Matthew Martinez, MD, director of the Atlantic Health System Sports Cardiology at Morristown Medical Center and a nationally recognized HCM expert, spoke with Cardiovascular Business at the American Society of Echocardiography (ASE) 2023 meeting. He explained how HCM care management is changing and how it is not as rare of a disease as previously believed. 

"There has never been a better time to be focused on HCM or to be a patient with HCM, because of the energy associated with diagnosis, treatment and all the medical options now available. And you are seeing this at this year's ASE meeting where there is an incredible focus on how to manage HCM," Martinez explained. 

He said the care landscape for these patients has changed significantly in the past year or so with the U.S. FDA approval of Camzyos (mavacamten), the first drug to treat HCM. Recommendations for exercise in these patients also has changed, which was the main topic he discussed in an ASE session. 

Exercise should be part of the care for HCM patients

"In previous decades there was concern about the risk associated with exercise, and we haven't forgotten that HCM is still a cause for sudden death in those who are exercising, but we have a better handle on how to risk stratify individuals," Martinez explained. "It turns out that exercise is good medicine in HCM, just like it is in every other disease."

Based on research over the past 15 years, he said there is a way to be evaluated by a HCM expert to determine what a safe exercise plan might be. Previously HCM had a one size fits all approach, but each patient's condition is different and various presentations of HCM have different risk levels. For this reason, he said there is a movement toward personalized medicine in HCM care. 

He explained the level of exercise a patient can do also may be determined by factors such as co-morbidities, if they already have an implantable cardioverter defibrillator (ICD), the patient's age, what sport they want to participate in and what their disease looks like individually. 

"Every patient who comes to see me in our HCM program gets an exercise discussion and we also discuss diet and weight. That should all go into a shared decision-making discussion with every patient with HCM," Martinez said. 

While patients may have these discussions with a sports medicine cardiologist, he said the concept of the patient being an athlete means they are participating in some level of physical activity for health benefits, not necessarily for competition sports. Athletes also have overlap in physiologic changes seen in HCM patient hearts, such as enlargement of the left ventricle, so HCM can easily be missed, or misinterpreted. 

"The take home message is that the days of disqualification across the board for HCM patients in athletics and exercise are no longer here," he said.

Mavacamten is a major expansion for treating HCM

Martinez said mavacamten has clinical data showing the HCM-specific modifying drug works effectively, which has led to the creation of mavacamten clinics at many hospitals. He said the drug is having a major impact on care and alters all the discussions on HCM going forward.

"Unlike previous times when we could only try to control their heart rate, this is a medicine specifically to act on HCM patients. So like never before, we are having dramatic improvements in symptoms, reductions in left ventricular outflow tract (LVOT) gradients, marked improvements in symptoms and all the benefits in life that go with that. It certainly makes it easier for them to exercise and if they can go further than they did before and are not breathless when they do it. So mavacamten has absolutely had an important impact on improving the symptoms and the quality of life for patients with HCM," Martinez explained. 

The drug is not a cure-all, but can be used as another tool to help manage these patients. He said it can be used in combination with patients who still require a septal myectomy or septal alcohol ablation to reduce the amount of excess tissue that can cause LVOT obstruction or other issues. 

How rare is HCM?

HCM has long been considered a rare cardiac disease, but with the creation of dedicated HCM centers of excellence and the FDA clearance of mavacamten, there has been a lot more awareness about the disease among patients and physicians. This has led to many more patients being diagnosed with HCM that previous thought to make up that patient population. 

"It is exceedingly common, making up between one in 200, or one in 500 folks who have hypertrophic cardiomyopathy. But we are doing a less than stellar job of diagnosing HCM. We estimate that up to 80-90% of people with HCM are going undiagnosed in the United States. So there is a real opportunity," Martinez said.