The value of CMR-derived left atrial strain parameters in differential diagnosis of cardiac amyloidosis and hypertrophic cardiomyopathy
Background Differentiating cardiac amyloidosis (CA) from hypertrophic cardiomyopathy (HCM) is clinically challenging due to overlapping phenotypes of left ventricular hypertrophy. This study aimed to evaluate the diagnostic value of cardiac magnetic resonance (CMR)-derived left atrial strain parameters in differentiating CA from HCM. Methods A retrospective analysis was performed on CMR data obtained from 37 patients with HCM, 41 patients with CA, and 29 individuals in the normal control group. Left ventricular and left atrial functions were quantified using CVI42 software (version 5.14.2). Left atrial strain parameters were assessed using the tissue tracking module, including left atrial reservoir strain (εs) and strain rate (SRs), conduit strain (εe) and strain rate (SRe), and booster strain (εa) and strain rate (SRa). Differences in left ventricular and left atrial functional parameters, as well as left atrial strain parameters among the three groups, were analyzed using the Kruskal-Wallis test. Pairwise comparisons were conducted using the Mann-Whitney U test. Receiver operating characteristic (ROC) curve analysis was performed using MedCalc (version 15.2.2) to determine the diagnostic efficacy of left atrial strain parameters in differentiating CA from HCM. Results The absolute values of εs, εe, εa, SRs, SRe, and SRa were significantly lower in both the HCM and CA groups compared with the normal control group (P<0.05). Furthermore, the absolute values of these parameters were markedly lower in CA compared with HCM (P<0.05). Among these parameters, εs demonstrated the highest diagnostic performance for distinguishing CA from HCM, with an area under the ROC curve of 0.921. Conclusions CMR-derived left atrial strain parameters, particularly εs, might serve as a reliable means for differentiating between HCM and CA, which need further prospective study including patients with all HCM types and conducting internal and external validation to confirm credibility and expand generalizability.