Rumberger J A, Behrenbeck T, Breen J F, Sheedy P F
Department of Cardiovascular Diseases, Mayo Clinic and Foundation, Rochester, Minnesota, USA.
J Am Coll Cardiol. 1999 Feb;33(2):453-62. doi: 10.1016/s0735-1097(98)00583-x.
The purpose of this study was to determine if electron beam computed tomography (EBCT) has potential as a cost-effective approach to diagnosis of obstructive coronary disease.
Coronary calcification quantified by EBCT is closely related to the extent of atherosclerosis.
A model based upon published sensitivities (Se)/specificities (Sp) for diagnosis in an ambulatory patient of obstructive coronary disease (> or =50% stenosis) and population prevalence was tested for angiography alone, or treadmill exercise, stress echocardiography, stress thallium or predetermined EBCT calcium score outpoints, followed by angiography if indicated.
Total direct testing costs increased in proportion to disease prevalence whereas cost-effectiveness, direct costs/patient diagnosed correctly with disease, decreased as a function of prevalence. Using an EBCT calcium score of 168 (Se/Sp = 71%/90%) provided for the least costly and most cost-effective noninvasive pathway. Calcium scores of 80 (Se/Sp = 84%/84%) and 37 (Se/Sp = 90%/77%) were also cost-effective when prevalence of disease was < or =70%; but results for a >0 calcium score (Se/Sp = 95%/46%) cutpoint were not superior to conventional methods. Calcium score cutpoints of 37, 80 or 168 provided similar or superior overall negative and positive predictive values to conventional noninvasive testing pathways across all prevalence subgroups.
In ambulatory patients evaluated for obstructive coronary disease, a testing pathway utilizing quantification of coronary calcium by EBCT as an initial noninvasive testing approach minimized direct costs, and maximized cost-effectiveness in population groups with low/ moderate disease prevalence (< or =70%); as expected, direct angiography as the first and only test proved most cost-effective in patients with a high prevalence (>70%) of disease.
本研究旨在确定电子束计算机断层扫描（EBCT）是否具有作为阻塞性冠状动脉疾病经济有效的诊断方法的潜力。
EBCT量化的冠状动脉钙化与动脉粥样硬化程度密切相关。
基于已发表的在门诊患者中诊断阻塞性冠状动脉疾病（狭窄≥50%）的敏感度（Se）/特异度（Sp）以及人群患病率建立模型，对单独进行血管造影，或进行平板运动试验、负荷超声心动图、负荷铊扫描或预先确定的EBCT钙评分切点进行测试，如有指征则随后进行血管造影。
总直接检测成本与疾病患病率成比例增加，而成本效益，即正确诊断疾病的患者的直接成本，随患病率的变化而降低。使用EBCT钙评分168（Se/Sp = 71%/90%）可提供成本最低且最具成本效益的非侵入性检查途径。当疾病患病率≤70%时，钙评分80（Se/Sp = 84%/84%）和37（Se/Sp = 90%/77%）也具有成本效益；但钙评分>0（Se/Sp = 95%/46%）切点的结果并不优于传统方法。在所有患病率亚组中，钙评分切点37、80或168提供的总体阴性和阳性预测值与传统非侵入性检测途径相似或更佳。
在评估阻塞性冠状动脉疾病的门诊患者中，利用EBCT对冠状动脉钙化进行量化作为初始非侵入性检测方法的检测途径可使直接成本降至最低，并在低/中度疾病患病率（≤70%）的人群中使成本效益最大化；正如预期的那样，对于疾病患病率高（>70%）的患者，直接血管造影作为首个也是唯一的检测方法被证明最具成本效益。
