Hereditary Transthyretin Amyloidosis: How to Differentiate Carriers and Patients Using Speckle-Tracking...

Area of Science:

• Cardiology
• Genetics
• Neurology

Background:

• Hereditary transthyretin amyloidosis results from transthyretin (TTR) gene mutations.
• Early identification of cardiac involvement is crucial for differentiating carriers from patients with TTR-related diseases.

Purpose of the Study:

• To identify early indicators of cardiac involvement in TTR mutation carriers.
• To distinguish between carriers, patients with polyneuropathy, and those with both cardiac amyloidosis and polyneuropathy.

Main Methods:

• A case-control study involving 31 subjects with TTR mutations.
• Patients categorized into three groups: cardiac amyloidosis/polyneuropathy, polyneuropathy only, and carriers.
• Speckle-tracking echocardiography assessed left-ventricular global longitudinal strain (GLS), atrial stiffness, apical/basal longitudinal strain ratio (SAB), and relative apical sparing (RAS).

Main Results:

• Significant differences in SAB and RAS were observed between carriers (Group C) and patients with polyneuropathy (Group B).
• SAB and RAS were more impaired in patients with cardiac amyloidosis and polyneuropathy (Group A) compared to those with only polyneuropathy (Group B).
• Atrial stiffness was significantly impaired in both Group A and Group B compared to Group C.

Conclusions:

• The apical/basal longitudinal strain ratio (SAB) and relative apical sparing (RAS) show diagnostic potential for cardiac amyloidosis.
• SAB and RAS demonstrate a progressive decline from carriers to patients with neurological and cardiac involvement.
• SAB, RAS, and atrial stiffness may serve as monitoring tools for TTR mutation carriers, warranting further investigation.