Best-Yet Study of Footballers Raises New Questions Over Preparticipation Cardiac Tests for Athletes

In a large analysis of adolescent players participating in the English Football Association (FA), only a fraction of participants screened with ECG and echocardiography on top of a detailed family history and physical exam were found to have a cardiac abnormality associated with sudden cardiac death.

Moreover, among the 23 athletes who died from any cause during follow-up, eight were sudden deaths attributed to cardiac disease, including seven attributable to an underlying cardiomyopathy. The incidence of sudden cardiac death was 6.8 events per 100,000 athletes, which is higher than in previous studies, report investigators.

“The strongest aspect of this study is that the denominator was very complete,” said senior investigator Sanjay Sharma, MBChB, MD (University of London, England). “It wasn’t an estimate. We knew how many people had been tested. The numerator—the number of deaths—was also completely accurate. So, as far as I’m aware, this is the first study to accurately give us the incidence of sudden cardiac death in young soccer players. At roughly seven deaths per 100,000 athletes, that is threefold greater than any other study has reported to date.”

Previous estimates have suggested the incidence of sudden cardiac death could be as low as one event per 200,000 athletes, he said. A recent review of the data suggested that the rate of sudden death ranged from approximately one event per 40,000 to one event per 80,000 athletes. “Our study shows a death rate of one out of every 14,794 athletes,” said Sharma.

Benjamin Levine, MD (UT Southwestern Medical Center, Dallas, TX), said the new analysis is “as good as we’re ever going to get.” In addition to the top-notch clinical investigators, there was a clearly outlined study protocol and use of a “state of the art” algorithm designed by experts and consensus groups for the evaluation and management of detected cardiovascular diseases. “Nevertheless, it’s quite clear that not all deaths can be prevented,” said Levine. 

The new study, led by Aneil Malhotra, MB BChir, PhD(University of London), was published online August 8, 2018, in the New England Journal of Medicine.  

ECG Picked Up Most Cardiac Abnormalities

Between 1996 and 2016 in the United Kingdom, more than 11,100 youth academy football players—average age 16.4 years—associated with 92 professional teams underwent testing as part of the FA mandatory cardiac screening program. The assessment included a health questionnaire, physical examination, 12-lead ECG, and echocardiography.

In total, 42 athletes (0.38%) had cardiac disorders linked with sudden cardiac death, including five who were diagnosed with hypertrophic cardiomyopathy, two with arrhythmogenic right ventricular cardiomyopathy, one with dilated cardiomyopathy, and three athletes with long-QT syndrome. Of these 42 individuals, abnormal ECGs were obtained in 36 athletes and abnormal echocardiograms in 12 athletes. Overall, just three patients had symptoms that would have warranted referral to a physician.

“If we had relied on the American strategy, ie, a health questionnaire and a physical examination, we’d have missed the vast majority of people with serious cardiac conditions,” said Sharma. “The ECG was the most effective tool for identifying people with serious diseases in this study.”

But overall, six of the eight sudden deaths occurred in athletes who had normal results during cardiac screening.

“You can imagine if you’re antagonistic towards screening, you could say, ‘There you go, there’s my answer—screening is a complete waste of time. It missed 75% of those people who died,’” said Sharma. “Our argument is that it didn’t miss them. It’s just that the disease had not shown itself by age 16. We know that heart muscle diseases, such cardiomyopathies, experience an age-related penetrance whereby many have the disease by the time they hit puberty. Many others don’t actually show the condition until they’re in their 20s, sometimes in their 30s.”

“The question is still undetermined: does doing all of this actually help people? Benjamin Levine

The mean time between screening and sudden cardiac death was 6.8 years, he noted. “Our message is that if we’re going to screen, a one-off normal screen at the age of 16 should not provide reassurance,” said Sharma. “There should be serial evaluations—maybe every 2 years—while the individual is participating in competitive sport.”

Aaron Baggish, MD (Brigham and Women’s Hospital, Boston, MA), who was not involved in the study, agreed with the assessment, noting the study highlights the ineffectiveness of simply screening an athlete once in his or her teenage years. Like Sharma, he noted that the majority of patients who died did not have their cardiomyopathy identified during the initial screening process.

“I don’t think there’s any reason to believe that the screeners missed them, but rather that the diseases don’t really start to show up, oftentimes, until people are older,” said Baggish. “For those of us that screen at the collegiate or national level, we get into this issue all the time. That is, if we’re going to screen should we do it at some repeat interval? With US Soccer, we screen our athletes every 4 years. At the collegiate level, we screen them once when they enter as freshman. Some would argue an additional screen would be appropriate.”

However, college athletes are at least a couple years older than the athletes in the FA study, and “I think we’re kind of getting the sweet spot with college freshman where most of the diseases would have manifested by then,” said Baggish. “We don’t know that for sure. It’s an unanswered question.”

Does Cardiac Screening Save Athlete Lives?

To TCTMD, Baggish and Levine both stressed that the “elephant in the room” with comprehensive preparticipation screening with ECG/echocardiography is whether it saves lives. The present study does not address that question.

Despite identifying 42 athletes with cardiac disorders, it’s unclear whether the interventions, such as radiofrequency ablation of Wolfe-Parkinson-White syndrome or surgical treatment of an anomalous coronary artery, altered clinical outcomes, said Levine. Additionally, it’s not certain whether stopping athletes from participating in sport did the same, he said, noting that most deaths among patients with hypertrophic cardiomyopathy do not occur during high-intensity sport.

“Just picking up a disease associated with poor cardiovascular outcomes doesn’t mean you change that outcome by your intervention,” said Levine. “And sometimes, your actions may hurt people.” 

He added, though, that the detection of long-QT syndrome was definitely beneficial because these patients were prescribed beta-blockers, a relatively benign therapy that has been shown to save lives and allow continued exercise in this population. “With the others, I have no idea what would have happened if they hadn’t been picked up,” Levine said. “The question is still undetermined: does doing all of this actually help people?”

To TCTMD, Sharma pointed out that among the athletes with cardiac disorders, 26 had the Wolff-Parkinson-White ECG pattern, two athletes had an anomalous coronary artery, and three had a bicuspid aortic valve with either had an enlarged aortic root or severe aortic regurgitation. “We picked up 42 people with serious diseases, and we were able to do something for 30 of them that allowed them to go to play,” said Sharma. “Something good did come out of it.”

In total, two of the patients who were advised against playing continued to compete and died of sudden cardiac death. Ten other athletes retired.

In England, preparticipation screening with ECG and echocardiography is confined to the upper echelons of sport, such as FA-caliber athletes. “You have to be someone who is elite, or the potential of becoming elite, to be worthy of this type of screening,” said Sharma. The FA approach is the most comprehensive with the inclusion of echocardiography, but other organizations, including the English Institute of Sport, have implemented ECG screening in addition to family history and physical examination.

In the United States, preparticipation screening for cardiovascular disease includes taking a personal/family history and a detailed physical examination, but the American Heart Association (AHA) and American College of Cardiology (ACC) do not advocate mandatory, widespread, population-based screening with an ECG (or echocardiography). The groups do say that ECG screening may be considered in small cohorts of young, healthy athletes, provided there is sufficient quality control with experts.

“In the US, for the first time, the guidelines really do allow individuals to choose the approach they see as the best fit,” said Baggish, one of the co-authors, along with Levine, of the AHA/ACC eligibility guidelines. “I think that’s the most sensible approach. An ECG-based screening program, when done well, represents the best approach. Without the right resources, it probably does more harm than good.”   

The European Society of Cardiology, in contrast, supports a more liberal approach, recommending that a 12-lead ECG be included as part of preparticipation screening protocols.