Each year, two in every 100,000 young athletes succumb to sudden cardiac death, fueling a debate over what constitutes a comprehensive health screening prior to sports participation. A new study by researchers at the Massachusetts General Hospital (MGH) Heart Center found the addition of electrocardiogram (ECG) testing to the standard medical history and physical examination for young athletes may better identify key cardiovascular abnormalities responsible for sports-related sudden death. In their report in the March 2 Annals of Internal Medicine, the researchers concluded that ECG improves the overall sensitivity of cardiovascular prescreenings but is also associated with a significant rate of false positive results.
"Adding ECG to the current standard of care improved the ability to detect underlying heart diseases — including cardiomyopathy and other important causes of sudden cardiac death that were missed by a history and examination alone," said Aaron Baggish, MD, of the MGH Heart Center, the lead author of the study.
Hidden cardiovascular disease is a leading cause of sudden death in young athletes. While the need to prescreen athletes prior to participation is undisputed, practice guidelines for such screenings are not uniform. The American College of Cardiology and American Heart Association (ACC/AHA) recommend athletes undergo a focused medical history and physical examination, while the European Society of Cardiology and the International Olympic Committee advocate the inclusion of a resting ECG in preparticipation screenings. In 1982, the Italian government instituted a national program of mandatory ECG screenings for all athletes under the age of 35, to which it has credited a significant reduction in the incidence of sports-related sudden death.
"One of issues has been a lack of data behind the athletic prescreening debate; it has been driven by opinion and observation," said Baggish. "This is the first prospective trial examining this issue, and the first time scientific data have shown us the strengths and weaknesses of the current standards of care."
This study was conducted over three years and enrolled 510 collegiate athletes at Harvard University. Prior to athletic participation, each individual had a standard medical history and physical evaluation in accordance with the ACC/AHA guidelines. Immediately following this evaluation, each athlete underwent a resting ECG and transthoracic echocardiography (TTE). The TTE found 11 of the athletes had underlying cardiac pathology suggesting valvular heart disease, and three of them had hypertrophic cardiomyopathy or myocarditis, conditions serious enough to require sports restriction. The ECG-integrated screening detected 10 of the 11 athletes with cardiac disease, including all three who required sport restriction. The physical examination and medical history alone diagnosed only 5 of the 11 participants with valvular heart disease and missed two of those with hypertrophic cardiomyopathy or myocarditis.
"These findings raise important concerns about the efficacy of medical history and physical examination health screenings alone, since it is the cardiomyopathies that account for the majority of sport-related sudden deaths," said Baggish. "Doctors who perform preparticipation screening and athletes who participate in this valuable practice should be aware of its advantages and limitations. The overall goal of this study was to provide sound scientific data to assist with future decision making about how to keep athletes safe."
However, the study also had a 16 percent false-positive rate, which complicates the overall findings. Baggish, an instructor in medicine at Harvard Medical School, notes that further long-term study documenting screening findings and the incidence of sports restrictions and sudden death is needed to determine the impact of including ECG on health care cost and patient outcomes.