Chamling Bishwas, Drakos Stefanos, Bietenbeck Michael, Klingel Karin, Meier Claudia, Yilmaz Ali
Division of Cardiovascular Imaging, Department of Cardiology I, University Hospital Münster, Albert Schweitzer Campus 1, Münster, Germany.
Institute for Pathology and Neuropathology, University Hospital Tübingen, Tübingen, Germany.
Front Cardiovasc Med. 2021 Sep 27;8:757642. doi: 10.3389/fcvm.2021.757642. eCollection 2021.
Diagnosis of cardiac involvement in amyloid A (AA) amyloidosis is challenging since AA amyloidosis is a rare disease and cardiac involvement even less frequent. The diagnostic yield of currently available non-invasive imaging methods is not well-studied and rather limited, and invasive endomyocardial biopsy (EMB) is rarely performed due to the potential risk of this procedure. Cardiovascular magnetic resonance (CMR)-based myocardial tissue characterization by late-gadolinium-enhancement (LGE) imaging and novel-mapping approaches may increase the diagnostic yield in AA amyloidosis. Two patients with AA amyloidosis in whom cardiac involvement was suspected based on CMR findings and subsequently proven by biopsy work-up are presented. CMR studies were performed on a 1.5-T system and comprised a cine steady-state free precession pulse sequence for ventricular function and a late-gadolinium-enhancement (LGE) sequence for detection of myocardial pathology. Moreover, a modified Look-Locker inversion recovery (MOLLI) T1-mapping sequence was applied in basal, mid and apical short-axes prior to contrast agent administration and ~20 min thereafter to determine native T1 and ECV values. Both patients showed slightly dilated left ventricles (LV) with mild to moderate LV hypertrophy and preserved systolic function. Only a very subtle pattern of LGE was observed in both patients with AA amyloidosis. However, markedly elevated native T1 (max. 1,108 and 1,112 ms, respectively) and extracellular volume fraction (ECV) values (max. 39 and 48%, respectively) were measured in the myocardium suggesting the presence of cardiac involvement - with subsequent EMB-based proof of AA amyloidosis. We recommend a multi-parametric CMR approach in patients with AA amyloidosis comprising both LGE-based contrast-imaging and T1-mapping-based ECV measurement of the myocardium for non-invasive work-up of suspected cardiac involvement. The respective CMR findings may be used as gatekeeper for additional invasive procedures (such as EMB) and as a non-invasive monitoring tool regarding assessment and modification of ongoing treatments.
诊断心脏受累的淀粉样蛋白A（AA）淀粉样变性具有挑战性，因为AA淀粉样变性是一种罕见疾病，而心脏受累更为少见。目前可用的非侵入性成像方法的诊断率尚未得到充分研究且相当有限，由于该操作存在潜在风险，侵入性心内膜心肌活检（EMB）很少进行。基于心血管磁共振（CMR）的心肌组织特征通过延迟钆增强（LGE）成像和新型映射方法可能会提高AA淀粉样变性的诊断率。本文介绍了两名基于CMR结果怀疑有心脏受累并随后经活检证实的AA淀粉样变性患者。CMR研究在1.5-T系统上进行，包括用于心室功能的电影稳态自由进动脉冲序列和用于检测心肌病变的延迟钆增强（LGE）序列。此外，在注射造影剂前以及注射后约20分钟，在基底、中间和心尖短轴上应用改良的Look-Locker反转恢复（MOLLI）T1映射序列，以确定固有T1和细胞外容积（ECV）值。两名患者均表现为左心室轻度扩张，伴有轻度至中度左心室肥厚，收缩功能保留。在两名AA淀粉样变性患者中仅观察到非常细微的LGE模式。然而，心肌中测得的固有T1（分别为最大值1108和1112毫秒）和细胞外容积分数（ECV）值（分别为最大值39%和48%）显著升高，提示存在心脏受累，随后经EMB证实为AA淀粉样变性。我们建议对AA淀粉样变性患者采用多参数CMR方法，包括基于LGE的对比成像和基于T1映射的心肌ECV测量，用于对疑似心脏受累进行非侵入性检查。各自的CMR结果可作为额外侵入性操作（如EMB）的把关手段，并作为评估和调整正在进行的治疗的非侵入性监测工具。
