Purpose

To evaluate right ventricular (RV) uptake measured by quantitative [^99mTc]Tc-DPD SPECT/CT to investigate its role in predicting and evaluating prognosis and therapeutic outcomes in patients with transthyretin amyloid cardiomyopathy (ATTR-CA).

Methods

Patients with ATTR-CA were consecutively enrolled for quantitative [^99mTc]Tc-DPD SPECT/CT. Ventricular amyloid burden was quantified by SUV_max and TBR. Differences in RV uptake (focal or diffuse) and associations with clinical characteristics and CMR data were evaluated. The primary endpoint was major adverse cardiac events (MACEs), including all-cause deaths, heart failure hospitalizations, complete atrioventricular block, sustained ventricular tachycardia, and atrial fibrillation/flutter. Prognostic associations were evaluated using Cox regression and Kaplan-Meier survival analysis. A secondary endpoint involved a longitudinal SPECT/CT analysis during Tafamidis therapy.

Results

The study included 76 patients, all showing both RV and LV uptake on SPECT imaging. Compared with patients with focal RV uptake, patients with diffuse RV uptake had higher serum troponin T levels (P < 0.05), septal thickness (P < 0.01), and external cardiac circulation volume (ECV) (P < 0.05). RV uptake was correlated with septal thickness, ECV, LV uptake, NT-proBNP and troponin-T (all P < 0.05). Among 53 patients, high LV and RV uptake significantly predicted MACEs (P < 0.001), with a median follow-up time of 16 months. A subgroup of 20 patients showed significant reductions in LV and RV uptake after Tafamidis treatment (P < 0.001).

Conclusion

Increasing RV amyloid burden quantified by SPECT/CT is associated with advanced disease stage and predicts MACEs, serving as valuable markers for prognosis and treatment monitoring in ATTR-CA.

中文翻译：

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[99mTc]Tc-DPD SPECT/CT定量评估转甲状腺素蛋白心脏淀粉样变性右心室淀粉样蛋白负荷的临床意义

 目的

评估通过定量 [^99mTc]Tc-DPD SPECT/CT 测量的右心室 （RV） 摄取，以研究其在预测和评估转甲状腺素蛋白淀粉样变性心肌病 （ATTR-CA） 患者预后和治疗结果中的作用。

 方法

连续入组 ATTR-CA 患者进行定量 [^99mTc]Tc-DPD SPECT/CT。心室淀粉样蛋白负荷通过 SUV_max 和 TBR 量化。评估了 RV 摄取 （局灶性或弥漫性） 的差异以及与临床特征和 CMR 数据的相关性。主要终点是主要不良心脏事件 （MACEs），包括全因死亡、心力衰竭住院、完全性房室传导阻滞、持续性室性心动过速和心房颤动/扑动。使用 Cox 回归和 Kaplan-Meier 生存分析评估预后关联。次要终点涉及 Tafamidis 治疗期间的纵向 SPECT/CT 分析。

 结果

该研究包括 76 名患者，所有患者在 SPECT 成像上均显示 RV 和 LV 摄取。与局灶性 RV 摄取患者相比，弥漫性 RV 摄取患者血清肌钙蛋白 T 水平 （P < 0.05） 、间隔厚度 （P < 0.01） 和体外心循环容积 （ECV） （P < 0.05） 较高。RV 摄取与间隔厚度、 ECV 、 LV 摄取、 NT-proBNP 和肌钙蛋白-T 相关 （均 P < 0.05）。在 53 例患者中，高 LV 和 RV 摄取显着预测 MACE （P < 0.001），中位随访时间为 16 个月。20 名患者的亚组显示 Tafamidis 治疗后 LV 和 RV 摄取显着降低 （P < 0.001）。

 结论

SPECT/CT 量化的 RV 淀粉样蛋白负荷增加与晚期疾病分期相关，可预测 MACE，可作为 ATTR-CA 预后和治疗监测的宝贵标志物。