Department of Cardiovascular Medicine, Ascension Providence Southfield Hospital, Southfield, MI 48075, USA.
Department of Cardiovascular Medicine, University of Texas Medical Branch of Galveston, Galveston, TX 77555, USA.
Medicina (Kaunas). 2023 Feb 16;59(2):378. doi: 10.3390/medicina59020378.
: Cardiac amyloidosis is a disorder caused by amyloid fibril deposition in the extracellular space of the heart. Almost all forms of clinical cardiac amyloidosis are transthyretin amyloidosis (ATTR) or light chain amyloidosis. technetium pyrophosphate (Tc PYP scan) has changed the landscape of the non-biopsy diagnosis of ATTR cardiac amyloidosis (ATTR-CA) by providing remarkably high diagnostic accuracy. We examined our experience with PYP scans in patients undergoing workup for ATTR-CA and evaluated the diagnostic workflow in patients with intermediate PYP scan results. : Retrospective chart review study in which we analyzed data of 84 patients who underwent c-99m pyrophosphate (PYP) SPECT scan for the diagnosis of ATTR-CA from 2017 till 2021 at our institution. We identified three groups: Low uptake (PYPL uptake ratio < 1.2 + visual grade 1/0), = 30, Intermediate uptake (PYPI uptake ratio 1.2-1.49, visual grade 2/3), = 25 and High uptake (PYPH uptake ratio ≥ 1.5 + visual grade 2/3), = 29. We reviewed patients' demographics, medical histories, echo parameters and diagnostic testing including light chain analysis, cardiac magnetic resonance results, and biopsies. : Mean patients' age was 73, male-to=female ratio 3:1, 59% of patients were African American. Cardiovascular comorbidities, cardiac biomarkers (BNP and Troponin) and amyloid-related neuropathy were similar in all groups. A statistically significant difference in septal thickness/posterior wall thickness and final diagnosis were found between the groups. The distribution of overall diagnostic testing ratios for the PYPI group included serum protein electrophoresis 92%, urine protein electrophoresis 65%, free light chain 80%, CMR 32%, tissue biopsy done in 20% and BM biopsy in 16%, which are similar to the ratios of other groups. Overall, 25% ( = 5, 4 TTR-CA and 1 AL Amyloid) of patients in the PYPI group had a final diagnosis of CA established with additional testing ( = 0.001 vs. other groups). : The PYP scan is an accurate noninvasive test for cardiac ATTR-CA. Importantly, 25% of the PYPI group had a final diagnosis of ATTR-CA reiterating that diagnosis needs to be pursued in PYPI cases based on clinical suspicion. Routine evaluation and exclusion of light chain disease and establishing a consistent workflow for amyloid diagnosis and continued education for technologists and readers of PYP scans is key to a successful amyloidosis workup.
心脏淀粉样变性是一种由心脏细胞外空间中淀粉样纤维沉积引起的疾病。几乎所有类型的临床心脏淀粉样变性都是转甲状腺素淀粉样变性（ATTR）或轻链淀粉样变性。锝焦磷酸盐（Tc PYP 扫描）通过提供极高的诊断准确性，改变了非活检诊断ATTR 心脏淀粉样变性（ATTR-CA）的格局。我们检查了我们在接受 ATTR-CA 检查的患者中进行 PYP 扫描的经验，并评估了中间 PYP 扫描结果患者的诊断工作流程。
我们对 2017 年至 2021 年在我们机构接受 c-99m 焦磷酸盐（PYP）SPECT 扫描以诊断 ATTR-CA 的 84 名患者进行了回顾性图表审查研究。我们确定了三组：低摄取（PYPL 摄取率<1.2+视觉等级 1/0），=30 例，中间摄取（PYPI 摄取率 1.2-1.49，视觉等级 2/3），=25 例，高摄取（PYPH 摄取率≥1.5+视觉等级 2/3），=29 例。我们回顾了患者的人口统计学、病史、超声心动图参数和诊断性检查，包括轻链分析、心脏磁共振结果和活检。
患者的平均年龄为 73 岁，男女比例为 3:1，59%的患者为非裔美国人。心血管合并症、心脏生物标志物（BNP 和肌钙蛋白）和淀粉样相关神经病在所有组中相似。组间在室间隔厚度/后壁厚度和最终诊断方面存在统计学显著差异。PYPI 组的总体诊断检测比值分布包括血清蛋白电泳 92%、尿蛋白电泳 65%、游离轻链 80%、CMR 32%、组织活检 20%和 BM 活检 16%，与其他组相似。总体而言，PYPI 组中有 25%（=5，4 例 TTR-CA 和 1 例 AL 淀粉样变性）的患者通过额外的检测建立了 CA 的最终诊断（=0.001 与其他组相比）。
PYP 扫描是一种用于心脏 ATTR-CA 的准确非侵入性检查。重要的是，PYPI 组中有 25%的患者最终诊断为 ATTR-CA，这再次强调了基于临床怀疑，需要在 PYPI 病例中进行诊断。常规评估和排除轻链疾病，建立一致的淀粉样变性诊断工作流程，并为 PYP 扫描的技术员和读者提供持续教育，是成功进行淀粉样变性检查的关键。
