'Silent Majority' of Young Nonathletes Also at Risk for Sudden Cardiac Death

Deborah Brauser

February 23, 2016

MINNEAPOLIS, MN — High school and college-age students who don't participate in sports are just as susceptible to sudden cardiac death (SCD) as student athletes—which may be a bigger public-health concern because of their larger population, new research suggests[1].

In a registry study of 27 SCDs in youth between the ages of 14 and 23 years, only three of the occurrences were in athletes—with the remaining 24 in nonathletes. Hypertrophic cardiomyopathy (HC) was the most common cause of these deaths, followed by arrhythmogenic right ventricular cardiomyopathy.

"These data raise ethical considerations inherent in limiting systematic screening for unsuspected genetic and/or congenital heart disease to competitive athletes," write the researchers.

"The nonathletes are not screened. We've got all this attention on sudden death in athletes, but the event rate there is extraordinarily low," lead investigator Dr Barry J Maron (Minneapolis Heart Institute Foundation, MN) told heartwire from Medscape.

However, he's not yet ready to call for universal screening of all young people.

"It's a question of logistics and practicality. Obviously we can't screen everybody. But are there certain situations where that could happen and where it wouldn't be prohibitive? I think there are some workable solutions," said Maron "

Dr Anne B Curtis (University at Buffalo, NY) added to heartwire that athletes already participate in preparticipation exams that include a "modest" CV screening. "This study raises the question: should we do this more universally?"

"I think it could potentially be argued that a simple, cost-effective questionnaire—even in the schools—wouldn't be a bad idea," said Curtis, who was not involved with this research.

The findings were published online February 1, 2016 in the American Journal of Cardiology.

Screening Debates

The investigators note that debate continues regarding the best ways to identify mechanisms for SCD in young athletes. "However, proponents of broad-based and mandatory national participation screening, including with 12-lead ECGs, have confined the focus to a relatively small segment of the youthful population," they write.

Maron added that SCDs in athletes garner high media attention, as they often occur in public settings. "So all of our data has been directed there. But completely forgotten have been nonathletes who die from the same diseases," he said.

"If a child who is not an athlete dies suddenly in gym class, does anybody hear about that outside of the obvious authorities? It doesn't get in the media and is a family tragedy only."

For this study, the researchers sought to investigate incidence of SCDs in both competitive athletes and nonathletes. They examined data from the forensic registry of Hennepin County, Minnesota for SCDs that occurred in youth between 2000 and 2014.

Of the 27 deaths assessed, 81% were boys. In addition, 16 were white, nine black, one Hispanic, and one Asian.

In the three SCDs occurring in athletes, the youngest was 17, played basketball, and had an "anomalous origin of the left main coronary artery," report the investigators. The other two included a high school wrestler "with a structurally normal heart" and a college football player with HC. Only one of these occurrences happened during intense physical activity.

In the nonathletes, all SCDs occurred during mild exertion or when being sedentary.

"Therefore, while physical activity can promote arrhythmia-related sudden death in the presences of underlying cardiovascular disease, only one of the 27 deaths in this study was associated with intense exertion," write the researchers.

Public-Health Burden

Six of the 27 decedents had normal heart weight and LV wall thickness. In the other 21 cases, six deaths were attributed to HC and four were attributed to arrhythmogenic right ventricular cardiomyopathy. Other cardiac abnormalities included atherosclerotic CAD, thrombotic coronary occlusion, ruptured ascending aorta, and anomalous left main coronary artery.

The numerical ratio was 24:3 or 8:1 for SCDs in nonathletes to athletes. "Incidence of 24 nonathlete sudden deaths among 946,889 person-years was one in 39,454—substantially exceeding by threefold that for the three sudden deaths in competitive athletes among 361,841 person-years (one in 120,614)," report the investigators.

"Of course there are more nonathletes who die suddenly who are not screened because there are far more nonathletes than athletes in the population," added Maron. "Therefore, the public-health burden is far greater in the nonathletes."

The investigators note that the low number of deaths in the athletes could partially be influenced by physical exams, commonly needed before participating in school-sanctioned sports, selecting out at-risk students. However, "we do not believe that the theoretic identification of athletes with [CVD] by preparticipation screening could have significantly influenced our mortality data."

Maron added that he hopes the study leads to some important conversations. "We need to start thinking about ways to make the nonathlete population safer," including the possible use of the American Heart Association's 14-point CV screening guideline within schools "or in the practicing community," he said.

"We should start to think about how to translate this into the higher-risk group, the nonathletes. Some people believe 'if you're not an athlete, you're not at risk.' We need to change that," said Maron.

"This is a silent majority of at-risk students."

Take-Home Messages

"I think this study supports a more universal approach to a history and physical screening in young people," said Curtis.

In addition to her earlier suggestion of a possible in-school questionnaire regarding CV risk, "the next level might be a screening electrocardiogram," she said. "But this is where a lot of the debate comes in. It's a relatively simple test, but not when you multiply it by hundreds of thousands of people."

She noted that although the study's overall findings did not surprise her, she was "astounded" that some of the participants died of coronary disease and MI at such a young age.

"I think the takeaway message is that [SCD] is not uniquely related to athletics, and most of the events didn't occur during exertion," said Curtis. "But I'd also point out the high number of young men who were affected, which has been shown before. This confirms that risk of sudden cardiac death at a young age is higher in boys than girls."

The study authors and Curtis report no relevant financial relationships.


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