Newest HCM Research Focuses on Exercise

Two articles published this week highlight how attitudes relating to exercise and HCM have changed in recent years.  Older recommendations that HCM patients should refrain from exercise appear to be outdated.

The first article, an editorial published in Circulation by Drs. Sara Saberi and Sharlene Day from the University of Michigan’s HCM Center, reviews the statistics relating to sudden death of athletes and questions the long held notion that participation in vigorous activity or competitive sports is dangerous in HCM.  This editorial also points out that moderate exercise is the only non-surgical intervention proven to increase exercise capacity in patients with HCM.

See this HCMBeat interview with Drs. Saberi and Day for more details about their groundbreaking study.

A second article from researchers in Australia used the number of a patient’s steps per day as an indicator of HCM disease severity and the patient’s functional limitations.

It seems that the time has come for HCM patients to get up off their couches and get moving!

Are HCM Kids With MYH7 Gene at Increased Risk?

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.

Restyle HCM Study: Ranolazine Doesn’t Improve HOCM Heart Failure Symptoms

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.

ESC Risk Assessment Tool Comes Up Short in Study

A recent study published in the American Journal of Cardiology found that the standards propounded by the American College of Cardiology Foundation with the American Heart Association (ACC/AHA) were superior in predicting which patients would benefit from an implantable cardiac defibrillator (ICD) compared to the calculator set forth by the European Society of Cardiology (ESC).  According to the study, the use of the ESC tool will result in more high-risk patients going unprotected against sudden death.

Specifically, the study found that out of a group of 288 HCM patients, 14 who experienced aborted sudden cardiac arrest (or 43%) would not have qualified for an ICD under the ESC risk model compared to 7% of patients under the ACC/AHA guidelines.

The ACC/AHA guidelines are:

ICD Guidelines rev.

A companion editorial by Dr. Andreas S. Barth pointed out the shortcomings of both models, and reaffirmed the necessity for shared decision making between physicians and patients.  Dr. Barth also expressed hope that a more accurate predictive model will evolve, though he acknowledged the impossibility of designing a model which could predict future events with certainty.

 

Chapter 4: MRI Safety for ICD & Pacemaker Patients

Yet another study has confirmed the safety of MRIs in patients with non-MRI conditional ICDs and pacemakers.

The latest study, from the University of Pennsylvania and published in the New England Journal of Medicine, found no adverse effects from 1.5 Tesla MRI scans performed on 1509 patients who underwent a total of 2103 scans.  58% had pacemakers and 42% had ICDs.

This study confirms previous findings relating to the safety of MRIs in ICD and pacemaker patients reported by HCMBeat here and here.

You can also read my personal experience trying to get a brain MRI in Los Angeles last year here.

Doctor with HCM Calls for Patient Access to Medical Device Data

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.

Atrial Fibrillation: Treatable HCM Complication

Updated to include editorial by Dr. Paolo Spirito in recent issue of Circulation.

HCM Beat

A recent paper by doctors at Tufts University’s HCM Center found that transient episodes of atrial fibrillation (AF) are treatable and do not often progress to permanent AF.

This study found that AF was not a frequent cause of death by heart failure or sudden cardiac arrest.  However, the researchers identified AF as an important cause of stroke in HCM patients.  Therefore, they recommend a low threshold for starting HCM patients on anti-coagulants following an initial AF episode.

Researchers in this study analyzed statistics from 1558 HCM patients, 20% of whom experienced AF.  74% experienced only sporadic episodes, while 26% went on to develop permanent AF.

At the time of publication, 91% of the 277 of the patients included in the sample were still alive and between the ages 49 and 75 years old.

According to an accompanying editorial by Italian HCM expert Dr. Paolo Spirito, the outlook for HCM…

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New Treatment for Arrhythmias

As reported in this New York Times article, radiation has been used as a successful treatment in five patients with ventricular arrhythmias who had previously failed standard treatment using catheter radiofrequency ablation.  The complete study was published last week in the New England Journal of Medicine.

Because long term effects of radiation to the heart are unknown, this method is still quite experimental and could potentially cause long term side effects such as lung and heart damage.  Science Daily reported that the researchers have performed the procedure on 23 patients to date, and are currently enrolling patients in a clinical trial.

Lifestyle Influences HCM

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.

Sudden Cardiac Death in Young Athletes

Editor’s Note:  This post originally appeared on the blog of Dr. Howard J. Luks. Dr. Luks  wrote this blog entry in collaboration with HCM expert Dr. Srihari S. Naidu of New York’s Westchester Medical Center. You can find the original post here.  You can find both Dr. Luks and Dr. Naidu on Twitter @hjluks and @SrihariNaiduMD.

Sudden cardiac death in young athletes continues with alarming frequency.  The most common cause of sudden death in the young athlete is hypertrophic cardiomyopathy or HCM.  Simply put, HCM means the heart muscle is bigger.  Many of us believe that bigger muscle means stronger muscle.  That is not always the case with the heart.  The heart is a mechanical pump with a complex arrangement of chambers which store the blood. How that pump works is controlled by a very complex electrical system.  Hypertrophic cardiomyopathy can interfere with one or both of these critical functions of the heart and lead to sudden cardiac death.

Continue reading “Sudden Cardiac Death in Young Athletes”