Breaking Down Four Misconceptions About Hypertrophic Cardiomyopathy (HCM)

·5 min read

Get the real information on this common genetic heart condition

Hypertrophic cardiomyopathy, also known as HCM, is the most common genetic heart condition and can affect the heart’s structure and function, causing the walls of the heart muscle to thicken and stiffen, making it difficult for the heart to pump blood. HCM is estimated to affect 1 in 500 people with that number possibly reaching as high as 1 in 200.*[1],[2]

Researchers like Jil Tardiff, M.D., Ph.D., a professor of biomedical engineering, medicine, and cellular and molecular medicine at the University of Arizona College of Medicine and a paid spokesperson for Bristol Myers Squibb have been studying HCM extensively over the past several decades and understand the importance of clearing up common misconceptions.

Misconception #1: HCM is Easy to Diagnose

Approximately 100,000 patients in the United States have been diagnosed with HCM, suggesting that approximately 85% may remain undiagnosed.^ Part of the reason for this gap in diagnoses? “There are other conditions that have symptoms similar to those of HCM, so it can be difficult to get an accurate diagnosis,” Dr. Tardiff says. Symptoms like shortness of breath, dizziness, heart palpitations, and lightheadedness can all signal HCM—but they can also accompany many other health problems, such as anxiety, asthma, hypertension or coronary artery disease.

HCM also varies greatly from patient to patient, which can make a diagnosis challenging. Dr. Tardiff explains that symptoms are not always consistent—some patients can feel them one day and not experience them at all the following day. Some people don’t have symptoms at all (but may have been identified through genetic testing if a family member has the disease), others may have moderate disease progression, and others may have acute symptoms. For all these reasons, HCM can be difficult to diagnose. Helping people understand the disease and when they should talk with their doctor about their symptoms is an important first step in identifying HCM.

Misconception #2: HCM Mostly Affects Younger Male Athletes

HCM often makes news headlines when a young male athlete passes suddenly while playing a sport due to undiagnosed HCM, which may have led some to assume that the disease mainly affects younger male athletes (the incidence rate of sudden cardiac death occurs in less than 1% of HCM patients annually).[3] While these incidences are unquestionably tragic and understandably stand out in people’s minds, they do not tell the whole story.

In reality, HCM can affect anyone ‒ regardless of age, gender or ethnicity. Dr. Tardiff explains that HCM can show up in late adolescence or early adulthood. “In my practice, I see everyone from 20-year-olds to 85-year-olds—males and females,” says Dr. Tardiff. “It runs the gamut.”

Misconception #3: HCM Has a High Mortality Rate

“The first thing I ask my patients is: ‘Have you Googled it?’”, says Dr. Tardiff. “And if they have and [have seen information indicating a high mortality rate], I reassure them that they have every expectation that it can be a manageable disease.” While the risk of sudden cardiac death is rare, it is still substantially higher for both younger and older people who have HCM compared to the general population, the overall mortality rate is thought to be as low as 0.5%.

While there are devastating stories of people losing their life suddenly to HCM, there are many other instances of people living full lives with HCM. Like many diseases, early diagnosis is critical, as is finding the right specialist to oversee your care. When the disease is detected early and a personalized management plan is outlined by a cardiologist, the disease can be manageable.

Symptoms most commonly associated with HCM may include sudden fainting, shortness of breath, and chest pain, especially during or shortly following exertion or exercise. If you are experiencing any of these symptoms or if someone in your family was diagnosed with HCM, it’s important to talk to your healthcare provider to learn more. Symptoms can be representative of many conditions. Only a healthcare provider can determine whether these symptoms indicate HCM or another condition.

Misconception #4: Diet & Exercise Can Prevent HCM

Proper diet and exercise can go a long way in warding off common conditions and diseases, such as high blood pressure, diabetes, and stroke, but it can’t prevent HCM. For someone with HCM, when considering diet and exercise, it’s important to discuss with your doctor a plan that works best for you.

Why Clearing Up Common Misconceptions Matters

While it’s understandable that misconceptions about HCM can arise, Dr. Tardiff says that it’s critical to take the time to dispel them, especially as our knowledge of the disease continues to grow. “Misconceptions about HCM can unnecessarily frighten patients,” she says. “Some patients who are referred to me keep cancelling their appointments [out of fear].” This can lead to delays in getting the care that they need.

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* CARDIA study (published in 1995) is a multicenter, US-population-based echocardiography study of 4,111 subjects (aged 23-35), identified the prevalence of HCM as 1:500 people in the general population. The 2015 Semsarian publication identified that the prevalence of HCM-gene carriers could be as high as 1:200.

^ Based on a 2013 ICD-9 claims database analysis (N = 169,089,614) that estimated/concluded: 1. ~ 600,000 patients with undiagnosed HCM (based on analysis’ assumption that 1 in 500 prevalence represents clinically unrecognized cases), 2. ~100,000 patients with diagnosed HCM (based on 2013 US Census population and the ratio of 59,009 patients with a claim for HCM over the total N, stratified by age/gender), and 3. ~700,000 overall US prevalence of HCM.

Data from the ShaRe registry (Sarcomeric Human Cardiomyopathy Registry) database were compared with the Centers for Disease Control and Prevention WONDER database to estimate US general population mortality rates from 1999 to 2014.

[1] Maron BJ, Gardin JM, Flack JM, Gidding SS, Kurosaki TT, Bild DE. Prevalence of hypertrophic cardiomyopathy in a general population of young adults. Echocardiographic analysis of 4111 subjects in the CARDIA study. Circulation. 1995;92(4):785-789.

[2] Semsarian C, Ingles J, Maron MS, Maron BJ. New perspectives on the prevalence of hypertrophic cardiomyopathy. J Am Coll Cardiol. 2015;65(12):1249-1254.

[3] O’Mahony C, Elliot P, McKenna W. Sudden Cardiac Death in Hypertrophic Cardiomyopathy. Circulation: Arrhythmia and Electrophysiology. 2013;6(2):443–451.