Department of Nuclear Medicine, National Taiwan University Cancer Center, Taipei (K.-Y.K.).
Graduate Institute of Clinical Medicine, College of Medicine (K.-Y.K.), National Taiwan University, Taipei.
Circ Cardiovasc Imaging. 2023 Jun;16(6):e015034. doi: 10.1161/CIRCIMAGING.122.015034. Epub 2023 Jun 14.
Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse form of vasculopathy and is the most common cause of long-term cardiovascular mortality in heart transplant patients. This study aimed to investigate the diagnostic performance of Tc and Tl tracers in the assessment of CAV using cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) for myocardial blood flow (MBF) and myocardial flow reserve (MFR) quantification, which was further validated using N-NH positron emission tomography (PET).
Thirty-eight patients with prior heart transplantation who underwent CZT SPECT and N-NH PET dynamic scans were included in this study. CZT SPECT with Tc-sestamibi was used in the first 19 patients and Tl-chloride for the remaining patients. To determine the diagnostic accuracy of angiographically defined moderate-to-severe CAV, the analysis included patients who underwent angiographic examinations within 1 year of their second scan.
There were no significant differences in the patient characteristics between the Tl and Tc tracer groups. Both Tl and Tc CZT SPECT-derived stress MBF and MFR values globally and in 3 coronary territories showed good correlations with N-NH PET. The Tl and Tc cohorts did not differ significantly in the correlation coefficients of CZT SPECT versus PET for MBF and MFR, except for stress MBF (Tl:0.95 versus Tc:0.80, =0.03). Tl and Tc CZT SPECT were satisfactory for detecting PET MFR <2.0 (Tl area under the curve, 0.92 [0.71-0.99], Tc area under the curve, 0.87 [0.64-0.97]) and angiographically defined moderate-to-severe CAV, and CZT SPECT results were comparable to that of N-NH PET (CZT area under the curve, 0.90 [0.70-0.99], PET area under the curve, 0.86 [0.64-0.97]).
This small study suggests that CZT SPECT using Tl and Tc tracers showed comparable MBF and MFR, and the results correlated well with those of N-NH PET. Hence, CZT SPECT with Tl or Tc tracers can be used to detect moderate-to-severe CAV in patients with prior heart transplantation. However, validation using larger studies is warranted.
心脏同种异体移植血管病（CAV）是一种闭塞性和弥漫性血管病，是心脏移植患者长期心血管死亡率的最常见原因。本研究旨在使用碲锌镉（CZT）单光子发射计算机断层扫描（SPECT）评估 Tc 和 Tl 示踪剂在心肌血流（MBF）和心肌血流储备（MFR）定量评估中的诊断性能，进一步使用 N-NH 正电子发射断层扫描（PET）进行验证。
本研究纳入了 38 例既往接受过心脏移植且接受过 CZT SPECT 和 N-NH PET 动态扫描的患者。在前 19 例患者中使用 Tc- sestamibi 进行 CZT SPECT，其余患者使用 Tl-氯化物。为了确定血管造影定义的中度至重度 CAV 的诊断准确性，分析包括在第二次扫描后 1 年内接受血管造影检查的患者。
Tl 和 Tc 示踪剂组患者的特征无显著差异。Tl 和 Tc CZT SPECT 衍生的应激 MBF 和 MFR 值在全球和 3 个冠状动脉区域均与 N-NH PET 具有良好的相关性。Tl 和 Tc 组之间 CZT SPECT 与 PET 之间的 MBF 和 MFR 相关性系数无显著差异，除了应激 MBF（Tl：0.95 与 Tc：0.80，=0.03）。Tl 和 Tc CZT SPECT 均可满意地检测 PET MFR<2.0（Tl 曲线下面积，0.92[0.71-0.99]，Tc 曲线下面积，0.87[0.64-0.97]）和血管造影定义的中度至重度 CAV，且 CZT SPECT 结果与 N-NH PET 相当（CZT 曲线下面积，0.90[0.70-0.99]，PET 曲线下面积，0.86[0.64-0.97]）。
这项小型研究表明，使用 Tl 和 Tc 示踪剂的 CZT SPECT 显示出可比的 MBF 和 MFR，且结果与 N-NH PET 相关性良好。因此，CZT SPECT 可使用 Tl 或 Tc 示踪剂检测既往心脏移植患者的中度至重度 CAV。然而，需要更大规模的研究进行验证。
