Performance of Diagnostic Tests for Intermediate Probabilities of Coronary Heart Disease: A Decision Making Analysis

Abstract Patients with intermediate probability of coronary disease are a diagnostic challenge and it is precisely in this population where the degree of uncertainty is greater that the diagnostic tests have their greater applicability. However, according to the current definition, subjecting to tests a population with a disease probability between 10 and 90% can generate unnecessary tests and misleading results. Knowing the characteristics of each test, as well as risks and benefits of drug treatment for coronary disease and combining this information through diagnostic thresholds brings a new perspective to decision making. To review the origin of the currently recommended concepts of intermediate probability and to determine the thresholds for diagnosis and treatment of noninvasive tests and, based on them, propose a new concept of intermediate probability of coronary disease. Through the bibliographic review, meta-analyses were extracted in which data of sensitivity, specificity, positive and negative likelihood ratio, risks and benefits of the tests and treatment were provided. Using an algorithm developed by Pauker et al. it was possible to obtain the diagnostic and treatment thresholds adjusted for each tests in question. The concept of intermediate probability of coronary disease is quite broad, ranging, according to the authors, between 10 and 90%, 1 and 92%, 15 and 85%, with different rationale. Considering the discriminatory power of each test, risks and treatment benefits, the diagnostic and treatment thresholds were defined for exercise testing (22-58%), eco-stress (10-72%), myocardial scintigraphy (12-80%), nuclear magnetic resonance (16-80%) and coronary angiotomography (6.7-81%). The decision to submit to diagnostic tests should be individualized, taking into account the diagnostic and treatment thresholds of each method in question.

摘要 冠心病概率处于中等水平的患者，其临床诊断颇具挑战性；而恰恰是在这类不确定性程度最高的人群中，诊断检测的应用价值得以最大化体现。然而，按照当前的定义，对疾病概率处于10%至90%区间的人群实施检测，可能会造成过度检测并得出误导性结果。明晰各项检测的特性、冠心病药物治疗的风险与获益，并通过诊断阈值整合此类信息，可为临床决策提供全新视角。本研究旨在梳理当前推荐的中等概率相关概念的起源，明确无创检测的诊断与治疗阈值，并以此为基础提出全新的冠心病中等概率概念。通过文献回顾，本研究提取了相关荟萃分析数据，其中包含检测与治疗的灵敏度、特异度、阳性及阴性似然比、风险与获益等信息。借助Pauker等人开发的算法，可针对所涉及的各项检测得出经校准的诊断与治疗阈值。现有冠心病中等概率的概念范畴较广，不同研究依据不同的理论基础，将其界定为10%~90%、1%~92%以及15%~85%等不同区间。结合各项检测的诊断效能、风险及治疗获益，本研究明确了不同检测方式对应的诊断与治疗阈值：运动负荷试验为22%~58%、负荷超声心动图（eco-stress）为10%~72%、心肌闪烁显像（myocardial scintigraphy）为12%~80%、核磁共振（nuclear magnetic resonance）为16%~80%，以及冠状动脉CT血管造影（coronary angiotomography）为6.7%~81%。临床决定是否实施诊断检测应实现个体化，需充分考量所选用检测方式对应的诊断与治疗阈值。