Comparison of the Frequency of Sudden Cardiovascular Deaths in Young Competitive Athletes Versus Nonathletes: Should We Really Screen Only Athletes?

International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death Tool

BACKGROUND

Studies reporting on the incidence of sudden cardiac arrest and/or death (SCA/D) in athletes commonly lack methodological and reporting rigor, which has implications for screening and preventative policy in sport. To date, there are no tools designed for assessing study quality in studies investigating the incidence of SCA/D in athletes.

METHODS AND RESULTS

The International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death tool (IQ-SCA/D) was developed following a Delphi process. Sixteen international experts in sports cardiology were identified and invited. Experts voted on each domain with subsequent moderated discussion for successive rounds until consensus was reached for a final tool. Interobserver agreement between a novice, intermediate, and expert observer was then assessed from the scoring of 22 relevant studies using weighted and unweighted κ analyses. The final IQ-SCA/D tool comprises 8 domains with a summated score of a possible 22. Studies are categorized as low, intermediate, and high quality with summated IQ-SCA/D scores of ≤11, 12 to 16, and ≥17, respectively. Interrater agreement was "substantial" between all 3 observers for summated IQ-SCA/D scores and study categorization.

CONCLUSIONS

The IQ-SCA/D is an expert consensus tool for assessing the study quality of research reporting the incidence of SCA/D in athletes. This tool may be used to assist researchers, reviewers, journal editors, and readers in contextualizing the methodological quality of different studies with varying athlete SCA/D incidence estimates. Importantly, the IQ-SCA/D also provides an expert-informed framework to support and guide appropriate design and reporting practices in future SCA/D incidence trials.

2024 HRS expert consensus statement on arrhythmias in the athlete: Evaluation, treatment, and return to play

Youth and adult participation in sports continues to increase, and athletes may be diagnosed with potentially arrhythmogenic cardiac conditions. This international multidisciplinary document is intended to guide electrophysiologists, sports cardiologists, and associated health care team members in the diagnosis, treatment, and management of arrhythmic conditions in the athlete with the goal of facilitating return to sport and avoiding the harm caused by restriction. Expert, disease-specific risk assessment in the context of athlete symptoms and diagnoses is emphasized throughout the document. After appropriate risk assessment, management of arrhythmias geared toward return to play when possible is addressed. Other topics include shared decision-making and emergency action planning. The goal of this document is to provide evidence-based recommendations impacting all areas in the care of athletes with arrhythmic conditions. Areas in need of further study are also discussed.

Can we screen for heart disease in children at public health centres? A multicentre observational study of screening for heart disease with a risk of sudden death in children

Sudden cardiac death in children is a rare event, but of great social significance. Generally, it is related to heart disease with a risk of sudden cardiac death (SCD), which may occur with cardiovascular symptoms and/or electrocardiographic markers; thus, a primary care paediatrician (PCP) could detect them. Therefore, we proposed a study that assesses how to put into practice and conduct a cardiovascular assessment within the routine healthy-child check-ups at six and twelve years of age; that reflects cardiovascular signs and symptoms, as well as the electrocardiographic alterations that children with a risk of SCD in the selected population present; and that assesses the PCP's skill at electrocardiogram (ECG) interpretation. In collaboration with PCPs, primary care nurses, and paediatric cardiologists, an observational, descriptive, multicentre, cross-sectional study was carried out in the Balearic Islands (Spain), from April 2021 to January 2022, inclusive. The PCPs gathered patient data through forms (medical record, electrocardiogram, and physical examination) and sent them to the investigator, together with the informed consent document and electrocardiogram. The investigator passed the electrocardiogram on to the paediatric cardiologists for reading, in an identical form to those the paediatricians had filled in. The variables were collected, and a descriptive analysis performed. Three paediatric cardiologists, twelve PCPs, and nine nurses from seven public health centres took part. They collected the data from 641 patients, but 233 patients did not participate (in 81.11% due to the PCP's workload). Therefore, the study coverage was around 64%, representing the quotient of the total number of patients who participated, divided by the total number of patients who were eligible for the study. We detected 30 patients with electrocardiographic alterations compatible with SCD risk. Nine of these had been examined by a paediatric cardiologist at some time (functional murmur in 8/9), five had reported shortness of breath with exercise, and four had reported a family history of sudden death. The physical examination of all the patients whose ECG was compatible with a risk of SCD was normal. Upon analysing to what extent the ECG results of the PCP and the paediatric cardiologist agreed, the percentage of agreement in the final interpretation (normal/altered) was 91.9%, while Cohen's kappa coefficient was 31.2% (CI 95%: 13.8-48.6%). The sensitivity of the ECG interpretation by the PCP to detect an ECG compatible with a risk of SCD was 29% and the positive predictive value 45%.     Conclusions: This study lays the foundations for future SCD risk screening in children, performed by PCPs. However, previously, it would be important to optimise their training in reading and interpreting paediatric ECGs. What is Known: • In Spain at present, there is a programme in place to detect heart disease with a risk of sudden death [1], but it targets only children who are starting on or are doing a physical activity as a federated sport. Implementing such screening programmes has proven effective in several countries [2]. However, several studies showed that the incidence of sudden cardiac death is no higher in children competing in sport activities than in those who do not do any sport [3]. This poses an ethical conflict, because at present, children who do not do any federated sport are excluded from screening. According to the revised literature, so far, only in two studies did they screen the child population at schools, and in both, they successfully detected patients with heart disease associated to the risk of sudden death [4, 5]. We have found no studies where the screening of these features was included within the routine healthy-child check-ups by primary care paediatricians. What is New: • We did not know whether-in our setting, at present-the primary care paediatrician could perform a screening method within the routine healthy-child check-ups, in order to detect presumably healthy children at risk of sudden cardiac death, as they present one of the SCD risks. In this regard, we proposed our project: to assess how to put into practice and conduct a cardiovascular assessment via SCD risk screening in the healthy child population by primary care paediatricians and appraise primary care paediatricians' skills in identifying the electrocardiographic alterations associated with SCD risk. The ultimate intention of this pilot study was to make it possible, in the future, to design and justify a study aimed at universalising cardiovascular screening and achieving a long-term decrease in sudden cardiac death events in children.

Current landscape in US schools for bystander CPR training and AED requirements

BACKGROUND

Out-of-hospital cardiac arrest is a public health crisis affecting about 356,000 adults and 23,000 children annually in the US with 90% fatality. Early bystander CPR and AED application improve survival. Less than 3% of the US population is CPR trained annually. Since 20% of the US population is at school daily, these represent ideal places to target CPR training. Having standardized state school CPR and AED laws will help with training.

METHODS

We performed a systemic search of the state-specific laws for school AED and CPR requirements within the US. We used PubMed and Google search using keywords: school CPR mandates, US laws for CPR in schools, US state laws for AED implementation, and gaps in US school CPR and AED. We searched for mandates for schools in other countries for comparison.

RESULTS

The state laws for CPR training for high school graduation and AED requirements in US. schools are highly variable, and funding for AEDs is inadequate, especially in schools in lower socio-economic zip codes. Recent AED legislative efforts focus mainly on athletic areas and don't adequately address school size, number of buildings, non-athletic areas, and engagement of student-led advocacy efforts.

CONCLUSION

To improve OHCA survival, we identified potential solutions to consolidate efforts and overcome the barriers-standardize state laws, involve student bodies, increase funding, and allocate appropriate resources. The CPR/AED education needs to start earlier in schools and be part of the standard curriculum rather than implemented as a stopgap check-box mandate.

Sudden Cardiac Death in Athletes: Facts and Fallacies

The benefits of exercise for cardiovascular and general health are many. However, sudden cardiac death (SCD) may occur in apparently healthy athletes who perform at the highest levels. A diverse spectrum of diseases is implicated in SCD in athletes, and while atherosclerotic coronary artery disease predominates in individuals of >35 years of age, primary cardiomyopathies and ion channelopathies are prevalent in young individuals. Prevention of SCD in athletes relies on the implementation of health policies aimed at the early identification of arrhythmogenic diseases (such as cardiac screening) and successful resuscitation (such as widespread utilization of automatic external defibrillators and training members of the public on cardiopulmonary resuscitation). This review will focus on the epidemiology and aetiologies of SCD in athletes, and examine fallacies in the approach to this controversial field. Furthermore, potential strategies to prevent these tragic events will be discussed, analysing current practice, gaps in knowledge and future directions.

Incidence and Causes of Sudden Cardiac Death in Athletes

Sudden cardiac death (SCD) is the leading cause of medical death in athletes; however, many studies are significantly flawed making an accurate estimation of risk difficult. Incidence studies need to have accurate case ascertainment, a defined study population, and should be stratified by both sex and age. The risk of SCA/d in college-aged males is 1 in 35,000 person-years, black males 1 in 18,000 person-years, and higher-risk sports include men's basketball, men's soccer, and American football. Inherited cardiomyopathies and electrical conditions account for ∼ 2/3 of off SCA/d and can be detected with an ECG. More research is needed to provide more granular estimates.

ECG evaluation in 11 949 Italian teenagers: results of screening in secondary school

AIM

There is lack of evidence regarding the screening role of ECG for sudden cardiac death (SCD) prevention. Our aim was to evaluate the prevalence of ECG abnormalities among teenagers according to sport participation and competitive status.

METHODS

Eleven thousand nine hundred and forty-nine Italian pupils from 179 secondary schools (13-19 years) were consecutively enrolled. ECG abnormalities were divided into minor and major. Medical history, clinical examination and sport activity information were acquired. Further evaluations were suggested in case of major ECG abnormalities. Follow-up was performed at 2 years.

RESULTS

N = 1945 (16%) pupils had ECG abnormalities. Major ECG abnormalities were detected in 13% of the cohort, minor in 34%. ECG abnormalities were more common in nonathletes compared with athletes. A diagnosis of cardiac disease was reached in 25 (1.6%) of the pupils with major ECG abnormalities.

CONCLUSION

ECG abnormalities are common among young populations and more prevalent in nonathletes. Among pupils with major ECG abnormalities 1.6% had a cardiac disease diagnosis. Our results are in line with the data supporting ECG screening in the general young population.

Reducing Barriers to Optimal Automated External Defibrillator Use: An Elementary School Intervention Study

Background

Timely use of an automated external defibrillator (AED) improves outcomes in sudden cardiopulmonary arrest (SCA). Our project aims were to: 1) identify the barriers to optimal AED use in the Québec City area elementary schools; 2) create targeted educational material regarding AEDs; and 3) measure the impact of the teaching module.

Methods

Using a quality improvement in health-care framework, a survey exploring the barriers to AED use was sent to 139 elementary schools. We then developed a video teaching module on using AEDs to address these barriers. A convenience sample of 92 elementary school professionals participated in a mock scenario. Metrics related to AED use were assessed at baseline and after completing the post-teaching module. The primary outcome was the time to first shock and secondary outcomes consisted of evaluating the completion of each step required for safe and effective AED use.

Results

The barrier analysis survey received a response rate of 52.5%. Most schools reported having an AED (95%), but 48.6% indicated that no formal training was offered. After the teaching module, the appropriate use of the AED in an SCA simulation improved from 53% to 92% (P < 0.001). The average time elapsed before first shock was 66 (95% confidence interval [CI], 63-70) seconds at baseline compared with 47 (95% CI, 45-49) seconds post-teaching module (P < 0.001).

Conclusions

Lack of training, the main barrier to optimal use of AEDs in elementary schools, can be addressed through a brief video teaching module, thus improving the ability to deliver timely and effective defibrillation.

Causes of sudden cardiac death in young athletes and non-athletes: systematic review and meta-analysis: Sudden cardiac death in the young

INTRODUCTION

The etiology of sudden cardiac death (SCD) in young people continues to attract much attention. This meta-analysis aimed to identify the most frequent causes of SCD in individuals aged ≤35 years, the differences between athletes and non-athletes and geographic areas.

METHODS

Studies published between 01/01/1990 and 01/31/2020 and evaluating post-mortem the aetiology of SCD in young individuals (≤35 years) were included. Individuals were divided into athletes and non-athletes. Studies that did not report separate data between athletes and non-athletes were excluded.

RESULTS

Thirty-four studies met the inclusion criteria, and a total population of 5,060 victims of SCD were analyzed (2,890 athletes, 2,170 non-athletes). Comparing the causes of SCD between athletes and non-athletes, non-ischemic left ventricular scar (NILVS) (5.1% vs. 1.1%, p=0.01) was more frequent in the former, while coronary artery disease (CAD) (19.6% vs. 9.1%, p=0.009), arrhythmogenic cardiomyopathy (ACM) (11.5% vs. 4.7%, p=0.03) and channelopathies (8.4% vs. 1.9%, p=0.02) were more frequent in the latter. In studies published in the last decade, hypertrophic cardiomyopathy (HCM) (p=0.002), dilated cardiomyopathy (p=0.047), and anomalous origin of coronary arteries (AOCA) (p=0.009) were more frequently the causes of SCD in athletes while aortic dissection (0.022) was the cause in non-athletes. HCM (p=0.01) and AOCA (p=0.004) were more frequently the causes of SCD in the US while ACM (p=0.001), structurally normal heart (p=0.02), and channelopathies (p=0.02) were more frequent in Europe.

CONCLUSIONS

Among the causes of SCD, NILVS was the more frequent cause in athletes, while CAD, ACM and channelopathies were more frequent causes in non-athletes. The causes of SCD differ between the US and Europe.

Incidence of sudden cardiac arrest and death in young athletes and military members: a systematic review and meta-analysis

OBJECTIVES

The goals of this review are to evaluate the quality of the evidence on the incidence of sudden cardiac arrest and death (SCA/D) in athletes and military members; and to estimate annual incidence of SCA/D.

DATA SOURCES

MEDLINE, Embase, Cochrane CENTRAL, Web of Science, BIOSIS, Scopus, SPORT discus, PEDro, and clinicaltrials.gov were searched from inception to dates between 2/21/19-7/29/19.

STUDY SELECTION

Studies which reported incidence of SCA/D or both in athletes, or military members under age 40 were eligible for inclusion. 40 studies were identified for inclusion Data Extraction: Risk of bias was assessed using a validated, customized tool for prevalence studies in all included studies. 12 were found to be low ROB, with the remaining 28 moderate or high ROB. Data was extracted for narrative review, and meta-analysis.

DATA SYNTHESIS

Random-effects meta-analysis was performed in studies judged to be low risk of bias in two separate categories: 5 studies on regional or national level data including athletes at all levels, and both sexes included 130 events of SCD, with a total of 11,272,560 athlete years showing a cumulative incidence rate of 0.98 [95%CI: 0.62, 1.53] per 100,000 athlete years, with high heterogeneity with I2 of 78%; 3 Studies on competitive athletes aged 14 to 25 were combined, and included 183 events, and 17,798758 athlete years showing an incidence rate of 1.91[95%CI: 0.71; 5.14] per 100,000 athlete years with high heterogeneity with I2 of 97%. The remaining low risk of bias studies were in military members, and were not synthesized.

CONCLUSION

The worldwide incidence of SCD is a rare event. Low risk of bias studies indicate incidence to be below 2 per 100,000 athlete years. Overall, the quality of the evidence available is low, but there are high quality individual studies to inform the question of incidence levels. PROSPERO Registration: CRD42019125560.

Clinical Findings and Diagnostic Yield of Arrhythmogenic Cardiomyopathy Through Genomic Screening of Pathogenic or Likely Pathogenic Desmosome Gene Variants

BACKGROUND

Genomic screening holds great promise for presymptomatic identification of hidden disease, and prevention of dramatic events, including sudden cardiac death associated with arrhythmogenic cardiomyopathy (ACM). Herein, we present findings from clinical follow-up of carriers of ACM-associated pathogenic/likely pathogenic desmosome variants ascertained through genomic screening.

METHODS

Of 64 548 eligible participants in Geisinger MyCode Genomic Screening and Counseling program (2015-present), 92 individuals (0.14%) identified with pathogenic/likely pathogenic desmosome variants by clinical laboratory testing were referred for evaluation. We reviewed preresult medical history, patient-reported family history, and diagnostic testing results to assess both arrhythmogenic right ventricular cardiomyopathy and left-dominant ACM.

RESULTS

One carrier had a prior diagnosis of dilated cardiomyopathy with arrhythmia; no other related diagnoses or diagnostic family history criteria were reported. Fifty-nine carriers (64%) had diagnostic testing in follow-up. Excluding the variant, 21/59 carriers satisfied at least one arrhythmogenic right ventricular cardiomyopathy task force criterion, 11 (52%) of whom harbored DSP variants, but only 5 exhibited multiple criteria. Six (10%) carriers demonstrated evidence of left-dominant ACM, including high rates of atypical late gadolinium enhancement by magnetic resonance imaging and nonsustained ventricular tachycardia. Two individuals received new cardiomyopathy diagnoses and received defibrillators for primary prevention.

CONCLUSIONS

Genomic screening for pathogenic/likely pathogenic variants in desmosome genes can uncover both left- and right-dominant ACM. Findings of overt cardiomyopathy were limited but were most common in DSP-variant carriers and notably absent in PKP2-variant carriers. Consideration of the pathogenic/likely pathogenic variant as a major criterion for diagnosis is inappropriate in the setting of genomic screening.

Diagnostic yield and financial implications of a nationwide electrocardiographic screening programme to detect cardiac disease in the young

Aims

There is limited information on the role of screening with electrocardiography (ECG) for identifying cardiovascular diseases associated with sudden cardiac death (SCD) in a non-select group of adolescents and young adults in the general population.

Methods and results

Between 2012 and 2014, 26 900 young individuals (aged 14–35 years) were prospectively evaluated with a health questionnaire and ECG. Individuals with abnormal results underwent secondary investigations, the costs of which were being based on the UK National Health Service tariffs. Six hundred and seventy-five (2.5%) individuals required further investigation for an abnormal health questionnaire, 2175 (8.1%) for an abnormal ECG, and 114 (0.5%) for both. Diseases associated with young SCD were identified in 88 (0.3%) individuals of which 15 (17%) were detected with the health questionnaire, 72 (81%) with ECG and 2 (2%) with both. Forty-nine (56%) of these individuals received medical intervention beyond lifestyle modification advice in the follow-up period of 24 months. The overall cost of the evaluation process was €97 per person screened, €17 834 per cardiovascular disease detected, and €29 588 per cardiovascular disease associated with SCD detected. Inclusion of ECG was associated with a 36% cost reduction per diagnosis of diseases associated with SCD compared with the health questionnaire alone.

Conclusion

The inclusion of an ECG to a health questionnaire is associated with a five-fold increase in the ability to detect disease associated with SCD in young individuals and is more cost effective for detecting serious disease compared with screening with a health questionnaire alone.

Availability and Utilization of Automated External Defibrillators in New York State Schools

Background: Use of automated external defibrillators (AEDs) in out-of-hospital cardiac arrests (OHCAs) improve survival. Professional health organizations recommend that AEDs be available in crowded places, including schools but currently only 18 US states require them. Sudden cardiac arrest (SCA) research in the school-age population has largely focused on school sub-groups, leaving out the majority of US students and adults working in schools. New York State (NYS) has one of the largest student populations in the US. Our objective was to gain epidemiologic data on SCA across a variety of school levels and examine the availability and utilization of AEDs in a state that requires them. Methods: This was an observational, cross-sectional study utilizing an electronic survey. We included NYS school nurses and collected electronic surveys in January-March, 2018. We analyzed demographic data of school characteristics, SCA occurrences and AED use and availability. Results: Of 876 respondents (36.1% response rate), 71 (8.2%) reported SCAs, with 41 occurring in adults. AEDs were deployed in 59 of 71 (84.3%) events, 40 individuals had long-term survival. Most SCAs occurred in middle-schools. School size or number of AEDs/school had no bearing on short-term or long-term survival. AEDs were widely available in private schools, though this was not required by state law. Conclusions: Our data suggest a need for more comprehensive examination of SCA in US schools. Research comparing the availability and utilization of school AEDs between states that do and do not require them is needed and may have important clinical and policy implications for SCA emergency preparedness in US schools.

Incidence of sudden cardiac death in the young: a systematic review

OBJECTIVE

To summarise studies describing incidence of sudden cardiac death in a general population of young individuals to inform screening policy.

DESIGN

Systematic review.

DATA SOURCES

Database searches of MEDLINE, EMBASE and the Cochrane library (all inception to current) on 29 April 2019 (updated 16 November 2019), and forward/backward citation tracking of eligible studies.

STUDY ELIGIBILITY CRITERIA

All studies that reported incidence of sudden cardiac death in young individuals (12-39 years) in a general population, with no restriction on language or date. Planned subgroups were incidence by age, sex, race and athletic status (including military personnel).

DATA EXTRACTION

Two reviewers independently assessed study eligibility, extracted study data and assessed risk of bias using the Joanna Briggs Institute critical appraisal checklist for prevalence studies.

ANALYSIS

Reported incidence of sudden cardiac death in the young per 100 000 person-years.

RESULTS

38 studies that reported incidence across five continents. We identified substantial heterogeneity in population, sudden cardiac death definition, and case ascertainment methods, precluding meta-analysis. Median reported follow-up years was 6.97 million (IQR 2.34 million-23.70 million) and number of sudden cardiac death cases was 64 (IQR 40-251). In the general population, the median of reported incidence was 1.7 sudden cardiac death per 100 000 person-years (IQR 1.3-2.6, range 0.75-11.9). Most studies (n=14, 54%) reported an incidence between one and two cases per 100 000 person-years. Incidence was higher in males and older individuals.

CONCLUSIONS

This systematic review identified variability in the reported incidence of sudden cardiac death in the young across studies. Most studies reported an incidence between one and two cases per 100 000 person-years.

PROSPERO REGISTRATION NUMBER

CRD42019120563.

Current controversies in pre-participation cardiovascular screening for young competitive athletes

INTRODUCTION

Pre-participation cardiovascular screening (PPCS) in athletes is recommended by numerous medical and sporting societies. While there is consensus that young athletes should be screened prior to participation in competitive sports, there are on-going debates regarding the true incidence of sudden cardiac death (SCD), the most frequent causes of SCD, and the optimal methods for PPCS.

AREAS COVERED

This review focuses on the current evidence for the incidence of SCD, causes of SCD, and the pros and cons of a history and physical exam (H&P) and electrocardiogram (ECG) in PPCS of young competitive athletes.

EXPERT OPINION

With significant controversy surrounding PPCS in athletes, a large-randomized trial powered for mortality is needed to assess the utility of PPCS and to define the optimal screening methods to detect cardiovascular diseases that may lead to SCD in competitive athletes. Until a trial of this caliber is created, controversy will remain and heterogeneity in care will exist. Future research should also define the optimal timing and frequency of PPCS given age-related penetrance of certain diseases, create evidence-based history questionnaires, continue to optimize ECG screening criteria, and create more learning modules for ECG interpretation in athletes.

Exercise-Related Acute Cardiovascular Events and Potential Deleterious Adaptations Following Long-Term Exercise Training: Placing the Risks Into Perspective-An Update: A Scientific Statement From the American Heart Association

Epidemiological and biological plausibility studies support a cause-and-effect relationship between increased levels of physical activity or cardiorespiratory fitness and reduced coronary heart disease events. These data, plus the well-documented anti-aging effects of exercise, have likely contributed to the escalating numbers of adults who have embraced the notion that "more exercise is better." As a result, worldwide participation in endurance training, competitive long distance endurance events, and high-intensity interval training has increased markedly since the previous American Heart Association statement on exercise risk. On the other hand, vigorous physical activity, particularly when performed by unfit individuals, can acutely increase the risk of sudden cardiac death and acute myocardial infarction in susceptible people. Recent studies have also shown that large exercise volumes and vigorous intensities are both associated with potential cardiac maladaptations, including accelerated coronary artery calcification, exercise-induced cardiac biomarker release, myocardial fibrosis, and atrial fibrillation. The relationship between these maladaptive responses and physical activity often forms a U- or reverse J-shaped dose-response curve. This scientific statement discusses the cardiovascular and health implications for moderate to vigorous physical activity, as well as high-volume, high-intensity exercise regimens, based on current understanding of the associated risks and benefits. The goal is to provide healthcare professionals with updated information to advise patients on appropriate preparticipation screening and the benefits and risks of physical activity or physical exertion in varied environments and during competitive events.

Prevalence and Electronic Health Record-Based Phenotype of Loss-of-Function Genetic Variants in Arrhythmogenic Right Ventricular Cardiomyopathy-Associated Genes

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with variants in desmosome genes. Secondary findings of pathogenic/likely pathogenic variants, primarily loss-of-function (LOF) variants, are recommended for clinical reporting; however, their prevalence and associated phenotype in a general clinical population are not fully characterized.

METHODS

From whole-exome sequencing of 61 019 individuals in the DiscovEHR cohort, we screened for putative loss-of-function variants in PKP2, DSC2, DSG2, and DSP. We evaluated measures from prior clinical ECG and echocardiograms, manually over-read to evaluate ARVC diagnostic criteria, and performed a PheWAS (phenome-wide association study). Finally, we estimated expected penetrance using Bayesian inference.

RESULTS

One hundred forty individuals (0.23%; 59±18 years old at last encounter; 33% male) had an ARVC variant (G⁺). None had an existing diagnosis of ARVC in the electronic health record, nor significant differences in prior ECG or echocardiogram findings compared with matched controls without variants. Several G⁺ individuals satisfied major repolarization (n=4) and ventricular function (n=5) criteria, but this prevalence matched controls. PheWAS showed no significant associations of other heart disease diagnoses. Combining our best genetic and disease prevalence estimates yields an estimated penetrance of 6.0%.

CONCLUSIONS

The prevalence of ARVC loss-of-function variants is ≈1:435 in a general clinical population of predominantly European descent, but with limited electronic health record-based evidence of phenotypic association in our population, consistent with a low penetrance estimate. Prospective deep phenotyping and longitudinal follow-up of a large sequenced cohort is needed to determine the true clinical relevance of an incidentally identified ARVC loss-of-function variant.

Canadian Cardiovascular Society Cardiovascular Screening of Competitive Athletes: The Utility of the Screening Electrocardiogram to Predict Sudden Cardiac Death

Prevention of sudden cardiac arrest/death (SCA/D) among athletes is a universal goal, although the optimal strategy for its achievement is controversial, with the inclusion of the 12-lead electrocardiogram (ECG) at the center of the debate. The ECG exhibits superior sensitivity over history and physical examination to detect conditions associated with SCA/D. However, the identification of disease does not necessarily lead to a significant reduction in SCA/D. The "Canadian Cardiovascular Society/Canadian Heart Rhythm Society Joint Position Statement on the Cardiovascular Screening of Competitive Athletes" recommended against the routine performance of an ECG for the initial cardiovascular screening of competitive athletes. The incidence of SCA/D among athletes (<35 years of age), the risk of SCA/D during sport participation among individuals with abnormalities found on screening ECG, the efficacy of the ECG to identify conditions associated with SCA/D, and the positive predictive value of an abnormal ECG to predict SCA/D are critically examined. This review presents the evidence informing the panel's recommendation.

There is No Reason to Adopt ECG s and Abandon American Heart Association/American College of Cardiology History and Physical Screening for Detection of Cardiovascular Disease in the Young

See Article Williams et al.

Usefulness of Focused Screening Echocardiography for Collegiate Athletes

Sudden cardiac death in a young healthy athlete is a rare but catastrophic event. The American Heart Association preparticipation screening guidelines recommend a focused history and physical without routine imaging or electrocardiogram screening. We hypothesized that a focused echocardiogram can identify structural abnormalities that may lead to sudden cardiac death in athletes, which might otherwise go undetected by history and physical. We retrospectively reviewed the charts of all incoming collegiate athletes at a single university from 2005 to 2013, all of whom had undergone a focused, 5-minute echocardiogram along with a guideline-based preparticipation history and physical (PPS H&P). Abnormal findings prompted further testing or referral. We report the prevalence of abnormal findings and the relation between an abnormal PPS H&P and screening echocardiogram. A total of 2,898 athletes were screened and 159 (5%) had findings. Forty athletes underwent further testing and evaluation. Of these athletes, 3 had newly diagnosed abnormalities that warranted restriction of participation: 1 apical-variant hypertrophic cardiomyopathy, 1 large bidirectional atrial septal defect with right ventricular dysfunction, and 1 dilated ascending aorta. Two of these athletes had a normal PPS H&P. Conversely, of the 661 athletes with an abnormal PPS H&P, only 1 (0.15%) had an abnormal screening echocardiogram. In conclusion, although the overall number was low, the 5-minute screening echocardiogram detected athletes at risk for sudden cardiac death not discovered on PPS H&P.

Diagnosis and Prognosis in Sudden Cardiac Arrest Survivors Without Coronary Artery Disease: Utility of a Clinical Approach Using Cardiac Magnetic Resonance Imaging

BACKGROUND

Determining the pathogenesis of sudden cardiac arrest or periarrest without significant coronary artery disease is crucial for management and prognosis. Cardiovascular magnetic resonance (CMR) can detect morphological, functional, or tissue abnormalities, and we sought to evaluate the role of CMR in determining sudden cardiac arrest pathogenesis and prognosis in survivors.

METHODS AND RESULTS

We retrospectively reviewed cardiac investigations and clinical outcomes in consecutive survivors of potentially fatal arrhythmias without coronary artery disease admitted to our institutions from 2008 to 2014. After coronary angiography and echocardiography, all underwent CMR and, when indicated, electrophysiology studies. Major adverse cardiac events (MACE), comprising significant nonfatal ventricular arrhythmia or death, was the primary outcome. Of 164 included subjects (65% men; mean age 48 [18-80] years), CMR contributed to the diagnosis in 80 (49%) and was decisive in 50 cases (30%). Dilated cardiomyopathy (n=27), myocarditis or sarcoidosis (n=22), occult myocardial infarction (n=13), and hypertrophic cardiomyopathy (n=9) were most frequent. Arrhythmic causes were found in 14% while no cause was identified in 36%. MACE occurred in 31% of subjects during a median follow-up of 32 months. MACE associated with presence of a CMR diagnosis, extent of late gadolinium enhancement, and left and right ventricular ejection fractions. Right ventricular ejection fraction was an independent predictor of MACE.

CONCLUSIONS

CMR identified a likely pathogenesis for sudden cardiac arrest in nearly half of survivors in whom coronary artery disease had been excluded. One in 3 subjects had MACE; risk doubled in those with a CMR diagnosis and some CMR parameters-late gadolinium enhancement, left ventricular ejection fraction, and especially right ventricular ejection fraction-associated with prognosis.

Defibrillation for Ventricular Fibrillation: A Shocking Update

Cardiac arrest is defined as the termination of cardiac activity associated with loss of consciousness, of spontaneous breathing, and of circulation. Sudden cardiac arrest and sudden cardiac death (SCD) are terms often used interchangeably. Most patients with out-of-hospital cardiac arrest have shown coronary artery disease or symptoms during the hour before the event. Cardiac arrest is potentially reversible by cardiopulmonary resuscitation, defibrillation, cardioversion, cardiac pacing, or treatments targeted at the underlying disease (e.g., acute coronary occlusion). We restrict SCD hereafter to cardiac arrest due to ventricular fibrillation, including rhythms shockable by an automatic external defibrillator (AED), implantable cardioverter-defibrillator (ICD), or wearable cardioverter-defibrillator (WCD). We summarize the state of the art related to defibrillation in treating SCD, including a brief history of the evolution of defibrillation, technical characteristics of modern AEDs, strategies to improve AED access and increase survival, ancillary treatments, and use of ICDs or WCDs.

State Requirements for Automated External Defibrillators in American Schools: Framing the Debate About Legislative Action

Installation of automated external defibrillators (AEDs) in schools has been associated with increased survival after sudden cardiac arrest. An authoritative academic research database was interrogated to identify all current state statutes pertaining to AEDs in schools. As of February 2016, 17 of 50 U.S. states (34%) require AED installation in at least some of their schools; the remaining states have no legislation. However, requirements are far from comprehensive in these 17 states. Only 5 states offer unequivocal funding to schools for purchasing AEDs. A minority of U.S. states have legislation requiring AED placement in schools, and even fewer provide funding. State legislatures that have not yet enacted legislation requiring AEDs in schools may look to neighboring states for examples of child and adult lifesaving law. Placement of an AED in schools should be implemented with an emergency response plan that trains staff in the recognition and response to cardiac arrest.

AMSSM Position Statement on Cardiovascular Preparticipation Screening in Athletes: Current Evidence, Knowledge Gaps, Recommendations and Future Directions

Cardiovascular screening in young athletes is widely recommended and routinely performed prior to participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for cardiovascular screening in athletes remains an issue of considerable debate. At the center of the controversy is the addition of a resting electrocardiogram (ECG) to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation cardiovascular screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcomes-based evidence at this time precludes AMSSM from endorsing any single or universal cardiovascular screening strategy for all athletes, including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate cardiovascular screening strategy unique to their athlete population, community needs, and resources. The decision to implement a cardiovascular screening program, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physician's assessment in the context of an emerging evidence-base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. AMSSM is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.

Demographics and Epidemiology of Sudden Deaths in Young Competitive Athletes: From the United States National Registry

BACKGROUND

Sudden deaths in young competitive athletes are tragic events, with high public visibility. The importance of race and gender with respect to sport and the diagnosis and causes of sudden death in athletes has generated substantial interest.

METHODS

The US National Registry of Sudden Death in Athletes, 1980-2011, was accessed to define the epidemiology and causes of sudden deaths in competitive athletes. A total of 2406 deaths were identified in young athletes aged 19 ± 6 years engaged in 29 diverse sports.

RESULTS

Among the 842 athletes with autopsy-confirmed cardiovascular diagnoses, the incidence in males exceeded that in females by 6.5-fold (1:121; 691 vs 1:787,392 athlete-years; P ≤.001). Hypertrophic cardiomyopathy was the single most common cause of sudden death, occurring in 302 of 842 athletes (36%) and accounting for 39% of male sudden deaths, almost 4-fold more common than among females (11%; P ≤.001). More frequent among females were congenital coronary artery anomalies (33% vs 17% of males; P ≤.001), arrhythmogenic right ventricular cardiomyopathy (13% vs 4%; P = .002), and clinically diagnosed long QT syndrome (7% vs 1.5%; P ≤.002). The cardiovascular death rate among African Americans/other minorities exceeded whites by almost 5-fold (1:12,778 vs 1:60; 746 athlete-years; P <.001), and hypertrophic cardiomyopathy was more common among African Americans/other minorities (42%) than in whites (31%; P ≤.001). Male and female basketball players were 3-fold more likely to be African American/other minorities than white.

CONCLUSIONS

Within this large forensic registry of competitive athletes, cardiovascular sudden deaths due to genetic and/or congenital heart diseases were uncommon in females and more common in African Americans/other minorities than in whites. Hypertrophic cardiomyopathy is an under-appreciated cause of sudden death in male minority athletes.

Cardiac Troponin and Tropomyosin: Structural and Cellular Perspectives to Unveil the Hypertrophic Cardiomyopathy Phenotype

Inherited myopathies affect both skeletal and cardiac muscle and are commonly associated with genetic dysfunctions, leading to the production of anomalous proteins. In cardiomyopathies, mutations frequently occur in sarcomeric genes, but the cause-effect scenario between genetic alterations and pathological processes remains elusive. Hypertrophic cardiomyopathy (HCM) was the first cardiac disease associated with a genetic background. Since the discovery of the first mutation in the β-myosin heavy chain, more than 1400 new mutations in 11 sarcomeric genes have been reported, awarding HCM the title of the “disease of the sarcomere.” The most common macroscopic phenotypes are left ventricle and interventricular septal thickening, but because the clinical profile of this disease is quite heterogeneous, these phenotypes are not suitable for an accurate diagnosis. The development of genomic approaches for clinical investigation allows for diagnostic progress and understanding at the molecular level. Meanwhile, the lack of accurate in vivo models to better comprehend the cellular events triggered by this pathology has become a challenge. Notwithstanding, the imbalance of Ca²⁺ concentrations, altered signaling pathways, induction of apoptotic factors, and heart remodeling leading to abnormal anatomy have already been reported. Of note, a misbalance of signaling biomolecules, such as kinases and tumor suppressors (e.g., Akt and p53), seems to participate in apoptotic and fibrotic events. In HCM, structural and cellular information about defective sarcomeric proteins and their altered interactome is emerging but still represents a bottleneck for developing new concepts in basic research and for future therapeutic interventions. This review focuses on the structural and cellular alterations triggered by HCM-causing mutations in troponin and tropomyosin proteins and how structural biology can aid in the discovery of new platforms for therapeutics. We highlight the importance of a better understanding of allosteric communications within these thin-filament proteins to decipher the HCM pathological state.

AMSSM Position Statement on Cardiovascular Preparticipation Screening in Athletes: Current evidence, knowledge gaps, recommendations and future directions

Cardiovascular screening in young athletes is widely recommended and routinely performed prior to participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for cardiovascular screening in athletes remains an issue of considerable debate. At the centre of the controversy is the addition of a resting ECG to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation cardiovascular screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcome-based evidence at this time precludes AMSSM from endorsing any single or universal cardiovascular screening strategy for all athletes, including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate cardiovascular screening strategy unique to their athlete population, community needs and resources. The decision to implement a cardiovascular screening programme, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physician's assessment in the context of an emerging evidence base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. AMSSM is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.