The Most Common Form of Genetic Heart Disease That You Might Not Know About
Ever since he was a teenager, Dave had been told that he had a heart murmur. Despite this, the murmur didn’t have an impact on his life, and he never really considered that he might have a heart disease. It wasn’t until he was in his mid-fifties when he was referred to a cardiologist in preparation for a minor routine procedure that he was diagnosed with symptomatic obstructive hypertrophic cardiomyopathy, or symptomatic oHCM, a chronic heart condition that, if left untreated, can lead to serious complications.
HCM is the most commonly inherited heart disease, impacting 1 in 200* to 1 in 500^ people in the general population,1,2 with obstructive HCM making up the majority of the diagnoses.†,3,4 HCM can affect anyone regardless of age, gender, or ethnicity, but it often remains undiagnosed until young adulthood and even as late as midlife, as in Dave’s case.5,6
“The reason [symptomatic oHCM] can be hard to diagnose even in patients who have symptoms is that the symptoms can be gradual and varied,” says Dr. Andrew Wang, a cardiologist from Duke University who serves as the director of the Duke Hypertrophic Cardiomyopathy (HCM) Clinic. “Patients routinely say that they have good days and bad days related to their condition. The symptoms can be nonspecific and intermittent, which makes the diagnosis challenging.”
Dave recalls experiencing periodic moments of light headedness both before and after his diagnosis with symptomatic oHCM, including one memorable occasion where he had to stop and lean on a tree for support while going on a familiar walk. For people diagnosed with symptomatic oHCM, other symptoms may include palpitations, chest pain, shortness of breath, dizziness, and fatigue.7
Symptomatic oHCM is a diverse disease and can be a diagnostic challenge for doctors because the specific symptoms and the course of the disease can vary across patients. Steps to confirm a symptomatic oHCM diagnosis can include a variety of tests, such as an electrocardiogram (ECG), echocardiogram (Echo), cardiac MRI, and genetic testing.8 For Dave, there was another important piece of the puzzle: he had a close relative that had also been diagnosed with HCM. While not all cases of HCM are genetic, it can be an inherited disease. Of all cases of HCM, 66% are obstructive.8
How Does Symptomatic Obstructive HCM Affect the Heart?
HCM causes the heart muscle wall to thicken and stiffen, making it harder for the heart to fill with blood. When HCM causes the heart muscle to get so thick that it blocks or reduces blood flow from the heart to the rest of the body, it’s called obstructive HCM. Obstructive HCM is also referred to as HoCM (short for hypertrophic obstructive cardiomyopathy), and you may have heard this term in discussions with your doctor.
Obstructive HCM makes it difficult for the heart muscle to relax, so the heart must work harder and use more energy. When you have symptoms with obstructive HCM, it’s called symptomatic obstructive HCM. These symptoms can increase with physical exertion and worsen over time.
Dr. Wang compares it to the narrowing of a hallway. For example, in cases where the thickening causes obstruction to the heart’s outflow track, or where blood flows out of the heart, the exit door isn’t “blocked,” he says, but it’s harder for the blood to get down the hallway and out the door. The obstruction is dynamic, meaning how much the “hallway” is narrowed can change even during a single day, one of the reasons the symptoms of obstructive HCM can feel so variable and affect the same person differently.
For Dave, the fact that his heart needs to work extra hard due to symptomatic obstructive HCM is possibly why he had moments of feeling lightheaded and needed to stop and catch his breath during routine activities.
Dr. Wang says when people are first diagnosed with symptomatic oHCM, they are often concerned about how it will affect their lifespan, or that something imminent or urgent will happen to them. It can be hard to come to terms with living with a chronic heart disease. He wants his patients to know they can and often do live a typical lifespan, and that complications like sudden cardiac death can happen to some patients, although this affects a small percentage of HCM patients. It is more common for HCM patients to develop symptoms that negatively affects their quality of life.
An Approved Treatment Option
This year, a first-in-class treatment option called CAMZYOS® (mavacamten) was approved by the U.S. Food and Drug Administration (FDA) for patients with symptomatic oHCM. CAMZYOS is the first and only FDA-approved cardiac myosin inhibitor that specifically targets the source of symptomatic oHCM.
Within the heart, there are two proteins called myosin and actin which contribute to your heart pumping by connecting and releasing. In symptomatic obstructive HCM, the myosin and actin form too many connections with each other, causing the heart to contract too much, which can make it difficult for it to relax. CAMZYOS binds to myosin so that it can “let go” of actin, which reduces the excessive connections between the two proteins, helping the heart muscle relax more. CAMZYOS may improve symptoms of NYHA class II-III** symptomatic obstructive HCM, as well as help a patient’s ability to be active.
Life With Symptomatic Obstructive HCM
Based on his family history and his own diagnosis, Dave has been encouraging his adult children to talk to their doctors. Dave feels that it’s important to share his story and raise awareness about symptomatic oHCM, given his own experience. He knows that there are common misconceptions about symptomatic oHCM.
“I want everyone to know that for most people diagnosed, it’s not a death sentence,” he said, “And that it’s important to speak to your doctor to determine your risk and come up with a plan to manage your symptomatic oHCM that suits you.”
* The 2015 Semsarian publication identified that the prevalence of HCM could be as high as 1 in 200.
^ The 1995 CARDIA study—a multicenter, US-population–based echocardiography study of 4111 subjects (aged 23-35) identified the prevalence of HCM as 1 in 500 in the general population.
† LVOT obstruction is defined by an LVOT peak gradient of ≥30 mmHg.
** Class II patients have mild symptoms (mild shortness of breath and/or angina) and slight limitation during ordinary activity. Class III patients have marked limitation in activity due to symptoms.
CAMZYOS® (mavacamten) is a prescription medicine used to treat adults with symptomatic obstructive hypertrophic cardiomyopathy (HCM). CAMZYOS may improve your symptoms and your ability to be active.
IMPORTANT SAFETY INFORMATION
CAMZYOS (mavacamten) may cause serious side effects, including:
Heart failure, a condition where the heart cannot pump with enough force. Heart failure is a serious condition that can lead to death. You must have echocardiograms before you take your first dose and during your treatment with CAMZYOS to help your healthcare provider understand how your heart is responding to CAMZYOS. People who develop a serious infection or irregular heartbeat have a greater risk of heart failure during treatment with CAMZYOS. Tell your healthcare provider or get medical help right away if you develop new or worsening shortness of breath, chest pain, fatigue, swelling in your legs, a racing sensation in your heart (palpitations), or rapid weight gain.
The risk of heart failure is also increased when CAMZYOS is taken with certain other medications. Tell your healthcare provider about the medicines you take, both prescribed and obtained over-the-counter, before and during treatment with CAMZYOS.
Because of the serious risk of heart failure, CAMZYOS is only available through a restricted program called the CAMZYOS Risk Evaluation and Mitigation Strategy (REMS) Program.
- Your healthcare provider must be enrolled in the CAMZYOS REMS Program in order for you to be prescribed CAMZYOS.
- Before you take CAMZYOS, you must enroll in the CAMZYOS REMS Program. Talk to your healthcare provider about how to enroll in the CAMZYOS REMS Program. You will be given information about the program when you enroll.
- Before you take CAMZYOS, your healthcare provider and pharmacist will make sure you understand how to take CAMZYOS safely, which will include returning for echocardiograms when advised by your healthcare provider.
- CAMZYOS can only be dispensed by a certified pharmacy that participates in the CAMZYOS REMS Program. Your healthcare provider can give you information on how to find a certified pharmacy. You will not be able to get CAMZYOS at a local pharmacy.
- If you have questions about the CAMZYOS REMS Program, ask your healthcare provider, visit www.CAMZYOSREMS.com or call 1-833-628-7367.
Before you take CAMZYOS, tell your healthcare provider about all of your medical conditions, including if you:
- are pregnant or plan to become pregnant. CAMZYOS may harm your unborn baby. Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with CAMZYOS. You may also report your pregnancy by calling Bristol Myers Squibb at 1-800-721-5072 or www.bms.com.
If you are a female and able to become pregnant:
- Your healthcare provider will do a pregnancy test before you start treatment with CAMZYOS.
- You should use effective birth control (contraception) during treatment with CAMZYOS and for 4 months after your last dose of CAMZYOS.
- CAMZYOS may reduce how well hormonal birth control works. Talk to your healthcare provider about the use of effective forms of birth control during treatment with CAMZYOS.
- are breastfeeding or plan to breastfeed. It is not known if CAMZYOS passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you take CAMZYOS.
Before and during CAMZYOS treatment, tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Taking CAMZYOS with certain medicines or grapefruit juice may cause heart failure. Do not stop or change the dose of a medicine or start a new medicine without telling your healthcare provider.
Especially tell your healthcare provider if you:
- Take over-the-counter medications such as omeprazole (for example, Prilosec), esomeprazole (for example, Nexium), or cimetidine (for example, Tagamet).
- Take other medications to treat your obstructive HCM disease.
- Develop an infection.
How should I take CAMZYOS?
- Take CAMZYOS exactly as your healthcare provider tells you to take it.
- Do not change your dose of CAMZYOS without talking to your healthcare provider first.
- Take CAMZYOS once a day.
- Swallow the capsule whole. Do not break, open, or chew the capsule.
- If you miss a dose of CAMZYOS, take it as soon as possible and take your next dose at your regularly scheduled time the next day. Do not take 2 doses on the same day to make up for a missed dose.
- Your healthcare provider may change your dose, temporarily stop, or permanently stop your treatment with CAMZYOS if you have certain side effects.
- If you take too much CAMZYOS, call your healthcare provider or go to the nearest hospital emergency room right away.
Possible side effects of CAMZYOS
CAMZYOS may cause serious side effects, including heart failure (a condition where the heart cannot pump with enough force).
The most common side effects of CAMZYOS include dizziness and fainting (syncope).
These are not all of the possible side effects of CAMZYOS. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects to Bristol Myers Squibb at 1-800-721-5072.
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 Ommen SR, Mital S, Burke MA, 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;142(25):e558-e631.
4 Stanford Health Care. Hypertrophic cardiomyopathy. Accessed September 20, 2022. https://stanfordhealthcare.org/medical-conditions/bloodheartcirculation/hypertrophic-cardiomyopathy.html
5 Marian AJ, Braunwald E. Hypertrophic cardiomyopathy: genetics, pathogenesis, clinical manifestations, diagnosis, and therapy. Circ Res. 2017;121(7):749-770.
6 Maron BJ, Ommen SR, Semsarian C, Spirito P, Olivotto I, Maron MS. Hypertrophic cardiomyopathy: present and future, with translation into contemporary cardiovascular medicine. J Am Coll Cardiol. 2014;64(1):83-99.
7 University of Maryland Medical Center. Hypertrophic cardiomyopathy types, symptoms and causes.
8 American Heart Association. Hypertrophic cardiomyopathy (HCM). Updated November 17, 2020. https://www.heart.org/en/health-topics/cardiomyopathy/what-is-cardiomyopathy-in-adults/hypertrophiccardiomyopathy.