Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program

Sudden cardiac death in athletes: where do we stand

We aimed to review the literature to explore the magnitude of sudden cardiac death (SCD) in young athletes. Although SCD in athletes is not a common event, it represents a tragedy of the apparently fit young population. SCD varies according to countries, age groups, and sex. In addition, it varies in the underlying causes and the screening tool. Therefore, we are in need for further research efforts. Guidelines, public and physician awareness, and education regarding the warning signs are integral part in the strategy to reduce SCD tragedy. However, all these requirements raise concern for cost-effectiveness in some countries for proper implementation.

Exercise increases age-related penetrance and arrhythmic risk in arrhythmogenic right ventricular dysplasia/cardiomyopathy-associated desmosomal mutation carriers

OBJECTIVES

This study sought to determine how exercise influences penetrance of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) among patients with desmosomal mutations.

BACKGROUND

Although animal models and anecdotal evidence suggest that exercise is a risk factor for ARVD/C, there have been no systematic human studies.

METHODS

Eighty-seven carriers (46 male; mean age, 44 ± 18 years) were interviewed about regular physical activity from 10 years of age. The relationship of exercise with sustained ventricular arrhythmia (ventricular tachycardia/ventricular fibrillation [VT/VF]), stage C heart failure (HF), and meeting diagnostic criteria for ARVD/C (2010 Revised Task Force Criteria [TFC]) was studied.

RESULTS

Symptoms developed in endurance athletes (N = 56) at a younger age (30.1 ± 13.0 years vs. 40.6 ± 21.1 years, p = 0.05); they were more likely to meet TFC at last follow-up (82% vs. 35%, p < 0.001) and have a lower lifetime survival free of VT/VF (p = 0.013) and HF (p = 0.004). Compared with those who did the least exercise per year (lowest quartile) before presentation, those in the second (odds ratio [OR]: 6.64, p = 0.013), third (OR: 16.7, p = 0.001), and top (OR: 25.3, p < 0.0001) quartiles were increasingly likely to meet TFC. Among 61 individuals who did not present with VT/VF, the 13 subjects experiencing a first VT/VF event over a mean follow-up of 8.4 ± 6.7 years were all endurance athletes (p = 0.002). Survival from a first VT/VF event was lowest among those who exercised most (top quartile) both before (p = 0.036) and after (p = 0.005) clinical presentation. Among individuals in the top quartile, a reduction in exercise decreased VT/VF risk (p = 0.04).

CONCLUSIONS

Endurance exercise and frequent exercise increase the risk of VT/VF, HF, and ARVD/C in desmosomal mutation carriers. These findings support exercise restriction for these patients.

Incidence of sudden cardiac death in Minnesota high school athletes 1993-2012 screened with a standardized pre-participation evaluation

OBJECTIVES

This study sought to determine the incidence of sudden cardiac death (SCD) during Minnesota State High School League (MSHSL) games and practices for high school (HS) athletes (12 to 19 years of age, with most age 15 to 18 years of age) using a uniform statewide pre-participation health screening examination (PPE) form every 3 years on a defined population across 19 academic years.

BACKGROUND

Adding electrocardiographic screening is being considered by some to reduce cardiac death rates in athletes, but the death rates in defined groups screened by the current U.S. PPE recommendations are unknown.

METHODS

MSHSL participation records were surveyed to determine the number of unduplicated athletes for 1993/1994 through 2011/2012 academic years, and catastrophic insurance records were used to find cardiac deaths.

RESULTS

There were 4 SCDs (2 cross country, 1 basketball, 1 wrestling), all male, during practice or games in 1,666,509 unduplicated athletes participating in ≥ 1 sports. The incidence of SCD in athletes screened every 3 years with a history and physical during MSHSL activities is 0.24 per 100,000 athlete-years over 19 years and 0.11 per 100,000 athlete-years over the past decade.

CONCLUSIONS

The incidence of SCD in athletes screened every 3 years with standard PPE during MSHSL activities is 0.24 per 100,000 athlete-years in 19 academic years. This incidence is much lower than that observed in studies of Division 1 National Collegiate Athletic Association and Italian athletes (ages 18 to 25 and mean age 24 years, respectively). Our data do not warrant screening HS athletes with electrocardiography to prevent SCD episodes. The decision to screen athletes with electrocardiography should consider age, training intensity, and genetic predisposition.

Ventricular mass in relation to body size, composition, and skeletal age in adolescent athletes

OBJECTIVE

To examine the contribution of chronological age (CA), skeletal age (SA), stature, sitting stature, fat-free mass (FFM), and fat mass (FM) to interindividual variability in left ventricular mass (LVM) in male adolescent roller hockey players using allometric models.

DESIGN

Cross sectional.

SETTING

Training and competitive sport during adolescence.

PARTICIPANTS

Seventy-three Portuguese male roller hockey players aged 14.5 to 16.5 years.

INDEPENDENT VARIABLES

Stature, sitting stature, body mass, estimated FM and FFM, and SA assessed by the Fels method.

MAIN OUTCOME MEASURES

Allometric modeling of LVM assessed in accordance with recommendations of the American Society of Echocardiography.

RESULTS

Hockey players (CA: 15.4 ± 0.6 years; SA: 16.4 ± 1.5 years) showed an eccentric remodeling of LV structure within the reference range (ie, 0.24-0.42), a dilated LV chamber, but no LVM increase. Exponents for body size descriptors were 2.69 for stature (R(2) = 27%; P < 0.001), 2.49 for sitting stature (R(2) = 37%; P < 0.001), 0.76 for FFM (R(2) = 31%; P < 0.001), and 0.22 for FM (R(2) = 26%; P < 0.001). The combination of size descriptors with CA and SA increased the explained variance in LVM slightly (26%-45%).

CONCLUSIONS

When stature and FM are used for indexing LVM in a sample of adolescent athletes, biological maturity status should also be considered.

Exercise: friend or foe?

Physical activity and exercise have been associated with reduced cardiovascular risk, morbidity, and mortality, as well as all-cause mortality, both in the general population and in patients with various forms of cardiovascular disease. Increasing amounts of exercise are associated with incremental reductions in mortality, but considerable benefits have been found even with a low level of exercise. Exercise is beneficial for most individuals, but risks exist. Exercise is associated with reduced long-term morbidity and mortality, but acute exercise can transiently increase the risk of fatal or nonfatal cardiovascular events. Although tragic, these events are very rare, and even to some extent preventable with screening programmes. Low-intensity physical activity is important and beneficial to all individuals, including those with a high risk of adverse cardiovascular events. In individuals who are physically fit and who do not have genetic predisposition to, or signs of, cardiovascular disease, the greater the intensity and amount of exercise, the greater the health benefits. Nevertheless, effective strategies to encourage exercise in the population are lacking. A sustained increase in physical activity is likely to require more than individual advice, and needs to include urban planning and possibly even legislation.

Exercise and heart disease: from athletes and arrhythmias to hypertrophic cardiomyopathy and congenital heart disease

The beneficial effects of regular physical activity on cardiovascular health are well established, with convincing evidence of improvements in blood pressure, lipid profile and overall mortality. Conversely, individuals with pre-existing congenital, inherited or acquired heart conditions may experience functional cardiac deterioration or sudden death during even moderate exertion. Exclusion from high-level sporting activity may be mandated in some cases, and pre-participation screening of competitive athletes plays an important role in the identification of such individuals. The issue of screening is complicated by the fact that physiological cardiovascular adaptation in healthy athletes, including modest left ventricular hypertrophy and biventricular cavity dilatation, may create a diagnostic overlap with pathological conditions such as hypertrophic cardiomyopathy. Furthermore, much interest has focused recently on the possibility of irreversible cardiac remodeling in a proportion of veteran endurance athletes, with the potential for arrhythmogenesis and adverse cardiac events.

Prognostic value of cardiovascular magnetic resonance in patients with suspected arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Early recognition and accurate risk stratification are important in the management of arrhythmogenic right ventricular cardiomyopathy (ARVC). Identification of predictors of outcome by cardiovascular magnetic resonance (CMR) in patients undergoing evaluation for ARVC is limited. We investigated the predictive value of morphological abnormalities detected by CMR for major clinical events in patients with suspected ARVC.

METHODS

We performed a longitudinal study on 369 consecutive patients with at least one criterion for ARVC. Abnormal CMR was defined by the presence of one of the following: increased right ventricular (RV) volumes, reduced RV ejection fraction, RV regional wall motion abnormalities, myocardial fatty infiltration, and myocardial fibrosis. The end-point was a composite of cardiac death, sustained ventricular tachycardia, ventricular fibrillation, and appropriate ICD discharge.

RESULTS

Twenty patients met the composite end-point over a mean follow-up of 4.3±1.5 years. An abnormal CMR was an independent predictor of outcomes (p<0.001). The presence of multiple abnormalities heralded a particular high risk of events (HR 23.0, 95% CI 5.7-93.2, p<0.001 for 2 abnormalities; HR 35.8, 95% CI 9.7-132.6, p<0.001 for 3 or more abnormalities). The positive predictive value of an abnormal CMR study was 21.0% for an adverse event, whilst the negative predictive value of a normal CMR study was 98.8% over the follow-up period.

CONCLUSIONS

CMR provides important prognostic information in patients under evaluation for ARVC. A normal study portends a good prognosis. Conversely, the presence of multiple abnormalities identifies a high risk group of patients who may benefit from ICD implantation.

Emergency preparedness in high school-based athletics: a review of the literature and recommendations for sport health professionals

Approximately 7.6 million high school students in the United States participate in sports. Although most sport-related injuries in adolescents are considered minor emergencies, life-threatening illnesses or injuries may occur, such as sudden cardiac arrest, heat stroke, status asthmaticus and exercise-induced asthma, catastrophic brain injuries, cervical spine injuries, heat- and cold-related illness, blunt chest/abdominal injuries, and extremity fractures resulting in compartment syndrome. Emergency preparedness in athletics involves the identification of and planning for medical services to promote the safety of the athlete, to limit injury, and to provide medical care at the site of practice or competition. Several national organizations have published guidelines for emergency preparedness in school-based athletics. Our article reviews guidelines for emergency preparedness put forth by the Sideline Preparedness collaboration (comprised of 6 major professional associations, including the American Academy of Family Physicians, American Academy of Orthopedic Surgeons, American College of Sports Medicine, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, and American Osteopathic Academy of Sports Medicine), the National Athletic Trainers' Association, the American Academy of Pediatrics' Committee on School Health, and the American Heart Association. Additionally, we review published data examining compliance of US high schools with these recommendations for emergency preparedness in school-based athletics, determine deficiencies, and provide recommendations for improvement based on these deficiencies.

Genetics of sudden cardiac death in children and young athletes

Sudden cardiac death is a rare but socially devastating event. The most common causes of sudden cardiac death are congenital electrical disorders and structural heart diseases. The majority of these diseases have an incomplete penetrance and variable expression; therefore, patients may be unaware of their illness. In several cases, physical activity can be the trigger for sudden cardiac death as first symptom. Our purpose is to review the causes of sudden cardiac death in sportive children and young adults and its genetic background. Symptomatic individuals often receive an implantable cardioverter-defibrillator, the preventive treatment for sudden cardiac death in most of cases due to channelopathies, which can become a challenging option in young and active patients. The identification of one of these diseases in asymptomatic patients has similarly a great impact on their everyday life, especially on their ability to undertake competitive physical activities, and the requirement of prophylactic treatment. We review main causes of sudden cardiac death in relation to its genetics and diagnostic work-up

Arrhythmias in athletes: evidence-based strategies and challenges for diagnosis, management, and sports eligibility

Assessment and management of cardiac rhythm disorders in athletes is particularly challenging. An accurate diagnosis and optimal risk-stratification are often limited because of substantial phenotypic overlap between pathological entities and adaptive cardiovascular responses that normally occur in athletes. An accurate diagnosis, however, is particularly important in this population, as 2 competing risks need to be cautiously balanced: the risk of under-diagnosis of an arrhythmogenic substrate that may trigger life-threatening events versus the risk of over-diagnosis that may result in an athlete's improper disqualification. Accordingly, the management of arrhythmias in athletes may pose therapeutic dilemmas, and often differs substantially compared with the general population. In this review, we present the most frequently observed arrhythmias in athletes and briefly discuss their pathophysiologic substrate. We further propose diagnostic and therapeutic strategies based upon current guidelines, official recommendations, and emerging evidence from relevant clinical investigations. We focus particularly on disparities in current guidelines regarding the management of certain rhythm disorders, as these areas of uncertainty may reflect the challenging nature of these disorders and may indicate the need for individualized approaches in every-day clinical practice. A better understanding of the normal electrophysiological responses to chronic exercise, and of the pathophysiological basis and the true clinical significance of arrhythmias in athletes, may enhance decision-making, and may allow for management strategies which more prudently weigh the risk-to-benefit ratio of each approach.

Noninvasive cardiac screening in young athletes with ventricular arrhythmias

The aim of this study was to analyze using noninvasive cardiac examinations a series of young athletes discovered to have ventricular arrhythmias (VAs) during the preparticipation screening program for competitive sports. One hundred forty-five athletes (mean age 17 ± 5 years) were evaluated. The study protocol included electrocardiography (ECG), exercise testing, 2-dimensional and Doppler echocardiography, 24-hour Holter monitoring, signal-averaged ECG, and in selected cases contrast-enhanced cardiac magnetic resonance imaging. Results of ECG were normal in most athletes (85%). VAs were initially detected prevalently during exercise testing (85%) and in the remaining cases on ECG and Holter monitoring. Premature ventricular complexes disappeared during exercise in 56% of subjects. Premature ventricular complexes during Holter monitoring averaged 4,700 per day, predominantly monomorphic (88%), single, and/or in couplets (79%). The most important echocardiographic findings were mitral valve prolapse in 29 patients (20%), congenital heart disease in 4 (3%), and right ventricular regional kinetic abnormalities in 5 (3.5%). On cardiac magnetic resonance imaging, right ventricular regional kinetic abnormalities were detected in 9 of 30 athletes and were diagnostic of arrhythmogenic right ventricular cardiomyopathy in only 1 athlete. Overall, 30% of athletes were judged to have potentially dangerous VAs. In asymptomatic athletes with prevalently normal ECG, most VAs can be identified by adding an exercise test during preparticipation screening. In conclusion, cardiac screening with noninvasive examinations remains a fundamental tool for the identification of a possible pathologic substrate and for the characterization of electrical instability.

Preventing sudden death of athletes with electrocardiographic screening: what is the absolute benefit and how much will it cost?

OBJECTIVES

This study sought to estimate the costs of a national electrocardiographic (ECG) screening of athletes in the United States and the number of lives that would be saved by that program.

BACKGROUND

A single study from Italy suggests that mandatory ECG screening of athletes reduces their risk of sudden cardiac death. Based on that study, ECG screening of athletes is endorsed by the European Society of Cardiology, though not by the American Heart Association. The widespread application of ECG screening remains controversial because the absolute reduction of sudden cardiac death risk provided, and its economic ramifications, have not been studied in detail.

METHODS

A cost-projection model was based on the Italian study, replicating its data in terms of athlete characteristics and physician performance. The size of the screening-eligible population was estimated from data provided by the National Collegiate Athletic Association and the National Federation of State High School Associations. The costs of diagnostic tests were obtained from Medicare reimbursement rates.

RESULTS

A 20-year program of ECG screening of young competitive athletes in the United States would cost between $51 and $69 billion and could be expected to save 4,813 lives. Accordingly, the cost per life saved is likely to range between $10.6 and $14.4 million.

CONCLUSIONS

Our cost-projection model suggests that replicating the Italian strategy of ECG screening in the United States would result in enormous costs per life saved.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is a common inherited cardiovascular disease present in one in 500 of the general population. It is caused by more than 1400 mutations in 11 or more genes encoding proteins of the cardiac sarcomere. Although hypertrophic cardiomyopathy is the most frequent cause of sudden death in young people (including trained athletes), and can lead to functional disability from heart failure and stroke, the majority of affected individuals probably remain undiagnosed and many do not experience greatly reduced life expectancy or substantial symptoms. Clinical diagnosis is based on otherwise unexplained left-ventricular hypertrophy identified by echocardiography or cardiovascular MRI. While presenting with a heterogeneous clinical profile and complex pathophysiology, effective treatment strategies are available, including implantable defibrillators to prevent sudden death, drugs and surgical myectomy (or, alternatively, alcohol septal ablation) for relief of outflow obstruction and symptoms of heart failure, and pharmacological strategies (and possibly radiofrequency ablation) to control atrial fibrillation and prevent embolic stroke. A subgroup of patients with genetic mutations but without left-ventricular hypertrophy has emerged, with unresolved natural history. Now, after more than 50 years, hypertrophic cardiomyopathy has been transformed from a rare and largely untreatable disorder to a common genetic disease with management strategies that permit realistic aspirations for restored quality of life and advanced longevity.

Myocardial bridging: what have we learned in the past and will new diagnostic modalities provide new insights?

The clinical significance of myocardial bridging has been a subject of discussion and controversy since the introduction of coronary arteriography (CAG) in the early 1960s. More recently computed tomography coronary angiography (CTCA) has made it possible to visualise the overlying muscular bands and appears to have a higher sensitivity for detecting myocardial bridging than CAG. Combining CTCA with invasive techniques such as CAG should make it possible to improve our understanding of the pathophysiology of myocardial bridging and to provide answers to hitherto unresolved questions. This paper critically reviews the outcomes of previous studies and defines remaining questions that should be answered to optimise the management of the presumably fast growing number of patients in whom a diagnosis of myocardial bridging has been made.