Echocardiographic Changes With Mavacamten in Nonobstructive Hypertrophic Cardiomyopathy: Exploratory Insights From the ODYSSEY-HCM Trial

doi:10.1016/j.jacc.2025.08.019

Heart failure & cardiomyopathies

Echocardiographic Changes With Mavacamten in Nonobstructive Hypertrophic Cardiomyopathy: Exploratory Insights From the ODYSSEY-HCM Trial

J Am Coll CardiolPublished 27 Aug 2025Secondary analysis of the ODYSSEY-HCM randomised trial

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Authors' conclusion

Symptomatic nHCM patients treated with mavacamten demonstrated directional improvements in markers of LV diastolic and LA function, modest regression in LV hypertrophy-related parameters, but 1 in 5 demonstrated an LVEF <50%, which reversed following therapy interruption.

Study context

Population: Symptomatic adults with nonobstructive hypertrophic cardiomyopathy (nHCM)
Participants: 580 adults

Comparison: Mavacamten vs placebo

Methodological detailsexploratory analysis, phase 3, placebo-controlled

Exploratory analysis
Phase 3
Placebo-controlled

Primary result

As reported in the abstract

Echocardiographic changes, placebo-corrected treatment difference · week 48

Mavacamten vs PlaceboPlacebo-corrected treatment difference, mm (95% CI)

Maximal LV wall thickness

−2.1(−2.5 to −1.7)

Mavacamten vs PlaceboPlacebo-corrected treatment difference, g/m2 (95% CI)

LV mass index

−3.8(−7.1 to −0.5)

Mavacamten vs PlaceboPlacebo-corrected treatment difference (95% CI)P value

E/e'

−1.3(−2.0 to −0.7)

LVEF reduction

−5.3%(−5.9% to −4.1%)

P < 0.01

Further findings

LV-global longitudinal strain, mavacamten patients maintaining LVEF ≥50% (n = 212) · week 48

Improvement in LV-global longitudinal strain: −0.4% [95% CI: −0.8% to −0.05%]; P < 0.05

Left atrial (LA) contractile and conduit strain · week 48

LA contractile strain improved significantly: −1.1% [95% CI: −1.8% to −0.4%]
LA conduit strain improved significantly: −1.4% [95% CI: −0.6% to −2.3%]

P < 0.05

LA volume, patients without AF · week 48

LA volume significantly reduced in patients without AF: −2.6 mL/m² [95% CI: −4.7 to −1.11 mL/m²]; P = 0.009

Safety

LVEF reduction <50% · recovered following drug interruption

Mavacamten21.5%

Placebo1.7%

Parts of this Brief are withheld: the automatic checks could not confirm them against the abstract.

Original publication

Echocardiographic Changes With Mavacamten in Nonobstructive Hypertrophic Cardiomyopathy: Exploratory Insights From the ODYSSEY-HCM Trial. J Am Coll Cardiol. Published 27 August 2025. doi:10.1016/j.jacc.2025.08.019

Read the original article ↗PubMed

Summarised from the published abstract; every number is checked against it