Wang Fangqing, Xu Xinghua, Wang Qing, Yu Dexin, Lv Lei, Wang Qian
Department of Radiology, Qilu Hospital of Shandong University, Jinan, China.
Quant Imaging Med Surg. 2023 Jan 1;13(1):449-461. doi: 10.21037/qims-22-329. Epub 2022 Sep 26.
Apical sparing of left ventricular (LV) strain can occur in light-chain cardiac amyloidosis (AL-CA). We employed indicators of the strain ratio of the apex to base (RAB) and the relative apical sparing of strain (RAS) on the basis of LV global and segmental strain to distinguish AL-CA from hypertrophic cardiomyopathy (HCM).
In all, 36 AL-CA patients, 37 HCM patients, and 36 healthy controls underwent 3.0 T cardiac magnetic resonance (CMR) examination. We compared LV strain parameters from CMR tissue tracking (CMR-TT), including global and segmental peak radial strain (PRS), peak circumferential strain (PCS), and peak longitudinal strain (PLS); the peak systolic strain rate in radial, circumferential, and longitudinal directions (PSSR_R, PSSR_C, PSSR_L); and the peak diastolic strain rate in radial, circumferential, and longitudinal directions (PDSR_R, PDSR_C, PDSR_L). We also assessed the values of RAB and RAS. Differences in all groups were compared using an independent t-test and a nonparametric rank sum test.
In the comparison of global strain parameters, all the peak strain, systolic, and diastolic peak strain rates of the AL-CA group significantly decreased compared with those of the HCM and healthy control groups (all P<0.001). The values of PSSR in all directions were lower in the AL-CA than in the HCM patients (PSSR_R, P<0.001; PSSR_C, P=0.004; PSSR_L, P=0.010) . In the analysis of segmental strain parameters, all peak strains in the basal segment showed significant differences between the AL-CA and HCM groups (all P<0.001). Some strain rate parameters in the basal segment were also noted to be significantly different (PSSR_R, P<0.001; PSSR_L, P<0.001; PDSR_R, P=0.015; PDSR_C, P=0.020). Both the RAB and RAS of peak strain in all directions showed significant differences between the AL-CA and HCM groups (all P<0.001). The RAB of the radial and circumferential PSSR showed statistical differences between the 2 groups (P<0.001 and P=0.001). The RAS in the radial direction of both the PSSR and PDSR was statistically different (P=0.003 and P=0.012).
The CMR-TT technique can be used to quantitatively compare global and segmental strain differences between AL-CA and HCM. In addition, RAB and RAS are reliable parameters for assessing the apical sparing pattern and thus, for distinguishing AL-CA from HCM.
左心室（LV）应变的心尖保留现象可发生于轻链型心脏淀粉样变（AL-CA）。我们基于左心室整体和节段应变，采用心尖与心底应变率（RAB）及应变相对心尖保留（RAS）指标，以区分AL-CA与肥厚型心肌病（HCM）。
共36例AL-CA患者、37例HCM患者及36例健康对照者接受了3.0T心脏磁共振（CMR）检查。我们比较了CMR组织追踪（CMR-TT）获得的左心室应变参数，包括整体和节段的峰值径向应变（PRS）、峰值圆周应变（PCS）和峰值纵向应变（PLS）；径向、圆周和纵向方向的峰值收缩期应变率（PSSR_R、PSSR_C、PSSR_L）；以及径向、圆周和纵向方向的峰值舒张期应变率（PDSR_R、PDSR_C、PDSR_L）。我们还评估了RAB和RAS值。使用独立t检验和非参数秩和检验比较所有组间差异。
在整体应变参数比较中，AL-CA组的所有峰值应变、收缩期和舒张期峰值应变率均显著低于HCM组和健康对照组（均P<0.001）。AL-CA组各方向的PSSR值均低于HCM患者（PSSR_R，P<0.001；PSSR_C，P=0.004；PSSR_L，P=0.010）。在节段应变参数分析中，AL-CA组和HCM组之间基底节段的所有峰值应变均有显著差异（均P<0.001）。还注意到基底节段的一些应变率参数有显著差异（PSSR_R，P<0.001；PSSR_L，P<0.001；PDSR_R，P=0.015；PDSR_C，P=0.020）。AL-CA组和HCM组在所有方向的峰值应变的RAB和RAS均有显著差异（均P<0.001）。径向和圆周PSSR的RAB在两组间有统计学差异（P<0.001和P=0.001）。PSSR和PDSR在径向方向的RAS有统计学差异（P=0.003和P=0.012）。
CMR-TT技术可用于定量比较AL-CA和HCM之间的整体和节段应变差异。此外，RAB和RAS是评估心尖保留模式的可靠参数，因此可用于区分AL-CA与HCM。
