Native T1 mapping in transthyretin amyloidosis

Area of Science:

• Cardiology
• Radiology
• Medical Imaging

Background:

• Transthyretin amyloidosis (ATTR amyloidosis) is an underdiagnosed cause of heart failure.
• Quantitative diagnostic tests for cardiac ATTR amyloidosis are lacking.
• Native T1 mapping shows high accuracy in cardiac immunoglobulin light-chain amyloidosis (AL amyloidosis).

Purpose of the Study:

• To assess native myocardial T1 mapping for detecting cardiac involvement in ATTR amyloidosis.
• To evaluate T1 mapping's ability to track cardiac amyloid burden.
• To determine if T1 mapping can identify early-stage ATTR amyloidosis.

Main Methods:

• Studied 85 ATTR amyloid patients, 8 healthy individuals with transthyretin mutations, and 79 AL amyloid patients.
• Included 52 healthy volunteers and 46 patients with hypertrophic cardiomyopathy (HCM) for comparison.
• Utilized T1 mapping (shortened modified look-locker inversion recovery) and cardiac 3,3-diphosphono-1,2-propanodicarboxylicacid (DPD) scintigraphy for ATTR patients and mutation carriers.

Main Results:

• T1 was significantly elevated in ATTR patients compared to HCM and normal subjects (p < 0.0001).
• T1 mapping demonstrated similar diagnostic performance for AL and ATTR amyloidosis versus HCM (AUC 0.84-0.85, p < 0.0001).
• T1 levels correlated with cardiac amyloid burden (DPD scintigraphy, p < 0.0001) and identified early disease (DPD grade 1).

Conclusions:

• Native myocardial T1 mapping is effective in detecting cardiac ATTR amyloidosis.
• T1 mapping offers similar diagnostic and tracking capabilities to AL amyloidosis, with lower maximal T1 elevation.
• T1 mapping shows potential as an early diagnostic marker for ATTR amyloidosis.