Researchers from the Sarcomere Human Cardiomyopathy Registry (or the acronym “SHaRe” for short) have again joined forces to look at a subset of hypertrophic cardiomyopathy (HCM) patients who have what is known as “end stage” HCM.  This term, which is a bit of a misnomer, is used to describe patients who experience left ventricular systolic dysfunction (LVSD) which occurs when the left ventricular ejection fraction (LVEF) is less than 50%.

According to the study published last week in the journal Circulation, of a total of 6,793 HCM patients included in the study, 553 or 8% fell into this category.   The paper goes on to highlight some important observations about patients that fall into this category which are highlighted below.

Predictors of HCM with Left Ventricular Systolic Dysfunction:

• increased left ventricular cavity size and wall thickness
• ejection fraction of between 50-60% (notably, patients with low normal ejection fractions were approximately 3 times more likely to develop left ventricular systolic dysfunction)
• the presence of late gadolinium enhancement on cardiac magnetic resonance imaging
• the presence of a HCM gene, particularly if located inside the thin filament genes

Factors Justifying More Aggressive Treatment for Patients with LVSD Include:

• multiple HCM gene mutations
• atrial fibrillation
• a left ventricular ejection fraction lower than 35%.

Important Takeaways From this Study:

• Patients with “end-stage” HCM do not all follow the same course.  Many of the patients in this study reported no serious events for many years following their decline in ejection fraction. Thus, the term “end-stage” does not accurately reflect the majority of patients.  Further research is necessary to better understand this subset of HCM patients.
• Since patients with left ventricular ejection fractions of between 50 and 59% are at heightened risk for developing end stage disease, they should be closely followed by their HCM team.
• This study found that post-myectomy patients may have a higher incidence of end stage disease.  Hence, the authors suggest that patients who have undergone septal reduction therapy, especially younger patients with one or more HCM gene mutations, continue to be closely monitored by their HCM team.

Another informative article focusing on the different stages and treatments for HCM can be found here.