.

Fusion cardiac resynchronization therapy in an left ventricular assist device patient from two devices and crossing leads: a case report.

BACKGROUND: Cardiac implanted electronic devices (CIED) have significantly improved the survival and quality of life in heart failure patients. Although implantable cardioverter-defibrillators (ICD) and cardiac resynchronization therapy (CRT) have a major role in patients with moderate to severe heart failure symptoms, the role of these devices in patients with a left ventricular assist device (LVAD) is not yet well defined. The burden of CIED-related procedures in patients with an LVAD is high. The price of lead malfunctions and pocket complications requires creative approaches to tackle CIED-related issues in this patient population. CASE SUMMARY: Here, we describe the clinical course of a 67-year-old ventricular pacing dependent LVAD patient with an ICD indication based on recurrent monomorphic ventricular tachycardias and a CRT indication due to previous deterioration of (right-sided) heart failure in the absence of biventricular pacing. We were confronted with impending right ventricular lead failure and bilateral venous access problems due to chronic subclavian vein occlusion in a patient with a total of five transvenous leads, therapeutic anticoagulation, and pronounced thoracic collaterals. We sought for a creative solution to be able to deliver effective biventricular fusion pacing with the existing leads from two contralateral pulse generators resulting in biventricular fusion pacing. This provided the solution to deliver effective CRT. DISCUSSION: This case illustrates the complexity of care and CIED-related decision-making in pacing dependent LVAD patients, in particularly those with an ICD and CRT indication.

Failing systemic right ventricle in a patient with dextrocardia and complex congenitally corrected transposition of the great arteries: a case report of successful transvenous cardiac resynchronization therapy.

BACKGROUND: Patients with congenitally corrected transposition of the great arteries (ccTGA) are prone to the development of advanced atrio-ventricular block requiring chronic ventricular pacing. The morphological right ventricle (RV) often develops systolic dysfunction as it is unable to withstand the chronic pressure overload it is exposed to when supporting the systemic circulation. CASE SUMMARY: A 56-year-old woman with dextrocardia and complex ccTGA with a history of dual-chamber implantable cardioverter-defibrillator (DDD-ICD, high degree atrio-ventricular-block and syncopal ventricular tachycardia), presented with progressive heart failure and symptomatic atrial arrhythmias. She underwent a successful ablation and concomitant invasive haemodynamic evaluation of potential alternative/biventricular pacing modalities. During biventricular pacing, the QRS narrowed and the systemic RV intraventricular pressure (Dp/Dt) increased with 30%. She underwent a successful transvenous upgrade to cardiac resynchronization therapy (CRT). The electrocardiogram post-implantation showed biventricular capture and patient showed subjective and objective clinical improvement. DISCUSSION: Systemic RV dysfunction in ccTGA can be aggravated by chronic pacing-induced dyssynchrony, contributing to progression of heart failure in this patient group. Transvenous CRT is feasible in ccTGA anatomy and may be pursued in order to improve or preserve the functional status of pacing-dependent ccTGA patients. Invasive haemodynamic contractility evaluation can help assess the potential benefit of CRT in patients with complex anatomy.

Development and external validation of prediction models to predict implantable cardioverter-defibrillator efficacy in primary prevention of sudden cardiac death.

AIMS: This study was performed to develop and externally validate prediction models for appropriate implantable cardioverter-defibrillator (ICD) shock and mortality to identify subgroups with insufficient benefit from ICD implantation. METHODS AND RESULTS: We recruited patients scheduled for primary prevention ICD implantation and reduced left ventricular function. Bootstrapping-based Cox proportional hazards and Fine and Gray competing risk models with likely candidate predictors were developed for all-cause mortality and appropriate ICD shock, respectively. Between 2014 and 2018, we included 1441 consecutive patients in the development and 1450 patients in the validation cohort. During a median follow-up of 2.4 (IQR 2.1-2.8) years, 109 (7.6%) patients received appropriate ICD shock and 193 (13.4%) died in the development cohort. During a median follow-up of 2.7 (IQR 2.0-3.4) years, 105 (7.2%) received appropriate ICD shock and 223 (15.4%) died in the validation cohort. Selected predictors of appropriate ICD shock were gender, NSVT, ACE/ARB use, atrial fibrillation history, Aldosterone-antagonist use, Digoxin use, eGFR, (N)OAC use, and peripheral vascular disease. Selected predictors of all-cause mortality were age, diuretic use, sodium, NT-pro-BNP, and ACE/ARB use. C-statistic was 0.61 and 0.60 at respectively internal and external validation for appropriate ICD shock and 0.74 at both internal and external validation for mortality. CONCLUSION: Although this cohort study was specifically designed to develop prediction models, risk stratification still remains challenging and no large group with insufficient benefit of ICD implantation was found. However, the prediction models have some clinical utility as we present several scenarios where ICD implantation might be postponed.

Mechanical extraction of cardiac implantable electronic devices leads with long dwell time: Efficacy and safety of the step up approach.

The aim of this study was to evaluate the efficacy and safety of the stepwise mechanical transvenous lead extraction approach in a patient population with chronically implanted transvenous leads with a long dwell time. From January 2014 till December 2018, all lead extractions with lead dwell time ≥5 years performed at our tertiary centre were retrospectively analysed. A total of 173 leads, from 78 patients (median age 68 years; 81% male) with a median dwell time of 9 years (interquartile range [IQR] 5) were extracted, with three or more leads in 42% of the patients. Right atrial leads: 41%; right ventricular pacing leads: 16%; implantable cardioverter-defibrillator (ICD) leads: 31% (72% dual coil); coronary sinus leads: 12%. The majority (75%) of the leads had an active fixation. Most frequent indication for extraction was pocket infection/erosion (76%). Overall clinical success was 97%, and complete procedural success was 93%. Venous patency, assessed with venous angiography, was well preserved in 93% of the cases. The overall procedural complication rate was 3.8% (2.6% major and 1.3% minor). Despite the complexity of the population and a very long dwell time (median 9 years), a clinical success rate of 97% was achieved with the stepwise mechanical approach. Analysis of impeding progression of pectoral extraction suggests that dense fibrosis and sharp lead curvature in the transvenous trajectory pose a challenge. Complication rate was low, and acute venous patency was generally well preserved.

Prophylactic Use of Implantable Cardioverter-Defibrillators in the Prevention of Sudden Cardiac Death in Dialysis Patients.

BACKGROUND: Patients with end-stage renal disease who are undergoing dialysis are reported to be at high risk of sudden cardiac death (SCD), and to date, no therapy has been shown to be effective in reducing this risk. The feasibility and value of prophylactic implantable cardioverter-defibrillator (ICD) implantation to prevent SCD is uncertain. METHODS: We conducted the ICD2 trial (Implantable Cardioverter-Defibrillator in Dialysis Patients), a prospective, randomized, controlled study investigating the value and safety of ICD implantation to prevent SCD in 200 patients on dialysis with a left ventricular ejection fraction ≥35%, after adequate screening and optimization of other treatments. The primary end point was SCD. Secondary end points were all-cause mortality and ICD-related complications. RESULTS: The trial was stopped as per the recommendation of the data and safety monitoring board for futility reasons after inclusion of 188 patients, 97 in the ICD group and 91 in the control group. The median duration of follow-up was 6.8 years (interquartile range, 3.8-8.8 years). SCD occurred in 19 of 188 cases (10.1%), 11 of 97 in the ICD group and 8 of 91 in the control group. The cumulative SCD incidence at 5 years was 9.7% (95% CI, 3.3%-16.2%) in the ICD group and 7.9% (95% CI, 1.7-14.0%) in the control group, resulting in a hazard ratio of 1.32 (95% CI, 0.53-3.29; P=0.55). Overall, 99 of 188 patients died (52.7%), 52 in the ICD group and 47 in the control group. Five-year survival probability was 50.6% (95% CI, 39.8%-61.5%) in the ICD group and 54.5% (95% CI, 43.0-66.0%) in the control group, resulting in a hazard ratio of 1.02 (95% CI, 0.69-1.52; P=0.92). Among 80 patients who received an ICD, 25 adverse events related to ICD implantation occurred. CONCLUSIONS: In a well-screened and well-treated population undergoing dialysis, prophylactic ICD therapy did not reduce the rate of SCD or all-cause mortality, which remained high. CLINICAL TRIAL REGISTRATION: URL: http://www.controlled-trials.com . Unique identifier: ISRCTN20479861.

Defibrillation testing and clinical outcomes after implantable cardioverter-defibrillator implantation in patients in atrial fibrillation at the time of implant: An analysis from the SIMPLE trial.

BACKGROUND: The Shockless IMPLant Evaluation (SIMPLE) trial showed that defibrillation testing (DT) at the time of implantable cardioverter-defibrillator (ICD) implant did not improve shock efficacy or reduce mortality. There are no data regarding the risk of complications, including stroke, among patients with atrial fibrillation (AF) who undergo DT. OBJECTIVE: The purpose of this prospectively planned substudy of SIMPLE was to evaluate the effect of DT vs no DT on clinical outcomes among patients with AF. METHODS: We compared efficacy (failed appropriate shock/arrhythmic death) and safety between patients who had AF on their immediate preprocedural ECG to the rest of the study patients. Then among patients with AF we compared these outcomes between patients randomized to DT vs no DT. RESULTS: Of the 2500 patients enrolled in SIMPLE, 251 (10%) were in AF immediately before ICD implant. AF patients had an increased risk of failed appropriate shock/arrhythmic death (adjusted hazard ratio [HR] 1.64; 95% confidence interval [CI] 1.13-2.39; P = .009) and higher all-cause mortality (adjusted HR 1.58; 95% CI 1.2-2.08; P = .001). Among AF patients, perioperative complications and stroke did not significantly differ between DT vs no-DT groups (9.2% vs 5.4%; P = .2; and 1.7% vs 1.5%; P >.999, respectively). Failed appropriate shock or arrhythmic death occurred in 35 of 251 AF patients (14%), and the no-DT group proved not inferior to the DT group (HR 0.58; 95% CI 0.30-1.15; Pnoninferiority = .006). CONCLUSION: ICD recipients with AF are at increased risk for adverse outcomes; however, DT does not improve arrhythmic survival or shock efficacy. There is no evidence that DT increased the occurrence of perioperative stroke.

Evaluation of the Impact of a Chronic Total Coronary Occlusion on Ventricular Arrhythmias and Long-Term Mortality in Patients With Ischemic Cardiomyopathy and an Implantable Cardioverter-Defibrillator (the eCTOpy-in-ICD Study).

BACKGROUND: Previous studies report conflicting results about a higher incidence of ventricular arrhythmias in patients with a chronic total coronary occlusion (CTO). We aimed to investigate this association in a large cohort of implantable cardioverter defibrillator patients with long-term follow-up. METHODS AND RESULTS: All consecutive patients from 1992 onwards who underwent implantable cardioverter defibrillator implantation for ischemic cardiomyopathy at the Leiden University Medical Center were evaluated. Coronary angiograms were reviewed for the presence of a CTO. The occurrence of ventricular arrhythmias and survival status at follow-up were compared between patients with and patients without a CTO. A total of 722 patients constitute the study cohort (age 66±11 years; 84% males; 74% primary prevention, median left ventricular ejection fraction 30% [first-third quartile: 25-37], 44% received a cardiac resynchronization therapy defibrillator). At baseline, 240 patients (33%) had a CTO, and the CTOs were present for at least 44 (2-127) months. The median follow-up duration was 4 (2-6) years. On long-term follow-up, CTO patients had a higher crude appropriate device therapy rate (37% versus 27%, P=0.010) and a lower crude survival rate (51% versus 67%, P<0.001) compared with patients without a CTO. Corrected for baseline characteristics including left ventricular ejection fraction, the presence of a CTO was an independent predictor for appropriate device therapy. CONCLUSIONS: The presence of a CTO in implantable cardioverter defibrillator patients was associated with more appropriate device therapy and worse prognosis at long-term follow-up. Further investigation is warranted regarding a potential beneficial effect of CTO revascularization on the incidence of ventricular arrhythmias.

Implantable cardioverter-defibrillator therapy in hypertrophic cardiomyopathy: A SIMPLE substudy.

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) are considered to be at high risk for elevated defibrillation thresholds, periprocedural complications, and failed appropriate shocks. OBJECTIVE: The purpose of this study was to determine the value of defibrillation testing (DT) in HCM patients undergoing implantable cardioverter-defibrillator (ICD) insertion. METHODS: Defibrillation thresholds, perioperative complications, and long-term outcomes were compared between patients with HCM and those with ischemic cardiomyopathy (ICM) or dilated cardiomyopathy (DCM) enrolled in the SIMPLE (Shockless IMPLant Evaluation) trial (Clinialtrials.gov Identifier: NCT00800384). In patients with HCM, outcomes were also compared between those randomized to DT vs no DT. RESULTS: Adequate defibrillation safety margin without system change was achieved in 46 of 52 (88.5%) HCM and 948 of 1047 (90.5%) ICM/DCM patients (P = .63). Perioperative complications occurred in 1 of 52 (1.9%) HCM patients with DT compared to 67 of 1047 (6.4%) ICM/DCM patients with DT (P = .37) or 3 of 42 (7.1%) HCM patients without DT (P = .32). During follow-up, there was no significant difference between HCM vs ICM/DCM patients in terms of all-cause mortality (adjusted hazard ratio [HR] 1.02, 95% confidence interval [CI] 0.45-2.34), composite of arrhythmic death or failed appropriate shock (adjusted HR 0.33, 95% CI 0.04-2.42), inappropriate shocks (adjusted HR 1.64, 95% CI 0.69-3.89), or system complications (adjusted HR 1.93, 95% CI 0.88-4.27). All-cause mortality (HR 0.26, 95% CI 0.03-2.20), appropriate (HR 0.24, 95% CI 0.03-2.05), and inappropriate shocks (HR 2.13, 95% CI 0.51-8.94) were similar in HCM patients without or those with DT. CONCLUSION: We did not find any difference in intraoperative defibrillation efficacy, perioperative complications, and long-term outcomes between patients with HCM and those with ICM/DCM. DT did not improve intraoperative or clinical shock efficacy in HCM patients.

Cardiac resynchronization therapy in adults with congenital heart disease.

Aims: In adults with congenital heart disease (CHD) heart failure is one of the leading causes of morbidity and mortality but experience with and reported outcome of cardiac resynchronization therapy (CRT) is limited. We investigated the efficacy of CRT in adults with CHD. Methods and results: This was a retrospective study including 48 adults with CHD who received CRT since 2003 in four tertiary referral centres. Responders were defined as patients who showed improvement in NYHA functional class and/or systemic ventricular ejection fraction by at least one category. Ventricular function was assessed by echocardiography and graded on a four point ordinal scale. Median age at CRT was 47 years (range 18-74 years) and 77% was male. Cardiac diagnosis included tetralogy of Fallot in 29%, (congenitally corrected) transposition of great arteries in 23%, septal defects in 25%, left sided lesions in 21%, and Marfan syndrome in 2% of the patients. The median follow-up duration after CRT was 2.6 years (range 0.1-8.8). Overall, 37 out of 48 patients (77%) responded to CRT either by improvement of NYHA functional class and/or systemic ventricular function. There were 11 non-responders to CRT. Of these, three patients died and four underwent heart transplantation. Conclusion: In this cohort of older CHD patients, CRT was accomplished with a success rate comparable to those with acquired heart disease despite the complex anatomy and technical challenges frequently encountered in this population. Further studies are needed to establish appropriate guidelines for patient selection and long term outcome.

Cardiac Resynchronization Therapy With Wireless Left Ventricular Endocardial Pacing: The SELECT-LV Study.

BACKGROUND: A total of 30% to 40% of patients with congestive heart failure eligible for cardiac resynchronization therapy (CRT) either do not respond to conventional CRT or remain untreated due to an inability or impediment to coronary sinus (CS) lead implantation. The WiSE-CRT system (EBR Systems, Sunnyvale, California) was developed to address this at-risk patient population by performing biventricular pacing via a wireless left ventricular (LV) endocardial pacing electrode. OBJECTIVES: The SELECT-LV (Safety and Performance of Electrodes implanted in the Left Ventricle) study is a prospective multicenter non-randomized trial assessing the safety and performance of the WiSE-CRT system. METHODS: A total of 35 patients indicated for CRT who had "failed" conventional CRT underwent implantation of an LV endocardial pacing electrode and a subcutaneous pulse generator. System performance, clinical efficacy, and safety events were assessed out to 6 months post-implant. RESULTS: The procedure was successful in 97.1% (n = 34) of attempted implants. The most common indications for endocardial LV pacing were difficult CS anatomy (n =12), failure to respond to conventional CRT (n = 10), and a high CS pacing threshold or phrenic nerve capture (n = 5). The primary performance endpoint, biventricular pacing on the 12-lead electrocardiogram at 1 month, was achieved in 33 of 34 patients. A total of 28 patients (84.8%) had improvement in the clinical composite score at 6 months, and 21 (66%) demonstrated a positive echocardiographic CRT response (≥5% absolute increase in LV ejection fraction). There were no pericardial effusions, but serious procedure/device-related events occurred in 3 patients (8.6%) within 24 h, and 8 patients (22.9%) between 24 h and 1 month. CONCLUSIONS: The SELECT-LV study demonstrates the clinical feasibility for the WiSE-CRT system, and provided clinical benefits to a majority of patients within an otherwise "failed" CRT population. (Safety and Performance of Electrodes Implanted in the Left Ventricle [SELECT-LV]; NCT01905670).