Berman D S, Hachamovitch R, Kiat H, Cohen I, Cabico J A, Wang F P, Friedman J D, Germano G, Van Train K, Diamond G A
Department of Imaging (Division of Nuclear Medicine), Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
J Am Coll Cardiol. 1995 Sep;26(3):639-47. doi: 10.1016/0735-1097(95)00218-S.
This study assessed the incremental prognostic implications of normal and equivocal exercise technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) and sought to determine its incremental prognostic value, impact on patient management and cost implications.
The prognostic implications of Tc-99m sestamibi SPECT are not well defined, and risk stratification using this test has not been explored.
We studied 1,702 patients referred for exercise Tc-99m sestamibi SPECT who were followed up for a mean (+/- SD) of 20 +/- 5 months. Patients with previous percutaneous transluminal coronary angioplasty or coronary artery bypass surgery were excluded. The SPECT studies were assessed using semiquantitative visual analysis. Cardiac death and myocardial infarction were considered "hard" events, and coronary angioplasty and bypass surgery > 60 days after testing were considered "soft" events.
Of the 1,702 patients studied, 1,131 had normal or equivocal scan results. A total of 10 events occurred in this group (1 cardiac death and 1 myocardial infarction [0.2% hard events]; 4 coronary angioplasty and 4 bypass surgery procedures [0.7% soft events]). The rates of hard events and referral to catheterization after SPECT were similarly low in patients with a low (< 0.15), intermediate (0.15 to 0.85) and high (> 0.85) post-exercise treadmill test (ETT) likelihood of coronary artery disease. With respect to scan type, patients with normal, probably normal or equivocal scan results had similarly low hard event rates. In the 571 patients with abnormal scan results, there were 43 hard events (7.5%) and 42 soft events (7.4%) (p < 0.001 vs. 1,131 patients with normal scan results for both). When the complete spectrum of scan responses was considered, SPECT provided incremental prognostic value in all patient subgroups analyzed. However, the nuclear scan was cost-effective only in patients with interpretable exercise ECG responses and an intermediate to high post-ETT likelihood of coronary artery disease and in those with uninterpretable exercise ECG responses and an intermediate to high pre-ETT likelihood of coronary artery disease.
Normal or equivocal exercise Tc-99m sestamibi study results are associated with a benign prognosis, even in patients with a high likelihood of coronary artery disease. Although incremental prognostic value is added by nuclear testing in all patient subgroups, a testing strategy incorporating nuclear testing proved to be cost-effective only in the groups with an intermediate to high likelihood of coronary artery disease before scanning.
本研究评估了正常及可疑的运动锝-99m（Tc-99m）甲氧基异丁基异腈单光子发射计算机断层扫描（SPECT）的增量预后意义，并试图确定其增量预后价值、对患者管理的影响及成本效益。
Tc-99m甲氧基异丁基异腈SPECT的预后意义尚不明确，且尚未探讨使用该检查进行风险分层。
我们研究了1702例因运动Tc-99m甲氧基异丁基异腈SPECT前来就诊的患者，平均随访时间为20±5个月（±标准差）。排除既往接受过经皮腔内冠状动脉成形术或冠状动脉搭桥手术的患者。采用半定量视觉分析评估SPECT检查结果。心源性死亡和心肌梗死被视为“硬”事件，检查后60天以上进行的冠状动脉成形术和搭桥手术被视为“软”事件。
在研究的1702例患者中，1131例扫描结果正常或可疑。该组共发生10起事件（1例心源性死亡和1例心肌梗死[0.2%硬事件]；4例冠状动脉成形术和4例搭桥手术[0.7%软事件]）。运动平板试验（ETT）后冠状动脉疾病可能性低（<0.15）、中等（0.15至0.85）和高（>0.85）的患者，SPECT后硬事件发生率及转诊至导管插入术的比例同样较低。就扫描类型而言，扫描结果正常、可能正常或可疑的患者硬事件发生率同样较低。在571例扫描结果异常的患者中，有43例硬事件（7.5%）和42例软事件（7.4%）（与1131例扫描结果正常的患者相比，两者p<0.001）。当考虑扫描反应的全谱时，SPECT在所有分析的患者亚组中均提供了增量预后价值。然而，核扫描仅在运动心电图反应可解释且ETT后冠状动脉疾病可能性为中等至高的患者以及运动心电图反应不可解释且ETT前冠状动脉疾病可能性为中等至高的患者中具有成本效益。
即使在冠状动脉疾病可能性高的患者中，正常或可疑的运动Tc-99m甲氧基异丁基异腈检查结果也与良好的预后相关。尽管核检查在所有患者亚组中均增加了增量预后价值，但仅在扫描前冠状动脉疾病可能性为中等至高的组中，纳入核检查的检测策略被证明具有成本效益。
