Up to 80% of athletes who die suddenly had no symptoms or family history of heart disease

Recommendations on how to use genetic testing to prevent sudden cardiac death in athletes and enable safe exercise are published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC ).1

“Genetic testing for life-threatening variants is more accessible than ever and this paper focuses on which athletes should be tested and when,” said author Dr Michael Papadakis of St George’s, University of London, UK. United. “Athletes should be informed of potential results before genetic testing, as this could mean exclusion or restricted play.”

In most cases, the clinical assessment will dictate the need for preventative therapy such as a defibrillator and advice on exercise and participation in competitive sports. Dr Papadakis explained: “Even if a genetic abnormality is discovered, recommendations on treatment and return to play generally depend on the clinical severity of the disease. Does it cause symptoms such as fainting? Is the heart excessively weak or thick? Can we see many irregular heartbeats (arrhythmias) and do they get worse during exercise? If the answer is ‘yes’ to any of these questions, the game may be restricted in some way.”

An 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 noted: “We used to be very conservative, but now our advice is more liberal. Athletes with HCM should undergo a full 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 deemed to be low risk can potentially participate in competitive sports after an informed discussion with their doctor. Others at high risk may be limited to moderate-intensity exercise. The exercise prescription should be as specific as possible and indicate how often, for how long, at what intensity, and which exercise or sport is safe.

In some cases, however, genetic testing may dictate management. An example is long QT syndrome (LQTS), which is an inherited electrical defect of the heart. Identifying different genetic subtypes (LQT 1-3) can inform the risk of arrhythmias, identify potential triggers to avoid, and help target medical therapies and plan exercise advice. Dr Papadakis said: “For example, sudden immersion in cold water is more likely to cause life-threatening arrhythmias in LQT type 1 rather than type 2 or 3, so more caution should be exercised with swimmers who have the type 1 genetic subtype than runners.

The only situation where genetic testing alone can result in exclusion from gambling is a condition of the heart muscle called arrhythmogenic cardiomyopathy (ADRC). “Even if an athlete has no clinical evidence of the disease, but has the gene for the disease, he or she should refrain from high intensity and competitive sports,” said Dr Papadakis .2 “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 serious disease which can cause life-threatening arrhythmia during sports.

Pre-test genetic counseling should be done to discuss the implications for athletes and their families. For example, an athlete’s mother is clinically diagnosed with ARVC and has the causative gene, the athlete is then screened and all clinical tests are normal. The athlete has two choices: 1) clinical follow-up, probably annually, to look for signs of illness; or 2) genetic testing. “The athlete should be aware that if the test is positive, it may signal the end of their career, even if there is no clinical evidence of the disease,” Dr Papadakis said. “On the other hand, if genetic testing is refused, the condition may worsen. Post-test counseling is essential given the potential psychosocial, financial and mental implications, particularly if the athlete is excluded from play. »

For child athletes, genetic counseling at an expert pediatric center with the help of a child mental health specialist may be necessary. Dr Papadakis underlined: “The psychological impact of a positive genetic test result can be significant for the child, especially if it leads to sports exclusion even in the absence of clinical disease as in ARVC. “

In children with a clinical diagnosis of an inherited disease, genetic testing can confirm the diagnosis and, in some cases, help predict the risk of sudden death during sports activities. For example, having the gene for an electrical defect in the heart called catecholaminergic polymorphic ventricular tachycardia (CPVT) may lead to guidance for preventative therapies, such as beta-blockers, and dictate decisions about exercise. . “This is important because CPVT predisposes to arrhythmias during exercise and can cause sudden death at a very young age,” Dr. Papadakis said. “In contrast, the timing of genetic testing in children with a family history of HCM is controversial because in the absence of clinical signs, it rarely causes sudden death in childhood.”

The scientific statement was prepared by the Sports and Exercise Cardiology Section of the European Association of Preventive Cardiology, the European Heart Rhythm Association, the ESC Working Group on Myocardial and Pericardial Diseases, the Council of the ESC on Cardiovascular Genomics, the European Society of Human Genetics and the European Association of Pediatric and Congenital Cardiology.