Objectives This study sought to investigate the regional uptake of technetium 99m-pyrophosphate (TcPYP) in transthyretin cardiac amyloidosis (ATTR) and its association with mortality.

Background TcPYP nuclear scintigraphy is a diagnostic and prognostic tool in ATTR. Echocardiography has identified a pattern of regional variation in longitudinal strain (LS) with a gradient of improved strain from base to apex in ATTR.

Methods Consecutive patients with ATTR were evaluated who underwent TcPYP nuclear scintigraphy with planar and attenuation corrected single-photon emission computed tomography (SPECT). Heart-to-contralateral lung (H/CL) ratio was calculated on planar images, and left ventricular (LV) uptake was determined in each of the 17 segments using SPECT. A measure of apical-sparing of myocardial TcPYP uptake, termed the apical-sparing ratio (ASR), was calculated as basal + mid / apical counts.

Results Overall, 54 patients with ATTR (age 78 ± 9 years, 76% male, 31% hereditary ATTR) were analyzed. There was increased TcPYP uptake in basal and mid relative to apical LV segments, and an apical-sparing LS pattern on echocardiography. The right ventricle similarly showed greater uptake in basal segments. There were 26 deaths over 1.8 years median follow-up. The ASR of TcPYP uptake was associated with age-adjusted all-cause mortality (p = 0.013) with worse prognosis seen at levels <2.75. Global LS was also prognostic (p = 0.01), whereas H/CL ratio and total LV uptake indexed to blood pool were not (p = 0.772 and p = 0.850, respectively). The prognostic utility of the ASR persisted in multivariable modeling (p = 0.003), whereas global LS did not.

Conclusions There is decreased TcPYP uptake in apical as compared to mid and basal segments in the LV, mimicking apical-sparing LS seen on echocardiography. Regional distribution of LV TcPYP uptake is associated with mortality, whereas overall amount of uptake as measured by H/CL ratio and indexed LV SPECT uptake is not.

目的本研究旨在研究跨甲状腺素蛋白淀粉样变性病（ATTR）中99m焦磷酸（（TcPYP）的区域吸收及其与死亡率的关系。

背景技术TcPYP核闪烁显像术是ATTR中的诊断和预后工具。超声心动图已确定出纵向应变（LS）区域变化的模式，以及ATTR中从基部到顶端的应变改善梯度。

方法对连续性ATTR患者进行TcPYP核闪烁显像，并进行平面和衰减校正的单光子发射计算机断层扫描（SPECT）。在平面图像上计算心-对侧肺（H / CL）的比率，并使用SPECT确定17个区段中每个区段的左心室（LV）摄取。计算心肌TcPYP吸收的心尖保留量，即心尖保留率（ASR），以基础数+中/心尖数计算。

结果总共分析了54例ATTR患者（年龄78±9岁，男性76％，遗传性ATTR 31％）。相对于心尖左室节段，基底和中段的TcPYP摄取增加，超声心动图上心尖保留LS模式。右心室同样显示出基底节段更大的摄取。在1.8年的中位随访中，有26例死亡。TcPYP摄取的ASR与年龄调整后的全因死亡率（p = 0.013）相关，在<2.75水平时预后较差。整体LS也是有预后的（p = 0.01），而H / CL比和总LV摄取指数却不能反映到血库中（分别为p = 0.772和p = 0.850）。ASR的预后效用在多变量建模中仍然存在（p = 0.003），而整体LS则没有。

结论与左心室中段和基底段相比，心尖的TcPYP摄取减少，模仿了超声心动图上的心尖保留的LS。LV TcPYP摄取的区域分布与死亡率相关，而通过H / CL比和索引的LV SPECT摄取测量的总摄取量则与死亡率无关。