Patients should be able to achieve 85% of age-predicted maximum heart rate. CABG indicates coronary artery bypass graft surgery; CCTA, cardiac computed tomography angiography; CMR, cardiac magnetic resonance; COR, class of recommendation; ECG, electrocardiogram; Echo, echocardiography; LOE, level of evidence; MPI, myocardial perfusion imaging; N/A, not available; SIHD, stable ischemic heart disease; and UA, unstable angina. cation or if the CCTA is intended to assess coronary stents less than 3 mm in diameter.158,161,1244 (Level of Evidence: B) Class III: No Benefit 1. CCTA should not be performed for assessment of native coronary arteries with known moderate or severe calcification or with coronary stents less than 3 mm in diameter in patients with known SIHD who have new or worsening symptoms not consistent with UA, irrespective of ability to exercise.1244 1248 (Level of Evidence: B) See Online Data Supplement 1 for additional data on nonin- vasive testing in known SIHD: recurrent or worsening symptoms. Strategies for the selection and use of noninvasive testing in the evaluation of new or worsening symptoms in patients with documented SIHD are similar to those in suspected SIHD. As always, in patients with interpretable rest ECGs who are capable of exercise, treadmill exercise ECG testing remains the first choice. Whenever possible, initial and follow-up testing should be performed with the same stress and imaging techniques so that any interval change can be attributed more reliably to alterations in clinical status rather than mere differences in technique. Loss of the ability to exercise on follow-up testing, in and of itself, suggests deterioration in functional and clinical status. In general, the diagnostic accuracy of stress testing is similar in patients with and without known SIHD (Section 2.2.3). 