Simplified apical four‐chamber view evaluation of relative apical sparing of longitudinal strain in diagnosing AL amyloid cardiomyopathy.

Aim of the study: To assess the diagnostic utility of a simplified approach to relative apical sparing of longitudinal strain (RAS LS) using only an apical four‐chamber view (A4C) in patients with AL amyloid cardiomyopathy (ALAC). Methods: We retrospectively evaluated echocardiographic recordings of 20 patients with ALAC, 20 patients with Fabry disease‐related cardiomyopathy (FD), and 20 patients with concentric hypertensive left ventricular hypertrophy (HLVH) matched for mean LV mean thickness. Peak segmental LS values of the interventricular septum and lateral LV wall were measured in the A4C using two‐dimensional speckle‐tracking echocardiography. RAS LS was calculated as average apical LS/(average basal LS + average midventricular LS). Results: Relative apical sparing of longitudinal strain values in patients with ALAC (1.23 ± 0.64) were significantly higher than those in FD patients (0.75 ± 0.19, P < 0.05) as well as in individuals with HLVH (0.75 ± 0.23, P < 0.05), but with a significant overlap. The optimal RAS LS value differentiating ALAC from FD and HLVH with 70% sensitivity and 75% specificity was 0.88 (AUC 0.79). In multivariate modeling, RAS LS was significantly additive to traditional predictors of ALAC (low QRS voltage and pseudoinfarct ECG patterns, pericardial effusion, E/e′ ratio, E‐wave deceleration time; P < 0.05 for all models). Conclusions: Simplified RAS LS evaluation represents an attractive approach for diagnostics of ALAC. However, because of considerable overlap with other disorders with hypertrophic phenotype, the analysis of RAS LS in the A4C should be combined with other traditional echocardiographic and ECG predictors in differentiating ALAC from other forms of concentric LV wall thickening. [ABSTRACT FROM AUTHOR]