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.
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.
A recent study of identical twins with HCM found significant variation in the expression of hypertrophic cardiomyopathy, even between twins carrying the same HCM-causing genetic mutation.
This paper concludes that epigenetics (things which influence expression of DNA like behavioral and environmental factors) greatly influence the expression of HCM genetic mutations.
The researchers studied 11 pairs of twins with HCM. 9 of the twin pairs had known HCM sarcomere mutations while 2 of the pairs had HCM of unknown cause. The siblings were followed for a time frame of between 5 to 14 years.
Researchers compared left ventricular wall thickness, left atrial size and left ventricular ejection fraction. Differences were found in the left ventricular wall thickness of all 11 pairs of twins, while left atrial size was similar in 3 of the 9 twin pairs who carried HCM mutations. Left ventricular ejection fraction was different in 4 of 7 twin pairs.
The researchers theorize that similarities in left atrial size may be due to impaired ventricular relaxation directly tied to sarcomere dysfunction. In contrast, environmental factors yield more influence over ventricular function.
HCM epigenetics is a field ripe for research. As HCM patients, we hope that it will yield actionable data in the near future.
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 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.
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.
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”
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!
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.
Researchers from the Sarcomere Human Cardiomyopathy Registry (or the acronym “SHaRe” for short) have again joined forces to look at a subset of hypertrophic cardiomyopathy (HCM) patients who have what is known as “end stage” HCM. This term, which is a bit of a misnomer, is used to describe patients who experience left ventricular systolic dysfunction (LVSD) which occurs when the left ventricular ejection fraction (LVEF) is less than 50%.
According to the study published last week in the journal Circulation, of a total of 6,793 HCM patients included in the study, 553 or 8% fell into this category. The paper goes on to highlight some important observations about patients that fall into this category which are highlighted below.
Continue reading “Share Registry Study Focuses on So-Called “End Stage” HCM”