In hypertrophic obstructive cardiomyopathy (HOCM), which medication is a recently approved first-in-class cardiac myosin inhibitor shown to reduce LVOT gradient in the EXPLORER-HCM trial?

• A Valsartan-sacubitril (Entresto)
• B Disopyramide as a novel agent
• C Dabigatran for HOCM-related AF prevention
• D Mavacamten (MYK-461) ✓

Explanation

Mavacamten is a first-in-class cardiac myosin inhibitor (allosteric inhibitor of beta-myosin heavy chain ATPase) that reduces the number of myosin-actin cross-bridges, decreasing excessive contractility and LVOT obstruction in HOCM. The EXPLORER-HCM trial (NEJM 2020) showed significant reduction in LVOT peak gradient, improvement in NYHA class, and exercise capacity. It received FDA approval in 2022. Sacubitril-valsartan is used in HFrEF, not HOCM. Disopyramide (existing therapy) reduces contractility through antiarrhythmic mechanism but is established, not novel.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.