Table 1.

Methods for Evaluating Intermediately Symptomatic Patients With Hypertrophic Cardiomyopathy and Obstruction

Method	Description
New York Heart Association (NYHA) Class	Class I: No limitation of physical activity. Class II: Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, or dyspnea. Class III: Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, or dyspnea. Class IV: Unable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increases
Kansas City Cardiomyopathy Questionnaires (KCCQ)	23‐item, self‐administered questionnaire. Clinical score includes physical limitations and total symptom frequency and burden. Overall Score includes the clinical score plus measures of the stability of symptoms, self‐efficacy or perceived ability to manage symptoms as an outpatient, quality of life, and social limitations. Also available as a short form
Cardiopulmonary Exercise Testing	Symptom‐limited treadmill exercise with respiratory gas analysis. Peak VO2 is measured over 30‐s intervals during the test and ventilatory threshold (the point where body demands exceed the capacity for aerobic metabolism) is calculated
6‐Minute Walk Test	Measures distance walked in a 6‐minute time period
NT‐Pro‐BNP	Blood test that is elevated in a variety of heart failure conditions

NT‐Pro‐BNP indicates N‐terminal pro‐brain natriuretic peptide.