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Cardiologists should work with experienced centers performing genetic testing to identify and manage inherited cardiac conditions in young athletes and inform patients of risks and benefits, according to a new joint scientific statement.
Genetic testing in athletes may aid diagnosis, inform arrhythmic risk and prognosis, guide management and ultimately facilitate safe “return to play” to recreational or competitive sport. However, the role of genetic testing in the evaluation and management of athletes with suspected cardiac conditions is often unclear beyond the context of specialist cardio-genetics centers, according to Michael Papadakis, MD, MRCP, FESC, associate professor in cardiology at St. George’s, University of London and St. George’s George’s University Hospitals NHS Foundation Trust, and president-elect of the European Association of Preventive Cardiology. Recently, a broader scope for genetic testing has been proposed, where genetic testing is used for diagnostic and prognostic purposes, including guiding medical therapy and exercise prescription, he said.
“This document was created to address the needs of the broader sports cardiology community, most of whom work outside specialized centers that deal with inherited heart conditions and genetic testing on a daily basis,” Papadakis told Healio. “We aim to provide the basic terminology and principles of genetic testing a physician should know, along with guidance on the appropriate use of genetic testing in the assessment of athletes.”
Papadakis said the statement also outlines key considerations when contemplating genetic testing, highlighting the potential benefits and pitfalls, along with a step-by-step roadmap to genetic testing.
‘Careful consideration’ needed before testing
Identification, evaluation, and management of inherited cardiac conditions are an integral part of sports cardiology practice, as inherited cardiac conditions are a leading cause of sudden cardiac death in young athletes, the researchers wrote. In particular, hypertrophic cardiomyopathy (HCM) accounts for most deaths in a longstanding national registry in the US; arrhythmogenic cardiomyopathy (ACM) has been reported as the main cause of death in the northeast Italy.
Papadakis said genetic testing can be used for diagnostic purposes in athletes who exhibit symptoms that mimic an inherited cardiac condition or borderline phenotypes, also referred to as the “grey zone.”
“This is particularly relevant in sports cardiology, as the effects of exercise on electrical and structural heart remodeling often pose significant challenges in differentiating between ‘athlete’s heart’ and an inherited heart condition,” Papadakis said. “Similar to the core principles of genetic testing in any setting, genetic testing for diagnostic purposes should only be used in athletes after careful consideration of a number of factors in the context of a multidisciplinary team and after appropriate counseling.”
The researchers wrote that a physician should assess the probability of a positive test based on the suspected condition and strength of the clinical phenotype and consider the potential prognostic and therapeutic implications. Additionally, careful variant interpretation and classification is essential to avoid diagnostic errors and should be performed in experienced centers.
“Only pathogenic and likely pathogenic variants should be viewed as causal variants and used for cascade genetic testing of relatives,” the researchers wrote.
In most cases, the athlete’s prognosis depends on the clinical expression of the disease. In some cases, however, genetic testing can dictate management, Papadakis said in an interview.
“For some conditions, such as Long QT syndrome, genetic testing in the athlete can inform the risk for arrhythmias, identify potential triggers to be avoided, such as swimming, and help target medical therapies and plan exercise advice,” Papadakis said. “Similarly, for arrhythmogenic cardiomyopathy, a cardiomyopathy predisposing to sudden cardiac death in athletes, genetic testing has significant implications regarding exercise prescription on its own right.”
The 2020 ESC Sports cardiology guidelines state that even if an athlete has no clinical evidence of the disease but has the gene for the condition, they should abstain from high intensity and competitive sport.
“This is because studies show that those who have the gene and exercise at high level tend to develop the disease earlier in life and tend to develop more severe disease,” Papadakis said.
Appropriate counseling, referrals key
The researchers noted that a multidisciplinary team through liaison with an experienced cardio-genetics center will ensure the physician and the athlete are supported during a genetic testing process. Appropriate pre- and post-test counseling will ensure that the athlete and all the stakeholders understand the potential implications of genetic testing in terms of ethical, legal and financial repercussions.
Papadakis said, going forward, more research is necessary in the field of sports cardiology focusing on borderline phenotypes.
“Becoming better at differentiating physiology from pathology is also likely to help us better utilize genetic testing,” Papadakis told Healio. “Moreover, research related to the influence of exercise in specific genetic subtypes of inherited cardiac conditions will help us to personalize prescription exercise in athletes and patients, alike.”
The scientific statement was prepared by the Sports Cardiology and Exercise Section of the European Association of Preventive Cardiology, the European Heart Rhythm Association, the European Society of Cardiology working group on myocardial and pericardial diseases, the ESC Council on Cardiovascular Genomics, the European Society of Human Genetics and the Association for European Pediatric and Congenital Cardiology.
For more information:
Michael Papadakis, MD, MRCP, FESC, can be reached at firstname.lastname@example.org; Twitter: @michaelpapadak2.