Hilton T C, Thompson R C, Williams H J, Saylors R, Fulmer H, Stowers S A
Department of Nuclear Cardiology, St. Luke's Hospital, Jacksonville, Florida.
J Am Coll Cardiol. 1994 Apr;23(5):1016-22. doi: 10.1016/0735-1097(94)90584-3.
The purpose of this investigation was to evaluate the practicality and short-term predictive value of acute myocardial perfusion imaging with technetium-99m sestamibi in emergency room patients with typical angina and a normal or nondiagnostic electrocardiogram (ECG).
Accuracy of emergency room chest pain assessment may be improved when clinical and ECG variables are used in conjunction with acute thallium-201 myocardial perfusion imaging. Technetium-99m sestamibi is a new radioisotope that is taken up by the myocardium in proportion to blood flow, but unlike thallium-201, it redistributes minimally after injection. Technetium-99m sestamibi can thus be injected during chest pain, and images acquired 1 to 2 h later (when patients have been clinically stabilized) will confirm whether abnormalities of perfusion were present at the time of injection.
One hundred two emergency room patients with typical angina (on the basis of a standardized angina questionnaire) and a normal or nondiagnostic ECG had a technetium-99m sestamibi injection during symptoms and were followed up for occurrence of adverse cardiac events (cardiac death, nonfatal myocardial infarction, coronary angioplasty, coronary surgery or coronary thrombolysis).
Univariate predictors of cardiac events included the presence of three or more coronary risk factors (p = 0.009, risk ratio 3.3) and an abnormal or equivocal acute technetium-99m sestamibi scan (p = 0.0001, risk ratio 13.9). Multivariate regression analysis identified an abnormal perfusion image as the only independent predictor of adverse cardiac events (p = 0.009). Of 70 patients with a normal perfusion scan, only 1 had a cardiac event compared with 15 patients with equivocal scans or 17 patients with abnormal scans, with a cardiac event rate of 13% and 71%, respectively (p = 0.0004).
Initial myocardial perfusion imaging with technetium-99m sestamibi when applied in emergency room patients with typical angina and a normal or nondiagnostic ECG appears to be highly accurate in distinguishing between low and high risk subjects.
本研究旨在评估采用锝-99m 甲氧基异丁基异腈进行急性心肌灌注显像在伴有典型心绞痛且心电图正常或无诊断意义的急诊患者中的实用性及短期预测价值。
当临床及心电图变量与急性铊-201 心肌灌注显像联合应用时，急诊胸痛评估的准确性可能会提高。锝-99m 甲氧基异丁基异腈是一种新的放射性同位素，其被心肌摄取的比例与血流成正比，但与铊-201 不同，注射后其再分布极少。因此，可在胸痛发作时注射锝-99m 甲氧基异丁基异腈，并于 1 至 2 小时后（此时患者临床症状已稳定）采集图像，以确认注射时是否存在灌注异常。
102 例伴有典型心绞痛（基于标准化心绞痛问卷）且心电图正常或无诊断意义的急诊患者在症状发作时接受了锝-99m 甲氧基异丁基异腈注射，并对不良心脏事件（心源性死亡、非致死性心肌梗死、冠状动脉成形术、冠状动脉手术或冠状动脉溶栓）的发生情况进行了随访。
心脏事件的单因素预测指标包括存在三种或更多冠状动脉危险因素（p = 0.009，风险比 3.3）以及急性锝-99m 甲氧基异丁基异腈扫描异常或不明确（p = 0.0001，风险比 13.9）。多因素回归分析确定灌注图像异常是不良心脏事件的唯一独立预测指标（p = 0.009）。在 70 例灌注扫描正常的患者中，仅 1 例发生心脏事件；相比之下，15 例扫描不明确或 17 例扫描异常的患者中分别有 15 例和 17 例发生心脏事件，心脏事件发生率分别为 13%和 71%（p = 0.0004）。
对于伴有典型心绞痛且心电图正常或无诊断意义的急诊患者，应用锝-99m 甲氧基异丁基异腈进行初始心肌灌注显像在区分低风险和高风险患者方面似乎具有很高的准确性。
