Can This Formula Predict AFib in HCM Patients?

HCM specialists at Tufts Medical Center and Toronto General Hospital have devised a formula which they hope will help predict which HCM patients may go on to develop atrial fibrillation (“AFib”) over time. This tool can assist doctors in determining which patients are at highest risk so that these patients can be closely monitored and treated appropriately. AFib can be extremely dangerous for HCM patients since it can precipitate a stroke if not appropriately treated.   

Because existing tools to predict atrial fibrillation have not proven to be accurate for HCM patients, the researchers studied 1900 HCM patients with the goal of devising a new tool to help HCM patients and their physicians learn their personal risk for AFib over a 2 and 5 year period.

CALCULATE YOUR RISK SCORE:

The formula works as follows:  Find your left atrial diameter on your most recent echocardiogram report.  On the chart below, find the number of points (listed in the 2nd column) that corresponds with your left atrial measurement (measured in millimeters). Then, find the number in the 2nd column that corresponds to your current age range.  Add these two numbers together. From that sum, subtract the number listed in the 2nd column that correlates with your age range when you were first diagnosed with HCM.  Lastly, if you have heart failure symptoms, add in 3 points.  The total is your score.

You can calculate using the table below, or you can use this online calculator which gives you your 2 and 5 year risk.

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WHAT DOES YOUR RISK SCORE MEAN:

Low Risk scores are between 8 – 17

Intermediate Risk scores are between 18 – 21

High Risk scores are between 22 – 31

As always, discuss with your doctor. Everyone has individual factors which will influence their degree of risk. This tool is intended as a general guideline to facilitate discussion with your physician.

Experts Put Mavacamten in Perspective

An article published today in Circulation by HCM experts Dr. Steve Ommen of Mayo Clinic and Dr. Martin Maron of Tufts Medical Center, discusses the prospective use of mavacamten as a treatment for obstructive hypertrophic cardiomyopathy. The doctors conclude that while mavacamten (assuming that it is FDA approved in early 2022) will have its place in the HCM tool kit, it should not replace septal reduction therapy for severe HOCM.

In particular, the article points out that the EXPLORER-HCM study showed modest improvements in symptoms and functional capacity (peak V02), comparable to those seen in the RESET-HCM study, which highlighted the ability of regular exercise to improve functional status in HCM.  

The article notes that there has not yet been a study directly comparing mavacamten with septal reduction therapies such as septal myectomy and alcohol septal reduction. The VALOR-HCM study, which is currently recruiting, will look at these therapies compared head-to-head.  It is noteworthy that the majority of patients in the EXPLORER trial had Class II heart failure and were not the more severely compromised Class III and IV patients most likely to benefit from myectomy or alcohol septal ablation.

This article compared historical myectomy data against the findings from EXPLORER, concluding that septal myectomy produces a better result for patients, with gradients abolished in more than 95% of patients compared to only 50% of patients with mavacamten.  And, the article points out that 25% of the patients in the EXPLORER trial continued to have left ventricular outflow tract gradients greater than or equal to 50mmHg, which still qualified them for septal reduction therapy.

Maron and Ommen’s take-home message is that mavacamten will be a welcome addition to the arsenal of HCM drugs and is potentially suitable for patients who do not have severe symptoms, who do not have access to septal reduction at a HCM specialty center, or who wish to avoid more invasive therapies.  It also may be used in the same way as disopyramide, to defer surgery by improving symptoms to a tolerable level.

Lastly, this article points out that there is a need for longer term follow up to study the effects of cardiac remodeling caused by mavacamten.

While it is wonderful to have options, it is important that patients and their medical team consider all available information, including potential benefit and risk, before moving forward with medical therapy. 

Docs Reliably Identify HCM Patients in Need of ICDs

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.

Continue reading “Docs Reliably Identify HCM Patients in Need of ICDs”

Atrial Fibrillation: Treatable HCM Complication

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 patients with atrial fibrillation has improved over the last twenty years due to significant advances in HCM treatment over that time period such as ICD implantation and myectomy, along with aggressive anti-coagulation for atrial fibrillation patients.

Spirito also noted that it is difficult to predict whether a given HCM patient will go on to develop permanent Afib after a single episode since many will not.  Additionally, permanent afib can be well tolerated when there is contemporaneous control of heart rate.  Therefore,  anti-arrhythmic medications, which can cause unpleasant side effects, may not be necessary for HCM patients with afib as long as anti-coagulation measures are taken.

 

 

 

Apical Aneurysm is Risk Factor for HCM Patients

A recent retrospective study of patients at Minneapolis Heart Institute and Tufts Medical Center published in the Journal of the American College of Cardiology found that HCM patients who also had left ventricular apical aneurysms were at increased risk of sudden cardiac death and stroke.  However, with increased surveillance and appropriate treatment, including the implantation of a implantable defibrillator, radiofrequency ablation and/or anti-coagulation, as appropriate, the authors suggest that the increased risk can be neutralized.

A summary of this article can be found here.