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Circulation. 2021;144:e368–e454. DOI: 10.1161/CIR.0000000000001029 November 30, 2021 e407 CLINICAL STATEMENTS AND GUIDELINES tained from performing a CAC scan or, when available, from a visual estimation of CAC based on prior noncardiac chest CT. Among the remaining patients classified as intermediate-high risk, selective testing may improve diagnosis of CAD and for risk stratification purposes.1-5 5.1.2 Low-Risk Patients With Stable Chest Pain and No Known CAD Recommendations for Low-Risk Patients With Stable Chest Pain and No Known CAD Referenced studies that support the recommendations are summarized in Online Data Supplements 27 and 28. COR LOE Recommendations 1 B-NR 1. For patients with stable chest pain and no known CAD presenting to the outpatient clinic, a model to estimate pretest probability of obstructive CAD is effective to identify patients at low risk for obstructive CAD and favorable prognosis in whom additional diagnostic testing can be deferred.1-5 2a B-R 2. For patients with stable chest pain and no known CAD categorized as low risk, CAC testing is reasonable as a first-line test for excluding calcified plaque and identifying patients with a low likelihood of obstructive CAD.6-9 2a B-NR 3. For patients with stable chest pain and no known CAD categorized as low risk, exercise testing without imaging is reasonable as a first-line test for excluding myocardial ischemia and determining functional capacity in patients with an interpretable ECG.10 Synopsis Over the past several decades, patient presentation and observed obstructive CAD prevalence has changed, thus affecting patient selection for diagnostic testing. Current observations in the United States include: • Typical exertional angina prevalence is generally low (<10%), with more patients presenting without the classic demand-related symptoms.11 Symptoms can be infrequent (ie, on a weekly or monthly basis),12,13 which challenges the diagnostic evaluation. • Among patients undergoing a diagnostic evaluation, there is a relatively low prevalence of obstructive CAD and ischemia (ie, ∼10%).11,14,15 • Traditional pretest risk scores largely overestimate disease probability and contribute to overtesting.16-19 • Current testing patterns result in a high normal coronary angiography rate (upward of 50%– 60%).20,21 For the aforementioned reasons, use of a contemporary pretest probability estimates to define low-risk patients not requiring additional diagnostic testing is a primary goal of the initial evaluation of symptomatic patients with suspected CAD.5 Even when contemporary pretest probability estimates are used, they have a low specificity for identifying patients with obstructive CAD. A CAC score of zero can be useful to identify patients with stable chest pain who are low risk, have a low likelihood of obstructive CAD, and a low risk of future Figure 11. Pretest Probabilities of Obstructive CAD in Symptomatic Patients According to Age, Sex, and Symptoms Modified from Juarez-Orozco et al1 and Winther et al.2 1) The pretest probability shown is for patients with anginal symptoms. Patients with lower-risk symptoms would be expected to have lower pretest probability. 2) The darker green– and orange-shaded regions denote the groups in which noninvasive testing is most beneficial (pretest probability >15%). The light green–shaded regions denote the groups with pretest probability of CAD ≤15% in which the testing for diagnosis may be considered based on clinical judgment.1 3) If CAC is available, it can also be used to estimate the pretest probability based on CAC score.2 CAC indicates coronary artery calcium; and CAD, coronary artery disease. Downloaded from http://ahajournals.org by on October 7, 2026