Department of Cardiology, Gifu Prefectural General Medical Center, Noisshiki 4-6-1, Gifu, Gifu, 500-8717, Japan.
Department of Cardiology, Asahi University Hospital, Gifu, Japan.
Heart Vessels. 2022 Sep;37(9):1506-1515. doi: 10.1007/s00380-022-02058-3. Epub 2022 Mar 27.
Technetium-99m-sestamibi (Tc-sestamibi) single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in patients with acute coronary syndrome (ACS) could be used to assess area-at-risks, as well as myocardial infarct or saved sizes. In patients with ACS, accelerated washout of Tc-sestamibi during early and delayed imaging in the acute phase may suggest mitochondrial dysfunction in the injured but salvaged myocardium. However, the link between Tc-sestamibi accelerated washout and exercise tolerance is unknown. The purpose of this study was to investigate a possible association between Tc-sestamibi accelerated washout and exercise tolerance in acute ACS patients as they progressed into the chronic phase. One hundred and sixty-five patients with ACS who underwent Tc-sestamibi SPECT MPI during the acute phase were recruited. On this basis, we calculated the total perfusion deficits (TPDs) for early (1 h after tracer injection) and delayed (4 h after tracer injection) images using automated quantification software. We then subtracted the early TPDs from the delayed TPDs to calculate the ΔTPD. We conducted a cardiopulmonary exercise test in acute and chronic phases. We divided two groups according to the median ΔTPD (the ΔTPD ≥ 4 group and the ΔTPD < 4 group) and compared anaerobic threshold (AT; ml/kg/min) between the groups. For anaerobic threshold (AT) improvement in data analysis, we employed multivariate logistic regression analysis. A total of 101 ST-segment elevation myocardial infarctions, 36 non-ST-elevation myocardial infarctions, and 28 unstable angina pectoris events were reported as ACS. From acute phase (10.8 ± 4.2 ml/kg/min) to chronic phase (11.9 ± 2.3 ml/kg/min), the AT in the ΔTPD ≥ 4 group was significantly increased (p < 0.0001). This trend was also seen in the ΔTPD < 4 group from acute (11.4 ± 1.8 ml/kg/min) to chronic phase (12.1 ± 2.2 ml/kg/min, p = 0.015). AT was lower in the ΔTPD ≥ 4 group in the acute phase (p = 0.027), but there was no difference in AT between the two groups in the chronic phase (p = 0.60). ΔTPD and the absence of diabetes were both independent predictors of AT improvement in multivariate logistic regression analysis. Receiver-operating characteristic curve analysis determined that ΔTPD = 6 was the best cut-off value, with 60.0% sensitivity and 71.4% specificity, respectively. The accelerated washout of Tc-sestamibi in patients with ACS during the acute phase could help to predict improvement in exercise tolerance in the chronic phase.
锝-99m 甲氧基异丁基异腈（Tc-sestamibi）单光子发射计算机断层扫描（SPECT）心肌灌注成像（MPI）可用于评估危险区域，以及心肌梗死或保存的大小。在急性冠状动脉综合征（ACS）患者中，Tc-sestamibi 在急性阶段的早期和延迟成像期间的加速洗脱可能表明受损但保存的心肌中线粒体功能障碍。然而，Tc-sestamibi 加速洗脱与运动耐量之间的联系尚不清楚。本研究旨在探讨急性 ACS 患者进入慢性期时 Tc-sestamibi 加速洗脱与运动耐量之间的可能关联。我们招募了 165 例在急性阶段接受 Tc-sestamibi SPECT MPI 的 ACS 患者。在此基础上，我们使用自动量化软件计算早期（示踪剂注射后 1 小时）和延迟（示踪剂注射后 4 小时）图像的总灌注缺陷（TPD）。然后，我们从延迟 TPD 中减去早期 TPD 以计算 ΔTPD。我们在急性和慢性阶段进行心肺运动试验。我们根据中位数 ΔTPD（ΔTPD≥4 组和 ΔTPD<4 组）将两组进行分组，并比较两组的无氧阈值（AT；ml/kg/min）。对于数据分析中的无氧阈值（AT）改善，我们采用多变量逻辑回归分析。总共报告了 101 例 ST 段抬高心肌梗死、36 例非 ST 段抬高心肌梗死和 28 例不稳定型心绞痛事件作为 ACS。从急性阶段（10.8±4.2 ml/kg/min）到慢性阶段（11.9±2.3 ml/kg/min），ΔTPD≥4 组的 AT 显著增加（p<0.0001）。这种趋势在 ΔTPD<4 组中也很明显，从急性（11.4±1.8 ml/kg/min）到慢性（12.1±2.2 ml/kg/min，p=0.015）。急性阶段 ΔTPD≥4 组的 AT 较低（p=0.027），但慢性阶段两组之间的 AT 无差异（p=0.60）。多元逻辑回归分析表明，ΔTPD 和无糖尿病是 AT 改善的独立预测因子。受试者工作特征曲线分析确定 ΔTPD=6 是最佳截断值，敏感性为 60.0%，特异性为 71.4%。ACS 患者在急性阶段 Tc-sestamibi 的加速洗脱有助于预测慢性期运动耐量的改善。
