College student-athletes may be more likely to die from cardiac arrest - when the heart suddenly stops beating - than previously believed, according to a new study.

The news comes less than 2 months after Michigan high school basketball player Wes Leonard collapsed and died when his heart stopped just moments after sinking a game-winning basket.

His death, combined with other recent highly publicized cases of young athletes suffering cardiac arrest, have led some to question whether it might be feasible to identify kids who are at risk of heart problems and prevent unnecessary deaths.

Cardiac arrest in athletes is still quite rare, and athletes aren’t any more likely than the rest of the population to have a small, often unnoticed heart defect.

Still, “because of the intense exertion that they are undergoing, (athletes) are more likely if they have one of these problems to have a sudden cardiac arrest because of it,” Dr. Kimberly Harmon of the University of Washington told Reuters Health.

In a study published in Circulation, Harmon and her colleagues estimated all cases of sudden cardiac death that occurred among National Collegiate Athletic Association (NCAA) student-athletes from 2004 through 2008.

The researchers combined data from the NCAA’s health and safety office with information from a memorial of student-athletes and weekly internet searches of sudden cardiac arrest in young people.

Those searches turned up 273 total deaths in NCAA student-athletes over the 5-year period. The majority of all deaths were accidents, with only 80 of them due to medical causes.

But of all deaths attributed to medical causes, heart-related sudden death claimed the most lives - 45, or one death for every 44,000 athletes playing in a given year.

Sudden cardiac death was most common among Division I male basketball players. One of those student-athletes died of sudden cardiac arrest for every 3,100 on team rosters each year.

Basketball players in general were the most likely to die of cardiac arrest, followed by swimmers and lacrosse players. Deaths from cardiac arrest were also more common in males and black athletes than in females and white athletes.

The overall statistics are higher than most previous estimates, but most striking is that “in some subgroups the numbers are amazingly high,” Dr. Sami Viskin, a cardiologist at the Tel Aviv Medical Center in Israel who was not involved in the study, told Reuters Health by email.

SHOULD ATHLETES BE SCREENED?

Harmon’s team said the findings may be a starting point in determining who is at greatest risk of cardiac arrest. Those athletes could then be targeted for screening that is meant to detect hidden heart abnormalities that predispose people to cardiac arrest.

There has been controversy about whether screening athletes using electrocardiography, or ECG, would cost more money than it would be worth. An ECG typically costs about $100.

But Harmon told Reuters Health that with the new, higher estimates of cardiac arrest, “In some sports and in some ethnic groups and sexes, screening may be cost-effective given these realities.”

Whether screening can prevent athlete deaths, however, is another question.

A recent study by Viskin and colleagues found that there was no difference in the rate of cardiac arrest deaths in competitive athletes in Israel before and after a law was implemented that required heart screening for all people playing organized sports.

Viskin said that one problem with screening is that heart defects are so rare, and ECGs sometimes confusing to read, that it would be more common for doctors to misread a screening test - and think an athlete had an underlying condition when they didn’t - then it would be to catch a defect.

“The level of evidence that we have regarding the life-saving effects of screening does not justify making it mandatory,” Viskin said, noting that he was not against the idea of individual athletes deciding on their own to get screened.

But, “We should not do mandatory tests when all too often we do not really know what to do with the results of those tests,” Viskin said.

Harmon said that another way to prevent deaths from cardiac arrest would be to make sure that athletes whose hearts stop while they are playing get treatment right away, such as with an automated external defibrillator, or AED.

The new estimates based on sport can tell schools that, “if you have a limited amount of defibrillators, put one in your basketball arena,” she said. Such devices cost about $3,000.

And because many people are wary of using an AED around a swimming pool, Harmon added that schools need to make sure “not only that you have a defibrillator there, but that people are trained to use it in special circumstances.”

SOURCE: Circulation, online April 4, 2011.