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There exist multiple risk factors for the development of heart failure. Lifestyle choices such as smoking or lack of exercise, and conditions like obesity can all increase the risk of developing heart failure. Hypertrophic Cardiomyopathy (HCM) is a genetic heart condition that may also lead to a patient developing heart failure.1,2
HCM Background
Hypertrophic cardiomyopathy (HCM) is the most common genetic abnormality of the heart. In HCM, a genetic mutation causes the muscle in the heart wall to become thicker and stiffer than normal, making it more difficult for the heart to pump and fill with blood. HCM affects approximately 750,000 people in the United States and an estimated 20 million globally. HCM occurs in many different countries, ethnic groups, and races. It affects both men and women and all age groups.2,3,4
Patient Evaluation and Path to a Diagnosis
The path and time to diagnosis may vary depending on patient circumstances. Patients with a known family history may seek medical attention and receive a diagnosis once they experience an unexplained heart issue. Others may seek medical attention for an unrelated health issue and are found to have heart problems that lead to a diagnosis. Some patients may delay diagnosis by declining necessary diagnostic testing out of concern of the implications of results. Others may not have received a diagnosis because their healthcare providers are not familiar with the symptoms and diagnosis of HCM.3,4
HCM diagnosis involves a visit to a cardiologist. The cardiologist evaluates a patient’s personal and family history. Echo or cardiac magnetic resonance imaging (CMR) is done to look at the structure and function of the heart. The cardiologist may order genetic testing depending on a patient's family history.5
Echo and CMR help the cardiologist see if the thickness of the heart wall meets the criteria for HCM. The cardiologist then determines what type of HCM a patient has. There are two main types of HCM: obstructive HCM (oHCM) and non-obstructive HCM (nHCM). Almost two-thirds of HCM patients have the obstructive form of the disease. This means their mitral valve moves abnormally, causing it to come in contact with the thickened heart muscle, and therefore partially obstructing flow of blood out of the heart. The remaining one-third of HCM patients have the non-obstructive form of the disease. This means their heart muscle is thickened but there is no obstruction to blood flow out of the heart at rest or with exercise.4
Symptoms and the Experience of Living With HCM
The most common symptoms experienced by patients are tiredness, shortness of breath, shortness of breath with physical activity, and dizziness/light-headedness. Other symptoms include chest pain, rapid heartbeat, and fainting. Some patients with HCM will not experience any symptoms. Data collected from a Hypertrophic Cardiomyopathy Association (HCMA) patient web survey (2,467 patients) and one-on-one interviews (27 patients) suggests HCM can significantly impact patients’ lives, including limitations to physical activities, emotional impacts, feelings of anxiety or depression, and impacts on work. Patients describe both negative and positive feelings about living with HCM. Some are fearful about the potential complications of the disease. Others feel like they have a new lease on life now that they have a diagnosis and become more mindful of their daily habits.2,3,6
Disease Complications and Outcomes
HCM is the most important cause of sudden death on the athletic field in the United States. Cardiologists should assess the risk of sudden cardiac death in patients diagnosed with HCM. Patients at increased risk may be candidates for an implantable cardioverter-defibrillator (ICD) device. The use of these devices has greatly reduced the risk of HCM-related death. About 20% of patients with HCM develop atrial fibrillation. Patients with HCM can also develop heart failure. Despite the risk of these complications, the risk of HCM-related death is one of the lowest among the most common chronic diseases.4
Treatment
The goals of hypertrophic cardiomyopathy treatment are to relieve symptoms and prevent sudden cardiac death in select patients at elevated risk. Treatment choice depends on how severe the symptoms are. Sudden death in patients with HCM can be prevented by using implanted cardioverter-defibrillator (ICDs) once the cardiologist completes a risk assessment. Medications such as beta blockers and calcium channel blockers relax the heart muscle, allowing it to fill better and pump more effectively. This can help relieve some of the symptoms patients experience. Other medications can help control heart rate or decrease the occurrence of arrhythmias such as atrial fibrillation.2,4,7
There is a new class of drugs called cardiac myosin inhibitors. FDA-approved cardiac myosin inhibitors treatments exist for symptomatic oHCM. Unlike other HCM medications, the cardiac myosin inhibitor mavacamten is used to improve symptoms and function in patients with the obstructive type of HCM who have mild to moderate symptoms while being treated with beta blockers or calcium channel blockers. Another next-in-class cardiac myosin inhibitor, aficamten, is an investigational agent that is currently tested in ongoing clinical trials and has not been approved by the US FDA or any regulatory agency. Its safety and efficacy have not been established. If oHCM patients continue to have symptoms after trying drug therapy, alternatives like surgery may be an option.
References
1. Benjamin E, et al. Heart Disease and Stroke Statistics – 2019 Update. Circulation. 2019;139:e56-e528
2. Ommen SR, et al. 2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2020 Dec 22;142(25):e558-e631.Maron BJ, et al.. Management of Hypertrophic Cardiomyopathy: JACC State-of-the-Art Review. J Am Coll Cardiol. 2022 Feb 1;79(4):390-414
3. Zytnick D, et al. Exploring experiences of hypertrophic cardiomyopathy diagnosis, treatment, and impacts on quality of life among middle-aged and older adults: An interview study. Heart Lung. 2021 Nov-Dec;50(6):788-793.
4. Maron BJ. Clinical Course and Management of Hypertrophic Cardiomyopathy. N Engl J Med. 2018 Aug 16;379(7):655-668.
5. Maron BJ, Desai MY, Nishimura RA, Spirito P, Rakowski H, Towbin JA, Rowin EJ, Maron MS, Sherrid MV. Diagnosis and Evaluation of Hypertrophic Cardiomyopathy: JACC State-of-the-Art Review. J Am Coll Cardiol. 2022 Feb 1;79(4):372-389
6. Zaiser E, et al. Patient experiences with hypertrophic cardiomyopathy: a conceptual model of symptoms and impacts on quality of life. J Patient Rep Outcomes. 2020 Dec 1;4(1):102.
7. Sebastian SA, Padda I, Lehr EJ, Johal G. Aficamten: A Breakthrough Therapy for Symptomatic Obstructive Hypertrophic Cardiomyopathy. Am J Cardiovasc Drugs. 2023.
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Helpful Resources
Visit the HFSA Patient Hub to explore tools and resources to help patients stay healthy while living with heart failure.
View Heart Failure Awareness 365 activities to stay up-to-date on tips for healthy living for people living with heart failure.