The aim of this study was to assess the diagnostic accuracy of bone scintigraphy in a large multicenter cohort of patients with cardiac amyloidotic involvement and Phe64Leu transthyretin (TTR) mutation. Diagnostic accuracy of bone scintigraphy for transthyretin-related cardiac amyloidosis (TTR-CA) is considered extremely high, enabling this technique to be the noninvasive diagnostic standard for TTR-CA. Nevertheless, this approach has not been systematically validated across the entire spectrum of TTR mutations. A total of 55 patients with Phe64Leu TTR mutation were retrospectively analyzed and evaluated between 1993 and 2018 at 7 specialized Italian tertiary centers. Cardiac involvement was defined as presence of an end-diastolic interventricular septum thickness ≥12 mm, without other possible causes of left ventricular hypertrophy (i.e., arterial hypertension or valvulopathies). A technetium-99m (99mTc)–diphosphonate (DPD) or 99mTc–hydroxyl-methylene-diphosphonate (HMDP) bone scintigraphy was reviewed, and visual scoring was evaluated according to Perugini’s method. Among 26 patients with definite cardiac involvement, 19 underwent 99mTc-DPD or 99mTc-HMDP bone scintigraphy. Of them, 17 (89.5%) patients had low or absent myocardial bone tracer uptake, whereas only 2 (10.5%) showed high-grade myocardial uptake. The sensitivity and the accuracy of bone scintigraphy in detecting TTR-CA were 10.5% and 37%, respectively. Patients with cardiac involvement and low or absent bone tracer uptake were similar to those with high-grade myocardial uptake in terms of age, sex, and electrocardiographic and echocardiographic findings. The sensitivity of bone scintigraphy (DPD and HMDP) in detecting TTR-CA is extremely low in patients with Phe64Leu TTR mutation, suggesting the need to assess diagnostic accuracy of bone scintigraphy to identify cardiac involvement across a wider spectrum of TTR mutations.

中文翻译：

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骨闪烁扫描检测 Phe64Leu 突变相关的甲状腺素运载蛋白心脏淀粉样变性的低灵敏度


本研究的目的是评估骨显像对患有心脏淀粉样变性和 Phe64Leu 运甲状腺素蛋白 (TTR) 突变的大型多中心患者队列的诊断准确性。骨显像对转甲状腺素蛋白相关的心脏淀粉样变性（TTR-CA）的诊断准确性被认为极高，使该技术成为 TTR-CA 的无创诊断标准。然而，这种方法尚未在整个 TTR 突变谱中得到系统验证。 1993 年至 2018 年间，意大利 7 个专业三级中心总共对 55 名 Phe64Leu TTR 突变患者进行了回顾性分析和评估。心脏受累的定义是舒张末期室间隔厚度≥12毫米，没有其他可能导致左心室肥厚的原因（即动脉高血压或瓣膜病）。回顾了锝-99m (99mTc)-二磷酸盐 (DPD) 或 99mTc-羟基亚甲基二磷酸盐 (HMDP) 骨显像，并根据佩鲁吉尼方法评估视觉评分。在 26 例明确心脏受累的患者中，19 例接受了 99mTc-DPD 或 99mTc-HMDP 骨闪烁扫描。其中，17 名（89.5%）患者心肌骨示踪剂摄取较低或不存在，而只有 2 名（10.5%）患者心肌骨示踪剂摄取较高。骨显像检测TTR-CA的灵敏度和准确度分别为10.5%和37%。心脏受累且骨示踪剂摄取低或缺乏的患者在年龄、性别以及心电图和超声心动图检查结果方面与心肌摄取高的患者相似。 在 Phe64Leu TTR 突变患者中，骨闪烁扫描（DPD 和 HMDP）检测 TTR-CA 的敏感性极低，这表明需要评估骨闪烁扫描的诊断准确性，以识别更广泛的 TTR 突变的心脏受累。