Cardiac MDCT for Early Triage of Patients with ACS

描述（由申请人提供）：本研究的目的是确定在疑似急性冠状动脉综合征（ACS）的急性胸痛患者中，通过多探测器计算机断层扫描（MDCT）无创检测冠状动脉狭窄和斑块是否能增强分诊、降低成本且具有成本效益。在美国每年急诊科（艾德）就诊的560万ACP患者中，有200万患者亚组住院，尽管初始心脏生物标志物检测和心电图（ECG）正常。该亚组在首次住院期间发生ACS的风险较低（20%）。大多数（80-94%）诊断为ACS的患者具有显著的心外膜冠状动脉狭窄（>50%管腔狭窄）。然而，在约10%的患者中，非狭窄性冠状动脉斑块触发事件，即血管痉挛，导致心肌缺血。由于没有斑块排除了胸痛的冠状动脉原因，理论上这些患者可以提前出院，减少不必要的住院。最近的出版物表明，与冠状动脉造影术和经血管内超声验证的冠状动脉斑块检测相比，MDCT检测显著冠状动脉狭窄的灵敏度和特异性较高。使用64层MDCT，我们建议研究400例ACP患者，阴性初始心脏生物标志物和非诊断性ECG。我们将分析MDCT图像是否存在显著的冠状动脉狭窄和斑块，并将数据与索引住院期间ACS的临床诊断（AHA指南）相关联，以确定灵敏度和特异性。MDCT数据、风险因素和MDCT时可用的标准诊断测试的结果将用于生成多变量预测函数并导出临床决策规则。基于这个决策规则，我们将比较诊断的准确性和成本效益的竞争战略。我们假设，与标准临床护理相比，基于MDCT的诊断策略将减少ACS诊断时间、住院次数和急性胸痛患者管理的绝对成本，并且具有成本效益。

DESCRIPTION (provided by applicant): The goal of this research is to determine noninvasively whether detection of coronary stenosis and plaque by multidetector computed tomography (MDCT) in patients with acute chest pain suspected of acute coronary syndrome (ACS) enhances triage, reduces cost and is cost effective. Among the 5.6 million patients with ACP presenting annually in emergency departments (ED) in the United States, a subgroup of two million patients is hospitalized despite normal initial cardiac biomarker tests and electrocardiogram (ECG). This subgroup is at low (20%) risk for ACS during the index hospitalization. Most (80-94%) patients with a diagnosis of ACS have a significant epicardial coronary artery stenosis ( >50% luminal narrowing). However, in -10% of patients non-stenotic coronary plaque triggers events, i.e. vasospasms, leading to myocardial ischemia. Since the absence of plaque excludes a coronary cause of chest pain, these patients could in theory be discharged earlier reducing unnecessary hospital admissions. Recent publications demonstrate high sensitivity and specificity of MDCT for the detection of significant coronary stenosis compared with coronary angiography and the detection of coronary plaque as validated with intravascular ultrasound. Using 64- slice MDCT we propose to study 400 patients with ACP, negative initial cardiac biomarkers and non-diagnostic ECG. We will analyze MDCT images for the presence of significant coronary artery stenosis and plaque and correlate the data with the clinical diagnosis of ACS (AHA guidelines) during the index hospitalization to determine the sensitivity and specificity. MDCT data, risk factors, and the results of standard diagnostic tests available at the time of MDCT will be used to generate a multivariate prediction function and derive a clinical decision rule. Based on this decision rule we will compare the diagnostic accuracies and cost effectiveness of competing strategies. We hypothesize that an MDCT- based diagnostic strategy will reduce the time to diagnosis of ACS, number of hospitalizations, and absolute cost of management of patients with acute chest pain compared to standard clinical care and is cost effective.