Toxicology Screening in Sports-Related Sudden Cardiac Death: A Multinational Observational Study.

BACKGROUND: Knowledge of toxicological findings among sports-related sudden cardiac death (SrSCD) is scarce. OBJECTIVES: This study aimed to describe postmortem toxicology findings in a multinational cohort of young SrSCD. METHODS: Patients with sudden cardiac death (SCD) aged 12 to 49 years with a complete post mortem were included from Denmark, Spain, and Australia. Postmortem findings were compared between SrSCD and non-SrSCD, and toxicology findings in SrSCD were assessed. RESULTS: We included 3,189 SCD, of which 219 (7%) were sports-related. SrSCD patients were younger (36 years vs 41 years; P < 0.001) and of male predominance (96% vs 75%; P < 0.001), and their death was more often caused by structural cardiac disease (68% vs 61%; P = 0.038). Positive toxicology screenings were significantly less likely among SrSCD than non-SrSCD (12% vs 43%; P < 0.001), corresponding to 82% lower odds of a positive toxicology screening in SrSCD. Patient characteristics were similar between SrSCDs with positive and negative toxicology screenings, but deaths were more often unexplained (59% vs 34%). Nonopioid analgesics were the most common finding (3%), and SCD-associated drugs were detected in 6% of SrSCD. SUD was more prevalent among the SrSCD with positive toxicology (59% vs 34%). CONCLUSIONS: Sports-related SCD mainly occurred in younger men with structural heart disease. They had a significantly lower prevalence of a positive toxicology screening compared with non-SrSCD, and detection of SCD-associated drugs was rare.

Cadaveric Adipose-Derived Stem Cells for Regenerative Medicine and Research.

Advances in regenerative medicine have enabled the search for new solutions to current health problems in so far unexplored fields. Thus, we focused on cadaveric subcutaneous fat as a promising source of adipose-derived stem cells (ADSCs) that have potential to differentiate into different cell lines. With this aim, we isolated and characterized ADSCs from cadaveric samples with a postmortem interval ranging from 30 to 55 h and evaluated their ability to differentiate into chondrocytes or osteocytes. A commercial ADSC line was used as reference. Morphological and protein expression analyses were used to confirm the final stage of differentiation. Eight out of fourteen samples from patients were suitable to complete the whole protocol. Cadaveric ADSCs exhibited features of stem cells based upon several markers: CD29 (84.49 ± 14.07%), CD105 (94.38 ± 2.09%), and CD44 (99.77 ± 0.32%). The multiparametric assessment of differentiation confirmed the generation of stable lines of chondrocytes and osteocytes. In conclusion, we provide evidence supporting the feasibility of obtaining viable postmortem human subcutaneous fat ADSCs with potential application in tissue engineering and research fields.

Genetically determined cardiomyopathies at autopsy: the pivotal role of the pathologist in establishing the diagnosis and guiding family screening.

Cardiomyopathies (CMP) comprise a heterogenous group of diseases affecting primarily the myocardium, either genetic and/or acquired in origin. While many classification systems have been proposed in the clinical setting, there is no internationally agreed pathological consensus concerning the diagnostic approach to inherited CMP at autopsy. A document on autopsy diagnosis of CMP is needed because the complexity of the pathologic backgrounds requires proper insight and expertise. In cases presenting with cardiac hypertrophy and/or dilatation/scarring with normal coronary arteries, a suspicion of inherited CMP must be considered, and a histological examination is essential. Establishing the actual cause of the disease may require a number of tissue-based and/or fluid-based investigations, be it histological, ultrastructural, or molecular. A history of illicit drug use must be looked for. Sudden death is frequently the first manifestation of disease in case of CMP, especially in the young. Also, during routine clinical or forensic autopsies, a suspicion of CMP may arise based on clinical data or pathological findings at autopsy. It is thus a challenge to make a diagnosis of a CMP at autopsy. The pathology report should provide the relevant data and a cardiac diagnosis which can help the family in furthering investigations, including genetic testing in case of genetic forms of CMP. With the explosion in molecular testing and the concept of the molecular autopsy, the pathologist should use strict criteria in the diagnosis of CMP, and helpful for clinical geneticists and cardiologists who advise the family as to the possibility of a genetic disease.

The EP300/TP53 pathway, a suppressor of the Hippo and canonical WNT pathways, is activated in human hearts with arrhythmogenic cardiomyopathy in the absence of overt heart failure.

AIMS: Arrhythmogenic cardiomyopathy (ACM) is a primary myocardial disease that typically manifests with cardiac arrhythmias, progressive heart failure, and sudden cardiac death (SCD). ACM is mainly caused by mutations in genes encoding desmosome proteins. Desmosomes are cell-cell adhesion structures and hubs for mechanosensing and mechanotransduction. The objective was to identify the dysregulated molecular and biological pathways in human ACM in the absence of overt heart failure. METHODS AND RESULTS: Transcriptomes in the right ventricular endomyocardial biopsy samples from three independent individuals carrying truncating mutations in the DSP gene and five control samples were analysed by RNA-Seq (discovery group). These cases presented with cardiac arrhythmias and had a normal right ventricular function. The RNA-Seq analysis identified ∼5000 differentially expressed genes (DEGs), which predicted suppression of the Hippo and canonical WNT pathways, among others. Dysregulated genes and pathways, identified by RNA-Seq, were tested for validation in the right and left ventricular tissues from five independent autopsy-confirmed ACM cases with defined mutations (validation group), who were victims of SCD and had no history of heart failure. Protein levels and nuclear localization of the cWNT and Hippo pathway transcriptional regulators were reduced in the right and left ventricular validation samples. In contrast, levels of acetyltransferase EP300, known to suppress the Hippo and canonical WNT pathways, were increased and its bona fide target TP53 was acetylated. RNA-Seq data identified apical junction, reflective of cell-cell attachment, as the most disrupted biological pathway, which were corroborated by disrupted desmosomes and intermediate filament structures. Moreover, the DEGs also predicted dysregulation of over a dozen canonical signal transduction pathways, including the Tec kinase and integrin signalling pathways. The changes were associated with increased apoptosis and fibro-adipogenesis in the ACM hearts. CONCLUSION: Altered apical junction structures are associated with activation of the EP300-TP53 and suppression of the Hippo/cWNT pathways in human ACM caused by defined mutations in the absence of an overt heart failure. The findings implicate altered mechanotransduction in the pathogenesis of ACM.

Facts and Gaps in Exercise Influence on Arrhythmogenic Cardiomyopathy: New Insights From a Meta-Analysis Approach.

Arrhythmogenic cardiomyopathy (ACM) is a genetic cardiac condition characterized by fibrofatty myocardial replacement, either at the right ventricle, at the left ventricle, or with biventricular involvement. Ventricular arrhythmias and heart failure represent its main clinical features. Exercise benefits on mental and physical health are worldwide recognized. However, patients with ACM appear to be an exception. A thorough review of the literature was performed in PubMed searching for original papers with the terms "ARVC AND sports/exercise" and "sudden cardiac death AND sports/exercise." Additional papers were then identified through other sources and incorporated to the list. All of them had to be based on animal models or clinical series. Information was structured in a regular format, although some data were not available in some papers. A total of 34 papers were selected and processed regarding sports-related sudden cardiac death, pre-clinical models of ACM and sport, and clinical series of ACM patients engaged in sports activities. Eligible papers were identified to obtain pooled data in order to build representative figures showing the global incidence of the most important causes of sudden cardiac death in sports and the global estimates of life-threatening arrhythmic events in ACM patients engaged in sports. Tables and figures illustrate their major characteristics. The scarce points of controversy were discussed in the text. Fundamental concepts were summarized in three main issues: sports may accelerate ACM phenotype with either structural and/or arrhythmic features, restriction may soften the progression, and these rules also apply to phenotype-negative mutation carriers. Additionally, remaining gaps in the current knowledge were also highlighted, namely, the applicability of those fundamental concepts to non-classical ACM phenotypes since left dominant ACM or non-plakophillin-2 genotypes were absent or very poorly represented in the available studies. Hopefully, future research endeavors will provide solid evidence about the safest exercise dose for each patient from a personalized medicine perspective, taking into account a big batch of genetic, epigenetic, and epidemiological variables, for instance, in order to assist clinicians to provide a final tailored recommendation.

[Peritoneal recurrence prediction for colon cancer based on immunoexpression]. / Predicción de recurrencia peritoneal mediante inmunoexpresión en cáncer de colon.

INTRODUCTION AND OBJECTIVES: Peritoneal relapse as an isolated form of recurrence in colon cancer occurs in 25% of cases during the first two years subsequent to a curative colectomy. Currently, the diagnostic limitations of imaging studies and the absence of predictive scales for peritoneal recurrence warrant "second look" surgery in high-risk patients. The aim of this study is to assess features of some epithelial-mesenchymal transition biomarkers (c-Met, IGF-1R and plexin ß1) in order to predict post-surgical peritoneal colonization and develop a mathematical model to predict carcinomatous relapse. METHODS: A retrospective study of the histopathological samples of 87 patients diagnosed with colon cancer who underwent radical resection was carried out, using immunohistochemical techniques for c-Met, IGF-1R and plexin ß1. The patients were divided into two groups; those who had presented peritoneal recurrence and those who only had risk factors for this kind of relapse. Every stained sample was assessed by the rate of stained cells and immunostaining intensity. A possible association between immunohistochemical findings and peritoneal relapse was evaluated. Statistical analysis of the biomarkers with higher prognostic value allowed a risk mathematical formula to be developed based on coefficients, providing a specific value to each biomarker and patient. RESULTS: c-Met expression in the primary tumour showed a high statistical trend (p: .074) while IGF-1 (p: .022) and plexin ß1 (p: .021) revealed a significative association with peritoneal relapse. However, the multivariate analysis selected c-Met y plexin ß1 as useful factors for a predictive mathematical model on peritoneal recurrence with a 75.8% sensitivity and 80.5% specificity in patients with a staining more than 50% for both biomarkers. CONCLUSION: c-Met and plexin B1 overexpression is related to an increased risk of peritoneal relapse in cases of colon cancer where a radical resection is feasible. The encouraging outcomes of the proposed mathematical model may prove useful clinically in the identification of candidates for carcinoprophylaxis.

Association of Left Ventricular Systolic Dysfunction Among Carriers of Truncating Variants in Filamin C With Frequent Ventricular Arrhythmia and End-stage Heart Failure.

Importance: Truncating variants in the gene encoding filamin C (FLNCtv) are associated with arrhythmogenic and dilated cardiomyopathies with a reportedly high risk of ventricular arrhythmia. Objective: To determine the frequency of and risk factors associated with adverse events among FLNCtv carriers compared with individuals carrying TTN truncating variants (TTNtv). Design, Setting, and Participants: This cohort study recruited 167 consecutive FLNCtv carriers and a control cohort of 244 patients with TTNtv matched for left ventricular ejection fraction (LVEF) from 19 European cardiomyopathy referral units between 1990 and 2018. Data analyses were conducted between June and October, 2020. Main Outcomes and Measures: The primary end point was a composite of malignant ventricular arrhythmia (MVA) (sudden cardiac death, aborted sudden cardiac death, appropriate implantable cardioverter-defibrillator shock, and sustained ventricular tachycardia) and end-stage heart failure (heart transplant or mortality associated with end-stage heart failure). The secondary end point comprised MVA events only. Results: In total, 167 patients with FLNCtv were studied (55 probands [33%]; 89 men [53%]; mean [SD] age at baseline evaluation, 43 [18] years). For a median follow-up of 20 months (interquartile range, 7-60 months), 29 patients (17.4%) reached the primary end point (19 patients with MVA and 10 patients with end-stage heart failure). Eight (44%) arrhythmic events occurred among individuals with baseline mild to moderate left ventricular systolic dysfunction (LVSD) (LVEF = 36%-49%). Univariable risk factors associated with the primary end point included proband status, LVEF decrement per 10%, ventricular ectopy (≥500 in 24 hours) and myocardial fibrosis detected on cardiac magnetic resonance imaging. The LVEF decrement (hazard ratio [HR] per 10%, 1.83 [95% CI, 1.30-2.57]; P < .001) and proband status (HR, 3.18 [95% CI, 1.12-9.04]; P = .03) remained independent risk factors on multivariable analysis (excluding myocardial fibrosis and ventricular ectopy owing to case censoring). There was no difference in freedom from MVA between FLNCtv carriers with mild to moderate or severe (LVEF ≤35%) LVSD (HR, 1.29 [95% CI, 0.45-3.72]; P = .64). Carriers of FLNCtv with impaired LVEF at baseline evaluation (n = 69) had reduced freedom from MVA compared with 244 TTNtv carriers with similar baseline LVEF (for mild to moderate LVSD: HR, 16.41 [95% CI, 3.45-78.11]; P < .001; for severe LVSD: HR, 2.47 [95% CI, 1.04-5.87]; P = .03). Conclusions and Relevance: The high frequency of MVA among patients with FLNCtv with mild to moderate LVSD suggests that higher LVEF values than those currently recommended should be considered for prophylactic implantable cardioverter-defibrillator therapy in FLNCtv carriers.

Characteristics of a COVID-19 confirmed case series in primary care (COVID-19-PC project): a cross-sectional study.

BACKGROUND: To estimate the prevalence of symptoms and signs related to a COVID-19 case series confirmed by polymerase chain reaction (PCR) for SARS-CoV-2. Risk factors and the associated use of health services will also be analysed. METHODS: Observational, descriptive, retrospective case series study. The study was performed at two Primary Care Health Centres located in Madrid, Spain. The subjects studied were all PCR SARS-CoV-2 confirmed cases older than 18 years, diagnosed from the beginning of the community transmission (March 13) until April 15, 2020. We collected sociodemographic, clinical, health service utilization and clinical course variables during the following months. All data was gathered by their own attending physician, and electronic medical records were reviewed individually. STATISTICAL ANALYSIS: A descriptive analysis was carried out and a Poisson regression model was adjusted to study associated factors to Health Services use. RESULTS: Out of the 499 patients studied from two health centres, 55.1% were women and mean age was 58.2 (17.3). 25.1% were healthcare professionals. The most frequent symptoms recorded related to COVID-19 were cough (77.9%; CI 95% 46.5-93.4), fever (77.7%; CI95% 46.5-93.4) and dyspnoea (54.1%, CI95% 46.6-61.4). 60.7% were admitted to hospital. 64.5% first established contact with their primary care provider before going to the hospital, with a mean number of 11.4 Healthcare Providers Encounters with primary care during all the follow-up period. The number of visit-encounters with primary care was associated with being male [IRR 1.072 (1.013, 1.134)], disease severity {from mild respiratory infection [IRR 1.404 (1.095, 1.801)], up to bilateral pneumonia [IRR 1.852 (1.437,2.386)]}, and the need of a work leave [IRR 1.326 (1.244, 1.413]. CONCLUSION: Symptoms and risk factors in our case series are similar to those in other studies. There was a high number of patients with atypical unilateral or bilateral pneumonia. Care for COVID has required a high use of healthcare resources such as clinical encounters and work leaves.

Muerte súbita relacionada con la actividad deportiva en España. Estudio poblacional multicéntrico forense de 288 casos / Sports-related sudden cardiac death in Spain. A multicenter, population-based, forensic study of 288 cases

Introducción y objetivos Conocer la incidencia, características clínico-patológicas, hábitos tóxicos y actividad deportiva relacionadas con la muerte súbita en la actividad deportiva en España.MétodosEstudio poblacional retrospectivo y multicéntrico, basado en autopsias forenses realizadas en 25 provincias durante 8 años (2010-2017).ResultadosSe investigaron 288 casos (el 98,6% varones; media de edad, 43,8±14,4 años). La incidencia fue de 0,38 casos/100.000 hab./año (0,82 entre deportistas habituales), la mayoría (54%) varones entre 35 y 54 años. Los deportes más frecuentes (el 96% recreativos) fueron ciclismo (28%), fútbol (18%) y carrera a pie (17%). La muerte fue de origen cardiovascular en el 99%: cardiopatía isquémica (63%), miocardiopatías (21%) y síndrome de muerte súbita arrítmica (6%). En los jóvenes, las miocardiopatías (38%) y la cardiopatía isquémica (30%), presente a partir de los 20 años, fueron las más prevalentes. La enfermedad se había diagnosticado en vida en 23 casos; se observaron antecedentes clínicos relevantes en 30 casos y factores de riesgo cardiovascular, principalmente obesidad, en 95. El análisis toxicológico detectó sustancias cardiotóxicas en el 7%, y destaca la relación entre cannabis y cardiopatía isquémica aguda.ConclusionesLa muerte súbita asociada a la actividad deportiva en España tiene una incidencia muy baja, afecta a varones de mediana edad que realizan deporte recreativo, principalmente ciclismo, fútbol y carrera, y es de origen cardiovascular, con aparición temprana de la cardiopatía isquémica. Los datos clínicos y los hábitos tóxicos deben tenerse en cuenta para desarrollar estrategias de prevención. (AU)

Introduction and objectives To determine the incidence of sports-related sudden cardiac death in Spain, and to identify the clinical-pathological characteristics, substance abuse, and sports activity associated with this entity.MethodsRetrospective, population-based, multicenter study of forensic autopsies conducted in 25 provinces during an 8-year period (2010-2017).ResultsWe investigated 288 cases (98.6% occurred in men with a mean age of 43.8±14.4 years). The incidence in the general population was 0.38 cases out of 100 000 inhabitants per year (0.82 among regular athletes), and most cases (54%) occurred in persons aged between 35 and 54 years. The most frequent sports (96% recreational) were cycling (28%), football (18%), and jogging (17%). Death was of cardiovascular origin in 99%. The main causes were ischemic heart disease (63%), cardiomyopathies (21%), and sudden arrhythmic death syndrome (6%). In young people, cardiomyopathies (38%) and ischemic heart disease (30%), present after the age of 20 years, were the most prevalent. The disease was diagnosed during life in 23 cases, relevant clinical antecedents were observed in 30 cases, and cardiovascular risk factors, mainly obesity, in 95 cases. Toxicological analysis detected cardiotoxic substances in 7%, highlighting the association between cannabis and acute ischemic heart disease.ConclusionsSports-related sudden cardiac death in Spain has a very low incidence and affects middle-aged men practicing recreational sports, mainly cycling, football, and jogging. This entity is of cardiovascular origin with early onset of ischemic heart disease. Clinical data and substance abuse should be taken into account to develop preventive strategies. (AU)

Corrigendum: Facts and Gaps in Exercise Influence on Arrhythmogenic Cardiomyopathy: New Insights From a Meta-Analysis Approach.

[This corrects the article DOI: 10.3389/fcvm.2021.702560.].

Sports-related sudden cardiac death in Spain. A multicenter, population-based, forensic study of 288 cases.

INTRODUCTION AND OBJECTIVES: To determine the incidence of sports-related sudden cardiac death in Spain, and to identify the clinical-pathological characteristics, substance abuse, and sports activity associated with this entity. METHODS: Retrospective, population-based, multicenter study of forensic autopsies conducted in 25 provinces during an 8-year period (2010-2017). RESULTS: We investigated 288 cases (98.6% occurred in men with a mean age of 43.8±14.4 years). The incidence in the general population was 0.38 cases out of 100 000 inhabitants per year (0.82 among regular athletes), and most cases (54%) occurred in persons aged between 35 and 54 years. The most frequent sports (96% recreational) were cycling (28%), football (18%), and jogging (17%). Death was of cardiovascular origin in 99%. The main causes were ischemic heart disease (63%), cardiomyopathies (21%), and sudden arrhythmic death syndrome (6%). In young people, cardiomyopathies (38%) and ischemic heart disease (30%), present after the age of 20 years, were the most prevalent. The disease was diagnosed during life in 23 cases, relevant clinical antecedents were observed in 30 cases, and cardiovascular risk factors, mainly obesity, in 95 cases. Toxicological analysis detected cardiotoxic substances in 7%, highlighting the association between cannabis and acute ischemic heart disease. CONCLUSIONS: Sports-related sudden cardiac death in Spain has a very low incidence and affects middle-aged men practicing recreational sports, mainly cycling, football, and jogging. This entity is of cardiovascular origin with early onset of ischemic heart disease. Clinical data and substance abuse should be taken into account to develop preventive strategies.

Effects of Leucine Administration in Sarcopenia: A Randomized and Placebo-controlled Clinical Trial.

Treating sarcopenia in older individuals remains a challenge, and nutritional interventions present promising approaches in individuals that perform limited physical exercise. We assessed the efficacy of leucine administration to evaluate whether the regular intake of this essential amino acid can improve muscle mass, muscle strength and functional performance and respiratory muscle function in institutionalized older individuals. The study was a placebo-controlled, randomized, double-blind design in fifty participants aged 65 and over (ClinicalTrials.gov identifier NCT03831399). The participants were randomized to a parallel group intervention of 13 weeks' duration with a daily intake of leucine (6 g/day) or placebo (lactose, 6 g/day). The primary outcome was to study the effect on sarcopenia and respiratory muscle function. The secondary outcomes were changes in the geriatric evaluation scales, such as cognitive function, functional impairment and nutritional assessments. We also evaluated whether leucine administration alters blood analytical parameters and inflammatory markers. Administration of leucine was well-tolerated and significantly improves some criteria of sarcopenia in elderly individuals such as functional performance measured by walking time (p = 0.011), and improved lean mass index. For respiratory muscle function, the leucine-treated group improved significantly (p = 0.026) in maximum static expiratory force compared to the placebo. No significant effects on functional impairment, cognitive function or nutritional assessment, inflammatory cytokines IL-6, TNF-alpha were observed after leucine administration compared to the placebo. The use of l-leucine supplementation can have some beneficial effects on sarcopenia and could be considered for the treatment of sarcopenia in older individuals.

Clinical characteristics and determinants of the phenotype in TMEM43 arrhythmogenic right ventricular cardiomyopathy type 5.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy type V (ARVC-5) is the most aggressive heterozygous form of ARVC. It is predominantly caused by a fully penetrant mutation (p.S358L) in the nondesmosomal gene TMEM43-endemic to Newfoundland, Canada. To date, all familial cases reported worldwide share a common ancestral haplotype. It is unknown whether the p.S358L mutation by itself causes ARVC-5 or whether the disease is influenced by genetic or environmental factors. OBJECTIVE: The purpose of this study was to examine the phenotype, clinical course, and the impact of exercise on patients with p.S358L ARVC-5 without the Newfoundland genetic background. METHODS: We studied 62 affected individuals and 73 noncarriers from 3 TMEM43-p.S358L Spanish families. The impact of physical activity on the phenotype was also evaluated. RESULTS: Haplotype analysis revealed that the 3 Spanish families were unrelated to patients with ARVC-5 with the Newfoundland genetic background. Two families shared 10 microsatellite markers in a 4.9 cM region surrounding TMEM43; the third family had a distinct haplotype. The affected individuals showed a 38.7% incidence of sudden cardiac death, which was higher in men. Left ventricular involvement was common, with 40% of mutation carriers showing a left ventricular ejection fraction of <50%. Compared with noncarriers, the R-wave voltage in lead V3 was lower (3.2 ± 2.8 mV vs 7.5 ± 3.6 mV; P < .001) and QRS complex in right precordial leads wider (104.7 ± 24.0 ms vs 88.2 ± 7.7 ms; P = .001). A history of vigorous exercise showed a trend toward more ventricular arrhythmias only in women (P = .053). CONCLUSION: ARVC-5 is associated with a high risk of sudden cardiac death and characteristic clinical and electrocardiographic features irrespective of geographical origin and genetic background. Our data suggest that, as in desmosomal ARVC, vigorous physical activity could aggravate the phenotype of TMEM43 mutation carriers.

RNA sequencing-based transcriptome profiling of cardiac tissue implicates novel putative disease mechanisms in FLNC-associated arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) encompasses a group of inherited cardiomyopathies including arrhythmogenic right ventricular cardiomyopathy (ARVC) whose molecular disease mechanism is associated with dysregulation of the canonical WNT signalling pathway. Recent evidence indicates that ARVC and ACM caused by pathogenic variants in the FLNC gene encoding filamin C, a major cardiac structural protein, may have different molecular mechanisms of pathogenesis. We sought to identify dysregulated biological pathways in FLNC-associated ACM. RNA was extracted from seven paraffin-embedded left ventricular tissue samples from deceased ACM patients carrying FLNC variants and sequenced. Transcript levels of 623 genes were upregulated and 486 genes were reduced in ACM in comparison to control samples. The cell adhesion pathway and ILK signalling were among the prominent dysregulated pathways in ACM. Consistent with these findings, transcript levels of cell adhesion genes JAM2, NEO1, VCAM1 and PTPRC were upregulated in ACM samples. Moreover, several actin-associated genes, including FLNC, VCL, PARVB and MYL7, were suppressed, suggesting dysregulation of the actin cytoskeleton. Analysis of the transcriptome for dysregulated biological pathways predicted activation of inflammation and apoptosis and suppression of oxidative phosphorylation and MTORC1 signalling in ACM. Our data suggests dysregulated cell adhesion and ILK signalling as novel putative pathogenic mechanisms of ACM caused by FLNC variants which are distinct from the postulated disease mechanism of classic ARVC caused by desmosomal gene mutations. This knowledge could help in the design of future gene therapy strategies which would target specific components of these pathways and potentially lead to novel treatments for ACM.

Filamin C variants are associated with a distinctive clinical and immunohistochemical arrhythmogenic cardiomyopathy phenotype.

BACKGROUND: Pathogenic variants in the filamin C (FLNC) gene are associated with inherited cardiomyopathies including dilated cardiomyopathy with an arrhythmogenic phenotype. We evaluated FLNC variants in arrhythmogenic cardiomyopathy (ACM) and investigated the disease mechanism at a molecular level. METHODS: 120 gene-elusive ACM patients who fulfilled diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) were screened by whole exome sequencing. Fixed cardiac tissue from FLNC variant carriers who had died suddenly was investigated by histology and immunohistochemistry. RESULTS: Novel or rare FLNC variants, four null and five variants of unknown significance, were identified in nine ACM probands (7.5%). In FLNC null variant carriers (including family members, n = 16) Task Force diagnostic electrocardiogram repolarization/depolarization abnormalities were uncommon (19%), echocardiography was normal in 69%, while 56% had >500 ventricular ectopics/24 h or ventricular tachycardia on Holter and 67% had late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMRI). Ten gene positive individuals (63%) had abnormalities on ECG or CMRI that are not included in the current diagnostic criteria for ARVC. Immunohistochemistry showed altered key protein distribution, distinctive from that observed in ARVC, predominantly in the left ventricle. CONCLUSIONS: ACM associated with FLNC variants presents with a distinctive phenotype characterized by Holter arrhythmia and LGE on CMRI with unremarkable ECG and echocardiographic findings. Clinical presentation in asymptomatic mutation carriers at risk of sudden death may include abnormalities which are currently non-diagnostic for ARVC. At the molecular level, the pathogenic mechanism related to FLNC appears different to classic forms of ARVC caused by desmosomal mutations.

Sports-related sudden cardiac death due to myocardial diseases on a population from 1-35 years: a multicentre forensic study in Spain.

This is a multicentre forensic study that identifies all sports-related sudden deaths (SRSDs) in young people, due to myocardial diseases (MDs) that occurred in a large area of Spain. The aim of the study is to assess the epidemiology, causes of death, and sport activities associated with these fatalities. This is a retrospective study based on forensic autopsies performed in the provinces of Biscay, Seville, Valencia and in the jurisdiction covered by the National Institute of Toxicology and Forensic Sciences in Madrid (Spain). The retrospective study encompasses from 2010 to 2017. All sudden cardiac deaths (SCDs) in persons 1-35 years old were selected. The total number of SCDs were divided into death occurred during exercise (SRSD) and death during rest, sleep or normal activities (non-SRSD). Each of these two groups was subdivided according to the cause of death into MD (primary cardiomyopathies and myocarditis) and non-MD. Clinic-pathological, toxicological and genetic characteristics of SRSD due to MD were analysed. Over the 8-year study period, we identified 645 cases of SCD in the young: 75 SRSD (11.6%) and 570 non-SRSD (88.4%). MD was diagnosed in 33 (44.0%) of the SRSD and in 112 (19.6%) of the non-SRSD cases. All cases of SRSD due to MD were males (mean age (24.0 ± 7.6) years) practicing recreational sports (85%). SRSDs were more frequent in arrhythmogenic cardiomyopathy (ACM) (37%) and hypertrophic cardiomyopathy (HCM) (24%), followed by myocarditis (15%) and idiopathic left ventricular hypertrophy (ILVH) (9%). Only in five cases of SRSD the MD responsible of death (HCM) had been diagnosed in life. Cardiovascular symptoms related to the disease were present in other seven patients (six of them with ACM). Postmortem genetic studies were performed in 15/28 (54%) primary cardiomyopathies with positive results in 12 (80%) cases. The most frequent sports disciplines were football (49%) followed by gymnastics (15%) and running (12%). In Spain, SRSD in young people due to MDs occurs in males who perform a recreational activity. Compared with control group we observed a strong association between MDs and exertion. One in three SRSDs are due to cardiomyopathy, especially ACM, which reinforces the need for preparticipation screening to detect these pathologies in recreational sport athletes. Further studies are warranted to understand the causes and circumstances of sudden death to facilitate the development of preventive strategies.

Arrhythmogenic cardiomyopathy with left ventricular involvement versus ischemic heart disease: lessons learned from the family study and the reviewed autopsy of a young male.

Ischemic heart disease (IHD) is the leading cause of sudden cardiac death (SCD) and often non-thrombosed severe coronary stenoses with or without myocardial scars are detected. Left dominant arrhythmogenic cardiomyopathy (LDAC) is a life-threating rare disease which has been more thoroughly studied in the last 10 years. The macroscopic study of an SCD victim was conducted and re-evaluated 9 years later. The cardiological work-up in his first-degree relatives initially comprised an electrocardiogram (ECG) and an echocardiogram. When they were re-evaluted 9 years later, a cardiac magnetic resonance, an ECG-monitoring, an exercise testing and a genetic study were performed and the pedigree was extended accordingly. In 2008, an IHD was suspected in the sports-triggered SCD of a 37-year-old man upon the postmortem (75% stenosis of the left main and circumflex coronary arteries; the subepicardial left ventricular fibrofatty infiltration with mild myocardial degeneration was assumed to be a past myocardial infarction). No cardiomyopathy was identified in any of the two proband's sisters. Nine years thereafter, distant relatives were diagnosed with LDAC due to a pathogenic desmoplakin mutation. The reanalysis of the two sisters showed ventricular arrhythmias in one of them without structural heart involvement and the reviewed postmortem of the proband was reclassified as LDAC based on the fibrofatty infiltration; both were mutation carriers. The completion of the family study on 19 family members yielded one SCD due to LDAC (the proband), three living patients diagnosed with LDAC (two with a defibrillator), one mutation carrier without structural ventricular involvement, and 14 healthy relatives (who were discharged) with a very good co-segregation of the mutation. Although rare, LDAC exists and sometimes its differential diagnosis with IHD has to be faced. Modifying previous postmortem misdiagnoses can help family screening to further prevent SCDs.