Value of Longitudinal Strain to Identify Wild-Type Transthyretin Amyloidosis in Patients With Aortic Stenosis.

Abstract

Wild-type transthyretin-related amyloidosis (ATTRwt) and degenerative aortic stenosis (AS) are both age-related. Diagnosis of cardiac amyloidosis (CA) among patients with AS may be difficult due to overlapping morphological and functional criteria. The aim of this study was to describe an echocardiographic longitudinal strain (LS) pattern among patients with AS with and without ATTRwt.Methods and Results:Patients who have AS with ATTRwt (n=30), AS without ATTRwt (n=50) and ATTRwt without AS (n=31) underwent two-dimensional speckle-tracking echocardiography. Transthyretin CA was based on positive bone scintigraphy without monoclonal gammopathy. All patients showed a gradual decrease in LS from the base to the apex resulting in a decrease of the global LS. A cut-off value of 1.0 for relative apical LS (average apical LS/[average basal LS+mid-LS]) was sensitive (88%) but less specific (68%) in differentiating ATTRwt among patients with severe AS. The best cut-off value for relative apical LS for identifying patients with ATTRwt among the whole population was 0.9 (sensitivity 74%, specificity 66%); however, 35%, 25% and 11% of patients who have ATTRwt without AS, with moderate AS and with severe AS, respectively, did not reach this threshold. A decrease of global and relative apical LS is common in patients with AS, even in the absence of ATTRwt. ATTRwt CA can be present even in the absence of relative apical sparing of LS.