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NEW YORK (Reuters Health) - Screening athletes for hidden heart problems may not help prevent sudden deaths, a new study from Israel finds.
The findings, published in the Journal of the American College of Cardiology, cast doubts on the usefulness of widespread, mandatory screening of young athletes with electrocardiography, or ECG.
The test measures the electrical activity of the heart and can detect disturbances that might spell trouble.
Mandatory screening has been in place in Italy and Israel for years, while in the U.S. there has been some debate over whether to launch similar policies.
It is rare for an athlete to die suddenly of cardiac arrest, where the heart stops beating due to a disruption in normal heart rhythm. A recent U.S. study estimated that between 2000 and 2006, an average of 66 athletes younger than 40 died each year from cardiac arrest.
But because those deaths are so tragic, some advocates have argued that ECG screening should be required for high school and college athletes. An abnormal result on an ECG prompts further testing to see if there is underlying heart disease.
Italy is the home to mandatory ECG screening of young athletes, where it has been done since the early 1980s. In 2005, the European Heart Society recommended that all European countries adopt such screening, based on an Italian study that found a sharp reduction in sudden deaths among athletes since its national law was introduced.
Since 1997, Israel has required ECG screening not only for competitive athletes, but for anyone who wants to join in an "organized" activity -- which includes joining a gym.
For the new study, researchers compared rates of sudden death from cardiac arrest during the decade before the law with rates in the decade after.
Using newspaper reports, they found a total of 24 documented cardiac-arrest deaths among competitive athletes between the ages of 12 and 44 -- 11 deaths before the law, and 13 after it.
Before the law, there were about 2.5 deaths per 100,000 athletes each year; after the law, there were roughly 2.6 deaths per 100,000 each year, the researchers estimate.
"The results are not at all surprising," senior researcher Dr. Sami Viskin, a cardiologist at Tel Aviv Medical Center, told Reuters Health in an email.
Sudden deaths among athletes are so uncommon -- and ECGs imperfect enough -- that the lack of benefit is to be expected, according to Viskin.
That sentiment was echoed by Dr. Barry J. Maron, of the Minneapolis Heart Institute Foundation in Minnesota, who was not involved in the study.
"Sudden death in athletes is a rare phenomenon," he said in an interview. "Each one is tragic, but if you try to demonstrate that an intervention is effective (at prevention), it's going to be difficult."
But even if screening were to prevent just a few deaths, why not do it?
Student athletes in the U.S. currently undergo a physical exam and have their family history of heart problems taken. If they appear to be at increased risk of heart disease -- based on a "murmur" detected through a stethoscope, for example -- they'll be referred for further testing.
Maron said that routine ECG screening "sounds good," but mandatory screening on a national level -- especially in a country as big as the U.S. -- is not really feasible.
One issue, he said, is who would do all the screening? There are only about 1,500 pediatric cardiologists nationwide, Maron noted.
But perhaps the biggest problem, he said, is the fact that any screening test can yield a "false-positive" result -- a suspected abnormality that turns out to be nothing upon further testing.
According to Maron, about 20 percent of ECG screening results could be expected to turn up a potential problem, most of which would be false-positives.
Maron also said that a national policy of screening young athletes would be "discriminatory." The rate of sudden death among non-athletes is actually higher, so limiting screening only to young people in sports would be exclusionary, he said.
None of that means that individual organizations should not have ECG screening, Maron noted.
Last year, a study at Harvard University found that ECG screening of student athletes picked up more cases of heart problems than did screening with a physical exam and family history alone.
"If Harvard wants to screen their athletes, that's different" than a mandatory national program, Maron said.
But what about the Italian study that found a sharp drop in sudden deaths among athletes after the country started mandatory screening (from 3.6 per 100,000 in 1980 to about 0.4 per 100,000 by 2004)?
Both Viskin and Maron pointed out that the Italian study included data from only the 2 years before the law was implemented. The current study, by contrast, looked at the decade preceding Israel's law.
Viskin's team says that if they had only included numbers from the 2 years before Israel's 1997 law went into effect, they too would have found the screening law to be "extremely effective" -- because there was a sharp spike in sudden deaths among athletes in the mid-1990s, versus the decade before.
Viskin doubted that the current findings will have any effect on Israel's law. "There is no going back," he said. "There is too much 'wishful thinking.'"
But he said the findings should inform debates in the U.S. and other countries that do not currently have mandatory ECG screening.
Viskin also pointed to a recent study from Denmark, where there is no athlete screening of any kind -- even physical exam and family history.
That study, he said, "claims that the sudden death rates among athletes in Denmark -- without any screening at all -- are as low as the sudden death rates in Italy, where screening is at its best."
SOURCE: bit.ly/d1cHYE Journal of the American College of Cardiology, March 7, 2011.