Sudden cardiac death in young football players is a worrying phenomenon, and, according to our latest study, it is also more common than previously thought.
For our study, published in the New England Journal of Medicine, we evaluated more than 11,000 football players, aged 15-17, over a 20-year period. The data revealed a prevalence of sudden cardiac death of seven in 100,000 players – higher than previous estimates of about two in every 100,000 players.
Sudden cardiac death is often the result of an undiagnosed inherited heart condition, but these heart conditions can usually be detected by routine cardiac screening.
Screening involves a questionnaire to determine any worrying cardiac symptoms or a family history of heart disease. This is followed by an electrocardiogram (a graphical display of the electrical activity within the heart) and an echocardiogram (an ultrasound of the heart). A diagnosis can be difficult, though, as athletes tend to have bigger hearts – which may look like diseased hearts – while some heart conditions appear mild and may be difficult to detect.
Read more: Explainer: sudden death in young athletes
In our study, we identified 42 players out of 11,000 who had heart conditions that could put these players at risk of sudden death. During a follow-up period, eight players died from a heart condition. Of those who died, six had had a normal cardiac screening result. The other two had been identified with a serious heart condition but continued to play against medical advice. It is important to note that some of the deaths occurred up to seven years after their cardiac screening tests.
Our study highlights the importance of cardiac screening, as it did detect a number of serious conditions, but it also demonstrates the limits of one-off cardiac screening. In view of this, the English Football Association (FA) and other sporting organisations have now increased screening frequency so that players are tested between the ages of 14 and 25.
Saving more players
The fact that six of the players who died had normal cardiac screening results highlights the need to develop a greater understanding of the hearts of teenage athletes and the subtle development of these heart conditions.
So, as well as frequent screening, sport scientists, cardiac physiologists and cardiologists at Liverpool John Moores University are collaborating to understand more about the heart’s structure and the nature of inherited heart disease. This will give us greater insight into the difference between normal athletic cardiac adaptation and heart disease.
By using new imaging techniques to detect subtle changes in the heart that may previously have been missed, we can make cardiac screening more sensitive and help to provide diagnosis, management and therapy to athletes with cardiac disease.
Although these initiatives may improve our ability to detect these conditions and save young footballers lives, there is still a risk of false negative results – where the tests wrongly show that the condition is absent. So it is important to encourage sporting organisations to have pitch-side defibrillators and trained staff to help resuscitate a player if they suffer a cardiac arrest from a condition that had not been previously detected during screening. This is certainly what saved Fabrice Muamba who survived after his heart stopped and he collapsed during an FA Cup match.
Overall, our study highlights the importance of an increased frequency of cardiac screening, continued research on the heart’s structure and the techniques used to diagnose an inherited condition. Hopefully, this strategy will help to reduce the rates of sudden cardiac death in athletes and save young people’s lives.