What question did this study set out to answer?

To evaluate the long-term structural effects of mavacamten therapy on hypertrophic obstructive cardiomyopathy.

March 12, 2026Open Access

One- and two-year structural changes of mavacamten therapy in hypertrophic obstructive cardiomyopathy: A case report with serial comprehensive CMR demonstrating continuous reverse remodeling

Key Result

Mavacamten therapy led to progressive reverse remodeling in a patient with HOCM, with reduced LV mass index and normalized extracellular volume after two years.

Key Points

To evaluate the long-term structural effects of mavacamten therapy on hypertrophic obstructive cardiomyopathy.
Case study of a 39-year-old male with symptomatic HOCM refractory to traditional therapy
Initiation of mavacamten therapy
Serial cardiovascular magnetic resonance (CMR) assessments at one- and two-year follow-up
Progressive reverse remodeling observed over two years with reduced left ventricular ejection fraction and mass index
Native T1 relaxation times decreased while extracellular volume fraction normalized after initially increasing
No change in late gadolinium enhancement mass

Structured PICO

Does mavacamten therapy improve long-term structural reverse remodeling assessed by CMR in a patient with symptomatic HOCM?

Population

39-year-old male with symptomatic hypertrophic obstructive cardiomyopathy (HOCM) refractory to bisoprolol and disopyramide (n=1)

Intervention

Mavacamten therapy

Outcome

Structural changes and reverse remodeling assessed by serial comprehensive cardiovascular magnetic resonance (CMR) at one and two yearssurrogate

Mavacamten therapy in a patient with HOCM demonstrated continuous structural reverse remodeling on CMR over a two-year follow-up period, extending known short-term benefits.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Abstract Background Hypertrophic obstructive cardiomyopathy (HOCM) is characterized by dynamic left ventricular outflow tract (LVOT) obstruction and impaired quality of life. Mavacamten, a first-in-class myosin inhibitor, offers a novel therapeutic approach for HOCM, which improves clinical symptoms and exercise capacity while leading to reduction of LVOT gradient and favourable cardiac remodeling in echocardiography and cardiovascular magnetic resonance (CMR). However, data on CMR-derived treatment effects remain limited to short follow-up studies. Case summary A 39-year-old male with symptomatic HOCM refractory to bisoprolol and disopyramide was initiated on mavacamten therapy. Serial CMR after one and two years demonstrated progressive reverse remodeling over the follow-up period, including ongoing reduction of LV ejection fraction and LV mass index. While late gadolinium enhancement mass remained unchanged, there were divergent changes to measures of interstitial fibrosis: While native T1 relaxation times steadily decreased, extracellular volume (ECV) fraction initially increased but normalized at two-year follow-up. Discussion This case indicates that mavacamten leads to longer-term cardiac remodeling up to two years after initiation of treatment beyond early hemodynamic improvement and reduction of LVOT obstruction. These observations nurture additional studies to investigate longer-term effects on myocardial structure, function, and interstitial fibrosis.