According to a paper published last week in JAMA Cardiology, doctors at Tufts University’s HCM Center have been able to identify 95% of their patients at high risk of sudden cardiac death (SCD) from HCM. Tufts applied an updated and modified version of the risk factors enumerated in the American College of Cardiology/American Heart Association Guidelines promulgated in 2011.
This story in the Wall Street Journal about genetic testing shows the speed of changes in the medical community’s understanding of how and whether certain genes cause hereditary disease.
The article quoted Dr. Jodie Ingles, a geneticist from the University of Sydney in Australia who specializes in HCM and has published a recent article on the subject. Dr. Ingles said that 22 out of 33 genes comprising a genetic testing panel commonly used to test for HCM had either limited or no evidence of being disease causative.
These false positives are dangerous, according to Dr. Ingles, because invasive treatment decisions, such as implantable defibrillator (ICD) placement, may be based on this erroneous genetic information.
Though they can be lifesaving if appropriate, ICDs also have potential to cause harm to the patient. ICDs may cause infection, may inappropriately discharge, or they can be subject to lead complications which may necessitate additional surgeries.
You can read more about Dr. Ingles’ research and study results here.
This week in the journal Annals of Internal Medicine, MyoKardia reported positive results from its open label phase 2 clinical trial of its drug mavacamten (formerly known as MYK-461) for obstructive hypertrophic cardiomyopathy. The study was conducted at 5 HCM centers and enrolled 21 subjects with obstructive HCM. All subjects saw some degree of improvement to their condition after taking mavacamten.
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.
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.
I had open heart surgery (a septal myectomy) to treat my hypertrophic cardiomyopathy in 2006. I went back to Mayo twice for the two years following the surgery, but after that I hadn’t felt the need to return since I was regularly following up with my local cardiologist. In April of 2018, it had been almost ten years since I had been back to Rochester. So, I decided it was time to take a trip and make sure that all was in order.
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.
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:
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.