Sudden cardiac death-update

Cardiac Channelopathies: Clinical Diagnosis and Promising Therapeutics

Cardiac channelopathies, also known as primary electrical heart diseases, are inherited genetic abnormalities of cardiomyocyte electrical behavior. Notable for their absence of structural heart diseases, they include a diverse group of diseases such as long QT syndrome, short QT syndrome, Brugada syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, and idiopathic ventricular fibrillation, and carry the risk of malignant arrhythmias leading to sudden cardiac death. The genetic and molecular foundations of these diseases are diverse and complex, with evolving research highlighting the multifactorial nature of their pathophysiology and the intricate interplay of various genes in the manifestation of arrhythmias. While advances in diagnostic techniques, such as genetic testing and electrophysiological studies, have improved the identification and management of these conditions, the relationship between specific genetic mutations and sudden cardiac death remains incompletely understood. This review provides an overview of the molecular and genetic mechanisms underlying those inherited arrhythmias, exploring both well-established and emerging data. Additionally, it discusses current diagnostic approaches and management strategies, aiming to enhance the understanding of these conditions and contribute to better sudden cardiac death prevention.

Insights from autopsy-initiated pathological studies of the pathogenesis and clinical manifestations of atherosclerosis and ischemic heart disease: Part II. Ischemic heart disease

CONTEXT

Ischemic heart disease (IHD) due to coronary atherosclerosis constitutes the leading cause of morbidity and mortality worldwide. This review was undertaken to retrospectively analyze the lines of research that generated the evidence for our contemporary understanding of atherosclerosis-based coronary artery disease and to provide a rationale for continued support for autopsy-based research in order to make further progress in reduction of the morbidity and mortaility from IHD.

OBJECTIVES

To analyze the contributions of the autopsy to complement and validate other lines of investigation in determining the complex interactions between coronary artery alterations linked to the major manifestations of coronary atherosclerosis, namely, coronary thrombosis, acute myocardial infarction, and sudden cardiac death.

DATA SOURCES

Systematic search on PubMed to gather relevant studies concerning autopsy studies and reviews of the pathology and pathogenesis of atherosclerosis, ischemic heart disease, coronary atherosclerosis, coronary thrombosis, myocardial infarction and sudden cardiac death.

CONCLUSIONS

An extensive search of the published literature has confirmed the continuing importance of the autopsy as a powerful tool to understand the pathogenesis, clinical features, and therapeutic options for the treatment of atherosclerosis and its major manifestation, ischemic heart disease. This has been described in the Part I companion of the present review. Autopsy-initiated studies have documented the prevalence and clinicopathological significance of atherosclerosis in different human populations and its relationship to risk factors. It has been shown that the clinically silent phase of ischemic heart disease (IHD) begins in the first decades of life. Pathological studies have clarified the complex relationship between coronary atherosclerosis, coronary thrombosis, and myocardial ischemic events. These studies also have elucidated the pathological basis of sudden cardiac death. Insights from these studies also have been important in developing and evaluating strategies for continued progress in reducing the morbidity and mortality attributed to atherosclerosis and IHD.

The Process of Inefficient Self-Management in Patients With Myocardial Infarction in Prehospital: A Grounded Theory

Introduction

Myocardial infarction (MI) is a cardiovascular emergency that needs immediate diagnosis and treatment. utilizing incorrect strategies during a MI may lead to adverse consequences and complications. This study was conducted to explore the process of prehospital management of patients with MI.

Methods

This study was conducted using the grounded theory design. fifteen patients with MI and six family members were purposefully and theoretically selected from a leading hospital in Kashan, Iran. Data were collected using unstructured and semi-structured interviews and were analyzed through the constant comparison method proposed by Corbin and Strauss (2015). The length of the interviews was 40-60 min and data collection were kept on to reach data saturation.

Results

The patients' mean age was 70.06 years, and 53.3% of them were male. The findings were categorized into three major categories and nine subcategories. The three major categories of "fighting between awareness and preference," "taking problematic arbitrary measures," and "consulting lay people" emerged from the participants' experiences, along with the theme of "inefficient self-management."

Conclusion

Complex situation, unfamiliarity with MI and its management makes MI management very difficult for patients and family members. Therefore, MI-specific educations are needed to improve patients' self-management abilities.

Sudden Cardiac Death in Pregnant Women-Literature Review and Autopsy Findings

Cardiovascular diseases increase among pregnant women and complicate 1-4% of pregnancies worldwide. The incidence of maternal deaths due to cardiovascular causes has increased dramatically, rising from 3% three decades ago to 15% in recent years. The aim of this study is to provide a comprehensive overview of the current status of knowledge in sudden maternal death (SMD) described in the literature and to present two cases of autopsy findings in sudden cardiac death in pregnant women. Among the most common causes of sudden maternal deaths are peripartum cardiomyopathies, aortic dissection, acute myocardial infarction, arrhythmias, ischemic heart disease, and coronary artery dissection, and among the less common causes, we list coronary artery dissection, congenital heart diseases, valvulopathies, hypertension, fibroelastosis, and borderline myocarditis. The Centers for Disease Control and Prevention (CDC) reported that over 80% of pregnancy-related deaths were preventable. To reduce the number of maternal deaths caused by cardiovascular diseases, the implementation of specialized multidisciplinary teams has been proposed. Molecular biology techniques are proving their effectiveness in forensic medicine. PCR or DNA sequencing can be utilized in "molecular autopsy", which holds particular value in cases of sudden death where the forensic autopsy is negative but there is a suspicion that death was caused by arrhythmia. Susceptibility genes can be analyzed, such as KCNQ1, KCNH2, KCNE1, and KCNE2, which are involved in long QT syndrome, the RYR2 gene implicated in catecholaminergic polymorphic ventricular tachycardia type 1, or the SCN5A gene associated with Brugada syndrome. Early identification of risk factors involved in sudden maternal death prenatally and during pregnancy is essential. At the same time, genetic determinations and molecular biology techniques are absolutely necessary to prevent the occurrence of sudden deaths among close relatives.

Risk Factors and Genetic Insights into Coronary Artery Disease-Related Sudden Cardiac Death: A Molecular Analysis of Forensic Investigation

Sudden cardiac death (SCD) is a major cause of mortality among patients with coronary artery disease (CAD). This study aimed to identify risk factors for CAD-related SCD (SCDCAD) through autopsy data and genetic screening with a particular emphasis on rare variants (minor allele frequency < 0.01). We included 241 SCDCAD cases (mean age 54.6 ± 12.8 years, 74.7% male) verified by medico-legal examination and 241 silent CAD controls (mean age 53.6 ± 15.2 years, 25.3% female) who died from severe craniocerebral trauma. Information about death characteristics was obtained from questionnaires, police reports and autopsy data. Whole-exome sequencing was performed on myocardial tissue samples. Polygenic risk score (PRS) from a previously validated model was applied and rare variant pathogenicity was predicted using in silico tools. SCDCAD victims predominantly died at night and showed higher mortality rates during summer and winter months, with more complex coronary disease. Nocturnal time (adjusted odds ratio [AOR] = 3.53, 95% CI: 2.37-5.25, p < 0.001), winter (AOR = 2.06, 95% CI: 1.33-3.20, p = 0.001), multiple vessel occlusion (AOR = 1.79, 95% CI: 1.16-2.77, p = 0.009), right coronary artery stenosis (AOR = 2.38, 95% CI: 1.54-3.68, p < 0.001) and unstable plaque (AOR = 2.17, 95% CI: 1.46-3.23, p < 0.001) were identified as risk factors of SCDCAD. The PRS score was associated with a 60% increased risk of SCDCAD (OR = 1.632 per SD, 95%CI: 1.631-1.633, p < 0.001). Genetic analysis identified MUC19 and CGN as being associated with SCDCAD. We identified both hereditary and acquired risk factors that may contribute to cardiac dysfunction and precipitate SCD in CAD patients, thereby facilitating the prevention and early recognition of high-risk individuals.

The application of vibrational spectroscopy in forensic analysis of biological evidence

Vibrational spectroscopy is a powerful analytical domain, within which Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy stand as exemplars, offering high chemical specificity and sensitivity. These methodologies have been instrumental in the characterization of chemical compounds for an extensive period. They are particularly adept at the identification and analysis of minute sample quantities. Both FTIR and Raman spectroscopy are proficient in elucidating small liquid samples and detecting nuanced molecular alterations. The application of chemometrics further augments their analytical prowess. Currently, these techniques are in the research phase within forensic medicine and have yet to be broadly implemented in examination and identification processes. Nonetheless, studies have indicated that a combined classification model utilizing FTIR and Raman spectroscopy yields exceptional results for the identification of biological fluid-related information and the determination of causes of death. The objective of this review is to delineate the current research trajectory and potential applications of these two vibrational spectroscopic techniques in the detection of body fluids and the ascertainment of causes of death within the context of forensic medicine.

A novel method for early prediction of sudden cardiac death through nonlinear feature extraction from ECG signals

Sudden cardiac death (SCD) is a critical cardiovascular issue affecting approximately 3 million individuals globally each year, often occurring without prior noticeable symptoms. While the precise etiology of SCD remains elusive, ventricular fibrillation is believed to play a pivotal role in its pathophysiology. Given that symptoms typically manifest only an hour before the event, timely prediction is crucial for effective cardiac resuscitation. This study aims to predict SCD using time-frequency analysis of ECG signals. We utilized two online datasets: the Sudden Cardiac Death Holter dataset and the MIT-BIH Normal Sinus Rhythm dataset. Our proposed method involves segmenting the 60-min interval preceding ventricular fibrillation into one-minute segments, which are then decomposed into time-frequency sub-bands using empirical mode decomposition (EMD). Nonlinear features are extracted from these decomposed signals, followed by classification using support vector machines (SVM) and K-nearest neighbors (KNN) algorithms. To enhance classification accuracy, we employed two statistical feature selection techniques: T-test and ANOVA. Results indicate that using the ANOVA feature selection method in conjunction with SVM and KNN algorithms achieves high accuracy in predicting SCD. Specifically, the average accuracy rates for the 60 min preceding SCD were 93.51% for ANOVA-SVM and 93% for ANOVA-KNN. With T-test feature selection, the average accuracy rates were 93.29% for SVM and 93.41% for KNN. These findings demonstrate the promising performance of our proposed approach in predicting SCD, potentially contributing to improved early intervention strategies and patient outcomes.

Challenges of genetics in the diagnosis of sudden cardiac death. Interest for forensic and legal medicine

Sudden cardiac death is the leading cause of death in developed countries and a small but significant number of cases cannot be explained after a thorough autopsy process. Cases of sudden cardiac death in people under 40years of age are mainly due to structural heart disease or cardiomyopathies and arrhythmogenic diseases or channelopathies. In these cases, the search for associated genetic factors through molecular autopsy may help to find the cause of unexplained sudden cardiac death, through genetic diagnosis of previously undiagnosed channelopathies or cardiomyopathies. The finding of genetic variants classified as pathogenic associated with cardiac pathology would conclude the autopsy result and provide the possibility of genetic screening in other family members.

Sudden Cardiac Death: The Role of Molecular Autopsy with Next-Generation Sequencing

Molecular autopsy is a term employed to describe the investigation of the cause of death through the analysis of genetic information using biological samples collected post-mortem. Its utility becomes evident in situations where conventional medico-legal autopsy methods are not able to identify the cause of death, i.e., in sudden cardiac death (SCD) cases in young individuals, where deaths are commonly due to genetic cardiac conditions, such as cardiomyopathies and channelopathies. The recent advancement in high-throughput sequencing techniques, such as next-generation sequencing (NGS), has allowed the investigation of a high number of genomic regions in a more cost-effective and faster approach. Unlike traditional sequencing methods, which can only sequence one DNA fragment at a time, NGS can sequence millions of short polynucleotide fragments simultaneously. This parallel approach reduces both the time and cost required to generate large-scale genomic data, making it a useful tool for applications ranging from basic research to molecular autopsy. In the forensic context, by enabling the examination of multiple genes or entire exomes and genomes, NGS enhances the accuracy and depth of genetic investigations, contributing to a better understanding of complex inherited diseases. However, challenges remain, such as the interpretation of variants of unknown significance (VUS), the need for standardized protocols, and the high demand for specialized bioinformatics expertise. Despite these challenges, NGS continues to offer significant promise for enhancing the precision of molecular autopsies. The goal of this review is to assess the effectiveness of contemporary advancements in molecular autopsy methodologies when applied to cases of SCD in young individuals and to present an overview of the steps involved in the analysis of NGS data and the interpretation of genetic variants.

Mitochondria dysfunction: A trigger for cardiovascular diseases in systemic lupus erythematosus

Cardiovascular disease (CVD), including pericarditis, myocarditis, sudden cardiac death, coronary heart disease, and stroke, are leading contributors to morbidity and mortality in systemic lupus erythematosus (SLE) patients. Emerging evidence highlights mitochondrial dysfunction as a key driver of cardiovascular pathology in SLE, with impaired oxidative phosphorylation, altered membrane potential, and disrupted metabolic processes promoting oxidative stress, inflammatory activation, and endothelial dysfunction. This review critically examines mitochondrial contributions to CVD in SLE, comparing these mechanisms with those in non-SLE CVD to highlight SLE-specific mitochondrial vulnerabilities. Furthermore, we discuss preclinical and clinical findings supporting mitochondrial pathways as potential therapeutic targets, aiming to bridge gaps in current understanding and outline future research directions. By synthesizing current knowledge of mitochondrial dysregulation, this review proposes therapeutic strategies to improve cardiovascular outcomes and advance patient care in SLE.

Lipidomic analyses reveal potential biomarkers for predicting death and heart failure after acute myocardial infarction

Background Acute myocardial infarction (AMI) and postmyocardial infarction heart failure (pMIHF) have high mortality rates worldwide. This study aimed to explore lipidomic profiles and identify potential biomarkers for the prediction of death and heart failure (HF) after AMI. Methods All serum samples were collected at Xuanwu Hospital, Capital Medical University, and their clinical characteristics and lipidomic profiles were analyzed in different groups. LC-MS/MS was used for lipidomic analyses, and underlying biomarkers were screened by receiver operating characteristic (ROC) curve analysis. Results Lipidomic analyses of the survival and nonsurvival groups revealed that the decrease of the content of SM (d18:1/22:0), PE (P-20:1/18:0), PC (18:2), LPE (18:2), PE (P-20:0/18:0), LPC (18:0) and PC (20:0/20:3) while increase of the content of PG (18:1/18:1) could increase the risk of death after AMI. In parallel, the lipidomic analysis of the HF and non-HF groups revealed that the decrease of the content of PC (20:3/20:4), LPC (20:3), LPC (18:0), LPC (18:2), LPC (20:0), LPC (18:3), LPE (16:1) and PC (18:2/20:3) could increase the risk of HF after AMI. Conclusion Several lipids could be potential biomarkers for the prediction of death and HF after AMI.

Successful percutaneous coronary intervention in a congenital single right coronary artery with acute myocardial infarction: A case report and literature review

RATIONALE

Single coronary artery (SCA) is a rare coronary artery malformation. SCA combined with atherosclerotic plaques can cause severe and widespread myocardial ischemia and infarction, leading to hemodynamic instability and even sudden death.

PATIENT CONCERNS

A 48-year-old Chinese man was admitted for treatment of persistent chest tightness and panic for 5 hours. The patient was a lorry driver with high work intensity and mental stress, with body mass index of 33.78, history of smoking and alcohol consumption, but no history of hypertension and diabetes.

DIAGNOSES

Admission examination showed Troponin was 183.083 µg/L and CK-MB value was >300 µg/L. The patient was diagnosed with a congenital single right coronary artery (RCA) with acute myocardial infarction (AMI) by coronary angiography (CAG). Due to atherosclerotic plaques rupture, a complete occlusion of the proximal RCA with thrombolysis in myocardial infarction grade 0 of distal blood flow were found.

INTERVENTIONS AND OUTCOMES

The patient was treated with thrombus aspiration and thrombolytic therapy by percutaneous coronary intervention under the support of intra-aortic balloon pump. Postoperative the chest tightness and panic were relieved, and CAG revealed that the proximal thrombus of the RCA was reduced, and distal blood flow was restored to thrombolysis in myocardial infarction grade 3. After 2 weeks of intensive antithrombotic and lipid-regulating drug therapy, the patient was successfully discharged. Follow-up for 6 months, the patient was able to live and work normally without experiencing chest tightness and chest pain. Computed tomography angiography (CTA) confirmed a congenital single RCA with patent lumen and no severe stenosis.

LESSONS

The congenital single RCA is very rare, and it is fatal in conjunction with acute coronary syndrome. Early detection and appropriate treatment is critical for AMI patient with single RCA. CAG is the gold standard for diagnosis of single RCA, and CTA is a necessary to describe the anatomical course of abnormal coronary arteries.

Sudden Cardiac Death-Etiology, Risk Factors and Demographic Characteristics: An Extensive Study of 1618 Forensic Autopsies

BACKGROUND

Sudden cardiac death (SCD) is a major public health concern worldwide, affecting all age and social groups.

METHODS

In this retrospective study, of the 8265 autopsies performed in the Institute of Legal Medicine, 1618 cases of SCD were included. The aim of this study is to identify demographic characteristics, etiological factors, epidemiological characteristics and risk factors that lead to SCD.

RESULTS

The highest incidence of SCD was in age group 40-69 years (65.0%), 71.6% of this age group being men. Of the total number, 32.1% (520) occurred in the emergency room. The most common cause of sudden death is represented by coronary atherosclerotic disease, reported in 89.8% (1453) of cases, tricoronary lesions being found in 60% (870) of cases. Etiological factors of SCD encountered during autopsies were acute myocardial infarction in 13.9% (225), dilated cardiomyopathy 43.9% (710), cardiac hypertrophy 579 (36.07%), pericarditis 1.9% (30), myocarditis 1.73% (28) and adipositas cordis 5% (81). Along with epicardial fat and BMI, alcohol consumption was recorded in 17.9% (290), this being a potential trigger.

CONCLUSIONS

Based on forensic autopsy and histological findings, a wide variety of factors are involved in the etiopathogenesis of SCD, some of which can be eliminated through preventive measures implemented early.

A narrative review of inherited arrhythmogenic syndromes in young population: role of genetic diagnosis in exercise recommendations

Sudden cardiac death is a rare but socially devastating event, especially if occurs in young people. Usually, this unexpected lethal event occurs during or just after exercise. One of the leading causes of sudden cardiac death is inherited arrhythmogenic syndromes, a group of genetic entities characterised by incomplete penetrance and variable expressivity. Exercise can be the trigger for malignant arrhythmias and even syncope in population with a genetic predisposition, being sudden cardiac death as the first symptom. Due to genetic origin, family members must be clinically assessed and genetically analysed after diagnosis or suspected diagnosis of a cardiac channelopathy. Early identification and adoption of personalised preventive measures is crucial to reduce risk of arrhythmias and avoid new lethal episodes. Despite exercise being recommended by the global population due to its beneficial effects on health, particular recommendations for these patients should be adopted considering the sport practised, level of demand, age, gender, arrhythmogenic syndrome diagnosed but also genetic diagnosis. Our review focuses on the role of genetic background in sudden cardiac death during exercise in child and young population.

Acute myocarditis: an overview of pathogenesis, diagnosis and management

Acute myocarditis encompasses a diverse presentation of inflammatory cardiomyopathies with infectious and non-infectious triggers. The clinical presentation is heterogeneous, from subtle symptoms like mild chest pain to life-threatening fulminant heart failure requiring urgent advanced hemodynamic support. This review provides a comprehensive overview of the current state of knowledge regarding the pathogenesis, diagnostic approach, management strategies, and directions for future research in acute myocarditis. The pathogenesis of myocarditis involves interplay between the inciting factors and the subsequent host immune response. Infectious causes, especially cardiotropic viruses, are the most frequently identified precipitants. However, autoimmune processes independent of microbial triggers, as well as toxic myocardial injury from drugs, chemicals or metabolic derangements also contribute to the development of myocarditis through diverse mechanisms. Furthermore, medications like immune checkpoint inhibitor therapies are increasingly recognized as causes of myocarditis. Elucidating the nuances of viral, autoimmune, hypersensitivity, and toxic subtypes of myocarditis is key to guiding appropriate therapy. The heterogeneous clinical presentation coupled with non-specific symptoms creates diagnostic challenges. A multifaceted approach is required, incorporating clinical evaluation, electrocardiography, biomarkers, imaging studies, and endomyocardial biopsy. Cardiovascular magnetic resonance imaging has become pivotal for non-invasive assessment of myocardial inflammation and fibrosis. However, biopsy remains the gold standard for histological classification and definitively establishing the underlying etiology. Management relies on supportive care, while disease-specific therapies are limited. Although some patients recover well with conservative measures, severe or fulminant myocarditis necessitates aggressive interventions such as mechanical circulatory support devices and transplantation. While immunosuppression is beneficial in certain histological subtypes, clear evidence supporting antiviral or immunomodulatory therapies for the majority of acute viral myocarditis cases remains insufficient. Substantial knowledge gaps persist regarding validated diagnostic biomarkers, optimal imaging surveillance strategies, evidence-based medical therapies, and risk stratification schema. A deeper understanding of the immunopathological mechanisms, rigorous clinical trials of targeted therapies, and longitudinal outcome studies are imperative to advance management and improve the prognosis across the myocarditis spectrum.

Cholecystitis may decrease the risk of sudden death: A 2-sample Mendelian randomization study

Some observational studies have highlighted a significant association between cholecystitis and factors leading to sudden death; however, the specific relationship between the 2 has not been fully elucidated. The primary objective of this study was to elucidate the causal interplay between cholecystitis and augmented risk of sudden cardiac death. We used large-scale genetic summary data from genome-wide association study, genetic summary statistics were sourced from 3 eminent repositories: the UK Biobank (N = 463,010), the FinnGen consortium (N = 215,027), and the European Bioinformatics Institute (N = 471,251). By employing 2-sample Mendelian randomization (MR) to decipher the causal interplay between cholecystitis and sudden death etiologies, a meta-analytical approach was employed to amalgamate the findings derived from these disparate data sources. The primary MR methodologies used included inverse variance weighting with random effects, inverse variance weighting with fixed effects, maximum likelihood, MR-Egger, and weighted median. Subsequently, we performed heterogeneity testing, polyvalency examination, and sensitivity analysis to bolster the robustness of causal relationship assessments. Meta-analysis and amalgamating variegated data sources revealed a statistically significant inverse correlation between cholecystitis and ventricular arrhythmias (odds ratio, 0.896; 95% confidence interval: 0.826-0.971; P = .008). Similarly, an inverse association was observed between cholecystitis and aortic aneurysm (odds ratio, 0.899; 95% confidence interval: 0.851-0.951, P < .001). This study substantiates the absence of a direct causal link between cholecystitis and cerebrovascular accidents (P = .771), pulmonary embolism (P = .071), and acute myocardial infarction (P = .388). A direct causal correlation existed between cholecystitis and sudden death associated with ventricular arrhythmias and aortic aneurysms. The onset of cholecystitis may mitigate the risk of sudden death due to ventricular arrhythmias and aortic aneurysms.

Duplication of Left Anterior Descending Artery: A Case Report on a Rare Abnormality

Duplication of the left anterior descending coronary artery (LAD) is a benign condition. The formation of a double LAD is a rare phenomenon among coronary artery anomalies. The categorization of the branching pattern of the LAD has been articulated well in numerous studies, owing to the widespread adoption of computed tomography angiography. Anomalous coronaries are a crucial pathological condition that should be examined. Individuals who are suffering from chest pain should be aware that it can potentially lead to myocardial ischemia, arrhythmia, or sudden cardiac death. Here is a unique case study detailing the diagnosis of dual LAD in a 50-year-old female patient.

Sudden Cardiac Death in the Young: State-of-the-Art Review in Molecular Autopsy

Sudden cardiac death (SCD) is defined as unexpected death due to a cardiac cause that occurs rapidly. Despite the identification of prevention strategies, SCD remains a serious public health problem worldwide, accounting for 15-20% of all deaths, and is therefore a challenge for modern medicine, especially when it affects young people. Sudden cardiac death in young people affects the population aged ≤ 35 years, including athletes and non-athletes, and it is due to various hereditary and non-hereditary causes. After an autopsy, if the cause remains unknown, it is called sudden unexplained death, often attributable to genetic causes. In these cases, molecular autopsy-post-mortem genetic testing-is essential to facilitate diagnostic and therapeutic pathways and/or the monitoring of family members of the cases. This review aims to elaborate on cardiac disorders marked by genetic mutations, necessitating the post-mortem genetic investigation of the deceased for an accurate diagnosis in order to facilitate informed genetic counseling and to implement preventive strategies for family members of the cases.

Single intravenous dose ondansetron induces QT prolongation in adult emergency department patients: a prospective observational study

BACKGROUND

Ondansetron is one of the most commonly used drugs in the emergency department (ED) for treating nausea and vomiting, particularly in intravenous (IV) form. Nevertheless, it has been shown to prolong QT interval and increase the risk of ventricular dysrhythmias. This study evaluated the associations between single IV ondansetron dosage and subsequent QTc prolongation in the ED.

METHODS

In this prospective observational study, a total number of 106 patients presenting to the ED in a 3-month period with nausea and vomiting treated with IV ondansetron were enrolled. QT and QTc intervals were measured at baseline (QT0 and QTc0), and 60 min (QT60 and QTc60) following a single-dose administration of ondansetron at 4 or 8 mg doses. To evaluate the predictive ability of these variables, we employed receiver operating characteristic (ROC) curve analyses.

RESULTS

The predictive models for QTc prolongation 1-hour post-ondansetron administration showed the following: at baseline, the area under curve of 0.70 for QT, 0.71 for QTc, and 0.64 for dosage. Conversely, a QTc0 = 375 msec indicated a QTc60 > 480 msec with a specificity of 97%. Additionally, a QTc0 of 400 msec had a sensitivity of 100% in predicting a QTc60 < 480 msec, while a QTc0 > 460 msec predicted a QTc60 > 480 msec with a specificity of 98%. Moreover, 8 mg doses were associated with higher rates of QTc60 prolongation, while 4 mg doses favored maintaining QTc60 within normal limits.

CONCLUSIONS

Our study demonstrates the predictive capacity of QT0, QTc0, and ondansetron dosage in forecasting QTc60 prolongation (> 480 msec) post-ondansetron administration. These findings advocate for their incorporation into clinical protocols to enhance safety monitoring in adult ED patients.

Sudden cardiac death among workers: a systematic review and meta-analysis

OBJECTIVE

Sudden cardiac death (SCD) is a rare and yet unexplained condition. The most frequent cause is myocardial infarction, while a small proportion is due to arrhythmogenic syndromes (e.g., channelopathies). This systematic review and meta-analysis aimed to provide a comprehensive overview of the prevalence and risk factors associated with SCD in workers.

MATERIAL AND METHODS

A search for eligible studies was performed utilizing three databases (PubMed, ISI Web of Knowledge, and Scopus). The inclusion criteria were fulfilled if sudden cardiac death due to channelopathy in workers was mentioned.

RESULTS

Out of the 1408 articles found across three databases, 6 articles were included in the systematic review but the meta-analysis was conducted on 3 studies The total sample included was 23,450 participants. The pooled prevalence of channelopathies in employees was 0.3% (95% CI 0.07-0.43%), of sudden cardiac death in employees was 2.8% (95% CI 0.37-5.20%), and of sudden cardiac death in employees with a diagnosis of cardiac channelopathies was 0.2% (95% CI 0.02- 0.30%).

CONCLUSIONS

SCD is a serious and potentially preventable condition that can occur among workers. By identifying and addressing work-related risk factors, providing appropriate screening and interventions, and promoting healthy lifestyle behaviors, we can work to reduce the incidence of SCD and improve the cardiovascular health and well-being of workers.

Determinants of COVID-19 vaccine-induced myocarditis

BACKGROUND

Following the roll-out of the Pfizer-BioNTech BNT162b2, Moderna mRNA-1273, and Janssen Ad26.COV2.S coronavirus disease 2019 (COVID-19) injections in the United States, millions of individuals have reported adverse events (AEs) using the vaccine adverse events reports system (VAERS). The objective of this analysis is to describe the myocarditis data in VAERS and the COVID-19 vaccines as potential determinants of myocarditis.

METHODS

We used VAERS data to examine the frequency of reporting myocarditis since the beginning of the mass vaccination campaign and compared this with historical values in VAERS and COVID-19 vaccine administration data from the Our World in Data database. We examined myocarditis reports in VAERS in the context of sex, age, and dose. Statistical analysis was done using the Student's t-test to determine statistically significant differences between ages among myocarditis adverse events (AEs) and the chi-square test to determine relationships between categorical variables with statistical significance.

RESULTS

We found the number of myocarditis reports in VAERS after COVID-19 vaccination in 2021 was 223 times higher than the average of all vaccines combined for the past 30 years. This represented a 2500% increase in the absolute number of reports in the first year of the campaign when comparing historical values prior to 2021. Demographic data revealed that myocarditis occurred most in youths (50%) and males (69%). A total of 76% of cases resulted in emergency care and hospitalization. Of the total myocarditis reports, 92 individuals died (3%). Myocarditis was more likely after dose 2 (p < 0.00001) and individuals less than 30 years of age were more likely than individuals older than 30 to acquire myocarditis (p < 0.00001).

CONCLUSION

COVID-19 vaccination is strongly associated with a serious adverse safety signal of myocarditis, particularly in children and young adults resulting in hospitalization and death. Further investigation into the underlying mechanisms of COVID-19 vaccine-induced myocarditis is imperative to create effective mitigation strategies and ensure the safety of COVID-19 vaccination programs across populations.

Molecular autopsy for sudden death in Japan

Japan has various death investigation systems; however, external examinations, postmortem computed tomography, macroscopic examinations, and microscopic examinations are performed regardless of the system used. These examinations can reveal morphological abnormalities, whereas the cause of death in cases with non-morphological abnormalities can be detected through additional examinations. Molecular autopsy and postmortem genetic analyses are important additional examinations. They are capable of detecting inherited arrhythmias or inherited metabolic diseases, which are representative non-morphological disorders that cause sudden death, especially in infants and young people. In this review, we introduce molecular autopsy reports from Japan and describe our experience with representative cases. The relationships between drug-related deaths and genetic variants are also reviewed. Based on the presented information, molecular autopsy is expected to be used as routine examinations in death investigations because they can provide information to save new lives.

Mortality trends, disparities, and social vulnerability in cardiac arrest mortality in the young: A cross-sectional analysis

BACKGROUND

Cardiac arrest (CA) is a leading cause of death in the United States (US). Social determinants of health may impact CA outcomes. We aimed to assess mortality trends, disparities, and the influence of the social vulnerability index (SVI) on CA outcomes in the young.

METHODS

We conducted a cross-sectional analysis of age-adjusted mortality rates (AAMRs) related to CA in the United States from the Years 1999 to 2020 in individuals aged 35 years and younger. Data were obtained from death certificates and analyzed using log-linear regression models. We examined disparities in mortality rates based on demographic variables. We also explored the impact of the SVI on CA mortality.

RESULTS

A total of 4792 CA deaths in the young were identified. Overall AAMR decreased from 0.20 in 1999 to 0.14 in 2020 with an average annual percentage change of -1.3% (p = .001). Black (AAMR: 0.30) and male populations (AAMR: 0.14) had higher AAMR compared with White (AAMR: 0.11) and female (AAMR: 0.11) populations, respectively. Nonmetropolitan (AAMR: 0.29) and Southern (AAMR: 0.26) regions were also impacted by higher AAMR compared with metropolitan (AAMR: 0.11) and other US census regions, respectively. A higher SVI was associated with greater mortality risks related to CA (risk ratio: 1.82 [95% CI, 1.77-1.87]).

CONCLUSIONS

Our analysis of CA in the young revealed disparities based on demographics, with a decline in AAMR from 1999 to 2020. There is a correlation between a higher SVI and increased CA mortality risk, highlighting the importance of targeted interventions to address these disparities effectively.

[Incidence of sudden cardiac death among diseases of the circulatory system during the COVID-19 pandemic in the Penza region]

OBJECTIVE

To study the incidence of sudden cardiac death (SCD) among overall and primary morbidity of diseases of the circulatory system (DCS) during the COVID-19 pandemic, as well as several years before it in urban and rural populations of the Penza region.

MATERIAL AND METHODS

Statistical analysis of data using correlation (Pearson's coefficient), regression methods, t-test was performed to determine the significance of results.

RESULTS

The higher incidence of DCS among men in urban areas has been found. COVID-19 morbidity did not cause an increase in the incidence of SCD in the rural population in comparison with primary DCS morbidity, which was strongly correlated with the prevalence of novel coronavirus infection.

Post-mortem genetic analysis of sudden unexplained death in a young cohort: a whole-exome sequencing study

Sudden unexplained death (SUD) constitutes a considerable portion of unexpected sudden death in the young. Molecular autopsy has proved to be an efficient diagnostic tool in the multidisciplinary management of SUD. Yet, many cases remain undiagnosed using the widely adopted targeted genetic screening strategies. Here, we investigated the genetic substrates of a young SUD cohort (18-40 years old) from China using whole-exome sequencing (WES), with the primary aim to identify novel SUD susceptibility genes. Within 255 previously acknowledged SUD-associated genes, 21 variants with likely functional effects (pathogenic/likely pathogenic) were identified in 51.9% of the SUD cases. More importantly, a set of 33 candidate genes associated with myopathy were identified to be novel susceptibility genes for SUD. Comparative analysis of the cumulative PHRED-scaled CADD score and polygenetic burden score showed that the amount and deleteriousness of variants in the 255 SUD-associated genes and the 33 candidate genes identified by this study were significantly higher compared with 289 randomly selected genes. A significantly higher genetic burden of rare variants (MAF < 0.1%) in the 33 candidate genes also highlighted putative roles of these genes in SUD. After incorporating these novel genes, the genetic testing yields of the current SUD cohort elevated from 51.9 to 66.7%. Our study expands understanding of the genetic variants underlying SUD and presents insights that improve the utility of genetic screenings.

Postmortem biochemistry in deaths from ischemic heart disease

Ischemic heart disease (IHD) is one of the leading causes of morbidity and sudden cardiac death worldwide and is an important public health problem. The presence of ischemia in clinical applications can be detected by ECG, biochemical markers, and radiological methods. Myocardial infarction is also frequently encountered in forensic autopsies. Postmortem diagnosis is determined as a result of histopathological examinations and additional exclusionary examinations (toxicology, microbiology, etc.). However, routine histopathological examinations are insufficient, especially when death occurs in the early period of ischemia. It creates a problem for forensic pathologists and forensic medicine specialists in such cases of sudden cardiac death. Postmortem biochemistry is one of the important and promising disciplines in which forensic applications work in order to diagnose these cases correctly. The issue of whether biomarkers used in the diagnosis of myocardial infarction in clinical studies can be used reliably in postmortem cases has been discussed by forensic medicine researchers for some time. This manuscript aims to review and summarize biomarkers belonging to various categories that have been studied in IHD-related deaths, in biological fluids taken at autopsy, or in animal experiments. Our study shows that the postmortem use of biochemical markers in the diagnosis of IHD yields promising results. However, it should not be forgotten that postmortem biochemistry is different from clinical applications due to its dynamics and that the body causes unpredictable changes in markers in the postmortem process. Therefore, comprehensive studies are needed to evaluate the postmortem stability of these markers in different biological fluids, their significance among various causes of death, and whether they are affected by any variable (Cardiopulmonary resuscitation, Postmortem interval, medications, etc.) before they are routinely applied. It is suggested by the authors that the cut-off values of biomarkers whose significance has been proven by these studies should be determined and that they should be used in this way in routine applications.

The Role of miRNA Expression Profile in Sudden Cardiac Death Cases

Sudden cardiac death (SCD) is one of the leading causes of death in the world and for this reason it has attracted the attention of numerous researchers in the field of legal medicine. It is not easy to determine the cause in a SCD case and the available methods used for diagnosis cannot always give an exhaustive answer. In addition, the molecular analysis of genes does not lead to a clear conclusion, but it could be interesting to focus attention on the expression level of miRNAs, a class of non-coding RNA of about 22 nucleotides. The role of miRNAs is to regulate the gene expression through complementary binding to 3'-untraslated regions of miRNAs, leading to the inhibition of translation or to mRNA degradation. In recent years, several studies were performed with the aim of exploring the use of these molecules as biomarkers for SCD cases, and to also distinguish the causes that lead to cardiac death. In this review, we summarize experiments, evidence, and results of different studies on the implication of miRNAs in SCD cases. We discuss the different biological starting materials with their respective advantages and disadvantages, studying miRNA expression on tissue (fresh-frozen tissue and FFPE tissue), circulating cell-free miRNAs in blood of patients affected by cardiac disease at high risk of SCD, and exosomal miRNAs analyzed from serum of people who died from SCD.

Evaluating the effect of Roxadustat on ventricular repolarization in patients undergoing peritoneal dialysis

BACKGROUND

Roxadustat is a novel oral medication used to treat anemia in CKD patients. Several studies have shown that Roxadustat can alleviate anemia in CKD patients by increasing hemoglobin levels and regulating iron metabolism. We aimed to evaluate the effect of Roxadustat on ventricular repolarization in PD patients. This study may provide a new integrated approach to the assessment and treatment of CKD.

METHODS

The present prospective cohort study enrolled 65 CKD patients who were treated with Roxadustat and 31 CKD patients who received conventional therapy between January 2021 and June 2022. All patients were examined for ECG in the absence of clinical symptoms and compared the ECG indicators. Demographic and clinical data of all patients were collected. All data used SPSS 18.0 for statistical analyses.

RESULTS

The T peak-to-end (Tpe) of PD patients in the Roxadustat group was remarkably slower than that of patients in the conventional group. Additionally, the Tpe/QT ratio in the conventional group was significantly elevated than that in the Roxadustat group. The results of logistic regression analysis showed that Tpe (95%CI 1.191 ~ 2.141, P = 0.002) and Roxadustat treatment (95%CI 1.357 ~ 42.121, P = 0.021) were the risk factors of PD patients with high Tp-e/QT ratio.

CONCLUSION

In summary, we found that Roxadustat could improve ventricular repolarization in peritoneal dialysis patients, which indicated a potential cardiovascular protective effect of Roxadustat. This study might provide a new integrated approach to the assessment and treatment of CKD.

Associations of MYPN, TTN, SCN5A, MYO6 and ELN Mutations With Arrhythmias and Subsequent Sudden Cardiac Death: A Case Report of an Ecuadorian Individual

Cardiac pathologies are among the most frequent causes of death worldwide. Regarding cardiovascular deaths, it is estimated that 5 million cases are caused by sudden cardiac death (SCD) annually. The primary cause of SCD is ventricular arrhythmias. Genomic studies have provided pathogenic, likely pathogenic, and variants of uncertain significance that may predispose individuals to cardiac causes of sudden death. In this study, we describe the case of a 43-year-old individual who experienced an episode of aborted SCD. An implantable cardioverter defibrillator was placed to prevent further SCD episodes. The diagnosis was ventricular fibrillation. Genomic analysis revealed some variants in the MYPN (pathogenic), GCKR (likely pathogenic), TTN (variant of uncertain significance), SCN5A (variant of uncertain significance), MYO6 (variant of uncertain significance), and ELN (variant of uncertain significance) genes, which could be associated with SCD episodes. In addition, a protein-protein interaction network was obtained, with proteins related to ventricular arrhythmia and the biological processes involved. Therefore, this study identified genetic variants that may be associated with and trigger SCD in the individual. Moreover, genetic variants of uncertain significance, which have not been reported, could contribute to the genetic basis of the disease.

Blood taken immediately after fatal resuscitation attempts yields higher quality DNA for genetic studies as compared to autopsy samples

BACKGROUND

The out-of-hospital cardiac arrest (OHCA) in the young may be associated with a genetic predisposition which is relevant even for genetic counseling of relatives. The identification of genetic variants depends on the availability of intact genomic DNA. DNA from autopsy may be not available due to low autopsy frequencies or not suitable for high-throughput DNA sequencing (NGS). The emergency medical service (EMS) plays an important role to save biomaterial for subsequent molecular autopsy. It is not known whether the DNA integrity of samples collected by the EMS is better suited for NGS than autopsy specimens.

MATERIAL AND METHODS

DNA integrity was analyzed by standardized protocols. Fourteen blood samples collected by the EMS and biomaterials from autopsy were compared. We collected 172 autopsy samples from different tissues and blood with postmortem intervals of 14-168 h. For comparison, DNA integrity derived from blood stored under experimental conditions was checked against autopsy blood after different time intervals.

RESULTS

DNA integrity and extraction yield were higher in EMS blood compared to any autopsy tissue. DNA stability in autopsy specimens was highly variable and had unpredictable quality. In contrast, collecting blood samples by the EMS is feasible and delivered comparably the highest DNA integrity.

CONCLUSIONS

Isolation yield and DNA integrity from blood samples collected by the EMS is superior in comparison to autopsy specimens. DNA from blood samples collected by the EMS on scene is stable at room temperature or even for days at 4 °C. We conclude that the EMS personnel should always save a blood sample of young fatal OHCA cases died on scene to enable subsequent genetic analysis.

Exertional-Related Sudden Cardiac Death in a Young, Presumed Healthy, and Medically Screened Population: A Military Case Series

ABSTRACT

Sudden cardiac death (SCD) is defined as death from cardiac causes with loss of consciousness occurring within 1 hour of a change in cardiovascular status. As subset, SCD associated with physical exertion (SCD/E) can be defined as a cardiac event whose symptoms start during or within 1 hour of physical exertion. The US military represents a unique opportunity for studying SCD/E because of medical screening at recruitment, mandatory physical training, an active surveillance system, and centralized autopsy services. Because of medical screening, recruits are presumed healthy, but significant conditions can go undetected. We present 4 diverse cases of SCD/E in the military setting. Sudden cardiac death associated with physical exertion is often the first indication of a serious occult cardiac pathology. Postmortem genetic testing revealed a causative pathogenic mutation in 1 of 4 cases, enabling genetic testing of family members to prevent similar catastrophic loss of life, underscoring the importance of postmortem evaluation including genetic testing. Further investigations will help direct screening and prevention to capture those at risk for SCD. The cases presented in this series are a sample of the diverse etiologies and contexts surrounding SCD/E in the military setting that have been captured by Armed Forces Medical Examiner System.

Characterization of global research trends and prospects on sudden coronary death: A literature visualization analysis

Background

Sudden coronary death is a major global public health issue that has a significant impact on both individuals and society. Nowadays, scholars are active in sudden coronary death all over the world. However, no relevant bibliometric studies have been published. Here, we aim to gain a better understanding the current state of research and to explore potential new research directions through bibliometric analysis.

Methods

Articles and reviews on sudden coronary death from 2012 to 2023 were retrieved from the Web of Science Core Collection (WoSCC). The topic search was conducted using the following keywords: ((("sudden cardiac death" OR "sudden death") AND (coronary OR "myocardial infarction")) OR "sudden coronary death"). Knowledge maps of authors, countries, institutions, journals, keywords, and citations were conducted by CiteSpace. Publication dynamics, hotspots, and frontiers were analyzed independently by authors.

Results

A total of 2914 articles were identified from January 1, 2012 to June 20, 2023. The USA (n = 972) contributed the greatest absolute productivity and UK (centrality = 0.13) built a robust global collaboration. Harvard University was the institution with the highest number of publications (n = 143). Huikuri HV and Junttila MJ were the most published authors who devoted to searching for biomarkers of sudden coronary death. American Journal of Cardiology was the journal with the most publications, and Circulation was the most cited journal. Left ventricular ejection fraction, society, inflammation, and fractional flow reserve became novel burst words that lasted until 2023. Research on etiology and pathology, role of early risk factors in risk stratification, potential predictive biomarkers and novel measurement methods for the prevention and management of sudden coronary death were identified as the research hotspots and frontiers.

Conclusion

Our knowledge and understanding of sudden coronary death have significantly improved. Ongoing efforts should focus on the various etiologies and pathologies of sudden coronary death. Furthermore, a novel sudden coronary death risk model, large-scale population studies, and the rational use of multiple indicators to individualize the assessment of sudden coronary death and other risk factors are other emerging research trends.

Sudden cardiac death in the adolescent population: a narrative review

Background

Death from unexpected circulatory arrest within 60 min of onset of symptom is known as sudden cardiac death (SCD). In spite of the advancement in treatment and prevention strategies, SCD remains the most common cause of death worldwide especially in the young.

Main body

This review focuses on highlighting how different cardiovascular diseases contribute to SCD. We discuss the clinical symptoms that the patient experience prior to sudden cardiac arrest and the treatment strategies including pharmacological and surgical treatment.

Conclusions

We conclude that since there are many causes of SCD and very few treatment options, prevention strategies, early detection, and resuscitation of those at greatest risk is important.

Reevaluation of ambiguous genetic variants in sudden unexplained deaths of a young cohort

Sudden death cases in the young population remain without a conclusive cause of decease in almost 40% of cases. In these situations, cardiac arrhythmia of genetic origin is suspected as the most plausible cause of death. Molecular autopsy may reveal a genetic defect in up to 20% of families. Most than 80% of rare variants remain classified with an ambiguous role, impeding a useful clinical translation. Our aim was to update rare variants originally classified as of unknown significance to clarify their role. Our cohort included fifty-one post-mortem samples of young cases who died suddenly and without a definite cause of death. Five years ago, molecular autopsy identified at least one rare genetic alteration classified then as ambiguous following the American College of Medical Genetics and Genomics' recommendations. We have reclassified the same rare variants including novel data. About 10% of ambiguous variants change to benign/likely benign mainly because of improved population frequencies. Excluding cases who died before one year of age, almost 21% of rare ambiguous variants change to benign/likely benign. This fact makes it important to discard these rare variants as a cause of sudden unexplained death, avoiding anxiety in relatives' carriers. Twenty-five percent of the remaining variants show a tendency to suspicious deleterious role, highlighting clinical follow-up of carriers. Periodical reclassification of rare variants originally classified as ambiguous is crucial, at least updating frequencies every 5 years. This action aids to increase accuracy to enable and conclude a cause of death as well as translation into the clinic.

Sudden cardiac death in synucleinopathies

The purpose of this study was to investigate the cause of death in subjects with α-synucleinopathies (ASs) and the confirmed presence of cardiac α-synuclein (α-syn), compared to non-AS disorders in a neuropathologically confirmed cohort. In total, 78 neuropathologically confirmed AS cases positive for cardiac α-syn were included in the study. Individuals with other neurocognitive diseases, having no α-syn in the brainstem or above, nor in cardiac nerves, served as controls (n = 53). Data regarding the cause of death, cardiac α-syn, pathological cardiac findings, and cardio- and cerebrovascular disease were assembled from autopsy reports and medical records. In the AS group, there was a significantly higher prevalence of sudden cardiac death ([SCD]; n = 40, 51.3%) compared to the control group (n = 12, 22.6%, p < 0.001). No statistically significant differences between the groups were reported regarding other cardiac conditions on autopsy or regarding cardio- and cerebrovascular disease from the medical records. The most prevalent cause of death in the AS group was SCD, which differed significantly from the control group. This suggests that α-syn deposits in cardiac nerves may cause lethal alterations in cardiac function, warranting further research.

Androgen receptor (CAG)n repeat polymorphism contributes to risk of sudden cardiac death originated from coronary artery disease with sex discrepancy

Sudden cardiac death (SCD) is the leading cause of natural death worldwide which is responsible for almost half of all heart disease deaths, making it a substantial public health problem. Previous epidemiological studies from different countries have demonstrated the significant SCD incident difference rate between males and females. Besides environmental and social effects, differential genetic architecture also underlines the SCD incidence discrepancy. To this end, the functional (CAG)_n repeat polymorphism within Androgen Receptor (AR) gene was analyzed to evaluate its associations with SCD originated from coronary artery disease (SCD-CAD) susceptibility in Chinese populations using 182 SCD-CAD cases and 564 healthy controls. At allelic level, the (CAG)₂₆ allele conferred a lower SCD-CAD risk in males (adjusted odds ratio [OR] = 0.428; 95% confidence interval [CI] = 0.254, 0.915; P = 0.023). On the contrary, the (CAG)₂₆ allele was reversely associated with a higher SCD-CAD risk in females (OR = 2.581; 95% CI = 0.944, 7.056; P = 0.057). Further cutoff strategy analysis revealed that those male subjects carrying shorter allele (≤26 repeats) had significantly lower SCD-CAD risk (OR = 0.343; 95% CI = 0.221, 0.531; P = 8.1653e^-7). Additionally, an allele-dependent SCD risk tendency was observed in male subjects. Specifically, compared with males carrying allele longer than 26 repeats, the SCD-CAD risk (OR value) for male subjects carrying shorter alleles (from 25 to 21) gradually increased from 0.437 to 0.533, indicating the (CAG)₂₆ allele of the repeat polymorphism may be the watershed in male SCD etiology. Lastly, the length variations associated with multiple phenotypes were also summarized. Collectively, our results revealed for the first time that the (CAG)_n repeat polymorphism within the AR gene was associated with SCD-CAD risk in Chinese populations with sex discrepancy, proposing a new candidate genetic marker for molecular diagnosis of SCD-CAD. Furthermore, a sex-dependent SCD-CAD risk stratification and prevention approach was encouraged. Further studies with more female samples were warranted to validate our findings.

Plasma extracellular vesicles microRNA-208b-3p and microRNA-143-3p as novel biomarkers for sudden cardiac death prediction in acute coronary syndrome

Acute coronary syndrome (ACS) occurs as a result of myocardial ischemia that can give rise to a variety of acute cardiovascular events, including arrhythmia, heart failure and sudden cardiac death (SCD). Currently, there are challenges and insufficient innovations regarding early diagnosis and therapeutic approaches within ACS patients experiencing SCD. Plasma extracellular vesicles (EVs) might serve as biomarkers of many diseases depending on the biological molecules of their cargo, such as miRNAs. This study aims to identify the plasma EVs containing miRNAs as novel biomarkers for the prediction of SCD in ACS patients. A total of 39 ACS patients experiencing SCD and 39 healthy control individuals (HC) were enrolled, among which 9 samples in each group were randomly selected as testing groups for miRNA sequencing in plasma EVs, and the remaining samples were assigned to the validation group. The top 10 significant expression miRNAs were verified by the real-time quantitative polymerase chain reaction. Upregulation of miR-208b-3p, miR-143-3p, miR-145-3p and miR-152-3p, and down-regulation of miR-183-5p were further validated in the validation group. Spearman's correlation analysis and the receiver operating characteristic (ROC) curve showed that both miR-208b-3p and miR-143-3p levels were positively correlated with myoglobin (MYO), and their predictive power for SCD was confirmed. In conclusion, our findings indicate that plasma EVs miR-208b-3p and miR-143-3p may serve as promising biomarkers in predicting SCD in patients with ACS, as well as postmortem forensic diagnosis of the cause of death due to ACS.

Sudden Cardiac Death in Young Individuals: A Current Review of Evaluation, Screening and Prevention

Sudden cardiac death (SCD) can affect all age groups, including young persons. While less common in the age < 35 population, the occurrence of SCD in the young raises concern, with multiple possible etiologies and often unanswered questions. While coronary artery disease is the leading cause in those > 35 years of age, the younger population faces a different subset of pathologies associated with SCD, including arrhythmias and cardiomyopathies. The tragic nature of SCD in the young entails that we explore and implement available screening methods for this population, and perform the necessary investigations such as electrocardiography (ECG) and echocardiography. In this review, we not only explore the vast etiology associated with SCD in those age < 35, but emphasize evaluation methods, who is at risk, and delve into screening of SCD in potential victims and their family members, in an attempt to prevent this traumatic event. Future research must work towards establishing preventative measures in order to reduce SCD, particularly unexplained SCD in the young.

Effect of implantable cardioverter defibrillator on primary prevention of sudden cardiac death in high-risk patients

OBJECTIVE

To investigate the effect of implantable cardioverter defibrillator (ICD) on primary prevention of sudden cardiac death (SCD) in patients with high risk.

METHODS

This retrospective analysis included 70 patients who received primary prevention of SCD by ICD implantation in Huzhou Central Hospital from March 2016 to May 2019. Based on survival, 15 patients who died during follow-up were placed into the death group and the 55 patients who survived were set as the survival group. The two groups were compared in terms of sex, age, non-sustained ventricular tachycardia (VT), diastolic pressure, systolic pressure, left ventricular ejection fraction (LVEF), urea nitrogen, serum creatinine, history of diabetes, history of atrial fibrillation, history of myocardial ischemia, history of dilated cardiomyopathy, history of hypertrophic cardiomyopathy, type I Brugada wave and cardiac function classification. Further, we analyzed the proportion of discharge, the survival of patients (Kaplan Meier method), and the risk factors of patient death (Logistic regression).

RESULTS

The analysis of baseline data showed that patients in the death group had older age and higher level of serum creatinine than the survival group (P<0.05), and the number of patients with non-sustained VT≥5 times/24 h in the survival group was higher than that in the death group (P<0.05). There was no obvious difference in other baseline indexes between the two groups (P>0.05). In addition, there was no difference in the proportion of patients receiving appropriate/inappropriate discharge (P>0.05) between the two groups. Follow-up data showed that 15 cases (21.43%) of spontaneous VT/ventricular fibrillation events were correctly diagnosed by pacemakers and properly treated by ICD (discharge or antitachycardia pacing (ATP)), while 55 cases (78.57%) received inappropriate ICD treatment. There were 15 patients (21.43%) who died during follow up, including 6 cases of cardiac insufficiency, 1 case of SCD, 2 cases of acute myocardial infarction, 1 case of respiratory failure, and 5 cases of unknown etiology; the survival time was (20.27±7.06) months. Logistic regression analysis showed that age and serum creatinine were the risk factors of patient death.

CONCLUSION

Primary prevention with ICD implantation benefits SCD patients. Non persistent VT≥5 times/24 h is a predictive value for ICD implantation in patients receiving primary prevention of SCD. Age and serum creatinine are risk factors for death.

Prognostic Impact of Different Types of Ventricular Tachyarrhythmias Stratified by Underlying Cardiac Disease

Limited data regarding the outcome of patients with different types of ventricular tachyarrhythmias is available. This study sought to assess the prognostic impact of different types of ventricular tachyarrhythmias stratified by underlying cardiac disease. A large retrospective registry was used including all consecutive patients presenting with ventricular tachycardia (VT) and fibrillation (VF) on admission from 2002 to 2016. Patients with non-sustained VT (ns-VT), sustained VT (s-VT) and VF were compared using uni- and multivariable Cox regression models. Risk stratification was performed after stratification by underlying cardiac disease (i.e., acute myocardial infarction (AMI), ischemic heart disease (IHD), non-ischemic cardiomyopathy (NICM) and patients considered as lower-risk for ventricular tachyarrhythmias). The primary endpoint was defined as all-cause mortality at 2.5 years. Secondary endpoints were cardiac death at 24 h, all-cause mortality at 5 years, cardiac rehospitalization and a composite arrhythmic endpoint at 2.5 years. In 2422 consecutive patients with ventricular tachyarrhythmias, most patients were admitted with VF (44%), followed by ns-VT (30%) and s-VT (26%). Patients with VF suffered most commonly from AMI (42%), whereas heart failure was more common in s-VT patients (32%). In patients with AMI (HR = 1.146; 95% CI 0.751-1.750; p = 0.527) and in the lower-risk group (HR = 1.357; 95% CI 0.702-2.625; p = 0.364), the risk of all-cause mortality did not differ in VF and s-VT patients. In IHD patients, VF was associated with impaired prognosis compared to s-VT (HR = 2.502; 95% CI 1.936-3.235; p = 0.001). In conclusion, VF was associated with worse long-term prognosis compared to s-VT in IHD patients, whereas the risk of all-cause mortality among VF and s-VT patients did not differ in patients with AMI, NICM and in patients considered at lower risk for ventricular tachyarrhythmias.

Stability of exosomes in the postmortem serum and preliminary study on exosomal miRNA expression profiling in serum from myocardial infarction cadavers

Exosome-encapsulated miRNAs could potentially be sensitive biomarkers of human diseases. Since a lipid bilayer membrane surrounds exosomes, the exosomal miRNA may stably exist in body fluids with diseases as well as biological fluids. Therefore, exosomal miRNA may be helpful for autopsy diagnosis. Assuming cadaver blood would be most useful, we initially examined serum exosome stability with regard to storage temperatures and periods. Characteristic analyses of the exosome revealed that exosomes and the content, miRNA, were stably preserved until at least three days when stored at below 20 °C. Subsequently, exosomal miRNA expression profiling was performed on the serum of acute myocardial infarction (AMI, 4 cases) autopsy bodies and on hemorrhagic shock bodies used as the control (CT, 3 cases). Results showed that significant twofold up- and downregulations of expression of 18 and 16 miRNAs were detectable in AMI as compared to the CT, respectively. miR-126-3p, which has been reported to be increased in serum of AMI patients and a mouse model, was one of the significantly upregulated miRNAs. Furthermore, dysregulation of exosomal miRNAs, such as miR-145-5p, miR-143-3p, and miR-222-3p, which are involved in cardioprotection, may be associated with AMI pathogenesis. These findings provide a novel perspective on the potential role of exosomal miRNA in determining the cause of death.

Potential prognostic biomarkers of sudden cardiac death discovered by machine learning

OBJECTIVE

Sudden cardiac death (SCD) is a serious public health burden. This study aims to find prognostic biomarkers of SCD using machine learning.

METHODS

The myocardial samples from 21 accidental death and 82 sudden death donors were compared to seek for differential genes. Enriched active genes were found according to the PPI interaction network. GSEA analyzed differences in function and pathway between control and experimental groups. Related diseases caused by active genes are mainly exhibited through DO enrichment. Prognostic biomarkers for SCD are identified via two machine learning algorithms. The CIBERSORT method was used to compare the immune microenvironment changes in patients with SCD.

RESULTS

SCD was mainly associated with heart and kidney diseases caused by atherosclerosis. DEFA1B, BGN, SERPINE1, CCL2 and HBB are considered to be prognostic biomarkers for SCD after machine learning. And immune infiltration plays an important role in the process of SCD.

CONCLUSION

We discovered 5 prognostic biomarkers for SCD. And immune microenvironment changes was also found in SCD. Moreover, atherosclerosis might be an important risk factor for SCD.

Use of potassium ion channel and spliceosome proteins as diagnostic biomarkers for sudden unexplained death in schizophrenia

Sudden unexplained death in schizophrenia (SUD-SCZ) is not uncommon and its incidence is approximately three times higher than that in the general population. However, diagnosis of SUD-SCZ remains a great challenge in forensic pathology. This study designed a two-phase study to investigate whether three proteins, namely two potassium ion channel proteins (KCNJ3 and KCNAB1) and one spliceosome protein (SF3B3) that were identified in our previous work, could be applied in the postmortem diagnosis of SUD-SCZ. Immunohistochemical staining of the three biomarkers, followed by a rigorous quantitative analysis, was performed on heart specimens from both SUD-SCZ and control groups. A diagnostic software based on the logistic regression formula derived from the test phase data was then constructed. In the test phase, we found that the staining intensities of KCNJ3, KCNAB1, and SF3B3 were all significantly lower in the SUD-SCZ group (n = 20) as compared with the control group that died from non-natural causes (n = 25), with fold-changes being 14.85 (p < 0.001), 4.13 (p = 0.028) and 2.12 (p = 0.048), respectively. Receiver operating characteristic analysis further illustrated that combination of the three biomarkers achieved the optimal diagnostic specificity (92%) and area under the curve (0.886). In the validation phase, the diagnostic software was confirmed to be a promising tool for predicting the risk of SUD-SCZ in authentic cases. Our study provided a valid strategy towards the practical diagnosis of SUD-SCZ by using KCNJ3, KCNAB1, and SF3B3 proteins as diagnostic biomarkers.

Effects and Complications of Subcutaneous Implantable Cardioverter-Defibrillator in the Prevention of Sudden Cardiac Death: A Narrative Review

An implantable cardioverter-defibrillator (ICD) is one of those devices that is a big boom for the prevention of sudden deaths due to heart failure. This particular device has been in use for just a couple of years, but its impact in the domain has brought about a considerable change in the way a specific issue of the cardiovascular system is tackled. Although subcutaneous or hypodermic implantable cardioverter-defibrillator (S-ICD) is considered to be a better alternative as far as transvenous implantable cardioverter-defibrillator (TV-ICD) is concerned, the former, being a newer introduction in the market, needs to be assessed in depth to clearly understand its effects and complications. Various types of research have been conducted on the efficacy of this device, and in most of the studies, the supremacy of this device is clearly evident when compared with other devices that are used for the same purpose. Better innovations in subcutaneous or hypodermic implantable cardioverter-defibrillators would enable them to be manufactured in a more efficient and cost-effective way so that a huge lot of people are benefited from this device. This review article is a whole peep into the various studies done in this domain, thereby providing adequate scientific insights about subcutaneous or hypodermic implantable cardioverter-defibrillators in a very simple and comprehensive manner.

Diagnostic value of cardiac miR-126-5p, miR-134-5p, and miR-499a-5p in coronary artery disease-induced sudden cardiac death

Background

The identification of coronary artery disease-induced sudden cardiac death (CAD-SCD) has always been a medical challenge. MicroRNAs (miRNAs) played vital roles in pathogenesis processes and served as potential biomarkers for cardiovascular and many other diseases. The aim of this study was to investigate the diagnostic value of the specific miRNAs for CAD-SCD.

Methods

A total of 30 autopsy-verified CAD-SCD victims were selected, including 18 individuals who experienced more than once asymptomatic myocardial ischemia (CAD-activated SCD) and 12 victims without prominent pathological features of insufficient blood supply (CAD-silent SCD). Meanwhile, 30 traumatic victims were enrolled as controls. Systematic postmortem examinations were performed in all study population. The expressions of cardiac miR-126-5p, miR-134-5p, and miR-499a-5p were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR).

Results

RT-qPCR showed significant downregulations of miR-126-5p and miR-499a-5p in CAD-SCD victims, with no obvious difference in miR-134-5p. Receiver-operating characteristic analysis revealed the diagnostic performance of miR-126-5p (areas under the curve [AUC] = 0.76) and validated miR-499a-5p (AUC = 0.82) as a sensitive marker. Additionally, the decreased expression of the two specific cardio-miRNAs was detected for discriminating CAD-silent SCD and CAD-activated SCD. Compared with the limited diagnostic value of single miR-126-5p and miR-499a-5p, their combination could achieve better discriminative capacity (AUC = 0.82, sensitivity = 91.7%, specificity = 77.8%).

Conclusion

Cardiac miR-126-5p and miR-499a-5p presented good diagnostic abilities for CAD-SCD, and their combination could help evaluate CAD condition. These targeted miRNAs as novel biomarkers are expected to be useful to discriminate the detailed causes in real SCD cases.

Post-mortem CT: A Useful Tool to Confirm a Case of Suspected Sudden Cardiac Death

Sudden cardiac death (SCD) is defined as the unexpected death of an individual, not due to any extracardiac cause, occurring within one hour of symptom onset or within 24 hours of last being seen in good health if the death is unwitnessed. Forensic pathologists routinely encounter several SCD cases in their practice. The presentation of such cases can be of two types; firstly, with typical signs and symptoms suggestive of cardiac pathology, and secondly, devoid of any presentation history. This history helps forensic pathologists look for relevant findings during the autopsy examination. The authors intend to explore the feasibility of using advanced radiological techniques like post-mortem CT (PMCT) in determining the cause of death through a minimally invasive approach. In the present case, a 65-year-old male was found unresponsive at his residence on the morning of his death. He had a history of dull chest pain for the past two days, which had resolved after he self-prescribed a few medications. The presenting complaint of chest pain had started the intervening night prior to his death. The deceased was a known case of hypertension and was not compliant with treatment, as stated by the relatives. He was declared as brought dead by the treating emergency medicine physician at the Fortis Flt. Lt. Rajan Dhall Hospital and the body was sent by the authorities to the mortuary of the Department of Forensic Medicine, AIIMS, New Delhi for autopsy examination since an autopsy should be conducted by a government hospital or institute by law. PMCT depicted an alternate hyperdense and hypodense region circumferentially surrounding the heart, indicating hemopericardium. It was followed by a traditional autopsy and histopathology examination, which confirmed the presence of hemopericardium and left ventricular rupture associated with acute coronary insufficiency. Such cases with an indicative history, circumstantial evidence, and PMCT findings can be considered for minimal invasive autopsy. If the external findings indicate the application of physical force, then an explorative dissection could be done. Therefore, we conclude that PMCT can be used as a reliable tool for determining the cause of death in SCDs on a case-to-case basis.

The Therapeutic Potential of Secreted Factors from Dental Pulp Stem Cells for Various Diseases

An alternative source of mesenchymal stem cells has recently been discovered: dental pulp stem cells (DPSCs), including deciduous teeth, which can thus comprise potential tools for regenerative medicine. DPSCs derive from the neural crest and are normally implicated in dentin homeostasis. The clinical application of mesenchymal stem cells (MSCs) involving DPSCs contains various limitations, such as high cost, low safety, and cell handling issues, as well as invasive sample collection procedures. Although MSCs implantation offers favorable outcomes on specific diseases, implanted MSCs cannot survive for a long period. It is thus considered that their mediated mechanism of action involves paracrine effects. It has been recently reported that secreted molecules in DPSCs-conditioned media (DPSC-CM) contain various trophic factors and cytokines and that DPSC-CM are effective in models of various diseases. In the current study, we focus on the characteristics of DPSC-CM and their therapeutic potential against various disorders.

Novel Indel Variation of NPC1 Gene Associates With Risk of Sudden Cardiac Death

Background and Aims: Sudden cardiac death (SCD) was defined as an unexpected death from cardiac causes during a very short duration. It has been reported that Niemann-Pick type C1 (NPC1) gene mutations might be related to cardiovascular diseases. The purpose of the study is to investigate whether common genetic variants of NPC1 is involved in SCD susceptibility.

Methods: Based on a candidate-gene-based approach and systematic screening strategy, this study analyzed an 8-bp insertion/deletion polymorphism (rs150703258) within downstream of NPC1 for the association with SCD risk in Chinese populations using 158 SCD cases and 524 controls. The association of rs150703258 and SCD susceptibility was analyzed using logistic regression. Genotype-phenotype correlation analysis was performed using public database including 1000G, expression quantitative trait loci (eQTL), and further validated by human heart tissues using PCR. Dual-luciferase assay was used to explore the potential regulatory role of rs150703258. Gene expression profiling interactive analysis and transcription factors prediction were performed.

Results: Logistic regression analysis exhibited that the deletion allele of rs150703258 significantly increased the risk of SCD [odds ratio (OR) = 1.329; 95% confidence interval (95%CI):1.03–1.72; p = 0.0289]. Genotype-phenotype correlation analysis showed that the risk allele was significantly associated with higher expression of NPC1 at mRNA and protein expressions level in human heart tissues. eQTL analysis showed NPC1 and C18orf8 (an adjacent gene to NPC1) are both related to rs150703258 and have higher expression level in the samples with deletion allele. Dual-luciferase activity assays indicate a significant regulatory role for rs150703258. Gene expression profiling interactive analysis revealed that NPC1 and C18orf8 seemed to be co-regulated in human blood, arteries and heart tissues. In silico analysis showed that the rs150703258 deletion variant may create transcription factor binding sites. In addition, a rare 12-bp allele (4-bp longer than the insertion allele) of rs150703258 was discovered in the current cohort.

Conclusion: In summary, our study revealed that rs150703258 might contribute to SCD susceptibility by regulating NPC1 and C18orf8 expression. This indel may be a potential marker for risk stratification and molecular diagnosis of SCD. Validations in different ethnic groups with larger sample size and mechanism explorations are warranted to confirm our findings.