4 out of 5 athletes who die suddenly had no symptoms or family history of heart disease

By Stephen Beech via SWNS

Up to four out of five athletes who die suddenly had no symptoms or family history of heart disease, according to new research.

Now new recommendations have been drawn up on how to use state-of-the-art gene testing to prevent the sudden cardiac deaths of sportsmen and women and enable safe exercise.

The guidelines were published in the European Journal of Preventive Cardiology.

Author Dr. Michael Papadakis of St George’s, University of London, said: "Genetic testing for potentially lethal variants is more accessible than ever before and this document focuses on which athletes should be tested and when.

“Sportspeople should be counselled on the potential outcomes prior to genetic testing since it could mean exclusion or restricted play.”

He explained that, in most cases, a clinical evaluation will dictate the need for preventive therapy such as a defibrillator and the advice on exercise and participation in competitive sports.

Dr. Papadakis said: “Even if a genetic abnormality is found, recommendations on treatment and return to play usually depend on how clinically severe the disease is.

"Is it causing symptoms such as fainting? Is the heart excessively weak or thick? Can we see many irregularities of the heart rhythm - arrhythmias - and do they get worse during exercise?

"If the answer is ‘yes’ to any of these questions then play is likely to be curtailed in some way.”

He says one example is an inherited condition that can cause sudden cardiac death in athletes called hypertrophic cardiomyopathy (HCM), where the heart muscle is abnormally thick.

Dr. Papadakis said: “We used to be very conservative, but now our advice is more liberal.

"Athletes with HCM should undergo a comprehensive clinical evaluation to assess their risk of sudden cardiac death and then be offered an exercise prescription.

"Genetic testing in this condition does not impact management in most cases. Asymptomatic athletes judged to be at low risk can potentially participate in competitive sports after an informed discussion with their doctor.

"Others at higher risk may be restricted to moderate intensity exercise. The exercise prescription should be as specific as possible and outline how often, for how long, at what intensity, and which exercise or sport is safe.”

However, in some cases, he says genetic testing can dictate management.

One example is long QT syndrome (LQTS), which is an inherited electrical fault of the heart.

Identification of different genetic subtypes (LQT 1-3) can inform the risk of arrhythmias, identify potential triggers to be avoided, and help to target therapies and plan exercise advice.

Dr Papadakis said: “For instance, sudden immersion in cold water is more likely to cause life-threatening arrhythmias in LQT type 1 rather than types 2 or 3, so one should be more cautious with swimmers who have the type 1 genetic subtype than runners.”

The only situation where genetic testing alone may result in exclusion from play is a heart muscle condition called arrhythmogenic cardiomyopathy (ARVC) which ended the playing career of former England cricketer James Taylor at the age of 26.

Dr Papadakis said: “Even if an athlete has no clinical evidence of the disease but has the gene for the condition, he or she should abstain from high intensity and competitive sport.

“This is because studies show that people with the gene who exercise at a high level tend to develop the disease earlier in life and tend to develop more severe disease which can cause a life-threatening arrhythmia during sport.”

Pre-test genetic counselling should be performed to discuss the implications for athletes and their families, according to the new guidelines.

Dr Papadakis said: “The athlete needs to know that if the test is positive that may signal the end of his or her career, even if there is no clinical evidence of disease.

“On the other hand, if genetic testing is refused the condition may get worse.

"Post-test counselling is critical given the potential psychosocial, financial and mental health implications, particularly if the athlete is excluded from play.”

For child athletes, he said genetic counselling in an expert paediatric centre with assistance from a child mental health specialist may be needed.

Dr Papadakis added: “The psychological impact of a positive genetic test result may be significant for the child, especially if this leads to sports exclusion even in the absence of clinical disease such as in ARVC.”