Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092, Zurich, Switzerland.
Department of Cardiology, University Heart Center, University Hospital Zurich, Zurich, Switzerland.
J Cardiovasc Magn Reson. 2019 Jan 31;21(1):10. doi: 10.1186/s12968-019-0519-6.
Cardiac involvement of amyloidosis leads to left-ventricular (LV) wall thickening with progressive heart failure requiring rehospitalization. Cardiovascular magnetic resonance (CMR) is a valuable tool to non-invasively assess myocardial thickening as well as structural changes. Proton CMR spectroscopy (H-CMRS) additionally allows assessing metabolites including triglycerides (TG) and total creatine (CR). However, opposing results exist regarding utilization of these metabolites in LV hypertrophy or thickening. Therefore, the aim of this study was to measure metabolic alterations using H-CMRS in a group of patients with thickened myocardium caused by cardiac amyloidosis.
H-CMRS was performed on a 1.5 T system (Achieva, Philips Healthcare, Best, The Netherlands) using a 5-channel receive coil in 11 patients with cardiac amyloidosis (60.5 ± 11.4 years, 8 males) and 11 age- and gender-matched controls (63.2 ± 8.9 years, 8 males). After cardiac morphology and function assessment, proton spectra from the interventricular septum (IVS) were acquired using a double-triggered PRESS sequence. Post-processing was performed using a customized reconstruction pipeline based on ReconFrame (GyroTools LLC, Zurich, Switzerland). Spectra were fitted in jMRUI/AMARES and the ratios of triglyceride-to-water (TG/W) and total creatine-to-water (CR/W) were calculated.
Besides an increased LV mass and a thickened IVS concomitant to the disease characteristics, patients with cardiac amyloidosis presented with decreased global longitudinal (GLS) and circumferential (GCS) strain. LV ejection fraction was preserved relative to controls (60.0 ± 13.2 vs. 66.1 ± 4.3%, p = 0.17). Myocardial TG/W ratios were significantly decreased compared to controls (0.53 ± 0.23 vs. 0.80 ± 0.26%, p = 0.015). CR/W ratios did not show a difference between both groups, but a higher standard deviation in patients with cardiac amyloidosis was observed. Pearson correlation revealed a negative association between elevated LV mass and TG/W (R = - 0.59, p = 0.004) as well as GCS (R = - 0.48, p = 0.025).
A decrease in myocardial TG/W can be detected in patients with cardiac amyloidosis alongside impaired cardiac function with an association to the degree of myocardial thickening. Accordingly, H-CMRS may provide an additional diagnostic tool to gauge progression of cardiac amyloidosis along with standard imaging sequences.
EK 2013-0132.
淀粉样变导致心脏受累，左心室（LV）壁增厚，随后出现心力衰竭并需要再次住院治疗。心血管磁共振（CMR）是一种有价值的工具，可以非侵入性地评估心肌增厚以及结构变化。质子磁共振波谱（H-CMRS）还可以评估包括甘油三酯（TG）和总肌酸（CR）在内的代谢物。然而，关于这些代谢物在 LV 肥厚或增厚中的应用存在相反的结果。因此，本研究的目的是使用 H-CMRS 在一组由心脏淀粉样变引起的心肌增厚的患者中测量代谢变化。
使用 1.5T 系统（Achieva，Philips Healthcare，Best，荷兰）和 5 通道接收线圈在 11 名心脏淀粉样变性患者（60.5±11.4 岁，8 名男性）和 11 名年龄和性别匹配的对照组（63.2±8.9 岁，8 名男性）中进行 H-CMRS。在评估心脏形态和功能后，使用双触发 PRESS 序列从室间隔（IVS）获取质子波谱。使用基于 ReconFrame（GyroTools LLC，苏黎世，瑞士）的自定义重建管道进行后处理。使用 jMRUI/AMARES 对光谱进行拟合，并计算甘油三酯与水（TG/W）和总肌酸与水（CR/W）的比值。
除了与疾病特征相关的 LV 质量增加和 IVS 增厚外，心脏淀粉样变性患者还表现出整体纵向应变（GLS）和周向应变（GCS）降低。与对照组相比，LV 射血分数保持不变（60.0±13.2%比 66.1±4.3%，p=0.17）。与对照组相比，心肌 TG/W 比值显著降低（0.53±0.23%比 0.80±0.26%，p=0.015）。两组之间的 CR/W 比值没有差异，但心脏淀粉样变性患者的标准差更高。Pearson 相关性显示 LV 质量升高与 TG/W（R=-0.59，p=0.004）和 GCS（R=-0.48，p=0.025）呈负相关。
心脏淀粉样变性患者可检测到心肌 TG/W 降低，同时伴有心脏功能受损，与心肌增厚程度相关。因此，H-CMRS 可能是一种额外的诊断工具，可与标准成像序列一起评估心脏淀粉样变性的进展。
EK 2013-0132。
