According to a recent study by doctors in the Netherlands published in the journal Circulation: Heart Failure, women who had undergone septal myectomy had more diastolic dysfunction and myocardial fibrosis than men who had also undergone myectomy.
Hence, the researchers suggest that sex-specific treatment for HCM may become customary and should be a subject for future inquiry.
These findings raise concern, especially when looked at in conjunction with a recent study by doctors at the Mayo Clinic who found that women with hypertrophic cardiomyopathy have a statistically reduced rate of survival when compared to men with HCM.
Here’s hoping that upcoming researchers will focus their efforts on improved outcomes for women with HCM.
A retrospective study of HCM patients with implantable defibrillators conducted at eight centers worldwide has demonstrated that ICDs are not only lifesaving, the shocks they generate are not harmful to those in whom they are implanted.
The study looked at 486 patients with HCM with an ICD implanted for either primary or secondary cardiac arrest prevention. Of the 486 patients, 94 (19%) experienced at least one appropriate shock from their ICDs. 44 of those who had been shocked had experienced one or more shocks over the period of the study, including 6 patients who had at least 3 shocks over a 24 hour period. Inappropriate shocks occurred in 96 patients (20%).
Despite the shocks, appropriate or not, at the end of the follow-up period the ICD discharges did not appear to cause the patients to suffer from increased heart failure or sudden cardiac arrest. Furthermore, their general health and well-being were good: they did not suffer from significant degrees of anxiety and depression.
A recent editorial published in Circulation: Genomic and Precision Medicine suggests that current HCM screening protocols may need adjustment to account for recent findings by a study by researchers in the Netherlands. The Dutch study, published in the same journal, found that of 620 relatives of HCM patients who underwent genetic testing, 43% were found to be genetically positive for HCM, while 30% were diagnosed with HCM at the initial screening. 16% more went on to develop HCM during 7 years of repeated cardiac evaluation.
On the other hand, the 57% of relatives found to be genotype-negative were released from clinical HCM follow-up.
The Australian authors of the editorial, Semsarian and Ingles, note that current screening protocols would have failed to identify the 6 children (15%) who were diagnosed under the age of 12, half of which had a particularly malignant family history.
Additionally, few teens were diagnosed with HCM, which stands in contrast to current opinion that HCM is most likely to develop during adolescence. Indeed, most newly diagnosed family members were older than the age of 36, with 44% being over the age of 50.
Lastly, Semsarian and Ingles note their concern with general utilization of the Dutch practice of releasing a gene negative family member from serial follow up since the impact of all genes which have a role in causing HCM is not yet known while new genes which may cause HCM are still being identified.
Semsarian and Ingles also note that the Dutch patient sample differs from more typical patient populations found in the U.S. and Australia where causes of HCM are more diverse and cannot be easily tied to a specific gene.
A recent article by doctors from the University of Utah Health Sciences Center found that patients with HCM who are in need of heart transplantation may wait longer for a new heart than patients with other cardiomyopathies. Additionally, HCM patients may experience stroke or other adverse consequences while awaiting transplant.
The discrepancy is attributable, in part, to the fact that HCM patients are not often candidates for LVADs (left ventricular assist devices) and other types of mechanical circulatory support devices which are used to bridge patients awaiting transplant.
Hence, the article argues, United Network for Organ Sharing (UNOS -the organization responsible for the allocation of donor organs in the U.S.) should take these factors into consideration as it revises its system of heart allocation for patients awaiting transplant.
On a positive note, the article points out that long-term survival in HCM patients has improved over time, and HCM patients now do as well or better following transplant than patients who have been transplanted for other types of cardiomyopathy.
An article entitled Psychosocial Impact of a Positive Gene Result for Asymptomatic Relatives at Risk of Hypertrophic Cardiomyopathy was published in this week’s Journal for Genetic Counseling.
The article focuses on the motivation for and the impact of HCM genetic testing on family members. The 32 participants in the study all encouraged family members to undergo genetic testing with the hope that the knowledge gained would benefit family members down the line. However, the study found that the psychological impact of a positive result, in the absence of overt disease, was highly variable. Some gene positive individuals perceived that they had an absolute risk of developing HCM, with substantial detriment to their lifestyle choices, while others were not at all affected by the result and made no lifestyle changes.
Continue reading “Continuing Genetic Counseling Helpful for Silent HCM Gene Carriers”
A recent Canadian study found that children with HCM who carry a single mutation in the MYH7 gene or who have multiple HCM-causative genetic mutations are at increased risk of major adverse cardiac events when compared to children who carry a single mutation in another gene.
Of the 98 gene positive children in this study, those with a MYH7 mutation or those with multiple mutations were more likely to need a myectomy or an ICD or to experience a sudden cardiac arrest or a heart transplant when compared to children with other HCM causative mutations.
The article also suggests that current screening protocols which recommend clinical and genetic screening for HCM beginning at age 12 may be insufficient.
Dr. Iacopo Olivotto and a team of Italian researchers conducted a recent multi-center trial of the late sodium channel blocker ranolazine. The results of the trial showed that the drug failed to improve functional capacity, diastolic function, quality of life or brain natriuretic peptide (BNP) levels in 80 non-obstructive HCM patients.
Nevertheless, the researchers found that ranolazine is a very safe drug which may still be useful in the treatment of HCM by reducing arrhythmias and improving angina.
A companion editorial by Dr. Perry Elliot from the U.K. shed light on the difficulties inherent in designing clinical trials for HCM. Dr. Elliot noted that Restyle HCM was the third unsuccessful attempt at finding a new drug for HCM in the past year since a study on eleclazine, a drug with similar properties, and another for the drug perhexilene were both halted last year due to lack of efficacy.
Regardless, Dr. Elliot stated that increasing worldwide collaboration between HCM centers and expanding knowledge of certain sub-types of HCM treatable with specifically targeted therapies substantially improve the outlook for upcoming HCM drug trials.
In an editorial entitled “It’s My Heart, Why Not My Data” by Dr. Ira Nash in the January 2, 2018 edition of Circulation, Nash calls for device manufactures to allow patients to access the data generated by their implantable devices.
Nash, a cardiologist who himself has hypertrophic cardiomyopathy, calls the paternalistic practice of limiting data access to physicians anachronistic in a world which has become more and more focused on empowering patients to make collaborative decisions with their physician.
Dr. Nash explains in a postscript to the article that after being denied patient access to the data generated by his implantable loop recorder, he was ultimately granted access to his data as a physician. Most of us don’t have that ability. It would certainly be nice if patients were given the option to access their data simply because it is most important and relevant to them. It is the patient’s life, after all, which is at stake.
According to this recent article published in the Journal of the American Heart Association, lifestyle choices can influence the development and/or progression of HCM.
In particular, the authors made the following recommendations:
- Exercise: Recreational exercise should be encouraged in HCM patients.
- This recommendation was largely based on the findings of the recent RESET-HCM study which found that moderate exercise, specifically tailored to each individual patient’s capacity, was beneficial to the patient’s general health and well being. **For an in-depth look at the RESET-HCM study, check out this recent HCMBeat interview with the authors of the study, Drs. Sara Saberi and Sharlene Day.
- Eating and Drinking:
- Patients should avoid large meals and should not exercise immediately after eating.
- Care should be taken to avoid becoming dehydrated.
- Alcohol should only be consumed in moderation.
- Healthy weight should be maintained.
- Hypertension should be treated aggressively, though treatment may be challenging, especially in obstructive HCM.
- Obstructive Sleep Apnea, which may exist in as many as 70% of HCM patients, should be treated to minimize potential for arrhythmia and to improve blood flow.