Mavacamten (Maifantuo): A Targeted Therapy for Obstructive Hypertrophic Cardiomyopathy

　　Mavacamten(brand name Maifantuo)marks a breakthrough as the first oral targeted therapy for obstructive hypertrophic cardiomyopathy(HCM).As a cardiac myosin inhibitor,it addresses the root cause—excessive myocardial contraction leading to LVOT obstruction—by fine-tuning contractile protein activity,offering new hope for symptom relief and disease progression delay.

　　1.Core Mechanism:Braking"Excessive Contraction"

　　The key pathology of obstructive HCM is abnormal binding of myosin and actin,causing sustained overcontraction and LVOT blockage.Mavacamten selectively inhibits cardiac myosin ATPase,reducing their binding efficiency and abnormal"cross-bridge"formation.Like easing the accelerator on runaway contraction,it relieves obstruction and enhances cardiac pumping.

　　2.Approved Indications:Precision Targeting

　　Mavacamten is indicated for symptomatic obstructive HCM patients​meeting:①NYHA class II-III(limited but not lost daily activity);②LVOT pressure gradient≥50 mmHg(at rest or provocation).It is particularly valuable for those with inadequate response to or intolerance of traditional therapies(e.g.,beta-blockers).

　　3.Dosing Guidelines:Individualized Start,Dynamic Optimization

　　Starting Dose:5 mg once daily(with or without food)for initial safety.

　　Dose Adjustment:Flexible titration within 2.5-15 mg/day based on tolerance(no severe adverse events)and efficacy(symptom/gradient improvement),max 15 mg/day.

　　Key Monitoring:Regular(every 3 months)echocardiograms to check left ventricular ejection fraction(LVEF);pause if LVEF<50%and reassess.

　　4.Efficacy&Safety Monitoring:Multidimensional Assessment

　　Five metrics guide treatment response:

　　Symptom Relief:NYHA class improvement(e.g.,from III to II);

　　Obstruction Reduction:LVOT gradient decrease≥30%(echo-measured);

　　Cardiac Structure:Stable/reduced septal thickness and left atrial size;

　　Exercise Tolerance:Increased 6-minute walk distance;

　　Quality of Life:Improved scores via KCCQ questionnaire.

　　Re-evaluate every 3-6 months to refine the plan.

　　5.Long-Term Management:Duration Varies,Discontinuation Requires Caution

　　Mavacamten is not"one-size-fits-all"lifelong therapy.Some patients with significant improvement(LVOT gradient<30 mmHg,NYHA class I)may attempt short-term discontinuation under supervision,but 60%-70%relapse and restart.Thus,long-term use depends on symptom stability,cardiac reserve,and recurrence risk—never stop without medical advice.

　　Mavacamten ushers in an era of"precision contraction inhibition"for obstructive HCM.Maximizing benefits requires"individualized plans+monitoring":patients report symptoms honestly,doctors adjust doses data-driven.Only close collaboration ensures this innovation truly protects long-term cardiac health.