The Therapeutic Value of Mavacamten in Hypertrophic Cardiomyopathy With Mid-to-Apical Left Ventricular Obstruction

Official title

The Therapeutic Value of Mavacamten in Hypertrophic Cardiomyopathy With Mid-to-Apical Left Ventricular Obstruction: A Prospective, Interventional, Real-World Clinical Study.

Overview

This study is a prospective interventional cohort study aimed at evaluating the therapeutic efficacy and clinical utility of Mavacamten-a targeted myosin inhibitor specifically developed for obstructive hypertrophic cardiomyopathy (HCM)-in patients with HCM characterized by mid-to-apical left ventricular obstruction.

Interventions

• Drug mavacamten
  Add Mavacamten to guideline-directed standard medical therapy for patients with hypertrophic cardiomyopathy (HCM) and mid-to-apical left ventricular obstruction.
• Drug Beta Blocker (BB) - metoprolol, bisoprolol, carvedilol
  Administer an appropriate dose of beta-blockers according to the patient's tolerance.
• Drug diltiazem
  Administer an appropriate dose of diltiazem according to the patient's tolerance.

Primary outcome measures

• Percentage change in pressure gradient during the Valsalva maneuver [Time frame: Week 36]

Secondary outcome measures (11)

• Anterior papillary muscle to the interventricular septum distance [Time frame: Week 36]
• Left atrial global longitudinal strain [Time frame: Week 36]
• Left ventricular global longitudinal strain [Time frame: Week 36]
• Percentage change in resting pressure gradient [Time frame: Week 36]
• Absolute change in pressure gradient during the Valsalva maneuver [Time frame: Week 36]
• The proportion of patients with a pressure gradient <30 mmHg during the Valsalva maneuver [Time frame: Week 36]
• BNP [Time frame: Week 36]
• Troponin T [Time frame: Week 36]
• New-onset atrial fibrillation [Time frame: From baseline to week 36]
• LVEF<50% [Time frame: From baseline to week 36]
• LVEF<40% [Time frame: From baseline to week 36]

Eligibility criteria

Inclusion criteria

• Patients diagnosed with HCM according to the 2023 Chinese Guidelines for the Diagnosis and Treatment of Adult Hypertrophic Cardiomyopathy, meeting one of the following:

• Left ventricular wall thickness ≥15 mm at end-diastole in any segment as assessed by echocardiography or cardiac magnetic resonance imaging (CMR);
• Left ventricular wall thickness ≥13 mm in individuals with a confirmed pathogenic gene mutation or in genetically affected family members;
• Exclusion of other cardiovascular, systemic, or metabolic disorders that may cause ventricular hypertrophy.

• Symptomatic non-outflow tract obstructive HCM patients (meeting criterion a and at least one of b or c):

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• Presence of clinical symptoms such as dyspnea, chest pain, dizziness, palpitations, or syncope, with New York Heart Association (NYHA) functional class II-III;
• Maximal pressure gradient (PGmax) >30 mmHg in the mid-ventricle under resting or Valsalva maneuver as assessed by echocardiography;
• PGmax >30 mmHg in the apical region under resting or Valsalva maneuver on echocardiography.

③Ability to provide written informed consent (ICF) and any required privacy authorization prior to study enrollment.

Exclusion criteria

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• Obstructive hypertrophic cardiomyopathy (HCM), defined as a maximal left ventricular outflow tract pressure gradient (LVOT-PGmax) ≥30 mmHg at rest and during the Valsalva maneuver on echocardiography;

• Maximal right ventricular outflow tract pressure gradient (RVOT-PGmax) ≥16 mmHg at rest; ③ Left ventricular ejection fraction (LVEF) <50% on echocardiography;

• Uncontrolled primary hypertension;

• Moderate or severe aortic valve stenosis and/or primary mitral valve disease with severe mitral regurgitation; ⑥ Known infiltrative or storage disorders mimicking the HCM phenotype (e.g., Fabry disease, cardiac amyloidosis); ⑦ Presence of severe infections, hepatic dysfunction, renal impairment, or other serious conditions significantly affecting life expectancy.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

China · 1 center

• Second Affiliated Hospital, Zhejiang University School of Medicine — Hangzhou

Identifiers

NCT: NCT07103655 · 2025-1056

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗