This retrospective cohort study aims to evaluate the clinical efficacy and safety of mavacamten in adult patients with obstructive hypertrophic cardiomyopathy (oHCM). A total of 222 patients were included and categorized based on treatments received in routine clinical practice into a mavacamten group and a standard therapy group. The primary outcome is the change in resting left ventricular outflow tract (LVOT) gradient at Week 30. Secondary outcomes include changes in Valsalva LVOT gradient, New York Heart Association (NYHA) functional class, cardiac biomarkers, and echocardiographic parameters. Safety outcomes include adverse events and left ventricular systolic dysfunction. This study provides real-world evidence on the effectiveness and safety of mavacamten in Chinese patients with oHCM.
Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disorder characterized by left ventricular hypertrophy, with approximately two-thirds of patients presenting with obstructive physiology. Obstructive hypertrophic cardiomyopathy (oHCM) is associated with significant morbidity due to left ventricular outflow tract (LVOT) obstruction. Mavacamten, a first-in-class cardiac myosin inhibitor, directly targets the underlying pathophysiology of oHCM by reducing excessive myosin-actin cross-bridge formation. Although previous randomized clinical trials, such as EXPLORER-CN, have demonstrated its efficacy, real-world data in Chinese populations remain limited. This study is a retrospective cohort study conducted at Fuwai Central China Cardiovascular Hospital. Patients were not assigned to interventions. Instead, they were categorized based on treatments received in routine clinical practice. Eligible adult patients with oHCM who initiated mavacamten therapy were included in the treatment group, while patients receiving standard pharmacological therapy served as the control group. Clinical data were collected from January 2024 to May 2025, with final database lock completed in June 2025. Baseline characteristics, echocardiographic parameters, and laboratory biomarkers were obtained from medical records. The primary endpoint was the change in resting LVOT peak gradient at Week 30 compared with baseline. Secondary endpoints included changes in Valsalva LVOT gradient, NYHA functional class improvement, NT-proBNP, high-sensitivity cardiac troponin I (hs-cTnI), left ventricular ejection fraction (LVEF), and tricuspid annular plane systolic excursion (TAPSE). Safety endpoints included adverse events, serious adverse events, treatment discontinuation, and reduction of LVEF below 50%. This study aims to provide real-world evidence regarding the clinical effectiveness and safety of mavacamten in adult patients with oHCM in China.
Study Type
OBSERVATIONAL
Enrollment
222
Mavacamten was administered as part of routine clinical care for patients with obstructive hypertrophic cardiomyopathy. This observational study did not assign interventions; instead, patients were categorized based on treatments received in real-world clinical practice. The initial dose was 2.5 mg once daily, with dose adjustments based on left ventricular ejection fraction and LVOT gradient as clinically indicated.
Fuwai Central China Cardiovascular Hospital
Zhengzhou, Henan, China
Change in Resting Left Ventricular Outflow Tract (LVOT) Peak Gradient at Week 30
Change from baseline in resting left ventricular outflow tract (LVOT) peak gradient measured by Doppler echocardiography (unit: mmHg). Higher values indicate greater obstruction.
Time frame: Baseline to Week 30
Change in Valsalva-Induced Left Ventricular Outflow Tract (LVOT) Peak Gradient at Week 30
Change from baseline in LVOT peak gradient induced by the Valsalva maneuver measured by Doppler echocardiography (unit: mmHg). Higher values indicate greater obstruction.
Time frame: Baseline to Week 30
Proportion of Participants with Improvement in New York Heart Association (NYHA) Functional Classification at Week 30
Proportion of participants achieving at least one class improvement in New York Heart Association (NYHA) functional classification compared with baseline. NYHA class ranges from I to IV, where higher classes indicate worse functional status.
Time frame: Baseline to Week 30
Change in N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) Levels at Week 30
Change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels (unit: pg/mL). Higher values indicate worse cardiac function.
Time frame: Baseline to Week 30
Change in High-Sensitivity Cardiac Troponin I (hs-cTnI) Levels at Week 30
Change from baseline in high-sensitivity cardiac troponin I (hs-cTnI) levels (unit: ng/L). Higher values indicate greater myocardial injury.
Time frame: Baseline to Week 30
Change in Left Ventricular Ejection Fraction (LVEF) at Week 30
Change from baseline in left ventricular ejection fraction (LVEF) measured by echocardiography (unit: %). Higher values indicate better cardiac systolic function.
Time frame: Baseline to Week 30
Change in Tricuspid Annular Plane Systolic Excursion (TAPSE) at Week 30
Change from baseline in tricuspid annular plane systolic excursion (TAPSE) measured by echocardiography (unit: mm). Higher values indicate better right ventricular function.
Time frame: Baseline to Week 30
Incidence of Adverse Events
Number and proportion of participants experiencing any adverse events.
Time frame: Up to Week 30
Incidence of Serious Adverse Events
Number and proportion of participants experiencing serious adverse events.
Time frame: Up to Week 30
Incidence of Treatment Discontinuation Due to Adverse Events
Number and proportion of participants who discontinued treatment due to adverse events.
Time frame: Up to Week 30
Incidence of Left Ventricular Ejection Fraction Reduction Below 50%
Number and proportion of participants with LVEF \<50% during treatment.
Time frame: Up to Week 30
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