Cardiopulmonary Exercise Testing in Athletes With Hypertrophic Cardiomyopathy

Patients with hypertrophic cardiomyopathy (HCM) have historically been restricted from athletic participation because of the perceived risk of sudden cardiac death. More contem-porary research has highlighted the relative safety of competitive athletics with HCM. However, lack of published data on reference values for cardiopulmonary exercise testing (CPET) complicates clinical management and counseling on sports participation in the individual athlete. We conducted a single-center, retrospective cohort study to investigate CPET in athletes with HCM and clinical characteristics associated with objective meas-ures of aerobic capacity. We identified 58 athletes with HCM (74% male, mean age 18 +/- 3 years, mean left ventricular (LV) wall thickness 20 +/- 7 mm). LV outflow tract obstruction was present in 22 (38%). A total of 15 (26%) athletes were taking a b blocker (BB), but only 4 (7%) reported exertional symptoms. Overall, exercise capacity was mildly reduced, with a peak myocardial oxygen consumption (peak VO2) of 37.9 ml/min/kg (83% of predicted peak VO2). Both LV outflow tract obstruction and BB use were associated with reduced exercise capacity. Limited peak heart rate was more common in athletes tak -ing BB (47% vs 9%, p = 0.002). At a mean 5.6 years follow-up, 5 patients underwent myec-tomy (9%), and 8 (14%) received an implantable cardioverter defibrillator (ICD) for primary prevention. One individual with massive LV hypertrophy experienced recurrent ICD shocks for ventricular fibrillation and underwent myectomy 7 years after initial eval-uation and was no longer participating in sports. There were no deaths over the follow-up period. In conclusion, the prognostic role of CPET remains unclear in athletes with HCM. Mildly reduced exercise capacity was common; however, reduced peak VO2 did not corre-late with symptom status or clinical outcomes. A significant proportion went on to require myectomy and/or ICD, thus highlighting the need for close follow-up. These data provide some initial insight into the clinical evaluation of real world athletes with HCM; how -ever, further study is warranted to help guide shared decision-making, return-to-play dis-cussions, and the potential long-term safety of competitive athletic participation. (c) 2022 Elsevier Inc. All rights reserved.