Kids with HCM

A recent study published in the European Heart Journal using data collected from the SHaRe Registry found that while childhood onset HCM (15% of all HCM) is far less common than adult onset HCM, it is often more serious.

Children with HCM are more likely to have sarcomere mutations, have a higher risk of ventricular arrhythmias, and are twice as likely as adults to require advanced interventions like ventricular assist devices, heart transplant or other advanced heart failure therapies. 

Experts Put Mavacamten in Perspective

An article published today in Circulation by HCM experts Dr. Steve Ommen of Mayo Clinic and Dr. Martin Maron of Tufts Medical Center, discusses the prospective use of mavacamten as a treatment for obstructive hypertrophic cardiomyopathy. The doctors conclude that while mavacamten (assuming that it is FDA approved in early 2022) will have its place in the HCM tool kit, it should not replace septal reduction therapy for severe HOCM.

In particular, the article points out that the EXPLORER-HCM study showed modest improvements in symptoms and functional capacity (peak V02), comparable to those seen in the RESET-HCM study, which highlighted the ability of regular exercise to improve functional status in HCM.  

The article notes that there has not yet been a study directly comparing mavacamten with septal reduction therapies such as septal myectomy and alcohol septal reduction. The VALOR-HCM study, which is currently recruiting, will look at these therapies compared head-to-head.  It is noteworthy that the majority of patients in the EXPLORER trial had Class II heart failure and were not the more severely compromised Class III and IV patients most likely to benefit from myectomy or alcohol septal ablation.

This article compared historical myectomy data against the findings from EXPLORER, concluding that septal myectomy produces a better result for patients, with gradients abolished in more than 95% of patients compared to only 50% of patients with mavacamten.  And, the article points out that 25% of the patients in the EXPLORER trial continued to have left ventricular outflow tract gradients greater than or equal to 50mmHg, which still qualified them for septal reduction therapy.

Maron and Ommen’s take-home message is that mavacamten will be a welcome addition to the arsenal of HCM drugs and is potentially suitable for patients who do not have severe symptoms, who do not have access to septal reduction at a HCM specialty center, or who wish to avoid more invasive therapies.  It also may be used in the same way as disopyramide, to defer surgery by improving symptoms to a tolerable level.

Lastly, this article points out that there is a need for longer term follow up to study the effects of cardiac remodeling caused by mavacamten.

While it is wonderful to have options, it is important that patients and their medical team consider all available information, including potential benefit and risk, before moving forward with medical therapy. 

Mavacamten Approaches Finish Line

The United States Food and Drug Administration (FDA) is expected to complete its review of mavacamten and release its decision on whether to approve the drug for sale in the U.S. by January 28, 2022.

This week, Bristol Myers Squibb submitted its New Drug Application for mavacamten to the FDA. Mavacamten is the first drug specifically designed to treat obstructive hypertrophic cardiomyopathy. The application was based on the recent positive results of the Phase 3  EXPLORER-HCM trial

In October of last year, Bristol Myers Squibb paid $13.1 billion to purchase MyoKardia, the San Francisco based biotech company which developed mavacamten as a novel cardiac myosin modulator for the treatment of of HCM.

The FDA has assigned a Prescription Drug User Fee Act goal date of January 28, 2022 to the drug, which means that the FDA is expected to complete its review of mavacamten by January 28, 2022.

 

 

 

 

 

 

DISCLOSURES:  CYNTHIA BURSTEIN WALDMAN OF HCMBEAT SERVED AS A PATIENT ADVISOR ON THE STEERING COMMITTEE OF MYOKARDIA’S EXPLORER TRIAL AND IS AN AUTHOR OF THE STUDY AS PUBLISHED IN THE LANCET.  CYNTHIA ALSO SERVES ON MYOKARDIA’S PATIENT ADVISORY BOARD.

 

HCM Genetics Discovery by British Researchers

A recent discovery by British researchers sheds light on how a type of common genetic mutation – a so called “common variant” – influences the expression of hypertrophic cardiomyopathy caused by mutation(s) in the cardiac sarcomere. 

How do Common Variants Impact Sarcomere Mutations?

This research, funded by the British Heart Foundation and spearheaded by Dr. Hugh Watkins of the University of Oxford, explains why some individuals with a particular sarcomere mutation develop a severe case of HCM, while their family members with the same mutation may develop only mild HCM symptoms or show no signs of the disease at all.  It also may explain why people who lack sarcomere mutations develop the disease.

The researchers compared the DNA of 2,780 people with HCM and 47,486 people without HCM and found that common variants acting in concert with rare sarcomere mutations determine whether a person will develop HCM. 

Common Variant HCM Not Hereditable

In addition, the researchers found that HCM attributable to common variants alone is unlikely to be passed on to future generations. This is good news for the children of HCM patients caused by common variants.

Watch your Blood Pressure

Lastly, this paper found that high diastolic blood pressure was associated with the development of  HCM caused by common variants. Hence, keeping blood pressure under control is something that patients can do to minimize their risk of developing HCM in the future.

A link to the study in Nature Genetics can be found here;
You can access a thorough summary by the British Heart Foundation here;
and you can find a short summary at Medical Xpress here.

Could Septal Reduction Outcomes Vary by Gender?

A retrospective analysis recently published in JACC: Cardiovascular Interventions suggests that that the risks of septal reduction therapy may differ for men and women.

In particular, the study found that the need for a pacemaker following septal alcohol ablation was almost 3 times more likely for a female than for a male.

The authors suggested that the reason for this difference may have been more advanced disease among female patients, and a higher instance of myocardial fibrosis and calcification.  

Whatever the reason, this is another factor for patients to consider before deciding which method of septal reduction is best for them.

Crypts Sign of HCM? Study Says No

According to a recently published study by doctors in Copenhagen, Denmark, myocardial crypts (clefts, cracks or fissures in the myocardium) are found in the general population. Therefore, this article concludes that crypts seen on scans of the heart are not necessarily an indicator of HCM and do not warrant further investigation. 

This paper is a departure from a 2012 paper by doctors at Tufts, which concluded that myocardial crypts were associated with HCM, and that they were often found in relatives of HCM patients found to be gene positive for HCM, but lacking the hallmark thickening of the ventricle. 

Here is an example of what the crypts look like on MRI.

HCM Treatment: The View from OHSU

If you are looking for a good survey of current practices in the treatment of HCM, a recent article published in the journal Structural Heart by Dr. Ahmad Masri and the team at Oregon Health and Sciences University (OHSU) provides an informative overview of thirty controversies and considerations in the treatment of HCM. This article explains in some detail how the doctors at this HCM Center approach these situations. 

Continue reading “HCM Treatment: The View from OHSU”

More Bad News for Women with HCM

A recent retrospective study by researchers using data from the SHaRe Registry found that women with hypertrophic cardiomyopathy have an increased risk of death and/or severe heart failure symptoms when compared to their male counterparts.  This study also found that women tended to be older when diagnosed with HCM than men. 

This study echoes a 2017 study from Mayo Clinic with similar findings.

Editor’s Note:  It is clear that serious research into gender differences in HCM is needed. And, it is vitally important that women with HCM be persistent and diligent in obtaining expert care for their HCM. Their lives depend on it!

 

2020 AHA/ACC HCM Diagnosis & Treatment Guidelines Released

The highly anticipated 2020 American Heart Association/American College of Cardiology Guidelines for the Diagnosis and Treatment of Patients with Hypertrophic Cardiomyopathy have been released.

This document, drafted with reference to published HCM literature, and with input from a committee of HCM experts with broad expertise, updates the prior version published in 2011.  It contains clinical practice guidelines for the broad spectrum of issues which may confront medical professionals as they approach the diagnosis and treatment of patients and families affected by hypertrophic cardiomyopathy.

Continue reading “2020 AHA/ACC HCM Diagnosis & Treatment Guidelines Released”

Atrial Fibrillation May Cause Negative Outcomes in HCM

 

A recent study published in Clinical Research in Cardiology  found that atrial fibrillation is a frequent complication of HCM and can be an important predictor of negative outcomes.

These findings suggest that practitioners should aggressively screen for and treat atrial fibrillation in HCM patients to improve long term outcomes.