Levinson J R, Boucher C A, Coley C M, Guiney T E, Strauss H W, Eagle K A
Department of Medicine (Cardiac Unit), Massachusetts General Hospital, Harvard University School of Medicine, Boston 02114.
Am J Cardiol. 1990 Aug 15;66(4):406-10. doi: 10.1016/0002-9149(90)90694-v.
Preoperative dipyridamole-thallium-201 scanning is sensitive in identifying patients prone to ischemic cardiac complications after vascular surgery, but most patients with redistribution do not have an event after surgery. Therefore, its positive predictive value is limited. To determine which patients with thallium redistribution are at highest risk, dipyridamole-thallium-201 images were interpreted semiquantitatively. Sixty-two consecutive patients with redistribution on preoperative dipyridamole-thallium-201 planar imaging studies were identified. Each thallium scan was then analyzed independently by 2 observers for the number of myocardial segments out of 15, the number of thallium views out of 3 and the number of coronary artery territories with redistribution. Seventeen patients (27%) had postoperative ischemic events, including unstable angina pectoris, ischemic pulmonary edema, myocardial infarction and cardiac death. Thallium predictors of ischemic operative complications included thallium redistribution greater than or equal to 4 myocardial segments (p = 0.03), greater than or equal to 2 of the 3 planar views (p = 0.005) and greater than or equal to 2 coronary territories (p = 0.007). No patient with redistribution in only 1 view had an ischemic event (0 of 15). Thus, determining the extent of redistribution by dipyridamole-thallium-201 scanning improves risk stratification before vascular surgery. Patients with greater numbers of myocardial segments and greater numbers of coronary territories showing thallium-201 redistribution are at higher risk for ischemic cardiac complications. In contrast, when the extent of thallium redistribution is limited, there is a lower risk despite the presence of redistribution.
术前双嘧达莫 - 铊 - 201扫描在识别血管手术后易发生缺血性心脏并发症的患者方面很敏感，但大多数有再分布现象的患者术后并未发生不良事件。因此，其阳性预测价值有限。为了确定哪些铊再分布患者风险最高，对双嘧达莫 - 铊 - 201图像进行了半定量解读。确定了62例术前双嘧达莫 - 铊 - 201平面成像研究中有再分布现象的连续患者。然后由2名观察者独立分析每次铊扫描，观察15个心肌节段中出现铊再分布的节段数、3个平面视图中出现铊再分布的视图数以及出现再分布的冠状动脉区域数。17例患者（27%）术后发生缺血性事件，包括不稳定型心绞痛、缺血性肺水肿、心肌梗死和心源性死亡。缺血性手术并发症的铊预测指标包括铊再分布大于或等于4个心肌节段（p = 0.03）、3个平面视图中大于或等于2个视图出现铊再分布（p = 0.005）以及大于或等于2个冠状动脉区域出现铊再分布（p = 0.007）。仅1个视图出现再分布的患者无缺血性事件发生（15例中0例）。因此，通过双嘧达莫 - 铊 - 201扫描确定再分布的程度可改善血管手术前的风险分层。显示铊 - 201再分布的心肌节段数和冠状动脉区域数较多的患者发生缺血性心脏并发症的风险较高。相比之下，当铊再分布程度有限时，尽管存在再分布，风险也较低。
