The Enigma of HCMP: Eligibility Recommendations for Competitive Athletes

Difficulty in determining recommendations for athletic eligibility in the setting of hypertrophic cardiomyopathy (HCMP) lies in recognizing that its natural history is particularly heterogeneous, and sudden cardiac death (SCD) in HCMP usually occurs in the absence of previous symptoms.

Parameters for identifying HCMP via echocardiography (the sine qua non of clinical diagnosis) based on diastolic left ventricular wall thickness are established. The pattern and extent of left ventricular hypertrophy often are diverse and incompletely expressed in patients in the age range of many competitive athletes (i.e. <18 years). In some instances, full morphologic manifestations of HCMP may not be evident until young adulthood.

The relative risk of sudden death with HCMP secondary to participating in competitive athletics is largely unknown. Some athletes tolerate extreme athletic life styles without incurring SCD. Also, insufficient data are available to support a particular invasive or noninvasive approach (such as electrophysiologic studies or genotyping DNA) to definitively stratify risk for sudden death in individual youths with HCMP. It is known that all afflicted with HCMP do not harbor the same risk for SCD.

Follow this Expert Advice

The following eligibility recommendations for competitive athletes are suggested by experts:

o Individuals with unequivocal diagnosis of HCMP should not participate in most competitive sports.

o The risk for SCD may be less in older patients with HCMP, which makes individual judgment in assessing eligibility appropriate in selected athletes >30 years old for whom the following clinical features are absent:

• sustained or nonsustained ventricular tachycardia;

• family history of SCD due to HCMP, particularly if occurring at <40 years of age;

• history of syncope or other relevant episodes of impaired consciousness;

• severe hemodynamic abnormalities, including a "dynamic" left ventricular outflow tract gradient;

• exercise-induced hypotension;

• moderate to severe mitral regurgitation and/or an enlarged left atrium, or paroxsysmal atrial fibrillation;

• and evidence of abnormal myocardial perfusion (ischemia manifested as chest pain may be induced by an imbalance between coronary supply and a hypertrophied ventricular demand).

(Editor’s note: This information was part of the 26th Bethesda Conference, sponsored by the American College of Cardiology in Bethesda. The goal was to develop consensus recommendations on the eligibility of athletes with cardiovascular abnormalities for competition in a sport. See Maron BJ, McKenna WJ. Task Force 3: Hypertrophic cardiomyopathy, myocarditis and other myopericardial diseases and mitral valve prolapse. JACC 1994;24:880-883.)