Restricted left atrial dilatation can visually differentiate cardiac amyloidosis from hypertrophic cardiomyopathy

Abstract

Aims Cardiac amyloidosis (CA) is an infiltrative myocardial disease that occasionally mimics hypertrophic cardiomyopathy (HCM). The aim of this study is to investigate the discriminatory ability of visual assessment of left atrial (LA) function between CA and HCM on echocardiography. Methods and results In total, 93 patients with cardiac magnetic resonance imaging (CMR)-confirmed HCM and 34 with cardiac biopsy-confirmed CA were retrospectively assessed. LA dilatation was assessed via echocardiography in an apical four-chamber view. Visual assessment was performed to identify LA dilatation grade (preserved = 1, abnormal = 2, and restricted = 3) based on the extent of outward expansion in the LA reservoir phase. Regarding the reproducibility of visually assessing LA dilatation grade, the kappa values between intra-and inter-observer measurements were 0.82 and 0.70, respectively. Of 127 participants, 57 (45%), 42 (33%), and 28 (22%) presented with LA dilatation Grades 1, 2, and 3, respectively. All 57 patients with preserved LA dilatation (Grade 1) had HCM, and 20 of 28 patients (71%) with restricted LA dilatation (Grade 3) presented with CA. Patients with CA had a higher LA dilatation grade than those with HCM (P < 0.01). LA emptying fraction and reservoir strain were also quantitatively evaluated. The area under the curves of LA dilatation grade (0.88) and LA emptying fraction (0.88) for differentiation of these two diseases were higher than that of LA reservoir strain (0.73) (P < 0.01, respectively). During follow-up, nine patients with HCM and 16 with CA experienced cardiac event (cardiac death or hospitalization due to heart failure). In Kaplan-Meier analysis including both groups of HCM and CA, the incidence of cardiac events was higher in patients with restricted LA dilatation than in those with preserved or abnormal LA dilatation (log-rank test, P < 0.01). Conclusions Restricted LA dilatation is an indicator for the diagnosis of CA. Further, visual assessment of abnormal LA motion may facilitate diagnosis in patients with CA and high-risk patients with HCM.

Echocardiographic Assessment of Atrial Function: From Basic Mechanics to Specific Cardiac Diseases

“…Recently, we demonstrated the usefulness of visual assessment of the left atrium to differentiate cardiac amyloidosis from hypertrophic cardiomyopathy [ 76 ]. As shown in Figure 4 , we classified the LA dilatation motion into three grades (preserved: grade 1, abnormal: grade 2, and restricted: grade 3) based on the apical four-chamber view and defined it as the LA dilatation grade (Inoue grade).…”

A Machine Learning Challenge: Detection of Cardiac Amyloidosis Based on Bi-Atrial and Right Ventricular Strain and Cardiac Function

“…Impairment of nearly all functional phases for left and right atrial longitudinal strain appears to be a further valuable discriminative characteristic contributing towards diagnostic accuracy, as previously observed for the left atrium [ 11 ]. Additionally, visual characteristics such as atrial enlargement, interatrial septal thickening and atrial dysfunction are generally associated with CA rather than HCM phenotype [ 14 ]. These morphological differences appear to be associated with greater atrial strain impairment in CA patients compared to HCM patients.…”

“…However, recent investigations have shown that cardiac strain provides discriminative value for all cardiac chambers and thus may support differentiation of CA from hypertrophic cardiomyopathy (HCM) and healthy control subjects (CTRL) [ 6 , 11 , 12 , 13 , 14 , 15 ]. Based on previous observations [ 11 , 12 , 14 , 15 , 16 ] and in the hope of optimizing CMR diagnostic accuracy for CA detection, we hypothesize that strain measurements of the diagnostically less popular cardiac chambers along with general cardiac functional parameters may achieve a high CA diagnostic accuracy. Cardiac strain parameters would thus solely derive from both atria and the right ventricle.…”

Multi-parametric analyses to investigate dependencies of normal left atrial strain by cardiovascular magnetic resonance feature tracking

“…Clinical utility of MRI-attained LA strain has experienced extensive growth in its diagnostic value. For example, the challenge of distinguishing between hypertrophic cardiomyopathy from cardiac amyloidosis 6 , 26 , 27 or even the differentiation between subtypes of amyloidosis 24 were shown to be facilitated through left atrial strain quantification. The majority of previous studies were performed using echocardiography, whereby MRI data still remains limited and partially inconsistent, particularly regarding specific parameter dependencies (e.g.…”