Table 1.

Prospective Risk Stratification of Noninvasive Imaging Test Results in the Anatomic (Coronary Computed Tomographic Angiography) and Functional (Exercise Treadmill Test, Stress Myocardial Perfusion Imaging, and Stress Echocardiography) Testing Arms of the Study

Test Strata	Anatomic Testing	Functional Testing
	Coronary Computed Tomographic Angiography	Exercise Treadmill Test	Stress Myocardial Perfusion Imaging	Stress Echocardiography
Severely abnormal	High-risk coronary artery disease: ≥2 vessel disease (≥70%) OR ≥50% left main stenosis OR ≥70% proximal left anterior descending stenosis	Ischemic electrocardiography: ST changes consistent with ischemia during stress + either severe ventricular arrhythmia OR hypotension	Large territory inducible ischemia or mixed defect: septal/anterior/apical territory or other single territory with transient ischemic dilatation or ≥2 coronary territories with ischemia	Large territory inducible ischemia or mixed defect: wall motion abnormality or mixed abnormality (infarct and ischemia) OR isolated septal/anterior/apical or other single territory +↓EF <35% during stress or ≥2 coronary territories
Moderately abnormal	Obstructive coronary artery disease: ≥70% stenosis in 1 major vessel/branch	Early positive TM: failure to reach stage 2 (<3:00 min) with ST changes OR symptoms reproduced OR any arrhythmia or hypotension	Inducible ischemia or mixed defect: perfusion abnormality in 1 coronary territory (lateral or inferior/posterior) OR normal imaging but early positive TM: failure to reach stage 2 (<3:00 min) with ST changes or symptoms reproduced or any arrhythmia or hypotension	Inducible ischemia or mixed defect: wall motion abnormality or mixed abnormality (infarct and ischemia) in 1 coronary territory (lateral or inferior/posterior) OR normal imaging but early positive TM: failure to reach stage 2 (<3:00 min) with ST changes or symptoms reproduced OR any arrhythmia or hypotension
Mildly abnormal	Nonobstructive coronary artery disease:* 1%–69% stenosis in any major vessels/branch OR <50% left main stenosis	Late positive TM: more than stage 2 (>3:00 min) but failure to finish protocol or target heart rate achieved as a result of ST changes OR symptoms reproduced OR any arrhythmia or hypotension	Positive electrocardiography: normal perfusion or fixed perfusion defect (scar) OR normal imaging but late positive TM: more than stage 2 (>3:00 min) but failure to finish protocol or target heart rate achieved because of ST changes OR symptoms reproduced OR any arrhythmia or hypotension	Positive electrocardiography: normal wall motion or resting wall motion abnormality without inducible ischemia OR normal imaging but late positive TM: morethan stage 2 (>3:00 min) but failure to finish protocol or target heart rate achieved as a result of ST changes OR symptoms reproduced OR any arrhythmia or hypotension
Normal	Absence of coronary atherosclerosis	Normal electrocardiography, absence of symptoms during exercise, and normal exercise duration†	Normal electrocardiography, absence of symptoms during exercise, normal exercise duration, and normal imaging (absence of any findings suggesting myocardial abnormalities including fixed perfusion defects)†	Normal electrocardiography, absence of symptoms during exercise, normal exercise duration, and normal imaging (absence of any findings suggesting myocardial abnormalities including fixed wall motion abnormalities)†

To standardize test reporting, site-reported test results were abstracted by a cardiology faculty or senior fellow physician using a prospectively designed protocol to deal with ambiguous test results, thereby standardizing interpretation of ambiguous test reports and harmonizing data across imaging modalities. TM indicates treadmill test.

^*For secondary risk stratification, nonobstructive coronary artery disease was defined as 1% to 49% luminal narrowing.

^†For secondary risk stratification, normal functional testing was defined as normal imaging plus a Framingham Risk Score >10%