Heart failure & cardiomyopathiesResearch article
Cardiac Myosin Inhibition in Heart Failure With Normal and Supranormal Ejection Fraction
- Single-arm trial
- phase 2a
- open-label
- multicenter
- 20 sites in the US and Canada
- Conducted November 6, 2020, to February 26, 2024
Authors' conclusion
In an open-label trial in patients with HFpEF with LVEF of 60% or greater, mavacamten was associated with improvements in biomarkers of cardiac wall stress and injury, with no sustained reductions in LVEF observed.
Study context
- Population
- Symptomatic heart failure with preserved ejection fraction (HFpEF) (NYHA II or III) with left ventricular ejection fraction (LVEF) ≥60%, elevated NTproBNP and LV hypertrophy
- Participants
- 30 participants
- Outcome
- Change in NTproBNP and high-sensitivity troponin T (hsTnT)
- Follow-up
- Baseline to week 26
Main finding
As reported in the abstract
MavacamtenMean reduction (95% CI)P value
NTproBNP
−26%(−44% to −4%)
P = 0.04hsTnT
−13%(−23% to −3%)
P = 0.02Further findings
High-sensitivity troponin I (hsTnI) change · baseline to week 26
| Comparison | mean reduction (95% CI) | P value | |
|---|---|---|---|
| Mavacamten · single-arm, change from baseline | −20% (−32% to −6%) | P = 0.01 | |
| −40−20020Difference (linear scale) |
Cardiac biomarkers after drug discontinuation · 8 weeks after discontinuation
- Cardiac biomarker values returned toward baseline levels
NYHA class improvement · end of treatment
- NYHA class improved (patients with evaluable NYHA data)
- 10 of 24 patients (41.7%)
Echocardiographic markers of LV diastolic function
- Improvements in echocardiographic markers of LV diastolic function observed
Deaths, LVEF <30%, worsening HF
- Deaths
- 0
- LVEF less than 30%
- 0
- Worsening HF, deemed unrelated to study drug
- 1
Safety
LVEF change · during treatment
- Mean LVEF decrease (absolute percentage points)
- 3.2 (95% CI, 1.1-5.4; P = .005)
Treatment interruption (prespecified LVEF criteria)
- Mavacamten interrupted
- 3 patients (10% of the study population; 95% CI, 2.1%-26.5%)
- LVEF less than 50%
- 2
- >20% relative decrease from baseline (nadir LVEF 58%)
- 1
- LVEF recovery observed
- all 3 patients
Original publication
Cardiac Myosin Inhibition in Heart Failure With Normal and Supranormal Ejection Fraction. JAMA Cardiol. Published 1 February 2025. doi:10.1001/jamacardio.2024.3810
Summarised from the published abstract; every number is checked against it