Study of Exercise Training in Hypertrophic Cardiomyopathy

The goal of this randomized clinical pilot trial is to establish the safety profile and
potential benefits of moderate intensity exercise in patients with hypertrophic
cardiomyopathy (HCM). Participation in competitive athletics is associated with an increased
risk of sudden cardiac death (SCD) in individuals with structural heart disease, including
HCM. This has appropriately led to the establishment of national guidelines based on expert
opinion that discourage participation in high intensity competitive sports, burst exertion
(e.g., sprinting), or isometric exercise (e.g., heavy lifting). Non-competitive, low to
moderate intensity exercise is allowable, although many physicians and HCM patients are still
understandably apprehensive. Data on the safety of a recreational exercise program, and how
to gauge appropriate intensity level, are desperately needed so that HCM patients can reap
the well established health benefits of regular physical activity. Limited, but compelling
animal data suggest that moderate intensity exercise is not only safe, but may also prevent
or even reverse cardiac hypertrophy, fibrosis, myocellular disarray, and apoptosis associated
with HCM. There are no published studies on exercise in patients with HCM, although large
clinical trials in heart failure have shown exercise training to be safe, to improve peak VO2
and quality of life, and to lower cardiovascular mortality. The pilot randomized control
trial proposed here is the first to determine the safety of moderate intensity exercise
training and explore its potential benefits in patients with HCM.

Inclusion Criteria:

- Age ≥ 18 years and ≤ 80.

- Diagnosis of HCM, defined by the presence of unexplained left-ventricular hypertrophy
> 13 mm in any wall segment.

- Agreement to be a participant in the study protocol and willing/able to return for
follow-up.

Exclusion Criteria:

- History of exercise-induced syncope or arrhythmias (ventricular tachycardia or
non-sustained ventricular tachycardia).

- Medically refractory left ventricular outflow tract obstruction being evaluated for
septal reduction therapy.

- Less than 3 months post septal reduction therapy (surgery or catheter based
intervention).

- Hypotensive response to exercise (> 20 mm Hg drop in systolic blood pressure from peak
blood pressure to post exercise blood pressure).

- Pregnancy.

- Implantable Cardioverter-Defibrillator (ICD) placement in last 3 months or scheduled.

- Left ventricular systolic dysfunction (left ventricular ejection fraction < 55% by
echocardiography).

- Worsening clinical status in the last 3 months, advanced heart failure (New York Heart
Association class IV symptoms) or angina (Canadian Cardiovascular Society class IV
symptoms).

- Life expectancy less than 12 months.

- Inability to exercise due to orthopedic or other non-cardiovascular limitations.

- Unwillingness to refrain from competitive sports, burst activity, or heavy isometric
exercise for the duration of the study.