Mavacamten for the treatment of postoperative obstructive hypertrophic cardiomyopathy: a case report and literature review

Hypertrophic cardiomyopathy (HCM) is a major type of cardiovascular disease worldwide, posing a serious threat to human health. The clinical symptoms of HCM patients are highly variable: some patients may remain asymptomatic for a long time, while sudden cardiac death (SCD) is the first symptom in others. SCD represents a catastrophic clinical outcome of HCM. Patients diagnosed with HCM in childhood or adolescence tend to have more symptoms and may have a poorer prognosis. According to the 2023 Chinese Guidelines for the Diagnosis and Treatment of Adult Hypertrophic Cardiomyopathy, HCM is clinically classified into two subtypes: obstructive hypertrophic cardiomyopathy (oHCM) and nonobstructive hypertrophic cardiomyopathy (nHCM). Obstructive HCM is defined as a peak left ventricular outflow tract pressure gradient (LVOTG) of ≥ 30 mmHg at rest or after provocation; nonobstructive HCM is defined as a peak LVOTG of ＜ 30 mmHg both at rest and after provocation. Traditional non-specific drugs, such as beta-blockers, calcium channel blockers, and disopyramide, have limited efficacy. Mavacamten, the targeted therapeutic agent classified as first myocardial myosin inhibitor, cardiovascular drug for precision treatment based on the etiology and pathogenesis of the disease. This article reports a case of a patient diagnosed with oHCM, whose clinical symptoms improved significantly after treatment with mavacamten.