Saijo Yoshihito, Yamada Hirotsugu, Yamaguchi Natsumi, Nishio Susumu, Zheng Robert, Takahashi Tomonori, Hara Tomoya, Kadota Muneyuki, Kawabata Yutaka, Ueno Rie, Matsuura Tomomi, Ise Takayuki, Yamaguchi Koji, Yagi Shusuke, Soeki Takeshi, Wakatsuki Tetsuzo, Sata Masataka
Cardiovascular Department, Tokushima University Hospital, Tokushima, Japan.
Department of Community Medicine for Cardiology, Tokushima University Graduate School of Biomedical Sciences, Takamatsu, Japan.
Echocardiography. 2025 Feb;42(2):e70087. doi: 10.1111/echo.70087.
Speckles tracking echocardiography imaging enables clinicians to detect subtle systolic dysfunction. The aim of the present study was to elucidate the differences in speckle tracking echocardiographic findings between immunoglobulin light chain amyloid cardiomyopathy (AL-CM) and transthyretin amyloid cardiomyopathy (TTR-CM).
The patients with a confirmed diagnosis of cardiac amyloidosis through cardiac biopsy from March 2013 to October 2022 were included. The relative apical sparing index (RASI) was calculated using speckle tracking echocardiography by the following equation; average apical strain/(average basal strain + mid strain).
The final study population consisted of 35 patients with cardiac amyloidosis (AL-CM: 10 patients, TTR-CM: 25 patients). The mean age was 74 ± 12 years. Although both subgroups had a gradual change of strain values from basal to apical segments, RASI was significantly lower in AL-CM compared to TTR-CM (0.92 ± 0.29 vs. 1.46 ± 0.53, p = 0.001). A RASI cutoff value of <1.0 proved useful in differentiating the diagnosis of AL-CM from TTR-CM (sensitivity: 81%, specificity: 70%, AUC: 0.82). A significant positive correlation with left ventricular mass index and RASI was found in AL-CM, but not in TTR-CM.
The apical sparing phenomenon was more remarkable in TTR-CM compared with AL-CM. RASI might be useful for the discrimination of cardiac amyloidosis subtypes. There was a difference in the relationship of RASI with left ventricular wall thickness between the cardiac amyloidosis subtypes.
斑点追踪超声心动图成像使临床医生能够检测到细微的收缩功能障碍。本研究的目的是阐明免疫球蛋白轻链淀粉样心肌病（AL-CM）和转甲状腺素蛋白淀粉样心肌病（TTR-CM）在斑点追踪超声心动图检查结果上的差异。
纳入2013年3月至2022年10月期间经心脏活检确诊为心脏淀粉样变性的患者。使用斑点追踪超声心动图通过以下公式计算相对心尖保留指数（RASI）：平均心尖应变/（平均基底应变+中间应变）。
最终研究人群包括35例心脏淀粉样变性患者（AL-CM：10例，TTR-CM：25例）。平均年龄为74±12岁。尽管两个亚组从基底节段到心尖节段的应变值都有逐渐变化，但与TTR-CM相比，AL-CM中的RASI显著更低（0.92±0.29对1.46±0.53，p = 0.001）。RASI临界值<1.0被证明有助于区分AL-CM和TTR-CM的诊断（敏感性：81%，特异性：70%，AUC：0.82）。在AL-CM中发现左心室质量指数与RASI呈显著正相关，而在TTR-CM中未发现。
与AL-CM相比，TTR-CM的心尖保留现象更显著。RASI可能有助于鉴别心脏淀粉样变性的亚型。心脏淀粉样变性亚型之间RASI与左心室壁厚度的关系存在差异。
