Framing Obstructive Hypertrophic Cardiomyopathy: Epidemiology, Pathophysiology, and Clinical Focus

In this introductory discussion, host Martin Maron, MD, director of the hypertrophic cardiomyopathy (HCM) program at the Leahy Clinic in Burlington, Massachusetts, and guest Ahmed Masri, MD, PA-C, director of the HCM program at Oregon Health and Science University, establish obstructive HCM as the primary focus of the program. Maron notes that approximately two thirds of the HCM population exhibits left ventricular outflow tract (LVOT) obstruction, defined hemodynamically by mitral valve–septal contact and the resultant pressure gradient, typically assessed by transthoracic echocardiography. This obstructive physiology is positioned as the central therapeutic target in contemporary HCM management.

Maron emphasizes that in obstructive HCM, the LVOT gradient and associated systolic anterior motion (SAM)–mediated mitral regurgitation are now recognized as key determinants of exertional limitation and symptomatic burden. The clinicians highlight that treatment paradigms in this population are fundamentally aimed at improving functional capacity and quality of life by reducing or abolishing the LVOT gradient at rest and with provocation. This conceptual framework underpins the subsequent discussion of both historical therapies and novel sarcomere-directed agents.

Together, Maron and Masri set the stage for a treatment-focused exploration, signaling a shift from merely accommodating a fixed structural disease toward precise modulation of pathologic hypercontractility. The segment prepares clinicians to consider how evolving therapies—including cardiac myosin inhibitors—fit into a landscape previously dominated by negative inotropes and invasive septal reduction strategies, with the LVOT gradient as the unifying therapeutic endpoint.