This study is testing a medicine called aficamten to see if it helps people with a heart problem called non-obstructive hypertrophic cardiomyopathy (nHCM). nHCM means the heart's muscle walls are too thick, making it harder for the heart to work well. Doctors will compare aficamten to a placebo (a pill with no medicine) to see which works better.

To join, you must be 18 to 85 years old and have nHCM. You’ll need an echocardiogram, which is a test that uses sound waves to make pictures of your heart. They’ll check how thick your heart walls are and how well your heart pumps blood. People with other heart diseases or who can't do exercises like walking on a treadmill can't join.

• The study will measure how aficamten affects exercise ability, life quality, and heart health.
• Participants will be randomly given either aficamten or a placebo.
• Doctors will check health changes through tests and exercises over time.

Consider joining if you want to help test this new treatment, but be sure to discuss any potential risks with your doctor.