Prospective evaluation of real-world safety, symptoms improvement and adherence to mavacamten among Iranian patients with hypertrophic obstructive cardiomyopathy (PERSIA-HOCM): protocol of a multicentre observational study.

introductionHypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disorder affecting approximately 1 in 200 to 1 in 500 adults, with nearly 70% exhibiting the obstructive phenotype Hypertrophic Obstructive Cardiomyopathy (HOCM). Randomised trials have demonstrated the efficacy of mavacamten, a first-in-class cardiac myosin inhibitor which significantly reduced outflow tract gradients and improved symptoms, exercise capacity and quality of life in the HOCM cases. Despite these findings, prospective real-world data on its safety and effectiveness remain limited, particularly in non-Western populations and further evidence from routine clinical practice is needed. METHODS AND ANALYSIS: PERSIA-HOCM is a prospective, multicentre, observational study to be conducted at 19 cardiovascular referral centres in Iran. Adults aged 18 years or older with symptomatic obstructive HCM, defined as New York Heart Association (NYHA) class II to IV and a left ventricular outflow tract (LVOT) gradient of at least 50 mm Hg at rest or with provocation, who are prescribed mavacamten, will be enrolled. Key exclusions include left ventricular ejection fraction below 55%, non-obstructive phenotype and lack of consent. Participants will be followed for 1 year at 4-week intervals. Data collection will include symptoms, NYHA class, vital signs, echocardiographic parameters (including outflow gradients and ejection fraction), mavacamten dosing and adjustments and concomitant therapies. Echocardiography will be performed at weeks 4, 8, 12 and 24. Safety will be assessed using a predefined adverse event framework that includes mortality, hospitalisations and major clinical events. At weeks 12 and 48, cardiac troponin, N-terminal pro B-type natriuretic peptide and quality of life will be assessed. Primary endpoints will be safety, change in the NYHA class, resting and provoked LVOT gradient, quality of life, cardiac biomarkers and left ventricular ejection fraction. Secondary endpoints will include cardiac magnetic resonance imaging parameters for cardiac fibrosis, peak oxygen intake and genotype-based outcome. Analyses will be performed using R V.4.5.1, employing descriptive statistics, paired sample t tests and McNemar's test. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Research Ethics Committee of Rajaie Cardiovascular, Medical and Research Institute/Iran National Committee for Ethics in Biomedical Research (Code: IR.RHC.REC.1404.210). Written informed consent will be required and filled by the patients. Considering full data confidentiality, analysis reports will be public every 6 months. Findings will be disseminated through peer-reviewed publications and scientific conferences.