Title: Mavacamten for treating symptomatic obstructive hypertrophic cardiomyopathy [ID3928]
Funder: Department of Health and Social Care

Abstract: Hypertrophic cardiomyopathy (HCM) is a genetic condition that is most often caused by a change or fault (or mutation) in one or more genes and is characterised by the thickening of the muscular wall of the heart (the myocardium). Thickening of the septum (the dividing wall between the left and the right side of the heart), resulting in reduced or restricted blood flow is classified as obstructive HCM. Most people with HCM may initially have few or no symptoms. However, the disease is progressive, and symptoms may develop or worsen at any age. Common symptoms of HCM include shortness of breath, chest pain, palpitations, light headedness, and fainting. People with obstructive HCM can develop serious complications such as atrial fibrillation, heart failure, malignant ventricular arrhythmias, and sudden cardiac death._x000D_ _x000D_ HCM is the most common genetic cardiovascular disease and has a prevalence of around 1 in 500 people in the general population. However, most people with HCM have few, if any, symptoms[1] .The disease most commonly presents in the second or third decade of life but may present at any age. HCM is the most common cause of sudden unexpected death in childhood and in young athletes[2] ._x000D_ _x000D_ There is no curative treatment for HCM. Treatment approaches vary depending on symptoms and risk of sudden disease. People with HCM often need to make lifestyle changes, such as limiting their activity, to adjust for their disease. European Society of Cardiology (ESC) Guidelines on hypertrophic cardiomyopathy recommend that people with symptomatic disease, predominately with left ventricular outflow tract obstruction, receive beta-blockers to reduce symptoms and obstruction. If betablockers are ineffective or contraindicated, non-dihydropyridine calcium channel blockers (such as verapamil and diltiazem) are suitable alternatives. Disopyramide, alone or in combination with either beta-blockers or non-dihydropyridine calcium channel blockers, can also be considered. If severe symptoms persist despite maximally tolerated medical therapy, people may be offered surgical myectomy or non-surgical reduction of the myocardial septum (NICE interventional procedures guidance 40). For people with obstructive HCM who progress to heart failure, the only ESC guideline recommended treatment options are those recommended to manage left ventricular outflow obstruction. People with HCM, regardless of the presence of obstruction, should undergo clinical risk assessment for sudden cardiac death risk. In cases where individuals are considered to be at high risk of arrhythmias and sudden cardiac death, implanted devices such as a pacemaker or an implantable cardioverter defibrillator may be used._x000D_ _x000D_ References_x000D_ 1 Hypertrophic cardiomyopathy. British Heart Foundation. Accessed May 2021._x000D_ 2 Cardiomyopathy. NHS. Accessed May 2021.

Lay abstract: To appraise the clinical and cost effectiveness of mavacamten within its marketing authorisation for treating symptomatic obstructive hypertrophic cardiomyopathy.

Research activity codes: 6.1 PHARMACEUTICALS
Health categories: CARDIOVASCULAR