What are the Newest Treatment Options Available for Hypertrophic Cardiomyopathy?
- Lifestyle modifications, medications, surgery, and medical devices are all options for treating people with hypertrophic cardiomyopathy.
- The decision of which treatment to take will be decided by your doctor depending on your age, overall health, medical history, treatment response, and severity of the disease.
- Camzyos is a new FDA-approved medication for the treatment of adult patients with obstructive hypertrophic cardiomyopathy which works on improving the heart’s functional capacity and reducing the symptoms of the disease.
- If your doctor decides to put you on Camzyos, you will need to be monitored through a safety program.
Dr. Aeshita Dwivedi, a cardiologist at Lenox Hill Hospital and assistant professor of cardiology in at the Hofstra School of Medicine explains HCM simply “Hypertrophic cardiomyopathy is an abnormal thickening of the muscle of the heart with each beat, your heart pumps out blood, but in order to do that, it also has to receive the blood. When the walls of the heart get very thick and abnormal, your heart becomes stiff and becomes less compliant and is not able to accept the blood as it should.”Read More
New Treatments for Cardiomyopathy
Dr. Philip Weintraub, a cardiologist at NYU Langone Health explains to SurvivorNet that “treatment depends on the severity of the symptoms and the response or failure to respond to most agents”.
Treatment for hypertrophic cardiomyopathy (HCM) can be divided into three categories:
- Rhythm management devices
Until recently, there have been no medications approved specifically for use in patients with HCM. Treatment guidelines relied on drugs that had been approved for other cardiovascular conditions, such as atrial fibrillation and heart failure.
Dr. Dwivedi reiterates the importance of routine doctor-patient visits, “Living with hypertrophic cardiomyopathy, can be challenging for a lot of people, but it is important that you follow up with your doctor regularly, you get the right treatment.”
Treatment is generally guided by symptoms and by the New York Heart Association (NYHA) Functional Classification. The NYHA class system divides patients into categories based on associated symptoms.
NYHA classes are as follows:
- I: Physical activity is not limited by symptoms; Ordinary physical activity does not cause excessive fatigue, heart palpitations, or shortness of breath
- II: Comfortable at rest and only some limitation in physical activity; Ordinary physical activity may cause symptoms
- III: Comfortable at rest but little activity (less than normal) can cause symptoms
- IV: Symptoms of heart failure at rest and unable to perform any physical activity without discomfort
Before exploring surgery and rhythm management devices, your healthcare team will likely begin with a trial of medications. Previously, the only medications used to treat HCM were:
Treatment typically was provided in a step-wise approach, with beta-blockers, verapamil, or diltiazem being first-line agents. These medications are used to reduce heart rate and allow your heart to beat with less power.
If first-line treatment alone did not help, your provider may add disopyramide onto treatment. Disopyramide is an antiarrhythmic drug, meaning it is used to control your heart’s rhythm. The use of disopyramide in patients with hypertrophic cardiomyopathy has also been shown to decrease symptoms related to the disease.
Although these medications can help treat symptoms, there was still a largely unmet clinical need for new additional therapy.
Camzyos (Mavacamten) for the Treatment of HCM
The FDA recently approved Camzyos (mavacamten) in April 2022 for the treatment of adult patients with symptomatic NYHA class II and III obstructive hypertrophic cardiomyopathy to improve functional capacity and symptoms. Dr. Weintraub explains to SurvivorNet “The drug has been studied and it appears to be quite effective in improving the quality of life where people who experience heart failure generally can move to a lower class in terms of how symptomatic they are.”
Role of Sarcomeres in Hypertrophic Cardiomyopathy
Sarcomeres are proteins within the heart muscle. These proteins work by helping the heart contract to pump blood throughout the body. When sarcomeres are acting normally, their shortening will contract the heart muscle through a myosin and actin bridge.
The normal heart will have an “off state” for myosin roughly half of the time. However, patients with HCM have an overactive myosin bridge which results in too much power and forces during each contraction of the heart.
This dysfunction seen in patients with HCM is typically due to genetic abnormalities.
How Camzyos (Mavacamten) Works
Camzyos (drug name mavacamten) is a new, first-in-class medication that works to reprogram sarcomeres within the heart. It works by inhibiting the formation of the myosin and actin bridge within the sarcomeres. When this happens, it allows the myosin to be in an “off state”, reducing the amount of power and force that occurs during the heart contractions.
The manufacturer reports that this medication can be taken with or without other medications used in the treatment of HCM. Most patients in clinical trials continued their previous medications and used Camzyos (mavacamten) as an additional therapy.
Your doctor will determine if this medication is right for your regimen and if any medications need to be discontinued before beginning Camzyos (mavacamten).
The EXPLORER-HCM pivotal trial was a randomized, double-blind, 30-week phase III trial examining the efficacy of Camzyos compared to placebo. Results from the pivotal trial were published in the Lancet, a peer-reviewed medical journal.
The trial’s main clinical endpoint was looking at how many patients had increased exercise capacity and decreased symptom burden after 30 weeks of treatment. After 30 weeks of therapy, 37% of patients taking Camzyos met the primary endpoint, compared to only 17% on placebo.
The data from the long-term extension interim analysis demonstrates promising outcomes that are achieved with Camzyos treatment and maintained with continued use.
Safety Considerations for New HCM Treatments
If you and your healthcare team decide Camzyos is an appropriate medication to add to your treatment plan, you will need to participate in the Camzyos REMS program.
For certain medications, the FDA requires healthcare professionals, patients, and pharmacies to participate in a Risk Evaluation and Mitigation Strategy (REMS) program.
REMS programs are designed to make sure medications that may have safety concerns are being properly monitored to minimize the risk of certain fetal adverse events from occurring.
An echocardiogram (echo) is a procedure that creates images of your heart by using sound waves. These images can be used to monitor the function of your heart’s valves and chambers.
You will need to receive an echocardiogram before beginning treatment, monthly for three months, and then continuously every three months while on therapy.
If you stop treatment, change the dose, or start a new medication that might interact with Camzyos, you may need to have an echo done more frequently.
Monitoring for Side Effects
Patients who take Camzyos may feel dizzy or faint while on medication. It is essential to discuss any new, persistent, or worsening side effects with your healthcare team to ensure this medication is right for you.
Camzyos can interact with many medications, including medications used to treat:
- Heartburn (ex: esomeprazole)
- Depression (ex: fluoxetine)
- Anti-fungal (ex: fluconazole)
- Seizure (ex: phenytoin)
This list is not all-inclusive. Because it interacts with many medications, you must inform your healthcare team of any new medications you may be taking, including over-the-counter medications, vitamins, herbals, and supplements.
Your Next Doctor’s Visit – Being Prepared
Remembering questions to ask your doctor or healthcare team can be difficult. The Hypertrophic Cardiomyopathy Association created a patient card for you to use to stay on top of your condition and make sure you are asking the right questions at the right time.
The card allows patients to track their visits by easily identifying if there were any of the following:
- Any new imaging performed (ex: Echocardiogram, CMR)
- Categorizing HCM as either obstructed or non-obstructed
- Identifying if there is mitral regurgitation
- Measurement of the heart (ex: septal, posterior wall, left atrial)
- Gradient and ejection fraction measurement
The card also allows you to verify if you have reviewed your current medication regimen and any related changes. All of these topics will help you better understand your individualized condition and be able to have a conversation with your healthcare team if any new therapies are appropriate for you.
Moving Forward – Questions to Ask Your Doctor
- What drugs are available to treat my hypertrophic cardiomyopathy?
- Is my HCM considered obstructive?
- What should I expect from treatment with Camzyos?
- What side effects should I monitor for while on therapy?