Value of CMR feature-tracking imaging in discriminating subtypes of cardiac amyloidosis
Objective:To obtain the myocardial strain values of the left ventricle at the global and regional level in patients with different subtypes of cardiac amyloidosis(CA)through cardiovascular magnetic resonance feature tracking(CMR-FT).Materials and Methods:This study included patients with CA who had undergone endocardial biopsy,and 20 cases of immunoglobulin light chain cardiac amyloidosis(AL-CA)and 22 cases of transthyretin cardiac amyloidosi(ATTR-CA)were retrospectively included according to immunohistochemistry,serum immunofixation electrophoresis,and Tcm/HMDP/PYP scintillation imaging.The type and range of late gadolinium enhancement in the two groups were evaluated to reflect the differences in histological characteristics.The radial,circumferential and longitudinal strains(2D and 3D)of the whole left ventricle and myocardium layers(subepicardial and subendocardial)were obtained by CMR-FT technique,and the differences of each parameter between groups were analyzed.Receiver operator characteristic curve analysis was used to analyze the accuracy of strain parameters in distinguishing the two CA types.Results:Compared with the ATTR-CA group,the left ventricular ejection fraction was slightly lower in the AL-CA group,and the left ventricular end-diastolic volume was relatively smaller,but didn't reach statistically significant.After body surface area correction,left ventricular mass in ATTR-CA group was slightly higher than that in AL-CA group[left ventricular mass index:(106.38±29.79)mL/m2 vs.(100.04±36.73)mL/m2].The distribution of late gadolinium enhancement was more diffuse in patients with ATTR-CA type(60%)and more subendocardial in patients with AL-CA type.The absolute values of left ventricular global radial strain(3D)(12.96%±5.21%vs.16.58%±4.39%),global longitudinal strain(2D)(-6.70%±1.94%vs.-7.87%±1.70%),global circumferential strain-epicardial(GCSepi)(-8.41%±2.78%vs.-10.51%±3.10%)and global longitudinal strain-epicardial(GLSepi)(-6.49%±2.03%vs.-8.15%±1.86%)in ATTR-CA group were lower than that in AL-CA group(all P<0.05).The accuracy of GPSepi and GLSepi were the highest,and the AUC values were both reached 0.705.Logistic regression analysis showed that GLSepi was an independent factor in distinguishing different subtypes(OR=1.60,P=0.021).Conclusions:CMR-FT imaging can provide valuable information about myocardial function and strain in patients with CA.Moreover,it is capable of distinguishing between the two common subtypes,ATTR-CA and AL-CA.The left ventricular myocardial strains in ATTR-CA are lower than those in AL-CA.
万方数据
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