Shear wave velocity measurements in the basal anteroseptal and right ventricular walls differed between transthyretin and light chain cardiac amyloidosis when conventional echocardiographic parameters did not.
To evaluate whether myocardial stiffness measured with three-dimensional shear wave elastography can differentiate between light chain cardiac amyloidosis and transthyretin cardiac amyloidosis.
Approach:
Study Design: A study of 72 patients with cardiac amyloidosis assessed myocardial stiffness using transthoracic three-dimensional shear wave elastography, alongside echocardiography, scintigraphy, biopsy, and blood testing.
Patient Cohort: The cohort included 44 patients with transthyretin cardiac amyloidosis, 24 patients with light chain cardiac amyloidosis, and 4 patients with nontypable amyloidosis.
Measurement Technique: Ten three-dimensional shear wave elastography measurements were acquired in each myocardial segment during diastasis using electrocardiographic gating.
Algorithm Development: An algorithm was developed incorporating patient age, N-terminal pro-B-type natriuretic peptide, and median shear wave velocity measurements.
Key Findings:
Shear wave velocity was higher in patients with transthyretin cardiac amyloidosis compared to those with light chain cardiac amyloidosis in the basal anteroseptal wall and right ventricular wall.
No echocardiographic parameters discriminated between the two types of cardiac amyloidosis.
The developed algorithm achieved 100% sensitivity and 100% specificity in distinguishing the two subtypes.
