Diagnostic Utility of Left Atrial Strain Parameters in Cardiac Amyloidosis Using Magnetic Resonance Imaging Feature Tracking: Comparison With Hypertrophic Cardiomyopathy and Healthy Controls

Purpose: This study aimed to evaluate the diagnostic utility of left atrial (LA) strain parameters in cardiac amyloidosis using cardiac magnetic resonance imaging (MRI) feature tracking and to compare them with hypertrophic cardiomyopathy (HCM) and healthy controls. Materials and Methods:This retrospective, single-center study included 63 patients with cardiac amyloidosis, 61 patients with HCM, and 12 healthy controls.LA strain parameters, including the reservoir, conduit, and booster strains and their respective strain rates, were analyzed.Left ventricular (LV) parameters and extracellular volume (ECV) were assessed.Group comparisons were performed, and multiple linear regression analyses between strain parameters and ECV were conducted within the amyloidosis group.Results: LA strain was significantly reduced in cardiac amyloidosis compared to HCM and controls (reservoir strain: 12.3% ± 8.3% vs. 21.0%± 8.6% vs. median [interquartile range] 36.3% [29.2%-42.6%],p < 0.001; conduit strain: 6.9% ± 4.8% vs. 11.0%± 5.2% vs. 22.8% [19.6%-28.5%],p < 0.001; booster strain: 6.2% ± 4.8% vs. 10.7% ± 4.6% vs. 13.1% [8.6%-16.5%],p < 0.001).Among LA strain values, reservoir strain showed the highest area under the curve (0.81), and booster strain demonstrated the strongest inverse correlation with ECV (β = -1.306,p < 0.001, adjusted R 2 = 0.354).Conclusion: LA strain parameters derived from cardiac MRI feature tracking differed significantly among patients with cardiac amyloidosis, HCM, and healthy controls.LA strain assessment may provide complementary information for the noninvasive evaluation of cardiac amyloidosis, particularly when contrast-enhanced imaging is not feasible.