Cardiac Involvement in Female Elite Athletes with Carriers Status of Duchenne Muscular Dystrophy

Simon Wernhart^1,2*Tom Kastner^3,4Martin Halle^1,2Stephan Mueller^1,2Veronika Schmid¹Cihan Akbulut¹Cordula Wolf¹Christian Meierhofer¹Teresa Trenkwalder¹Isabel Diebold⁵Christopher Herzog⁶Richard Brill⁷Mark Haykowsky⁸Stephen Foulkes⁸Bernd Wolfarth^3,4Eimo Martens¹Dominik Sebastian Westphal¹

• ¹Technical University of Munich, Munich, Germany
• ²Partner site Munich Heart Alliance,DZHK, (German Centre for Cardiovascular Research), Munich, Bavaria, Germany
• ³Humboldt University of Berlin, Berlin, Baden-Wurttemberg, Germany
• ⁴Leipzig University, Leipzig, Lower Saxony, Germany
• ⁵Medizinisch Genetisches Zentrum München, Munich, Germany
• ⁶Radiologisches Zentrum München - RZM, München, Germany
• ⁷University Hospital in Halle, Halle, Saxony-Anhalt, Germany
• ⁸University of Alberta, Edmonton, Alberta, Canada

Duchenne muscular dystrophy is a muscle wasting, progressive and X-chromosomal inherited disease in young male individuals, who -aside from peripheral muscular impairment -may also suffer from severe cardiac complications. In females, who only have a muscular dystrophy carrier status (MDC), muscular symptoms and cardiac complications are less severe or even absent. While strenuous exercise is mostly not possible in males, females may exercise at mild intensity or even unlimited. However, in females the impact of performing elite sports, particularly of endurance type with high cardiopulmonary exercise strain, is uncertain.Here we describe two rare cases of female elite athletes with MDC performing endurance sports. We describe their clinical presentation, kinetics of cardiac biomarkers and peripheral muscle enzymes during acute exercise as well as cardiac manifestations in the context of sports eligibility including an interdisciplinary shared decision-making approach to continue sports. This is viewed with respect to pathophysiology and genetics in dystrophinopathies with particular focus on genetic carrier status. While the primary concern is risk stratification for sudden cardiac death and its prevention, potential risk of early onset of myocardial dysfunction or even heart failure also needs to be considered in MDC.To optimize exercise recommendations, these complex and rare cases of athletes require an interdisciplinary approach of experts in sports cardiology, sports medicine, radiology, and genetics and should be included in a long-term international sports cardiology registry.