Tubben Alwin, Prakken Niek H J, Ivashchenko Oleksandra V, Tingen Hendrea S A, Glaudemans Andor W J M, Noordzij Walter, Nienhuis Hans L A, van der Meer Peter, Slart Riemer H J A
Department of Cardiology, University of Groningen, University Medical Center Groningen, the Netherlands; Amyloidosis Center of Expertise, University of Groningen, University Medical Center Groningen, the Netherlands.
Department of Radiology, University Medical Center Groningen, University of Groningen, the Netherlands.
J Nucl Cardiol. 2025 Mar;45:102146. doi: 10.1016/j.nuclcard.2025.102146. Epub 2025 Feb 3.
Cardiac sympathetic neuronal dysfunction is an early marker in wild-type transthyretin amyloidosis cardiomyopathy (ATTRwt-CM). Iodine-123-labeled norepinephrine analog meta-iodobenzylguanidine ([I]-MIBG) imaging evaluates cardiac sympathetic innervation but lacks volumetric activity quantification in current methods. This study aims to quantify cardiac sympathetic neuronal dysfunction in ATTRwt-CM using [I]-MIBG single-photon emission computed tomography/ computed tomography (SPECT/CT) and correlate findings with functional and structural cardiac parameters from echocardiogram and cardiac magnetic resonance imaging (CMR).
We conducted a single-center, descriptive, cross-sectional study to quantify absolute myocardial sympathetic function in ATTRwt-CM using [I]-MIBG SPECT/CT. Retrospective reconstruction allowed for absolute tracer-uptake quantification of the left ventricle, overall and segmented, in kBq/mL, standard uptake value (SUV), and percentage of the injected dose (%ID). Echocardiography, CMR, and bone scintigraphy were performed according to clinical standards. Segmented [I]-MIBG SPECT/CT values were correlated with global longitudinal systolic strain (GLSS) on echocardiography, native-T1, and extracellular volume (ECV) on CMR using SPECT/CT fused with CMR.
Twenty-nine ATTRwt-CM patients (75.8 ± 6.6 years, 90% male) were prospectively included. All exhibited cardiac sympathetic neuronal dysfunction, with a median late heart-to-mediastinum ratio of 1.69 (1.45-1.89) and a washout rate of 22.7% (16.4%-27.3%). SUV, SUV, SUV, and %ID were 1.80 ± .78, 3.84 ± 1.41, 4.46 ± 1.68, and .46 ± .18, respectively, correlating with semiquantitative [I]-MIBG measures. No correlations were found with GLSS on echocardiography or native T1 and ECV on CMR.
The current study demonstrates the feasibility of volumetric quantification of [I]-MIBG SPECT/CT in ATTRwt-CM. SUV, SUV, SUV, and %ID correlate with semi-quantitative measures but not with key cardiac parameters on echocardiography or CMR. This confirms the sensitivity of [I]-MIBG SPECT/CT to different aspects of cardiac function or pathology.
EudraCT ref. 2020-003350-72, retrospectively registered March 20, 2023. https://classic.
gov/ct2/show/NCT05776212.
心脏交感神经功能障碍是野生型转甲状腺素蛋白淀粉样变心肌病（ATTRwt-CM）的早期标志物。碘-123标记的去甲肾上腺素类似物间碘苄胍（[I]-MIBG）成像可评估心脏交感神经支配情况，但目前的方法缺乏体积活性定量。本研究旨在使用[I]-MIBG单光子发射计算机断层扫描/计算机断层扫描（SPECT/CT）对ATTRwt-CM患者的心脏交感神经功能障碍进行定量，并将结果与超声心动图和心脏磁共振成像（CMR）的心脏功能和结构参数相关联。
我们进行了一项单中心、描述性横断面研究，以使用[I]-MIBG SPECT/CT对ATTRwt-CM患者的绝对心肌交感神经功能进行定量。回顾性重建允许对左心室进行绝对示踪剂摄取定量，包括整体和分段的，以kBq/mL、标准摄取值（SUV）和注射剂量百分比（%ID）表示。根据临床标准进行超声心动图、CMR和骨闪烁显像。使用与CMR融合的SPECT/CT，将分段的[I]-MIBG SPECT/CT值与超声心动图上的整体纵向收缩应变（GLSS）、CMR上的固有T1和细胞外容积（ECV）相关联。
前瞻性纳入了29例ATTRwt-CM患者（75.8±6.6岁，90%为男性）。所有患者均表现出心脏交感神经功能障碍，晚期心脏与纵隔比值的中位数为1.69（1.45-1.89），洗脱率为22.7%（16.4%-27.3%）。SUV、SUV、SUV和%ID分别为1.80±0.78、3.84±1.41、4.46±1.68和0.46±0.18，与半定量[I]-MIBG测量值相关。未发现与超声心动图上的GLSS或CMR上的固有T1和ECV相关。
本研究证明了在ATTRwt-CM中对[I]-MIBG SPECT/CT进行体积定量的可行性。SUV、SUV、SUV和%ID与半定量测量值相关，但与超声心动图或CMR上的关键心脏参数无关。这证实了[I]-MIBG SPECT/CT对心脏功能或病理不同方面的敏感性。
EudraCT编号2020-003350-72，于2023年3月20日进行回顾性注册。https://classic.
gov/ct2/show/NCT05776212。
