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A mandatory cardiac screening program for elite adolescent British soccer players gave perhaps the best estimate yet of sudden cardiac death prevalence in such a group: 6.8 per 100,000 screened athletes.

The health questionnaire, physical examination, 12-lead ECG, and echocardiography program of the English Football Association turned up 0.38% (42 of 11,168 screened from 1996 through 2016) with cardiac disorders associated with sudden cardiac death.

Another 2% had congenital or valvular abnormalities discovered on screening, Sanjay Sharma, MB, ChB, MD, of the University of London, and colleagues reported in the New England Journal of Medicine.

However, most of the cardiac-related deaths -- "all of which were sudden and occurred during exercise" -- were due to cardiomyopathies that went undetected on screening. Cardiomyopathy accounted for seven of the eight cardiac arrest fatalities (88%), and six of those cases (75%) had a normal cardiac screening an average of 6.8 years prior.

"The absence of a systematic registry of deaths in young athletes (<35 years old) has been a major obstacle to ascertaining the precise incidence of sudden cardiac death in this group; estimates vary between 0.5 and 13 deaths per 100,000 athletes, depending on the population studied and methods of data collection used," the researchers noted.

"I think everybody in our community is starved for this information. There's never been a large cohort like this that's been screened with physical examination, echo, and ECG and followed prospectively for outcome," commented Peter Aziz, MD, a pediatric cardiologist at the Cleveland Clinic.

Their mandatory program included all high-ranking youth academy players, ages 15 to 17, in England's soccer league system who were offered a formal contract with a view to progressing to a professional career. The screening was done by accredited sonographers in mobile screening units and was reviewed by an expert regional cardiologist.

Perhaps the most interesting, though, was the number of cases of "missed" cardiomyopathy, Aziz and others reached by 乌鸦传媒 noted.

"Even with intensive evaluation that exceeds that provided to most adolescent athletes, including both electrocardiography and echocardiography, six athletes subsequently died from undetected high-risk cardiac conditions," commented Thomas Schwenk, MD, of the University of Nevada in Reno. "Implementing intense screening programs for cardiac risk in elite athletes can prevent some deaths, but it is not perfect."

Robert Pass, director of pediatric cardiac electrophysiology at the Children's Hospital at Montefiore in New York City, agreed.

"Thus, the question is, is the type of screening that we believe is most 'aggressive' as done in this work -- ECG/ECHO/History and physical exam -- not actually adequate? Do patients need continued annual re-evaluations even if the initial evaluation is negative?" he told 乌鸦传媒. "The notion that seven patients at age 16 could not be identified to have hypertrophic cardiomyopathy is VERY worrisome."

Blind reading by independent experts in inherited cardiac diseases showed 100% agreement between the two reviewers for all six sudden cardiac deaths who the screening called normal.

Repeat testing may not be realistic on a population scale, Aziz suggested. "Doing the screening once is probably a monumental task with a pretty rigorous bill in terms of cost. Suggesting to repeat this when your hit rate is so low to begin with is ... probably isn't best way to go about it."

Notably, most of the cases where screening picked up cardiac problems actually would have been negative by history and physical alone, commented John Higgins, MD, MPhil, MBA, a sports cardiologist at the University of Texas Health Sciences Center at Houston. Some cases had abnormalities found only on ECG, others only on echocardiography. Of the 42 with conditions associated with sudden cardiac death, history picked up three and the exam caught two.

"It shows the importance if we are going to do screening, of including some sort of imaging but also screening of the electrical system," he argued.

The cost of the screening program averaged to $342 per athlete for the preliminary investigation with consultation, $16,167 to detect one case of any cardiac disorder, and $102,782 to detect one case of serious cardiac disease associated with sudden cardiac death.

Aziz, though, pointed out that "regardless of what screening program or score methodology we decide to use in the U.S or U.K. or anywhere else, we have to come to terms with fact that we're going to miss some life-threatening cardiovascular disorders."

"So if we're willing to accept this fact as a medical community, perhaps what's more efficient and effective is establishing abortive mechanisms in the unlikely event a cardiac arrest does occur," Aziz concluded. "Ensuring [automated external defibrillators] are ubiquitous and trained CPR providers are part of the sports infrastructure may be the most effective way of preventing sudden cardiac death in the young."

Daphne Hsu, chief of pediatric cardiology at Montefiore, added, though, that the findings do provide some reassurance of current practice, in that two of the five patients identified as having hypertrophic cardiomyopathy at screening subsequently died suddenly. "Although this is a small number, it does support the recommendation to restrict patients with hypertrophic cardiomyopathy from competitive sports."

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