Longitudinal strain in Friedreich Ataxia: a potential marker for early left ventricular dysfunction

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Friedreich's ataxia (FRDA) is a neurodegenerative disease caused by frataxin deficiency, leading to cardiac issues like hypertrophy and heart failure.
• The precise changes in cardiac remodeling and function, particularly using novel measures like myocardial strain, are not well understood in FRDA patients.

Purpose of the Study:

• To compare cardiac remodeling and function in FRDA patients versus healthy controls using echocardiography.
• To investigate the relationship between cardiac remodeling, myocardial strain, and time-dependent changes in cardiac function in FRDA.

Main Methods:

• Echocardiographic parameters including cardiac size, hypertrophy, and function were assessed in 50 FRDA patients and 50 controls.
• Measures quantified included left ventricular (LV) volumes, mass, relative wall thickness (RWT), ejection fraction (EF), and myocardial strain.
• Linear regression analysis was employed to identify significant differences between groups, adjusting for age, sex, and body surface area.

Main Results:

• FRDA patients exhibited significant differences in cardiac remodeling (LV mass, RWT, volumes) and function compared to controls.
• Longitudinal strain was significantly decreased in FRDA patients (-12.4%) versus controls (-16.0%), despite comparable and normal left ventricular ejection fraction (LVEF).
• Over a 3-year follow-up, no significant changes in strain, LV size, LV mass, or LVEF were observed in FRDA patients.

Conclusions:

• Reduced longitudinal strain in FRDA patients suggests subclinical cardiac dysfunction, even when LVEF remains normal.
• Longitudinal strain may serve as an earlier indicator of myocardial dysfunction in FRDA, preceding declines in LVEF.