Autopsy of all young sudden death cases is important to increase survival in family members left behind.

Sudden cardiac death (SCD) is an important public health problem worldwide, accounting for an estimated 6 to 20% of total mortality. A significant proportion of SCD is caused by inherited heart disease, especially among the young. An autopsy is crucial to establish a diagnosis of inherited heart disease, allowing for subsequent identification of family members who require cardiac evaluation. Autopsy of cases of unexplained sudden death in the young is recommended by both the European Society of Cardiology and the American Heart Association. Overall autopsy rates, however, have been declining in many countries across the globe and there is a lack of skilled trained pathologists able to carry out full autopsies. Recent studies show that not all cases of sudden death in the young are autopsied, likely due to financial, administrative, and organizational limitations as well as awareness among police, legal authorities, and physicians. Consequently, diagnoses of inherited heart disease are likely missed, along with the opportunity for treatment and prevention among surviving relatives. This article reviews the evidence for the role of autopsy in sudden death, how the cardiologist should interpret the autopsy-record and how this can be integrated and implemented in clinical practice. Finally, we identify areas for future research along with potential for healthcare reform aimed at increasing autopsy awareness and ultimately reducing mortality from SCD.

The role for ambulatory electrocardiogram monitoring in the diagnosis and prognostication of Brugada syndrome: a sub-study of the Rare Arrhythmia Syndrome Evaluation (RASE) Brugada study.

AIMS: Brugada syndrome (BrS) diagnosis and risk stratification rely on the presence of a spontaneous type 1 (spT1) electrocardiogram (ECG) pattern; however, its spontaneous fluctuations may lead to misdiagnosis and risk underestimation. This study aims to assess the role for repeat high precordial lead (HPL) resting and ambulatory ECG monitoring in identifying a spT1, and evaluate its prognostic role. METHODS AND RESULTS: HPL resting and ambulatory monitoring ECGs of BrS subjects were reviewed retrospectively, and the presence of a spT1 associated with ventricular dysrhythmias and sudden cardiac death (SCD). Three-hundred and fifty-eight subjects (77 with spT1 pattern at presentation, Group 1, and 281 without, Group 2) were included. In total, 1651 resting HPL resting and 621 ambulatory monitoring ECGs were available for review, or adequately described. Over a median follow-up of 72 months (interquartile range - IQR - 75), 42/77 (55%) subjects in Group 1 showed a spT1 in at least one ECG. In Group 2, 36/281 subjects (13%) had a newly detected spT1 (1.9 per 100 person-year) and 23 on an HPL ambulatory recording (8%). Seven previously asymptomatic subjects, five of whom had a spT1 (four at presentation and one at follow-up), experienced arrhythmic events; survival analysis indicated that a spT1, either at presentation or during lifetime, was associated with events. Univariate models showed that a spT1 was consistently associated with increased risk [spT1 at presentation: hazard ratio (HR) 6.3, 95% confidence interval (CI) 1.4-28, P = 0.016; spT1 at follow-up: HR 3.1, 95% CI 1.3-7.2, P = 0.008]. CONCLUSION: Repeated ECG evaluation and HPL ambulatory monitoring are vital in identifying transient spT1 Brugada pattern and its associated risk.

Ethnicity and Sudden Cardiac Death in Athletes: Insights from a Large United Kingdom Registry.

BACKGROUND AND AIMS: The relationship between ethnicity and causes of sudden cardiac death (SCD) in athletes is poorly understood. OBJECTIVES: To investigate etiology of SCD among different ethnicities in a large cohort of athletes. METHODS: Between 1994 and November 2022, 7880 cases of SCD were consecutively referred from all over the United Kingdom to our national cardiac pathology centre; 848 (11%) were athletes. All cases underwent detailed autopsy evaluation by expert cardiac pathologists. Clinical information was obtained from referring coroners. RESULTS: Most of athletes were white (n = 758; 89%). Black and Asian athletes were 51 (6%) and 39 (5%) respectively. A structurally normal heart, indicative of sudden arrhythmic death syndrome (SADS) was the most common autopsy finding (n = 385, 45%), followed by myocardial diseases (n = 275; 32%) cases, atherosclerotic coronary artery disease (CAD) (n = 58, 7%) and coronary artery anomalies (n = 29, 3%). In most of cases, death occurred during exercise (n = 737; 87%) . Arrhythmogenic cardiomyopathy (ACM) was more common in black (n = 13; 25%) than in white (n = 109; 14%) and Asian (n = 3; 8%) athletes (p = 0.03 between black and white athletes; p = 0.04 between black and Asian athletes); in contrast, CAD was more common in Asians (n = 6; 15% vs n = 51; 7% in whites vs 2% n = 1; in blacks, p = 0.02 between Asian and black athletes). Among white athletes, ACM was more common in individuals who died during exercise than in the ones who died at rest (p = 0.005). Such a difference was not observed in Asian and black athletes. In Asian athletes, CAD was the diagnosis at autopsy in 18% of individuals who died during exercise and in none of individuals who died at rest. CONCLUSIONS: A structurally normal heart at autopsy and myocardial diseases are the most common findings in athletes who died suddenly. While ACM is more common in black athletes, atherosclerotic CAD is more common in Asian athletes, with a strong association with exercise-induced SCD. ACM appears to be a driver of exercise-induced SCD in white athletes, however this is not the case in black and Asian athletes.

A sudden death in an athlete is an uncommon but highly tragic event which appears almost paradoxical, as athletes epitomize the healthiest segment of society. Inherited and familiar cardiac conditions are the main causes of sudden death in young individuals and athletes. Studies on this matter have mainly focused on Caucasian athletes and the frequency or the causes of sudden death in athletes of other ethnicities is largely unknown. Our study focusses on this aspect and reveals that causes of sudden death may highly vary among athletes of different race. The circumstances of death differ significantly among various ethnicities, even looking at the same underlying cardiac condition.

Arrhythmia detection using an implantable loop recorder after a negative electrophysiology study in Brugada syndrome: Observations from a multicenter international registry.

BACKGROUND: Risk stratification in Brugada syndrome (BrS) remains controversial. In this respect, the role of the electrophysiology study (EPS) has been a subject of debate. In some centers, it is common practice to use an implantable loop recorder (ILR) after a negative EPS to help in risk stratification. However, the diagnostic value of this approach has never been specifically addressed. OBJECTIVE: The aim of this study was to describe the baseline characteristics and the main findings of a diagnostic workup strategy with an ILR after a negative EPS in BrS. METHODS: We conducted a retrospective international registry including patients with BrS and negative EPS (ie, noninducible ventricular tachycardia or ventricular fibrillation) before ILR monitoring. RESULTS: The study included 65 patients from 8 referral hospitals in The Netherlands, Spain, and the United Kingdom (mean age, 39 ± 16 years; 72% male). The main indication for ILR monitoring was unexplained syncope/presyncope (66.2%). During a median follow-up of 39.0 months (Q1 25.0-Q3 47.6 months), 18 patients (27.7%) experienced 21 arrhythmic events (AEs). None of the patients died during follow-up. Bradyarrhythmias were the most common finding (47.6%), followed by atrial tachyarrhythmias (38.1%). Only 3 patients presented with ventricular arrhythmias. AEs were considered incidental in 12 patients (66.7%). In 11 patients (61.1%), AEs led to specific changes in treatment. CONCLUSION: The use of ILR after a negative EPS in BrS is a safe strategy that reflected the high negative predictive value of EPS for ventricular arrhythmia in this syndrome. In addition, it allowed the detection of AEs in a significant proportion of patients, with therapeutic implications in most of them.

Insights into adherence to medication and lifestyle recommendations in an international cohort of patients with catecholaminergic polymorphic ventricular tachycardia.

AIMS: In patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), a rare inherited arrhythmia syndrome, arrhythmic events can be prevented by medication and lifestyle recommendations. In patients who experience breakthrough arrhythmic events, non-adherence plays an essential role. We aimed to investigate the incidence and potential reasons for non-adherence to medication and lifestyle recommendations in a large, international cohort of patients with CPVT. METHODS AND RESULTS: An online multilingual survey was shared with CPVT patients worldwide by their cardiologists, through peer-recruitment, and on social media from November 2022 until July 2023. Self-reported non-adherence was measured using the validated Medication Adherence Rating Scale (MARS) and a newly developed questionnaire about lifestyle. Additionally, validated questionnaires were used to assess potential reasons for medication non-adherence. Two-hundred-and-eighteen patients completed the survey, of whom 200 (92%) were prescribed medication [122 (61%) female; median age 33.5 years (interquartile range: 22-50)]. One-hundred-and-three (52%) were prescribed beta-blocker and flecainide, 85 (43%) beta-blocker, and 11 (6%) flecainide. Thirty-four (17%) patients experienced a syncope, aborted cardiac arrest or appropriate implantable cardioverter defibrillator shock after diagnosis. Nineteen (13.4%) patients were exercising more than recommended. Thirty (15%) patients were non-adherent to medication. Female sex [odds ratio (OR) 3.7, 95% confidence interval (CI) 1.3-12.0, P = 0.019], flecainide monotherapy compared to combination therapy (OR 6.8, 95% CI 1.6-31.0, P = 0.010), and a higher agreement with statements regarding concerns about CPVT medication (OR 1.2, 95% CI 1.1-1.3, P < 0.001) were independently associated with non-adherence. CONCLUSION: The significant rate of non-adherence associated with concerns regarding CPVT-related medication, emphasizes the potential for improving therapy adherence by targeted patient education.

Yield of molecular autopsy in sudden cardiac death in athletes: data from a large registry in the UK.

AIMS: Sudden cardiac death (SCD) may occur in apparently healthy individuals, including athletes. The aim was to investigate the diagnostic role of post-mortem genetic testing, molecular autopsy (MA), in elucidating the cause of SCD in athletes. METHODS AND RESULTS: We reviewed a database of 6860 consecutive cases of SCD referred to our specialist cardiac pathology centre. All cases underwent detailed cardiac autopsy, and 748 were deemed to be athletes. Of these, 42 (6%) were investigated with MA (28 using a targeted sequencing, 14 exome sequencing). Variants were classified as pathogenic, likely pathogenic, or variant of unknown significance using international guidelines. Clinical information was obtained from referring coroners who completed a detailed health questionnaire. Out of the 42 decedents (average age 35 years old, 98% males) who were investigated with MA, the autopsy was in keeping with a structurally normal heart [sudden arrhythmic death syndrome (SADS)] in n = 33 (78%) cases, followed by arrhythmogenic cardiomyopathy (ACM) in eight (19%) individuals and idiopathic left ventricular fibrosis in one (2%). Death occurred during exercise and at rest in 26 (62%) and 16 (38%) individuals, respectively. Variants that were adjudicated clinically actionable were present in seven cases (17%). There was concordance between the genetic and phenotypic findings in two cases of ACM (in FLNC and TMEM43 genes). None of the variants identified in SADS cases were previously linked to channelopathies. Clinically actionable variants in cardiomyopathy-associated genes were found in five cases of SADS. CONCLUSION: The yield of MA in athletes who died suddenly is 17%. In SADS cases, clinically actionable variants were found in cardiomyopathy-associated genes and not in channelopathy-associated genes. Arrhythmogenic cardiomyopathy is a common cause of SCD in athletes, and one in four decedents with this condition had a clinically actionable variant in FLNC and TMEM43 genes.

Seasonal Variation in Sudden Cardiac Death: Insights from a Large United Kingdom Registry.

BACKGROUND: Sudden cardiac death (SCD) is relatively common and may occur in apparently healthy individuals. The role of seasonal variation as a risk factor for SCD is poorly understood. The aim of this study was to investigate whether SCD exhibits a predilection for specific seasons. METHODS: We reviewed a database of 4751 cases of SCD (mean age 38 ± 17 years) referred to our Center for Cardiac Pathology at St George's University of London between 2000 and 2018. Clinical information was obtained from referring coroners who were asked to complete a detailed questionnaire. All cases underwent macroscopic and histological evaluation of the heart, by expert cardiac pathologists. RESULTS: SCD was more common during winter (26%) and rarer during summer (24%), p = 0.161. Significant seasonal variation was not observed among cases of sudden arrhythmic death syndrome (SADS, 2910 cases) in which the heart is structurally normal. In contrast, a significant difference in seasonal distribution among decedents exhibiting cardiac structural abnormalities at the post-mortem examination (n = 1841) was observed. In this subgroup, SCDs occurred more frequently during winter (27 %) compared to summer (22%) (p = 0.007). In cases diagnosed with a myocardial disease (n = 1399), SCD was most common during the winter (27%) and least common during the summer (22%) (p = 0.027). CONCLUSIONS: While SADS occurs throughout the year with no seasonal variation, SCD due to structural heart disease appears to be more common during the winter. Bio-meteorological factors may be potential triggers of SCD in individuals with an underlying structural cardiac abnormality.

Clinical Management of Brugada Syndrome: Commentary From the Experts.

Although there is consensus on the management of patients with Brugada Syndrome with high risk for sudden cardiac arrest, asymptomatic or intermediate-risk patients present clinical management challenges. This document explores the management opinions of experts throughout the world for patients with Brugada Syndrome who do not fit guideline recommendations. Four real-world clinical scenarios were presented with commentary from small expert groups for each case. All authors voted on case-specific questions to evaluate the level of consensus among the entire group in nuanced diagnostic and management decisions relevant to each case. Points of agreement, points of controversy, and gaps in knowledge are highlighted.

Consensus on the assessment of systemic sclerosis-associated primary heart involvement: World Scleroderma Foundation/Heart Failure Association guidance on screening, diagnosis, and follow-up assessment.

Introduction: Heart involvement is a common problem in systemic sclerosis. Recently, a definition of systemic sclerosis primary heart involvement had been proposed. Our aim was to establish consensus guidance on the screening, diagnosis and follow-up of systemic sclerosis primary heart involvement patients. Methods: A systematic literature review was performed to investigate the tests used to evaluate heart involvement in systemic sclerosis. The extracted data were categorized into relevant domains (conventional radiology, electrocardiography, echocardiography, cardiac magnetic resonance imaging, laboratory, and others) and presented to experts and one patient research partner, who discussed the data and added their opinion. This led to the formulation of overarching principles and guidance statements, then reviewed and voted on for agreement. Consensus was attained when the mean agreement was ⩾7/10 and of ⩾70% of voters. Results: Among 2650 publications, 168 met eligibility criteria; the data extracted were discussed over three meetings. Seven overarching principles and 10 guidance points were created, revised and voted on. The consensus highlighted the importance of patient counseling, differential diagnosis and multidisciplinary team management, as well as defining screening and diagnostic approaches. The initial core evaluation should integrate history, physical examination, rest electrocardiography, trans-thoracic echocardiography and standard serum cardiac biomarkers. Further investigations should be individually tailored and decided through a multidisciplinary management. The overall mean agreement was 9.1/10, with mean 93% of experts voting above 7/10. Conclusion: This consensus-based guidance on screening, diagnosis and follow-up of systemic sclerosis primary heart involvement provides a foundation for standard of care and future feasibility studies that are ongoing to support its application in clinical practice.

An mTORC1-Dependent Mouse Model for Cardiac Sarcoidosis.

Background Sarcoidosis is an inflammatory, granulomatous disease of unknown cause affecting multiple organs, including the heart. Untreated, unresolved granulomatous inflammation can lead to cardiac fibrosis, arrhythmias, and eventually heart failure. Here we characterize the cardiac phenotype of mice with chronic activation of mammalian target of rapamycin (mTOR) complex 1 signaling in myeloid cells known to cause spontaneous pulmonary sarcoid-like granulomas. Methods and Results The cardiac phenotype of mice with conditional deletion of the tuberous sclerosis 2 (TSC2) gene in CD11c+ cells (TSC2fl/flCD11c-Cre; termed TSC2KO) and controls (TSC2fl/fl) was determined by histological and immunological stains. Transthoracic echocardiography and invasive hemodynamic measurements were performed to assess myocardial function. TSC2KO animals were treated with either everolimus, an mTOR inhibitor, or Bay11-7082, a nuclear factor-kB inhibitor. Activation of mTOR signaling was evaluated on myocardial samples from sudden cardiac death victims with a postmortem diagnosis of cardiac sarcoidosis. Chronic activation of mTORC1 signaling in CD11c+ cells was sufficient to initiate progressive accumulation of granulomatous infiltrates in the heart, which was associated with increased fibrosis, impaired cardiac function, decreased plakoglobin expression, and abnormal connexin 43 distribution, a substrate for life-threatening arrhythmias. Mice treated with the mTOR inhibitor everolimus resolved granulomatous infiltrates, prevented fibrosis, and improved cardiac dysfunction. In line, activation of mTOR signaling in CD68+ macrophages was detected in the hearts of sudden cardiac death victims who suffered from cardiac sarcoidosis. Conclusions To our best knowledge this is the first animal model of cardiac sarcoidosis that recapitulates major pathological hallmarks of human disease. mTOR inhibition may be a therapeutic option for patients with cardiac sarcoidosis.

Clinical presentation of calmodulin mutations: the International Calmodulinopathy Registry.

AIMS: Calmodulinopathy due to mutations in any of the three CALM genes (CALM1-3) causes life-threatening arrhythmia syndromes, especially in young individuals. The International Calmodulinopathy Registry (ICalmR) aims to define and link the increasing complexity of the clinical presentation to the underlying molecular mechanisms. METHODS AND RESULTS: The ICalmR is an international, collaborative, observational study, assembling and analysing clinical and genetic data on CALM-positive patients. The ICalmR has enrolled 140 subjects (median age 10.8 years [interquartile range 5-19]), 97 index cases and 43 family members. CALM-LQTS and CALM-CPVT are the prevalent phenotypes. Primary neurological manifestations, unrelated to post-anoxic sequelae, manifested in 20 patients. Calmodulinopathy remains associated with a high arrhythmic event rate (symptomatic patients, n = 103, 74%). However, compared with the original 2019 cohort, there was a reduced frequency and severity of all cardiac events (61% vs. 85%; P = .001) and sudden death (9% vs. 27%; P = .008). Data on therapy do not allow definitive recommendations. Cardiac structural abnormalities, either cardiomyopathy or congenital heart defects, are present in 30% of patients, mainly CALM-LQTS, and lethal cases of heart failure have occurred. The number of familial cases and of families with strikingly different phenotypes is increasing. CONCLUSION: Calmodulinopathy has pleiotropic presentations, from channelopathy to syndromic forms. Clinical severity ranges from the early onset of life-threatening arrhythmias to the absence of symptoms, and the percentage of milder and familial forms is increasing. There are no hard data to guide therapy, and current management includes pharmacological and surgical antiadrenergic interventions with sodium channel blockers often accompanied by an implantable cardioverter-defibrillator.

From gene-discovery to gene-tailored clinical management: 25 years of research in channelopathies and cardiomyopathies.

In the early nineties, few years before the birth of Europace, the clinical and scientific world of familial arrhythmogenic conditions was revolutionized by the identification of the first disease-causing genes. The explosion of genetic studies over a 15-year period led to the discovery of major disease-causing genes in practically all channelopathies and cardiomyopathies, bringing insight into the pathophysiological mechanisms of these conditions. The birth of next generation sequencing allowed a further step forward and other significant genes, as CALM1-3 in channelopathies and FLN C and TTN in cardiomyopathies were identified. Genotype-phenotype studies allowed the implementation of the genetic results in diagnosis, risk stratification, and therapeutic management with a different level of evidence in different arrhythmogenic conditions. The influence of common genetic variants, i.e. SNPs, on disease manifestation was proved in mid-twenties, and in the last 10 years with the advent of genome-wide association studies performed in familial arrhythmogenic diseases, the concept of polygenic risk score has been consolidated. Now, we are at the start of another amazing phase, i.e. the initiation of first gene therapy clinical trials.

Ethnic and sex-related differences at presentation in apical hypertrophic cardiomyopathy: An observational cross-sectional study.

BACKGROUND: We investigated whether ethnicity and sex are associated with different clinical presentations and cardiovascular magnetic resonance (CMR) findings in individuals with apical hypertrophic cardiomyopathy (ApHCM). METHODS: A retrospective observational cohort study of consecutive ApHCM patients from a large tertiary referral center in the United Kingdom (UK). Demographic, clinical, 12­lead electrocardiogram (ECG) and CMR findings were collected. Participants presented in our clinics between 2010 and 2020. 'Pure' ApHCM was defined as isolated apical hypertrophy and 'mixed' with both apical and septal hypertrophy but with the apical segments of a greater wall thickness. Deep T-wave inversion was defined as ≥5 mm in any electrocardiogram lead. RESULTS: A total of 150 consecutive ApHCM patients (75% men, 25% women; 37% White, 25% Black, 24% Asian and 15% of Mixed/Other ethnicity) were included. Females were diagnosed at an older age compared to men, had less prominent ECG changes, had higher left atrial area index, and were more hypertensive. Black patients had higher left ventricular mass index, more hypertension, and more of the 'mixed' type of ApHCM. The majority of hypertensive male patients showed the 'mixed' phenotype. CONCLUSIONS: Individuals of Black ethnicity and hypertensive male patients are more likely to present with mixed apical and basal hypertrophy, whereas White, Asian and non-hypertensive male patients tend to have hypertrophy limited to the apex. Females present at an older age and are less likely to have deep T wave inversion on ECG.

Subepicardial Cardiomyopathy: A Disease Underlying J-Wave Syndromes and Idiopathic Ventricular Fibrillation.

Brugada syndrome (BrS), early repolarization syndrome (ERS), and idiopathic ventricular fibrillation (iVF) have long been considered primary electrical disorders associated with malignant ventricular arrhythmia and sudden cardiac death. However, recent studies have revealed the presence of subtle microstructural abnormalities of the extracellular matrix in some cases of BrS, ERS, and iVF, particularly within right ventricular subepicardial myocardium. Substrate-based ablation within this region has been shown to ameliorate the electrocardiographic phenotype and to reduce arrhythmia frequency in BrS. Patients with ERS and iVF may also exhibit low-voltage and fractionated electrograms in the ventricular subepicardial myocardium, which can be treated with ablation. A significant proportion of patients with BrS and ERS, as well as some iVF survivors, harbor pathogenic variants in the voltage-gated sodium channel gene, SCN5A, but the majority of genetic susceptibility of these disorders is likely to be polygenic. Here, we postulate that BrS, ERS, and iVF may form part of a spectrum of subtle subepicardial cardiomyopathy. We propose that impaired sodium current, along with genetic and environmental susceptibility, precipitates a reduction in epicardial conduction reserve, facilitating current-to-load mismatch at sites of structural discontinuity, giving rise to electrocardiographic changes and the arrhythmogenic substrate.