ICD Implantation Research Articles

A VENTRICULAR TACHYCARDIA CASE NOT TREATABLE WITH TRANSCATHETER ABLATION DUE TO APICAL THROMBOSIS OF THE LEFT VENTRICLE RESOLVED WITH RADIOTHERAPY BASED ON THE NON–INVASIVE MAPPING SYSTE

Abstract The clinical case focuses on a 52–year–old man smoker, heavy alcohol consumer. In 2017 he began with sustained ventricular tachycardia (VT) effectively treated with DC–shock. The following ECG showed signs of anterior necrosis. Severe left ventricular (LV) dilatation, apical thrombosis and severe impairment of LV function were found on echocardiogram. Angiography was performed and LAD occlusion was found. Since of 68% necrosis of the LV at myocardial scintigraphy, no revascularization was performed. He underwent to a dual chamber ICD implantation and started oral anticoagulation therapy. In the following years recurrence of arrhythmic episodes, despite the optimization of antiarrhythmic therapy, led the patient to numerous hospitalizations. Unfortunately the persistence of the apical thrombosis, made transcatheter ablation NOT possible. The only chance for the patient remained stereotactic arrhythmia radioablation. But which area of the LV to highlight as responsible for the arrhythmia and how to program the radiotherapy treatment plan was a challenging problem. We proposed in March 2023 non–invasive mapping of arrhythmia using Cardioinsight. The patient performed heart high–resolution computed tomography (CT) for the anatomical reconstruction with precise spatial resolution of all LV aereas and surrounding structures. A 252–electrode vest is applied to the patient’s torso and connected to the system Cardioinsight. A programmed ventricular stimulation was performed using ICD inducing two VT morphologies. Through electroanatomical mapping we identified the mid LV antero–septal and infero–septal sites as target areas. Thanks to multidisciplinary team a personalized treatment plan was created to deliver an effective lesion in the target area and minimize exposure to nearby organs at risk. The treatment was generated, optimized and delivered by TrueBeam, lasted 3 minutes and no complications arose. The patient was quickly discharged in good clinical condition. After 3 months of clinical well–being he was hospitalized for a single episode of VT. Up to now no hospitalizations occurred. This treatment may represent a "bail–out" choice in patients with advanced heart failure with arrhythmic storm who have exhausted all other therapeutic options.

Relationship between ICD implantation volume and treatment parameters of patients receiving an ICD with remote monitoring.

Both highly specialized heart centres and less specialized hospitals care for patients with implantable ICDs/CRT-Ds with remote monitoring. To investigate potential differences in patient treatment according to centre's ICD implantation volume. Based on their 2012 ICD/CRT-D implantation volume, centres enrolled in the NORDIC ICD trial in Germany were assigned to one of three groups: high- (HV, n= 345), medium- (MV, n= 340) or low-volume (LV, n= 189). The HV-centres had a significant higher CRT-D proportion (41.7%; LV: 36.5%; MV: 23.2%; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001), significant shorter median procedure duration (49 min; MV: 58 min; LV: 60 min; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001) but significant longer median hospital stay (4 days; MV and LV: 3 days; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001) compared to MV- and LV-centres. The X-ray exposure was shorter in MV/HV-centres (MV: 3.4 min; HV: 3.6 min; LV: 5.5 min; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001). Only 3.5% (LV: 2.6%; HV: 3.5%; MV: 4.1%) patients received at least one delivered inappropriate shock and 2.5% (HV: 2.0%; LV: 2.6%; MV: 2.9%) patients had withheld inappropriate ICD shocks without subsequent inappropriate shock delivery within 24.5 months of median follow-up. Implantation volume-dependent differences were observed in the device selection, procedure duration and x-ray exposure duration. Remote monitoring in combination with adequate response pattern prevented imminent inappropriate shocks in all three groups.

Effect of Implantable Cardioverter-defibrillators in Nonischemic Heart Failure According to Background Medical Therapy: Extended Follow-up of the DANISH Trial

The Heart Failure Collaboratory (HFC) score integrates types and dosages of guideline-directed pharmacotherapies for heart failure (HF) with reduced ejection fraction (HFrEF). We examined the effects of cardioverter-defibrillator (ICD) implantation according to the modified HFC (mHFC) score in 1116 patients with nonischemic HFrEF from the Danish Study to Assess the Efficacy of ICDs in Patients with Nonischemic Systolic HF on Mortality (DANISH). Patients were assigned scores for renin-angiotensin-system inhibitors, beta-blockers and mineralocorticoid receptor antagonists (0, no use; 1, < 50% of maximum dosage; 2, ≥ 50% of maximum dosage). The maximum score was 6, corresponding to ≥ 50% of maximum dosage for all therapies. The median baseline mHFC score was 4, and the median follow-up was 9.5 years. Compared with an mHFC score of 3-4, an mHFC score of 1-2 was associated with a higher rate of all-cause death (mHFC = 1-2: adjusted HR 1.67 [95% CI, 1.23-2.28]; mHFC = 3-4, reference; mHFC = 5-6: adjusted HR 1.07 [95% CI, 0.87-1.31]). ICD implantation did not reduce all-cause death compared with control (reference) (HR 0.89 [95% CI, 0.74-1.08]), regardless of mHFC score (mHFC = 1-2: HR 0.98 [95% CI, 0.56-1.71]; mHFC = 3-4: HR 0.89 [95% CI,0.66-1.20]; mHFC = 5-6: HR 0.85 [95% CI, 0.64-1.12]; Pinteraction, 0.65). Similarly, ICD implantation did not reduce cardiovascular death (HR 0.87 [95% CI, 0.70-1.09]), regardless of mHFC score (Pinteraction, 0.59). The ICD group had a lower rate of sudden cardiovascular death (HR, 0.60 [95% CI,0.40-0.92]); this association was not modified by mHFC score (Pinteraction, 0.35). Lower mHFC scores were associated with higher rates of all-cause death. ICD implantation did not result in an overall survival benefit in patients with nonischemic HFrEF, regardless of mHFC score.

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

BackgroundAxillary 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. MethodsAll 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. ResultsThe 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. ConclusionAVP, 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.

Predicting postinfarct ventricular tachycardia by integrating cardiac MRI and advanced computational reentrant pathway analysis

BackgroundImplantable cardiac defibrillator (ICD) implantation can protect against sudden cardiac death after myocardial infarction. However, improved risk stratification for device requirement is still needed. ObjectiveThe purpose of this study was to improve assessment of postinfarct ventricular electropathology and prediction of appropriate ICD therapy by combining late gadolinium enhancement (LGE) and advanced computational modeling. MethodsADAS 3D LV (ADAS LV Medical, Barcelona, Spain) and custom-made software were used to generate 3-dimensional patient-specific ventricular models in a prospective cohort of patients with a myocardial infarction (N = 40) having undergone LGE imaging before ICD implantation. Corridor metrics and 3-dimensional surface features were computed from LGE images. The Virtual Induction and Treatment of Arrhythmias (VITA) framework was applied to patient-specific models to comprehensively probe the vulnerability of the scar substrate to sustaining reentrant circuits. Imaging and VITA metrics, related to the numbers of induced ventricular tachycardias and their corresponding round trip times (RTTs), were compared with ICD therapy during follow-up. ResultsPatients with an event (n = 17) had a larger interface between healthy myocardium and scar and higher VITA metrics. Cox regression analysis demonstrated a significant independent association with an event: interface (hazard ratio [HR] 2.79; 95% confidence interval [CI] 1.44–5.44; P < .01), unique ventricular tachycardias (HR 1.67; 95% CI 1.04–2.68; P = .03), mean RTT (HR 2.14; 95% CI 1.11–4.12; P = .02), and maximum RTT (HR 2.13; 95% CI 1.19–3.81; P = .01). ConclusionA detailed quantitative analysis of LGE-based scar maps, combined with advanced computational modeling, can accurately predict ICD therapy and could facilitate the early identification of high-risk patients in addition to left ventricular ejection fraction.

Internal Mammary Artery Graft Flow Steal by a Large Dialysis Arteriovenous Fistula Characterized by Electrical Storm

Background: Steal syndrome describes a condition in which a dilated vessel distal to a smaller artery attempts to compensate for decreased blood flow by “stealing” from the smaller artery. Steal syndrome is not uncommon and can be seen in certain physiologic and pathologic states. The classic example is an occluded atherosclerotic coronary artery resulting in a misdirection of blood flow into the open channels that have developed over time resulting in downstream ischemia. Case Report: A 66-year-old male fourteen years post 4-vessel coronary artery bypass grafting using his left internal mammary artery to bypass a stenotic segment of the left anterior descending artery, along with three saphenous venous conduits to the right coronary artery. He also had a stent placement by PCI. He was on dual antiplatelet therapy with aspirin and clopidogrel. An electrophysiology study revealed inducible VF and he underwent implantation of a dual chamber ICD 9 months prior to presentation. He experienced an unprovoked fall at home and a workup revealed the flow volume through the patient’s fistula increased to such a degree that the patient developed a steal syndrome from his left internal mammary artery graft. In addition, went into a state of electrical storm caused by ischemic damage to cardiac tissue distal to the graft. By ligating the fistula, the patient’s steal syndrome resolved and he did not suffer further ventricular arrhythmias. Conclusion: Both coronary bypass grafting and fistula formation are common and necessary interventions and providers should take care to monitor for interactions between these proposed interventions to best serve their patients without causing additional harm. Increased vascular flow through any portion of the body can induce a steal syndrome from an upstream region. Patients who undergo arteriovenous (AV) fistula placement may develop a steal syndrome from ipsilateral bypass grafts.

PATHFINDER-CHD: prospective registry on adults with congenital heart disease, abnormal ventricular function, and/or heart failure as a foundation for establishing rehabilitative, prehabilitative, preventive, and health-promoting measures: rationale, aims, design and methods

BackgroundAdults with congenital heart defects (ACHD) globally constitute a notably medically underserved patient population. Despite therapeutic advancements, these individuals often confront substantial physical and psychosocial residua or sequelae, requiring specialized, integrative cardiological care throughout their lifespan. Heart failure (HF) is a critical challenge in this population, markedly impacting morbidity and mortality.AimsThe primary aim of this study is to establish a comprehensive, prospective registry to enhance understanding and management of HF in ACHD. Named PATHFINDER-CHD, this registry aims to establish foundational data for treatment strategies as well as the development of rehabilitative, prehabilitative, preventive, and health-promoting interventions, ultimately aiming to mitigate the elevated morbidity and mortality rates associated with congenital heart defects (CHD).MethodsThis multicenter survey will be conducted across various German university facilities with expertise in ACHD. Data collection will encompass real-world treatment scenarios and clinical trajectories in ACHD with manifest HF or at risk for its development, including those undergoing medical or interventional cardiac therapies, cardiac surgery, inclusive of pacemaker or ICD implantation, resynchronization therapy, assist devices, and those on solid organ transplantation.DesignThe study adopts an observational, exploratory design, prospectively gathering data from participating centers, with a focus on patient management and outcomes. The study is non-confirmatory, aiming to accumulate a broad spectrum of data to inform future hypotheses and studies.ProcessesRegular follow-ups will be conducted, systematically collecting data during routine clinical visits or hospital admissions, encompassing alterations in therapy or CHD-related complications, with visit schedules tailored to individual clinical needs.AssessmentsBaseline assessments and regular follow-ups will entail comprehensive assessments of medical history, ongoing treatments, and outcomes, with a focus on HF symptoms, cardiac function, and overall health status.Discussion of the designThe design of the PATHFINDER-CHD Registry is tailored to capture a wide range of data, prioritizing real-world HF management in ACHD. Its prospective nature facilitates longitudinal data acquisition, pivotal for comprehending for disease progression and treatment impacts.ConclusionThe PATHFINDER-CHD Registry is poised to offer valuable insights into HF management in ACHD, bridging current knowledge gaps, enhancing patient care, and shaping future research endeavors in this domain.

Prior history of atrial fibrillation and arrhythmic outcomes: Data from the WEARIT-II prospective registry.

Wearable cardioverter defibrillator (WCD)is utilized in patients with assumed but not yet confirmed risk for sudden cardiac death (SCD).Many of these patients also present with atrial fibrillation (AF).However, the rate of WCD-detected ventricular or atrial arrhythmia events in this specific high-risk cohort is not well understood. In WEARIT-II,the cumulative probability of any sustained or nonsustained VT/VF(WCD-treatedand nontreated), and atrial/supraventricular arrhythmias during WCD use was assessed using the Kaplan-Meier method by prior AF, with comparisons by the log-rank test. The incidence of ventricular and atrial arrhythmia events were expressed as events per 100 patient-years, and were analyzed by prior AF using negative binomial regression. WEARIT-IIenrolled 2000 patients, 557 (28%) of whom had AF before enrollment. Cumulative probability of any sustained or nonsustained WCD-detected VT/VFduring WCD use was significantly higher among patients with a history of AF than without AF (6% vs. 3%, p = .001). Similarly, the recurrent rate of any sustained or nonsustained VT/VFwas significantly higher in patients with prior AF versus no prior AF (131.5 events per 100 patient-years vs. 22.7 events per 100 patient-years, p = .001). Patients with prior AF also had a significantly higher burden of any WCD-detected atrial arrhythmias/SVT/inappropriate arrhythmiastherapy (183.2 events per 100 patient-years vs. 74.8 events per 100 patient-years, p < .001). Our results demonstrate that patients with a history of AF wearing the WCD for risk assessment have a higher incidence of ventricular arrhythmias that may facilitate the decision making for ICD implantation.

Detection of gene mutation in the prognosis of a patient with arrhythmogenic right ventricular cardiomyopathy: a case report

BackgroundArrhythmogenic right ventricular cardiomyopathy (ARVC), or more recently known as arrhythmogenic cardiomyopathy (ACM), is an heritable disorder of the myocardium characterized by progressive fibrofatty replacement the heart muscle and risk of ventricular arrhythmias and sudden cardiac death (SCD). We report a case study to demonstrate the role of gene mutation detection in risk stratification for primary prevention of SCD in a young patient diagnosed with ARVC.Case presentationA 15-year-old Asian (Vietnamese) male patient with no history of documented tachyarrhythmia or syncope and a family history of potential SCD was admitted due to palpitations. Clinical findings and work-up including cardiac magnetic resonance imaging (MRI) were highly suggestive of ARVC. Gene sequencing was performed for SCD risk stratification, during which PKP2 gene mutation was found. Based on the individualized risk stratification, an ICD was implanted for primary prevention of SCD. At 6 months post ICD implantation, the device detected and successfully delivered an appropriate shock to terminate an episode of potentially fatal ventricular arrhythmia. ICD implantation was therefore proven to be appropriate in this patient.ConclusionsWhile gene mutations are known to be an important factor in the diagnosis of ARVC according to the 2010 Task Force Criteria and recent clinical guidelines, their role in risk stratification of SCD remains controversial. Our case demonstrated that when used with other clinical factors and family history, this information could be helpful in identifying appropriate indication for ICD implantation.

Navigating Heart Failure: Unveiling Sex Disparities in Guideline-Directed Medical Therapy Combinations

Major heart failure (HF) trials remain insufficient in terms of assessing the differences in clinical characteristics, biomarkers, treatment efficacy, and safety because of the under-representation of women. The study aimed to present sex-related disparities in HF management, including differences in demographics, co-morbidities, cardiac biomarkers, prescribed medications, and treatment outcomes. The study utilized anonymized data from the Turkish Ministry of Health's National Electronic Database between January 1, 2016, and December 31, 2022. The cohort analysis included 2,501,231 adult patients with HF. Specific therapeutic combinations were analyzed using a Cox regression model to obtain relative risk reduction for all-cause death. The primary end point was all-cause mortality. In the cohort, 48.7% (n = 1,218,911) were male, whereas 51.3% (n = 1,282,320) were female. Female patients exhibited a higher median age (71 vs 68 years) and manifested higher prevalence of diabetes mellitus, anemia, atrial fibrillation, anxiety, and ischemic stroke. Male patients demonstrated higher rates of previous myocardial infarction, dyslipidemia, chronic obstructive pulmonary disease, and chronic kidney disease. Higher concentrations of natriuretic peptides were observed in female patients. Renin-angiotensin aldosterone inhibitor, β blockers, mineralocorticoid receptor antagonists, sodium/glucose cotransporter 2 inhibitor (SGLT2i), and ivabradine were more commonly prescribed in male patients, whereas loop diuretics, digoxin, and ferric carboxymaltose were more frequent in female patients. Male patients had higher rates of cardiac resynchronization therapy and implantable cardioverter defibrillator implantation rates. All-cause mortality and hospitalization rates were higher in male patients. Compared with monotherapy, all combinations, including SGLT2i, showed a beneficial effect on all-cause mortality in both female and male patients with HF. In hospitalized patients with HF, the addition of digoxin to renin-angiotensin aldosterone inhibitor, mineralocorticoid receptor antagonists, and β blockers was superior to monotherapy regarding all-cause mortality in female patients with HF compared with male patients with HF. In conclusion, this study highlights that sex-specific responses to HF medication combinations compared with monotherapy and differences in co-morbidities underscore the importance of tailored management strategies. Digoxin showed a contrasting effect on all-cause mortality between both sexes after hospitalization, whereas SGLT2i exhibited a consistent beneficial effect in both sexes when added to all combinations.

Clinical and genetic characterization of patients with catecholaminergic polymorphic ventricular tachycardia: a case series

AIM: of the study was to evaluate the clinical and genetic characteristics, including the development of adverse events and outcomes in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT).&#x0D; MATERIALS AND METHODS: The clinical phenotype of eight patients with CPVT, two of whom were relatives of probands, was observed over 4 years. The clinical and instrumental study included ECG-12, 24-hour Holter ECG monitoring, genealogical history collection and family history of sudden cardiac death (SCD), transthoracic echocardiography and cardiac magnetic resonance imaging to detect structural myocardial changes, electrophysiologic study according to indications, and ICD monitoring. High-throughput sequencing (NGS) was utilized to search for mutations in genes linked to the onset of channelopathies and other inherited rhythm disorders.&#x0D; RESULTS: In 8 patients, nucleotide variants of pathogenicity classes III-V were identified according to the ACMG (2015) criteria in the RYR2 gene associated with CPVT. Pathogenic (IV-V class) and likely pathogenic (IV class) mutations in the RYR2 gene were found in 6 (75%) probands, variants with uncertain clinical significance (VUS, class III) were found in 2 patients. At the time of diagnosis, transient QTc interval prolongation of more than 480 ms was detected in 4 (50%) patients; bradycardia less than 54 beats/min — in 2 (25%) patients, sequences of supraventricular tachycardia and ventricular tachyarrhythmia — in 2 (25%) patients. The most severe form of the disease with marked clinical manifestations and an episode of clinical death with subsequent resuscitation, as well as a transient QTc interval prolongation exceeding 500 ms was observed in patients with mutations c.11814C A (p.Ser3938Arg, rs794728704); c.463G A (p.Gly155Arg) and c.14876G A (p.Arg4959Gln, rs794728811) in the RYR2 gene. Three (37.5%) patients underwent ICD implantation; one for primary SCD prevention and two for secondary prevention.&#x0D; CONCLUSION: In this study, the spectrum of clinical manifestations in patients with genetically confirmed CPVT was examined. The findings highlight transient QTc interval extensions, significant sinus bradycardia, and sequences of supraventricular tachyarrhythmias, which can escalate into life-threatening ventricular tachyarrhythmias in CPVT patients.

High-risk Brugada syndrome: factors associated with arrhythmia recurrence and benefits of epicardial ablation in addition to implantable cardioverter defibrillator implantation.

This study aims to evaluate the prognostic impact of the arrhythmogenic substrate size in symptomatic Brugada syndrome (BrS) as well as to validate the long-term safety and effectiveness of epicardial radiofrequency ablation (RFA) compared with no-RFA group. In this prospective investigational long-term registry study, 257 selected symptomatic BrS patients with implantable cardioverter defibrillator (ICD) implantation were included. Among them, 206 patients underwent epicardial RFA and were monitored for over 5 years post-ablation (RFA group), while 51 patients received only ICD implantation declining RFA. Primary endpoints included risk factors for ventricular fibrillation (VF) events pre-ablation and freedom from VF events post-ablation. In the RFA group, BrS substrates were identified in the epicardial surface of the right ventricle. During the pre-RFA follow-up period (median 27 months), VF episodes and VF storms were experienced by 53 patients. Independent risk factors included substrate size [hazard ratio (HR), 1.13; 95% confidence interval (CI), 1.08-1.18; P < 0.001], aborted cardiac arrest (HR, 2.98; 95% CI, 1.68-5.28; P < 0.001), and SCN5A variants (HR, 2.22; 95% CI, 1.15-4.27; P = 0.017). In the post-RFA follow-up (median 40 months), the RFA group demonstrated superior outcomes compared with no-RFA (P < 0.001) without major procedure-related complications. Our study underscores the role of BrS substrate extent as a crucial prognostic factor for recurrent VF and validates the safety and efficacy of RFA when compared with a no-RFA group. Our findings highlight the importance of ajmaline in guiding epicardial mapping/ablation in symptomatic BrS patients, laying the groundwork for further exploration of non-invasive methods to guide informed clinical decision-making.

Appropriateness of implantable cardioverter-defibrillator device implants in the United States

BackgroundThe appropriate use criteria (AUCs) are a diverse group of indications aimed to better evaluate the benefits of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy. ObjectiveThe purpose of this study was to quantify the proportion of ICD and cardiac resynchronization therapy with defibrillator (CRT-D) implants as appropriate, may be appropriate (MA), or rarely appropriate (RA) on the basis of the AUC guidelines. MethodsThis is a multicenter retrospective study of patients within the National Cardiovascular Data Registry undergoing ICD implantation between April 2018 and March 2019 at >1500 US hospitals. The appropriateness of ICD implants was adjudicated using the AUC. ResultsOf 309,318 ICDs, 241,438 were primary prevention implants (78.1%) and 67,880 secondary prevention implants (21.9%); 243,532 (79%) were mappable to the AUC. For primary prevention, 185,431 ICDs (96.4%) were appropriate, 5660 (2.9%) MA, and 1205 (0.6%) RA. For secondary prevention, 47,498 ICDs (92.7%) were appropriate, 2581 (5%) MA, and 1157 (2.3%) RA. A significant number of RA devices were implanted in patients with New York Heart Association class IV heart failure who were ineligible for advanced therapies (53.9%) and those with myocardial infarction within 40 days (18.1%). The appropriateness of the pacing lead was more variable, with 48,470 dual-chamber ICD implants (62%) being classified as appropriate, 29,209 (37.4%) MA, and 448 (0.6%) RA. Among CRT-D implants, 63,848 (82.2%) were appropriate, 9900 (12.7%) MA, and 3940 (5.1%) RA for left ventricular pacing. A total of 99,754 implants were deemed appropriate but excluded from Centers for Medicare & Medicaid Services National Coverage Determination. More than 92% of hospitals had an RA implant rate of <4%. ConclusionIn this large national registry, 95% of mappable ICD and CRT-D implants were considered appropriate, with <2% of RA implants. Nearly 100,000 appropriate implants are excluded by Centers for Medicare & Medicaid Services National Coverage Determination.

Predicting long-term survival after de novo cardioverter-defibrillator implantation for primary prevention: A population based study

BackgroundImplantable cardioverter-defibrillators (ICDs) reduce the risk of sudden cardiac death in patients with left ventricular dysfunction. While short-term mortality benefit of ICD insertion has been established in landmark randomized controlled trials, little is known about the long-term outcomes of patients with ICDs in clinical practice. In this paper, we describe the long-term survival of patients following de novo ICD implantation for primary prevention in clinical practice and determine the factors which help predict survival after ICD implant. MethodsRetrospective population-based study of all patients receiving a de novo ICD for primary prevention in Ontario, Canada from 2007 to 2011 using the Ontario ICD Database housed within ICES. Simple random selection was used to split the population into a derivation and internal validation cohort in a ratio of 2:1. Cox proportional hazards regression was used to determine predictors of interest and predict 10-year survival, model performance was assessed using calibration and validation. ResultsIn the derivation cohort (n = 3399), mean age was 65.3 years (standard deviation [SD] = 11.0), 664 patients were female (19.5 %) and 2344 patients (69.0 %) had ischemic cardiomyopathy. Ten year survival was 45.7 % (95 % confidence interval [CI] 44.0 %–47.4 %). The final prediction model included age, sex, disease factors (ischemic vs nonischemic cardiomyopathy, left ventricular ejection fraction) and patient factors (symptoms, comorbidities), and biomarkers at the time of ICD assessment. This model had good discrimination and calibration in derivation (0.79, 95 % CI 0.77, 0.81) and validation samples (0.78, 95 % CI 0.76, 0.79). ConclusionsA combination of demographic and clinical factors determined at baseline can be used to predict 10-year survival in patients with implantable cardioverter-defibrillators with good accuracy. Our findings help to identify individuals at risk of long-term mortality and may be useful in targeting future prevention strategies to enhance longevity in this high-risk population.

Prediction of incident atrial fibrillation in hypertrophic cardiomyopathy

Background and aimAtrial fibrillation (AF) is the most common sustained arrhythmia in hypertrophic cardiomyopathy (HCM) with significant effects on outcome. We aim to compare the left atrial (LA) diameter measurement with HCM-AF Score in predicting atrial fibrillation (AF) development in HCM. MethodsFrom the regional cohort of the Campania Region, Italy, 519 HCM patients (38% women, age45 ± 17 years) without history of AF, were enrolled in the study. The primary clinical endpoint was the development of AF, defined as at least 1 episode documented by ECG. ResultsDuring the follow-up (mean 8 ± 6, IQ range 2.5–11.2 years), 99 patients (19%) developed AF. Patients who developed AF were more symptomatic, had higher prevalence of ICD implantation, had larger LA diameter, greater left ventricular (LV) maximal wall thickness and LV outflow tract obstruction (p < 0.01). Both LA diameter and HCM-AF score were higher in patients who developed AF versus those who did not (LA diameter 49 ± 7 versus 43 ± 6 mm; HCM-AF score 22 ± 4 versus 19 ± 4; p < 0.0001); however, ROC curve analysis demonstrated that LA diameter had a significant greater area under the curve than HCM-AF Score (p < 0.0001). At 5 years follow-up, a LA diameter > 46 mm, showed a similar accuracy in predicting AF development of HCM-AF score ≥ 22, which identifies patients at high risk to develop AF. ConclusionOur analysis shows that LA diameter, a worldwide and simple echocardiographic measure, is capable alone to predict AF development in HCM patients.

Subcutaneous versus transvenous ICDs: a population-level comparison of incidence, patient characteristics, and complications of S-ICDs, ICDs, and CRT-Ds in a nationwide Dutch cohort (2018-2020)

Abstract Background Subcutaneous implantable cardioverter-defibrillators (S-ICDs) have emerged as a safe and effective alternative to ICDs for the prevention of sudden cardiac death. Compared to ICDs, S-ICDs aim to reduce morbidities associated with the transvenous lead including lead dislocation and infection. Limited evidence exists for the utilization, patient selection, and complications of S-ICDs in current real-world clinical practice. Purpose Our aim was to compare the implantation rate, patient characteristics, and complications of patients who underwent S-ICD, ICD, and CRT-D implants and replacements in the Netherlands from 2018 to 2020. Methods The Netherlands Heart Registration includes all adult patients who underwent an ICD implant or replacement at 28 hospitals in the Netherlands (2018-2020). Annual crude, age-, and sex-standardized incidence rates were assessed with Poisson regression models with robust variances. Patient characteristics and complications were compared between ICD types with ANOVA tests. Determinants of complications were identified with multivariable logistic regression models. Results Of 17,080 patients who had a de novo ICD implant (n=10,317) or replacement (n=6,763) in the Netherlands (2018-2020), 1408 (8.2%) patients had an S-ICD, 9441 (55.3%) patients received an ICD only, and 6231 (36.5%) patients received a CRT-D. The incidence of de novo S-ICDs were stable over time, however the incidence of de novo ICD only and CRT-D implants decreased by 5% and 11%, respectively (p&amp;lt;0.05 for both; Figure 1). Patients who received S-ICDs were younger (53 years, IQR 41-62) than ICD (66 years, IQR 57-73) and CRT-D (70 years, IQR 62-75) patients (p&amp;lt;0.05). A greater proportion women had S-ICDs (25.0%) and CRT-Ds (26.7%) implanted compared to ICDs (19.9%) (p&amp;lt;0.05). Further, less atrial fibrillation patients had S-ICDs (21.6% vs ICD 30.9%, and CRT-D 32.4%). ICDs for primary prevention were implanted in 56.4%, 48.4%, and 81.2% of S-ICD, ICD, and CRT-D patients, respectively (p&amp;lt;0.05). The incidence of lead dislocations was less among S-ICD patients compared to ICD and CRT-D patients (p&amp;lt;0.001; Figure 2). There was no difference detected for other complications or long-term mortality (p&amp;gt;0.05 for all; Figure 2). Infections in S-ICD patients [aOR 0.2 (95% CI 0.1-0.9)] and in-hospital bleeding for CRT-D patients [aOR 0.4 (95% CI 0.2-0.9)] decreased among patients who underwent an ICD implant in recent years. In addition, advancing age was identified as a risk factor for in hospital bleeding in S-ICD patients [aOR 1.1 (95% CI 1.0-1.2)] and for pneumothorax in CRT-D patients [aOR 3.6 (95% CI 2.0-6.8)]. Conclusion In real-world practice, S-ICDs were implanted in younger patients with fewer comorbidities and portended a lower risk of lead dislodgement than ICDs and CRT-Ds; however, the population-level implantation rate of S-ICDs did not vary between 2018 to 2020 in the Netherlands.

Mortality and appropriate therapies in ischaemic ICD recipients according to the electrophysiological study

Abstract Aims Current guidelines recommend ICD implantation for primary prevention in patients with ischaemic heart disease and LVEF ≤35%. We aimed to access the value of the EP study in prediction of the arrhythmic events in ischaemic patients with reduced EF (≤35%) who underwent EPS and ICD implantation and do address the impact of ICD implantation on the all-cause mortality. Methods We compared the risk for all-cause mortality in ischaemic patients with negative and positive EPS with and without ICD implantation and compared the risk for appropriate therapy according to the results of the EP study of patients who underwent ICD implantation in our institution. The median follow-up was 84 months. Results Of 235 patients, who underwent EPS, 115 were negative (noninducible to VT). These patients were more likely to be female and did not differ in age, presence of diabetes, hypertension, atrial fibrillation or ejection fraction. Kaplan-Meier survival analysis showed that there was no difference in mortality between the 2 groups (49.6% vs 44.2%, p=0.419). ICD was implanted in 168 patients: there was no difference in mortality between them (47%) and patients without implanted ICD (46.6%), p=0.861. This was true for patients with negative and positive EPS (p=0.136 and p=0.554, respectively) Of 167 patients who underwent ICD implantation, 66 had negative EPS. Kaplan-Meier analysis showed that these patients were significantly less likely to receive appropriate therapy (7.6% vs 25.7%, p=0.003) and appropriate shock (0% vs 10.9%, p=0.004. The time to first appropriate ICD therapy was significantly longer in EPS negative patients (112 vs 93 months, p&amp;lt;0.001). The incidence of inappropriate therapies was similar in both groups (2.6% vs 5.8%, p=0.221). Conclusion ICD implantation does not reduce mortality in ischaemic patients with reduced EF and both positive and negative EPS. Patients with negative EPS and implanted ICD had much lower incidence of appropriate ICD therapies and no appropriate shocks. The policy of implanting ICDs to all ischaemic patients with EF&amp;lt;35% should be reconsidered.ICD shocks according to the EPS resultsMortality with and without ICD

Marked differences in ICD therapy frequencies between phenotypes

Abstract Background Implantable cardioverter defibrillators (ICD) are implanted due to a broad range of cardiac conditions according to guidelines. Purpose The aim of this study was to compare the distribution of ICD therapies across different cardiac diseases. Methods In this descriptive study, we included patients from Eastern Denmark with an ICD implanted up until November 2021. Data was obtained from the national ICD registry and the diagnosis leading to implantation of the ICD was registered. ICD interrogations and number of episodes of appropriate ICD therapies (shock/anti-tachycardia pacing (ATP)) were obtained. End of follow-up was November 8, 2021 or date of death or heart transplantation. Cumulated numbers of therapies were calculated for each patient during the follow-up period (shock/ATP therapies per 1,000 patients per year). Results Data on 3,068 patients (median (IQR) age at implantation 65 years (56-72)) across 10 cardiac disorders was obtained (Figure). A total of 1,403 patients had the ICD implanted as primary prophylaxis and 1,554 as secondary prophylaxis and in 111 patients it was unclear. Mean follow-up time of 595 years per diagnostic subgroup (210-12,911 years). The median (IQR) shock/ATP rate per 1,000 patients per year was 1.47 (0.70-2.62). The numerically highest shock/ATP rate of 28.9 therapies per 1,000 patients per year was seen in patients with arrhythmogenic right ventricle cardiomyopathy and the lowest shock/ATP rate of 0.05 therapies per 1,000 patients per year was seen in patients with ischemic heart disease. In patients with ischemic heart disease, the shock/ATP rate per year was 0.06 in patients with an ICD implanted as primary prophylactic and 0.15 in patients with an ICD as secondary prophylactic. Conclusion The frequency of ICD shock/ATP therapy varies several-fold between cardiac disorders, with the highest rate in patient with arrhythmogenic right ventricle cardiomyopathy and the lowest rate in the major group of patients, i.e. patients with ischemic heart disease. These findings may indicate a need for adjustments of patient selection for ICD implantation.

Periodic Repolarization Dynamics (PRD) identifies patients who profit from ICD implantation, A meta-analysis of the predictive value of PRD

Abstract Background Periodic repolarization dynamics (PRD) is an electrocardiographic marker that quantifies sympathetic-activity associated instabilities of cardiac repolarization. PRD is a strong predictor of mortality in patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM) and has been proposed to identify patients who benefit from prophylactic ICD implantation. Purpose To conduct a systematic review and meta-analysis concerning the prognostic value of PRD for predicting all-cause mortality in relation to prophylactic ICD-implantation. Methods This meta-analysis follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A total of 25 articles were screened and 7 randomized and non-randomized controlled trials identified. Finally, a total of 5 could be included in the analysis (Fig.1). Patients were stratified into patients with or without prophylactic ICD-implantation (Fig.2). The prognostic value of PRD for predicting all-cause mortality was extracted from published data as hazard ratio (HR) per 1 deg2 increase in PRD. We used inverse-variance-weighted average meta-analysis to calculate fixed and random effect models to estimate the overall predictive value of PRD in both groups. The interaction between PRD and prophylactic ICD-implantation for predicting mortality was calculated using meta-regression analysis. All analyses were performed using CRAN R v. 4.1.2 and the meta-package v 5.2.0. Results We included 4,338 patients in this meta-analysis, of whom 3,167 (73%) suffered from ICM and 1,171 (27%) from NICM. 1,906 (44%) patients were treated with an ICD. During an estimated mean follow-up time of 3.2 years, 604 (14%) patients died. Fig. 2 (left) shows patients without ICD treatment (N = 2,432, 56%). In these patients, a 1 deg2 increase in PRD was significantly associated with an overall 8% increase in mortality (fixed effect HR 1.08; 95% CI 1.06-1.10; p&amp;lt; 0.001, random effect HR 1.08; 95% CI 1.06-1.11; p &amp;lt; 0.001). Fig. 2 (right) displays the prognostic value of PRD in patients treated by ICD (N = 1,906). In these patients, a 1 deg2 increase in PRD was significantly associated with an overall 3% increase in mortality (fixed-effect HR 1.03; 95% CI 1.01-1.05; p&amp;lt; 0.001, random-effect HR 1.03; 95% CI 1.00-1.06; p &amp;lt; 0.001). An increase in PRD was not significantly associated with an increase in mortality in patients from the EU-CERT-ICD and DANISH trial. There was a significant interaction between PRD and prophylactic ICD-implantation for predicting all-cause mortality (p = 0.008). Conclusion In patients with ICM and NICM, PRD is a strong predictor of all-cause mortality in patients with and without prophylactic ICD. The significant interaction between PRD and prophylactic ICD-implantation most probably implies a reduction in the risk identified by PRD through ICD implantation. Consequently, PRD could prove a useful tool for identifying patients that might benefit from ICD treatment.Figure 1Figure 2

Asymptomatic Brugada patients: long-term prognosis from a large prospective study

Abstract Background One of the greatest challenges concerning the Brugada syndrome is how to stratify and manage asymptomatic patients, who represent the majority of patients with Brugada ECG pattern (BrECG). Purpose Aim of our study was to evaluate the long-term prognosis of a large population of asymptomatic Brugada patients. Methods One thousand one hundred and forty-nine asymptomatic Brugada patients were collected. Patients were treated as follows: in the 539 subjects with spontaneous type 1 BrECG documented on basal ECG or at 12-lead 24-hour Holter monitoring (12L-Holter) an electrophysiological study (EPS) was proposed and ICD implantation was proposed on the basis of the EPS results; in the 610 subjects with drug-induced-only type 1, clinical follow-up with multiple ECGs and 12L-Holter was suggested to search for spontaneous type 1 BrECG. Results Over a median follow-up of 6 (4-9) years there were 17 arrhythmic events (1.5%). Sixteen events occurred in the 539 patients with spontaneous type 1 (3%; 0.4% person-years) and only 1 in the 610 patients with drug-induced type 1 BrECG (0.16%; 0.03% person-years, p 0.001). Patients with spontaneous type 1 had a 15-time higher risk of arrhythmic events than patients with drug- induced type 1 BrECG. Patients with spontaneous type 1 BrECG and positive EPS had a 3-time higher risk of arrhythmic events than patients with negative EPS (6.8% vs 1.6%, p 0.035). An ICD was implanted in 163 patients: 8 (5%) received an appropriate intervention, while 23% experienced device-related complications, including 1 death. Conclusions Asymptomatic patients with spontaneous type 1 BrECG have an event rate of 3% at a median follow-up of 6 years. In this group, EPS represents a useful risk stratification procedure, as a positive EPS identifies patients with a 3-time higher event rate as compared to subjects with negative EPS. A negative EPS identifies a population at low although not zero-risk. Asymptomatic patients with drug-induced only Brugada ECG pattern are a group at very low arrhythmic risk. ICD implantation is burdened by a high incidence of complications, therefore alternative therapeutic strategies are needed.