A recent study published in Circulation suggests that clinical testing of kids who are first degree family members of HCM patients (i.e. siblings and children of those who have already been diagnosed with HCM) could be improved by starting testing at a younger age. And, genetic testing should further improve diagnosis and treatment for this group.
Almost 5% of children included in this study were diagnosed with HCM at the time of their initial screening. The majority of these children (72%) had not yet reached the age of adolescence. Childhood diagnoses were not that unusual in this sample: a childhood diagnosis was made in 8% of families that were screened.
Hence, this article suggest that regular screenings of youth in HCM families should start before age 10. Note that current ACCF/AHA Guidelines followed in the U.S. (published in 2011 and set to be updated next year) make screening before age 12 optional. The 2014 ESC guidelines followed in Europe recommend screening of children in HCM families from age 10 onward, unless there is a particularly bad family history or other factors which might call for heightened scrutiny.
When Stanford biochemist Jim Spudich settled down in bed with a book recommended by his wife, he had no idea that the book would inspire one of the biggest discoveries of his career. Spudich drifted off to sleep while reading The Haunted Mesa, a science fiction novel by Louis L’Amour. His scientific discovery was based on an image he saw in his dreams when the image of a mesa morphed into a myosin molecule.
Myosins are proteins that make the contraction of heart muscle possible. In hypertrophic cardiomyopathy, these proteins work too well, causing a heartbeat that is too strong.
The mesa in the book inspired Spudich to look at the head of the myosin. His previous research had focused on random locations along the entire length of the myosin.
Spudich’s groundbreaking work ultimately led to current clinical trials of the drug mavacamten which is being developed by the San Francisco biotech company MyoKardia.
This article tells the whole story of the beginnings of this groundbreaking research.
Today, it was announced by the U.S. Department of Homeland Security that 750,000 implantable defibrillators manufactured by Medtronic could potentially be vulnerable to hacking.
As reported by the Minneapolis Star-Tribune, many Medtronic implantable defibrillators currently in use may contain vulnerabilities which could potentially be exploited by hackers via their use of programmer devices or bedside monitors. According to Medtronic, no such episodes have been reported and such interference is extremely unlikely because any would-be hacker would have to be within 20 feet of a patient and would also need in-depth and specialized knowledge of the device’s programming features.
Medtronic has assured patients that there is no imminent danger and it promises that the issue will be solved with a programming patch that will be forthcoming. No action is required by patients other than keeping their bedside monitors plugged in and secure in their homes. Patients should discuss any specific concerns with their physician.
You can read the notice from Homeland Security here which lists all models affected..
You can read the security bulletin issued by Medtronic here.
You can read another story about the issue from Ars Technica here.
A recent study by several HCM genetics researchers around the globe, led by Australia’s Dr. Jodie Ingles, found that 2/3 of genetic mutations previously reported to patients as HCM causative may actually NOT trigger HCM.
Dr. Ingles and the researchers looked at 33 genes frequently reported to patients as causative for HCM in commercial genetic tests. Surprisingly, of the 33 genes tested, only 8 were found to be definitively associated with HCM, 3 had moderate evidence to support their association with HCM and a whopping 22 or 66% of these genes were found to have limited or no association with HCM.
Mutations Definitive for HCM
Mutations with Moderate Evidence for HCM
These results should raise a red flag for consumers about genetic testing. Results of genetic tests require careful and informed interpretation. For accurate results, HCM patients should undergo genetic testing under the supervision of a genetic counselor with experience in HCM.
Not all genetic counselors are alike!
A recent study conducted in the U.K. evaluated whether the anti-anginal drug trimetazidine would improve symptoms and exercise capacity for those patients with non-obstructive hypertrophic cardiomyopathy.
Unfortunately, this study which was conducted by Dr. Perry Elliott and his colleagues at University College London, found that trimetatazidine did not improve exercise capacity in these patients. Following the results of this study, trimetazidine will now join ranolazine and spironolactone in the compost heap of drugs which tried and failed to improve HCM symptoms. While a third drug, perhexiline, was found to improve symptoms for non-obstructive HCM, its limitations, including potentially serious side effects, stand in the way of its common usage.
In a companion editorial to this study entitled “Non-Obstructive Hypertrophic Cardiomyopathy-the High Hanging Fruit,” Dr. Sharlene Day of the University of Michigan’s HCM Center discusses the difficulties seen in drug trials related to non-obstructive HCM.
Though seemingly a more benign form of the disease, in fact, patients with non-obstructive HCM share a similar risk of sudden death and heart failure with their obstructed counterparts. Because treatments available to treat non-obstructive disease have been largely limited to beta blockers, calcium channel blockers and diuretics, there is a great need for new medications directed at this problem.
The problem with setting up HCM Drug trials is complicated by several factors:
- Different Types of HCM: There appear to be multiple kinds of HCM. Some are genetic and some are not. We are now at a place where treatments for HCM should become more individualized.
- Difficulty in Recruitment: It is difficult to recruit enough patients to take part in these trials. Patients often travel considerable distances for care at dedicated HCM Centers. Multi-center trials provide a potential way to get around this issue.
- Duration of HCM: HCM is a disease process which takes place over decades which is not easily studied in a clinical trial of limited duration.
- The Unknown: Timing of interventions may be critical, and it is hard to know the proper window of time to target. The bottom line is that there is still so much that is unknown, HCM researchers much continually adapt as knowledge of the disease process unfolds.
In conclusion, Dr. Day suggests that while medical researchers continue to test new drugs and push forward studies of HCM, physicians should counsel their patients that in addition to medication, lifestyle choices like proper nutrition and exercise will improve their clinical course and the overall outlook for HCM patients.
This article, by Drs. Julio Panza and Srihari Naidu of New York’s Westchester Medical Center, describes early efforts to diagnose, categorize and treat hypertrophic cardiomyopathy, while explaining how these methods have evolved over time. A very interesting and informative read.
In May of this year, HCMBeat published this interview with Yale’s Dr. Daniel Jacoby and Dr. Nikolaos Papoutsidakis about their online survey of HCM patients who engage in risk-taking activities.
In this conversation, Drs. Jacoby and Papoutsidakis emphasized that the shared decision making process is an important facet of the patient/physician relationship for HCM patients. Risks should be explained, and decisions made with each patient’s set of values and priorities in mind. The doctors hoped that the results from their study would help to inform the shared decision-making process as applied to activities that involve any amount of patient risk-taking.
In a poster presented at this weekend’s American Heart Association Scientific Sessions in Chicago, Drs. Jacoby and Papousidakis made the results of this survey public.
After analyzing data from 633 patients (282 men and 351 women), 556 patients reported participating in thrill-seeking activities, while 331 continued such participation after their HCM diagnosis. The doctors found that only 33.6% of the patients who engaged in the thrill-seeking activities experienced such minor adverse events as dizziness, nausea, palpitations or chest pain, while only .02% experienced significant events during or within an hour following the activity. Only one ICD shock was reported.
Hence, the doctors concluded that the risks associated with such activities appear to be low.
MyoKardia is collaborating with 23andMe, a genetic testing company which provides ancestry and health information directly to consumers, to create an online patient community intended to advance research efforts related to hypertrophic cardiomyopathy. The companies plan to allow 23andMe customers access to the latest information about HCM, as well as the opportunity to participate in research.
The companies will use a custom designed survey to collect baseline and follow-up data from HCM patients. They are hopeful that this collaboration will yield unique insights into HCM.
Research findings gained through the collaboration will be shared with HCM patients through the 23andMe platform. Currently more than 6,000 HCM patients are customers of 23andMe
More details of the collaboration can be found:
Press release from MyoKardia and 23andMe
DISCLOSURES: HCMBeat has received unrestricted educational grants from MyoKardia. Additionally, Cynthia Burstein Waldman of HCMBeat serves as a Patient Advisor on the Steering Committee for MyoKardia’s Explorer trial.
MD Magazine has a nice feature about Dr. Robert Battle of the University of Virginia’s HCM Center. Read it here.
A recent paper published in the journal Circulation looked at the clinical course of approximately 4,600 HCM patients over the course of more than 24,000 clinical years, which the paper describes as the largest comprehensive cohort of HCM patients ever studied.
This study examined patients from eight high volume HCM centers which aggregated their institutional data into a database known as the Sarcomere Human Cardiomyopathy Registry (or the acronym the “SHaRe” for short). The results of the study showed that, in general, HCM patients are at substantially elevated risk for atrial fibrillation and heart failure, and have significantly higher mortality rates than that of the general U.S. population.
Continue reading “HCM Researchers Put their Heads Together to Improve Lives of HCM Patients”