Secondary Prevention Of Sudden Cardiac Death Research Articles

Epicardial ablation in patients with Brugada syndrome: a single centre experience

Abstract Introduction Brugada syndrome (BrS) is a rare disease associated with an increased risk of ventricular fibrillation (VF), ventricular tachycardia (VT), and sudden cardiac death (SCD). The standard prevention of SCD in patients with BrS is the implantation of an implantable cardioverter-defibrillator (ICD), especially in patients who have previously suffered cardiac arrest or arrhythmogenic syncope. Catheter ablation is an effective method to prevent recurrences of VF/VT in these patients. Purpose Retrospective analysis of the results of catheter ablation by epicardial approach and genetic testing in patients with a diagnosis of BrS and repeated adequate ICD interventions. Methods In 2013-2024, catheter ablation by epicardial approach was performed in our centre in 9 patients diagnosed with Brugada syndrome (mean age 41±6 years, nine males, left ventricular ejection fraction 57±4%). All patients had an ICD implanted for secondary prevention of SCD and presented with adequate ICD therapies (mean 9±11 shocks/patient in the last six months before catheter ablation). Before catheter ablation, two patients were treated with quinidine. Patients underwent cardiogenetic testing by next-generation sequencing of 228 genes. Results Type 1 electrocardiogram (ECG) pattern was present at baseline ECG in four (44%) patients; in five (56%) patients, type 1 was induced after ajmaline administration. Genetic testing was performed in seven patients, and only one patient (14%) was found to have a relevant pathogenic mutation in the SCN5A gene. Prior to ablation, sustained VT/VF could be induced by programmed electrical stimulation in three patients (33%). Epicardial ablation was targeted at areas of abnormal electrograms located over the right ventricular outflow tract. No complications were noted. The mean follow-up period was 25±30 months. In one patient (11%), reablation was required to suppress ventricular arrhythmias successfully. After the last ablation, no recurrence of VT/VF was observed in any patient. Conclusions Epicardial ablation is an effective method that leads to the suppression of ventricular arrhythmias in patients with a diagnosis of BrS and repeated ICD interventions. Despite the malignant arrhythmic phenotype, patients in our cohort had a rather low prevalence of signs associated with a high risk of VT/VF, such as spontaneous ECG pattern of BrS, inducibility of VT/VF during electrical programmed stimulation, or the presence of a causative genetic mutation.

Outcomes and complications of transvenous implantable cardioverter defibrillator systems in the pediatric population: a systematic review and meta-analysis

Abstract Background Implantable cardioverter defibrillators (ICDs) are an important therapy for prevention of sudden cardiac death (SCD). Data on transvenous (TV) ICD therapy rates, complications, and system survival in children ≤ 21 years is limited by absolute numbers and inclusion of adults with congenital heart disease. Purpose To determine ICD therapy rates and complications in pediatric patients ≤ 21 years of age. Methods A systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Medline, Embase, PubMed Ahead-of-Print and in-process records, and Cochrane Database of Systematic Reviews were searched for full-text articles on pediatric ICD. Articles were assessed for inclusion by two authors via a consensus process; the exclusion criteria included: case reports, review articles, abstracts, editorials, articles not in English, articles solely on epicardial or subcutaneous leads, articles on unrelated topics, articles with <50% ICD leads, and articles with any patients >21 years old. Data were extracted by 1 author and verified by a 2nd author. Meta-analysis of aggregate data was performed, where possible. Random effects models were used for pooled inferences. All reported rates are annualized rates based on reported follow-up times in each study. Results Of 1325 articles, 23 met all inclusion and no exclusion criteria (Figure) representing 1700 patients implanted from 1987-2020. The average age of patients was 12.8 years (95% confidence interval [CI]: 11.9 – 13.7) with weight of 51.1 kg (95% CI: 42.2 – 60.0) (Table). Primary prevention was the indication in 56.4 % (95% CI: 45.0% – 67.7%). Only 14.8% (95% CI: 10.6% – 19.0%) of the patients had congenital heart disease while 22.6% (95% CI: 15.8% – 29.3%) had long QT syndrome. The annualized rate of appropriate shock was 7.0% (95% CI: 5.6% – 8.8%) and the rate of inappropriate shock was 4.8% (95% CI: 3.8% – 6.0%). Annualized rates of reported adverse events included lead failure: 2.3% (95% CI: 1.6% – 3.3%) and infection: 0.8% (95% CI: 0.4% – 1.6%), which could have led to system revision: 4.4% (95% CI: 2.1% – 9.4%). The all-cause mortality rate was 0.8% (95% CI: 0.6% – 1.2%) across 17 studies. In 9 studies with 719 patients, the heart transplant rate was 1.6% (95% CI: 0.6% – 3.9%). Conclusion In this first systematic review and meta-analysis of ICDs in pediatric patients, ICD therapy was effective for prevention of SCD with a 7.0% annualized rate of appropriate ICD shocks. This is comparable to the annualized rate of appropriate ICD shock for secondary prevention of SCD in adult randomized controlled trials. Most common adverse events in the pediatric population were lead failure and system revision. Further refinements in patient selection criteria for implantation and improvements in lead and device technology are needed for pediatric patients.FigureTable

Racial and Ethnic Disparities in Implantable Cardioverter-Defibrillator Utilization: A Contemporary Review.

Sudden cardiac arrest is associated with high morbidity and mortality. Despite having a disproportionate burden of sudden cardiac death (SCD), rates of primary and secondary prevention of SCD with implantable cardioverter-defibrillator (ICD) therapy are lower among eligible racially minoritized patients. This review highlights the racial and ethnic disparities in ICD utilization, associated barriers to ICD care, and proposed interventions to improve equitable ICD uptake. Racially minoritized populations are disproportionately eligible for ICD therapy but are less likely to see cardiac specialists, be counseled on ICD therapy, and ultimately undergo ICD implantation, fueling disparate outcomes. Racial disparities in ICD utilization are multifactorial, with contributions at the patient, provider, health system, and structural/societal level. Racial and ethnic disparities have been demonstrated in preventing SCD with ICD use. Proposed strategies to mitigate these disparities must prioritize care delivery and access to care for racially minoritized patients, increase the diversification of clinical and implementation trial participants and the healthcare workforce, and center reparative justice frameworks to rectify a long history of racial injustice.

Subcutaneous implantable cardioverter-defibrillator in adults with congenital heart disease

Abstract Background Subcutaneous implantable cardioverter-defibrillators (S-ICD) are an established treatment option for the prevention of sudden cardiac death (SCD). However, data in adults with congenital heart disease (ACHD), especially in direct comparison to other patient groups (e.g. cardiomyopathies) are scarce. Methods Retrospective single-center study of all patients receiving a S-ICD in the time-period 2012-2020. ACHD patients were compared to non-ACHD patients. Primary outcome was all-cause mortality. Secondary outcome was a combined endpoint of all-cause mortality and appropriate shocks. Results Altogether, 79 patients (11 ACHD, 68 non-ACHD patients) with a mean age of 40.6 ± 16.0 years (29.1% female) were included. There was no significant difference for age and sex between both groups. Secondary prevention of SCD was more often the indication for a S-ICD in ACHD (81.8%) than in non-ACHD patients (48.5%; p=0.040). Betablockers were more commonly used in ACHD patients (100% vs. 64.7%; p=0.018). There was no significant difference for other heart failure medications. During a median follow up of 3.4 years [IQR 1.7-5.2], the primary endpoint occurred in 36.4% of ACHD vs. 2.9% of non-ACHD patients (p<0.001). The secondary endpoint occurred also more often in the ACHD patient group compared to non-ACHD patients (54.5% vs. 17.6%, p=0.007). There was a numerically higher number of inappropriate shocks in the ACHD group (27.3% vs. 9.0%), albeit without a statistically significant difference (p=0.078). Conclusions In ACHD patients with a S-ICD, mortality as well as a combined endpoint of mortality and appropriate shocks were more common than in non-ACHD patients. The numerically higher number of inappropriate shocks deserves further attention.

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

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

P162 ARRHYTHMIC MITRAL VALVE PROLAPSE OCCURRING AS ABORTED SUDDEN CARDIAC DEATH

Abstract Mitral valve prolapse (MVP) is the common valvular heart disease, with a prevalence about 1–3% in the population. MVP is characterized on echocardiography by an abnormal systolic displacement of mitral valve leaflets into left atrium (LA) ≥ 2 mm above the mitral annulus. We described a clinical case of a 15 years–old boy with a first clinical presentation of out–of–hospital cardiac arrest related to ventricular fibrillation (VF) with a successful resuscitation after 2 DC shocks. Retrospectively, an episode of loss of awareness reported as post–minational. No familiar history of sudden cardiac death (SCD) or MVP was noticed. In the emergency room, the patient was hemodynamically unstable and was sedated and intubated. The surface electrocardiogram (ECG) showed sinus rhythm, QRS with fragmentation, and frequent monomorphic isolated premature ventricular contractions (PVCs) with RBBB/LAFB configuration.Frequent monomorphic PVCs with bigeminy was observed during continuous ECG monitoring, so the patient was treated with magnesium sulphate and metoprolol. The patient was subsequently weaned from ventilation support, presenting good gas exchange and without neurological sequalae. The 24h Holter monitoring showed an average of 53 bpm, extremely rare supraventricular extrasystoles, high incidence of monomorphic PVCs (23% of the total beats) with 4 couplets. Transthoracic echocardiography documented normal size and thickness with systolic function (GLS –21%, mild asynchrony of posterior basal segments), bi–leaflet prolapse associated to mild–moderate mitral regurgitation, and mitral annular disjunction (MAD) of 6.2 mm. The late gadolinium enhancement cardiac magnetic resonance showed bi–leaflet prolapse with mild insufficiency and maximum MAD 9 mm, mild LA dilatation, and slightly dilated both ventricles, without regional wall motion abnormalities; no scar or fibrosis at the late gadolinium enhancement was observed. According to guidelines, the patient received a subcutaneous implantable cardiac defibrillator for the secondary prevention of SCD and maintained under betablockers in order to control the arrhythmic burden. The genetic sampling did not show any pathogenetic mutation potentially related to cardiomyopathies or channelopathies. This case show an arrhythmic MVP complex with probably posterior papillary muscle source. The early PVCs with R/T constituted a possible trigger of VF. The betablocker therapy exhibited a full suppression of extrasystolic burden.

220 MANAGING CARDIAC ARREST SECONDARY TO SPONTANEOUS CORONARY ARTERY DISSECTION: SHOULD WE ROUTINELY CONSIDER ICD IMPLANTATION?

Abstract Introduction Cardiac arrest secondary to a spontaneous coronary artery dissection (SCAD) represents a challenging scenario. It deserves specific considerations due to the dramatic presentation and the need for secondary sudden cardiac death prevention. Methods We collected clinical data of four women admitted during the last two years in the Coronary Care Unit of Parma University Hospital, whose presentation of SCAD were cardiac arrest due to ventricular fibrillation. Results Three patients survived the acute phases. One patient, being considered at high risk of SCAD recurrence, received a subcutaneous implantable cardioverter-defibrillator (S-ICD). Acute management of cardiac arrest related to SCAD deserves specific considerations. Our case series illustrates the importance of prompt resuscitation manoeuvres and early defibrillation. We propose a flow chart of management of cardiac arrest in patient with suspect of SCAD. Evaluating risk of SCAD recurrence and sudden cardiac death The management of SCAD patients complicated by malignant ventricular arrhythmias and cardiac arrest is challenging. Looking at published registries, it appears that SCAD patients are more likely to suffer from ventricular arrythmia or sudden cardiac death than non-SCAD MI patients. The risk-benefit ratio of ICD implantation in these patients remain uncertain . Evaluation of scar burden with CMR can help stratify the global arrhythmic risk, especially as extensive myocardial scar with a residual impaired LVEF increases the risk of future arrhythmic events. In our series, only one patient underwent S-ICD implantation, and the decision was mainly driven by the finding of underlying arteriopathy affecting other vascular territories, suggesting a potentially higher rate of SCAD recurrence. For this particular subset of patients, we propose an algorithm that combines predisposing factors and myocardia injury quantification data that could be useful for the estimate of the risk of malignant arrythmias, as well as the risk of recurrence of SCAD, but needs to be validated in larger case studies. Conclusions The acute management of cardiac arrest related to SCAD deserves specific consideration. The residual myocardial damage, predisposing and precipitants factors should be evaluated in order to estimate the SCAD recurrence and sudden cardiac death risks.

Implementation of an antibacterial envelope during de novo implantation of ICD system in secondary SCD prevention in a patient on immunosuppressive treatment

Implantation of cardioverter-defibrillator system is necessary and it needs to be performed as soon as possible in patients with secondary sudden cardiac death prevention including resynchronization therapy indications. Patients on active immunosuppressive treatment are at the highest risk of infective complications of every kind of surgical intervention. In the case of cardiac implantable devices implementation of an antibacterial envelope could be a relevant factor in infective risk prevention.

Inter-American Society of Cardiology (CIFACAH-ELECTROSIAC) and Latin-American Heart Rhythm Society (LAHRS): multidisciplinary review on the appropriate use of implantable cardiodefibrillator in heart failure with reduced ejection fraction

BackgroundOur main objective was to present a multidisciplinary review on the epidemiology of sudden cardiac death (SCD) and the tools that could be used to identify malignant ventricular arrhythmias (VAs) and to perform risk stratification. In addition, indications and contraindications for the use of implantable cardioverter defibrillator (ICD) in general and in special populations including the elderly and patients with chronic kidney disease (CKD) are also given.MethodsAn expert group from the Inter American Society of Cardiology (IASC), through their HF Council (CIFACAH) and Electrocardiology Council (ElectroSIAC), together with the Latin American Heart Rhythm Society (LAHRS), reviewed and discussed the literature regarding the appropriate use of an ICD in people with heart failure (HF) with reduced ejection fraction (HFpEF). Indications and contraindications for the use of ICD are presented in this multidisciplinary review.ResultsNumerous clinical studies have demonstrated the usefulness of ICD in both primary and secondary prevention of SCD in HFpEF. There are currently precise indications and contraindications for the use of these devices.ConclusionsIn some Latin American countries, a low rate of implantation is correlated with low incomes, but this is not the case for all Latin America. Determinants of the low rates of ICD implantation in many Latin American countries are still a matter of research. VA remains one of the most common causes of cardiovascular death associated with HFrEF and different tools are available for stratifying the risk of SCD in this population.

Abstract 11350: Arrhythmogenic Mitral Valve Prolaspe and Mitral Annular Disjunction

Background: Mitral valve prolapse (MVP) affects about 2-3% of the general population. A small proportion of persons may have arrhythmic symptoms, leading to ventricular arrhythmias and sudden cardiac death (SCD). Mitral annular disjunction is a recently described entity that may be present with MVP or independently. Case: A 55-year-old male patient presented to the hospital with cardiac arrest. He has a history of percutaneous coronary intervention with stenting to left anterior descending (LAD) and right coronary artery (RCA) in 2015. He had ventricular fibrillation (VF) and subsequently arrested and underwent resuscitation. Electrocardiogram (EKG) showed sinus rhythm with prolonged QTc 487msec with no ischemia; echocardiography showed mitral annular disjunction, severe left ventricular global hypokinesis with ejection fraction of 10%. Left heart catheterization revealed nonobstructive moderate coronary artery disease. Right heart catheterization showed a severely reduced cardiac index of 2.1, and he was placed on mechanical support (Impella) for cardiogenic shock. On day 5, repeat echocardiography revealed left ventricular ejection fraction of 60%. Subsequent cardiac magnetic resonance (CMR) showed no evidence of infiltrative diseases but revealed an inferolateral wall scar from previous myocardial infarction and MVP with MAD. An implantable cardiac defibrillator was placed for secondary prevention of SCD. Discussion: The potential etiology of our patient's ventricular fibrillation cardiac arrest may include a scar from previous myocardial infarction or arrhythmogenic MVP with MAD. Myocardial fibrosis arising from MAD may be an origin of ectopic activity and arrhythmia. EKG, echocardiographic, and cardiac magnetic resonance imaging (CMR) are essential in diagnosing arrhythmic MVP and MAD. Young patients with premature ventricular contractions without clear etiology should be evaluated for MAD, and incidental findings of MAD should warrant further investigations, given its arrhythmogenic potential. Conclusion: MVP with MAD is associated with life-threatening arrhythmias. Further studies are required to explore treatment options to reduce the incidence of malignant VAs and SCDs in patients with MVP.

Sport Related Sudden Death: The Importance of Primary and Secondary Prevention.

Sports are a double-edged sword. On the one hand, cardiovascular benefits from sports activity are well-known, and on the other hand, sports may increase the risk of sudden cardiac death (SCD) in subjects with known or unknown cardiovascular diseases. SCD is rare but has a very strong emotional issue. There are many examples involving famous professional athletes, but this is only scratching the surface of a widespread phenomenon that also involves amateur athletes. The importance of safely performing physical activity appears clear in both professional and amateur athletes. In particular, the former undergo a pre-participation screening for SCD primary prevention with different recommendations in each country. On the other hand, a medical examination is not mandatory for non-professional athletes and, therefore, for people who practice sports as an amateur. Widespread distribution of automatic external defibrillators and people trained for cardiopulmonary resuscitation are necessary to promote secondary prevention of SCD. We briefly report a case series of athletes with aborted SCD during sports activity in order to underline and discuss in this review the previously highlighted issues.

C12 MANAGING CARDIAC ARREST SECONDARY TO SPONTANEOUS CORONARY ARTERY DISSECTION: SHOULD WE ROUTINELY CONSIDER ICD IMPLANTATION? INSIGHTS FROM PARMA SCAD REGISTRY

Abstract Background Cardiac arrest secondary to a spontaneous coronary artery dissection (SCAD) represents a challenging scenario. It deserves specific considerations due to the dramatic presentation and the need for secondary sudden cardiac death prevention. Methods We collected clinical data of four women admitted during the last two years in the Coronary Care Unit of Parma University Hospital, whose presentation of SCAD were cardiac arrest due to ventricular fibrillation (Table1). Results Three patients survived the acute phases. One patient, being considered at high risk of SCAD recurrence, received a subcutaneous implantable cardioverter–defibrillator (S–ICD). Acute management of cardiac arrest related to SCAD deserves specific considerations. Our case series illustrates the importance of prompt resuscitation manoeuvres and early defibrillation. We propose a flow chart of management of cardiac arrest in patient with suspect of SCAD (Figure 2 A). Evaluating risk of SCAD recurrence and sudden cardiac death. The management of SCAD patients complicated by malignant ventricular arrhythmias and cardiac arrest is challenging. Looking at published registries, it appears that SCAD patients are more likely to suffer from ventricular arrythmia or sudden cardiac death than non–SCAD MI patients. The risk–benefit ratio of ICD implantation in these patients remain uncertain . Evaluation of scar burden with CMR can help stratify the global arrhythmic risk, especially as extensive myocardial scar with a residual impaired LVEF increases the risk of future arrhythmic events (Figure 2 B). In our series, only one patient underwent S–ICD implantation, and the decision was mainly driven by the finding of underlying arteriopathy affecting other vascular territories, suggesting a potentially higher rate of SCAD recurrence. For this particular subset of patients, we propose an algorithm that combines predisposing factors and myocardial injury quantification data (Figure 2 B) that could be useful for the estimate of the risk of malignant arrythmias, as well as the risk of recurrence of SCAD, but needs to be validated in larger case studies. Conclusions The acute management of cardiac arrest related to SCAD deserves specific consideration. The residual myocardial damage, predisposing and precipitants factors should be evaluated in order to estimate the SCAD recurrence and sudden cardiac death risks.

Implantable Cardioverter Defibrillator in Primary and Secondary Prevention of SCD-What We Still Don't Know.

Implantable cardioverter defibrillators (ICDs) are the cornerstone of primary and secondary prevention of sudden cardiac death (SCD) all around the globe. In almost 40 years of technological advances and multiple clinical trials, there has been a continuous increase in the implantation rate. The purpose of this review is to highlight the grey areas related to actual ICD recommendations, focusing specifically on the primary prevention of SCD. We will discuss the still-existing controversies strongly reflected in the differences between the international guidelines regarding ICD indication class in non-ischemic cardiomyopathy, and also address the question of early implantation after myocardial infarction in the absence of clear protocols for patients at high risk of life-threatening arrhythmias. Correlating the insufficient data in the literature for 40-day waiting times with the increased risk of SCD in the first month after myocardial infarction, we review the pros and cons of early ICD implantation.

Cost-effectiveness and budget impact analyses of using implantable cardioverter-defibrillators in the Russian Federation

Objective: to evaluate cost-effectiveness and budget impact of using single and dual chamber implantable cardioverter-defibrillators (ICD) adjunctive to the standard drug therapy (DT) compared to the standard DT alone for the primary and secondary prevention of sudden cardiac death (SCD).Material and methods. Original partitioned survival analysis model was developed to assess the cost-effectiveness of using ICD within the modelling horizon of 8 years. The following model outcomes were used: life years and quality-adjusted life years (QALY). Primary prevention model was focused on patients after myocardial infarction with left ventricular ejection fraction (LVEF) ≤30%, whilst secondary prevention model considered cardiac arrest survivors and/or patients diagnosed with ventricular tachycardia or ventricular fibrillation with LVEF ≤35%. The model summarizes treatment effect and costs for ICD and DT specific to the healthcare system of the Russian Federation (RF). The main scenario accounted for ICD implantation cost in accordance with general reimbursement price asserted in the high technology medical care list part 2 (HТMC 2). Additionally, alternative scenario of ICD reimbursement level was developed to account for general tariff split onto singleand dual-chamber ICD implantation reimbursement tariffs which can be financed through high technology medical care list part 1 (HТMC 1). Budget impact analysis compared the costs of using ICD within the current volume of the annual increase in ICD implantations and a threefold increased volume of ICD implantations.Results. By the end of the modelling period, additional 34% of patients survived in the ICD group compared to the DT group. Incremental cost-effectiveness ratio (ICER) per 1 QALY constituted 2.8 and 2.2 million rubles for primary and secondary prevention, respectively. ICER values are slightly above or lower than the willingness-to-pay threshold of 2.5 million rubles per 1 QALY in the RF in the segment of primary and secondary SCD prevention, respectively. Additional HТMC 1 scenario incorporating lower ICD implantation prices resulted in an average ICER drop by 13% compared to HTMC 2. Overall patient population requiring SCD prevention comprised of 7,161 and 3,341 patients in primary and secondary prevention, respectively. Budget impact analysis showed that threefold rise in the ICD implantations rate will require additional 648 million rubles for primary prevention cohort to provide additional 573 patients with ICD, and 230 million rubles for secondary prevention cohort with additional 267 patients covered with ICD. ICD reimbursement price drop within the HТMC 1 scenario will save 133 million rubles and allow to provide additional 143 patients with ICDs for a given budget.Conclusion. ICD is a cost-effective option of secondary prevention of SCD. Additional analysis of ICD reimbursement price drop drives ICER downwards to a considerable extent which in turn increases the accessibility of ICDs to patients. In scenario of ICD implantation financing within HТMC 1, ICD is established to be a cost-effective option for primary and secondary prevention of SCD in the RF.

Prediction of appropriate ICD therapy in patients with ischemic heart failure

BackgroundPrevious studies show inconsistent results on the role of innervation imaging (with I-123-mIBG) and perfusion imaging in predicting appropriate ICD therapy (aICDth). These studies included patients with both dilated and ischemic cardiomyopathy. This study compared the ability of 123I-mIBG imaging along with perfusion imaging (using thallium-199) to predict aICDth in patients with ischemic heart failure (IHF) in relation to indication for ICD implantation (primary vs. secondary prevention of sudden cardiac death (SCD)). MethodsmIBG/thallium SPECT imaging were performed before ICD implantation in 80 patients with IHF: 49 candidates for primary and 31 for secondary SCD prevention. ResultsDuring a mean follow-up of 18 months, the imaging results could not predict patients with appropriate ICD therapy among patients with ICD implants for primary SCD prevention.While in the secondary SCD prevention group, those who received a ICDth had significantly larger summed scores of regional perfusion and innervation impairment, but not higher heart-to-mediastinal mIBG ratio. The best results to predict aICDth were using mIBG summed score (cut-off point > 34%, sensitivity 72%, specificity 100%, AUC 0.909, P < 0.0001). ConclusionThe prognostic value of innervation and perfusion imaging in patients with IHF differ based on indication for ICD implantation (primary vs. secondary prevention of SCD).

Clinical characteristics of patients with various genetic types of long QT syndrome

The aim of the study is to evaluate clinical characteristics, including adverse events and outcomes, in patients with various genetic types of long QT syndrome (LQTS).Material and methods. We examined 24 patients with a clinical diagnosis of LQTS, observed in the for 5 years. The clinical and instrumental study included registration of electrocardiography (ECG), Holter monitoring, collection of a genealogical history with an ECG assessment of all family members and identification of cases of sudden cardiac death (SCD) in the family or the presence of a family form of the disease, echocardiography and cardiac magnetic resonance imaging to exclude structural changes in the myocardium. The search for mutations in the coding sequences of genes associated with the development of channelopathy and other hereditary heart rhythm disorders was carried out by next generation sequencing (NGS).Results. Mutations in 4 genes associated with LQTS (KCNQ1, KCNH2, CACNA1C, ANK2) were detected in 18 out of 24 (75.0%) patients. Mutations in the KCNQ1, KCNH2 and CACNA1C genes were detected in 14 (58.0%) patients. In 4 out of 24 (17%) patients, two or more variants of clinical significance (VUS) were detected in the genes associated with LQTS and hereditary arrhythmias, 6 patients had no genetic changes. The most severe form of the disease with pronounced clinical manifestations and episodes of clinical death with subsequent resuscitation measures, as well as a significant increase in the QTc interval exceeding 500 ms, was observed in patients with LQT2 and multiple mutations. Implantation of a cardioverter-defibrillator (CD) was required in 14 (58.3%) patients, including 11 (78.56%) - for secondary prevention of SCD and 3 (21.4%) - for primary prevention.Conclusion. A comparative analysis between different genetic types of LQTS (LQT1; LQT2; patients with multiple VUS) showed that in patients with LQT1 syndrome, despite the early manifestation of the disease and the presence of syncopal conditions, life-threatening arrhythmias, SCD and the frequency of CD implantation were significantly less often recorded than in other LQTS. The most severe form of the disease with pronounced clinical manifestations, episodes of clinical death with subsequent resuscitation and CD implantation was observed both in the group of probands with LQT2 and in patients with several nucleotide variants (VUS), one of which was in the CACNA1C or ANK2 genes.

Angiotensin Converting Enzyme Inhibitors versus Receptor Blockers in Patients with Ventricular Tachyarrhythmias.

Data investigating the prognostic value of treatment with angiotensin converting enzyme inhibitors (ACEi) and receptor blockers (ARB) usually focusses on patients presenting with heart failure (HF) or acute myocardial infarction (AMI). However, by preventing adverse cardiac remodeling, ACEi/ARB may also decrease the risk of ventricular tachyarrhythmias and sudden cardiac death (SCD). Although ventricular tachyarrhythmias are associated with significant mortality and morbidity, only limited data are available focusing on the prognostic role of ACEi/ARB, when prescribed for secondary prevention of SCD. Therefore, this study comprehensively investigates the role of ACEi versus ARB in patients with ventricular tachyarrhythmias. A large retrospective registry was used including consecutive patients with episodes of ventricular tachycardia (VT) or fibrillation (VF) from 2002 to 2015. The primary prognostic outcome was all-cause mortality at three years, secondary endpoints comprised a composite arrhythmic endpoint (i.e., recurrences of ventricular tachyarrhythmias, ICD therapies and sudden cardiac death) and cardiac rehospitalization. A total of 1236 patients were included (15% treated with ARB and 85% with ACEi) and followed for a median of 4.0 years. At three years, ACEi and ARB were associated with comparable long-term mortality (20% vs. 17%; log rank p = 0.287; HR = 0.965; 95% CI 0.689–1.351; p = 0.835) and comparable risk of the composite arrhythmic endpoint (HR = 1.227; 95% CI 0.841–1.790; p = 0.288). In contrast, ACEi was associated with a decreased risk of cardiac rehospitalization at three years (HR = 0.690; 95% CI 0.490–0.971; p = 0.033). Within the propensity score matched cohort (i.e., 158 patients with ACEi and ARB), ACEi and ARB were associated with comparable long-term outcomes at three years. In conclusion, ACEi and ARB are associated with comparable risk of long-term outcomes in patients presenting with ventricular tachyarrhythmias.

Arrhythmic Mitral Valve Prolapse and Mitral Annular Disjunction: Clinical Features, Pathophysiology, Risk Stratification, and Management

Mitral valve prolapse (MVP) is a common cause of valvular heart disease. Although many patients with MVP have a benign course, there is increasing recognition of an arrhythmic phenotype associated with ventricular arrhythmias and sudden cardiac death (SCD). Pathophysiologic mechanisms associated with arrhythmias include cardiac fibrosis, mechanical stress induced changes in ventricular refractory periods, as well as electrophysiologic changes in Purkinje fibers. Clinically, a variety of risk factors including demographic, electrocardiographic, and imaging characteristics help to identify patients with MVP at the highest at risk of SCD and arrhythmias. Once identified, recent advances in treatment including device therapy, catheter ablation, and surgical interventions show promising outcomes. In this review, we will summarize the incidence of ventricular arrhythmias and SCD in patients with MVP, the association with mitral annular disjunction, mechanisms of arrhythmogenesis, methods for arrhythmic and SCD risk stratification including findings with multimodality imaging, and treatments for the primary and secondary prevention of SCD.

Underrepresentation of women in implantable cardioverter defibrillator trials

There are sex differences in the epidemiology and presentation of ventricular arrhythmias. Sudden cardiac death (SCD) is less common in women than in men. Women have been under-represented in implantable cardioverter defibrillator (ICD) trials evaluating the benefit of ICD therapy for primary and secondary prevention of SCD. Following ICD implantation, women are less likely to experience appropriate ICD therapy for ventricular arrhythmias, consistent with epidemiological findings of a lower rate of SCD in women. Sex differences in ICD implantation rates have also been noted for primary and secondary prevention of SCD in registries and large observational cohort studies. Reasons for these differences are unclear. Age and comorbidities at the time of presentation may be partially responsible, although sex bias, patient preference, or contribution of social determinants of health cannot be excluded. There are many unanswered questions regarding reasons for sex differences in ICD usage and under-representation of women in clinical device trials. Additional investigation is needed to better understand these differences to improve outcome of all patients who are at risk for sudden cardiac arrest.

Имплантируемые кардиовертеры-дефибрилляторы в профилактике внезапной сердечной смерти: технические аспекты и дальнейшие перспективы применения. Что нужно знать практикующему врачу?

Currently, the prevention of sudden cardiac death (SCD) is an urgent issue as never, i.e., more than a half of patients with cardiovascular disorders die suddenly, one third of patients are young and middle-aged adults. The primary preventive strategy of SCD is an implantable cardioverter defibrillator (ICD) due to the lack of highly effective and, more important, safe antiarrhythmics. Forty years after the first ICD insertion, SCD is still the cause of more than 5 million of deaths annually worldwide. Therefore, a real need for ICD is significantly higher than the number of insertions. Meanwhile, primary physicians are not aware of this preventive tool. This paper reviews current approaches to ICD use for the primary and secondary prevention of SCD, types of ICDs, selection of electrode insertion sites, relevant aspects of ICD programming to detect and addresses arrhythmias by antitachycardial pacing or shock discharge, standards for outpatient follow-up after ICD insertion, distant monitoring and telemetry, and future perspectives of ICD insertion. KEYWORDS: sudden cardiac death, implantable cardioverter defibrillator, distant monitoring, perspectives. FOR CITATION: Talibullin I.V., Lebedeva N.B., Parfenov P.G., Mamchur S.E. Implantable cardioverter defibrillators for the prevention of sudden cardiac death: technical aspects and future perspectives. What a practitioner needs to know? Russian Medical Inquiry. 2022;6(1):21– 25 (in Russ.). DOI: 10.32364/2587-6821-2022-6-1-21-25.