Most, but not all, studies evaluating cohorts of patients undergoing both exercise ECG and stress imaging have shown that the addition of imaging information provides incremental benefit in terms of both diagnostic and prognostic information with an acceptable increase in cost (Section 2.2.1.5).106 117 Other factors affecting test choice include local availability of specific tests, local expertise in test performance and interpretation, the presence of multiple diagnostic or prog- nostic questions better addressed by one form of testing over another, and the existence of prior test results (especially when prior images are available for comparison). Finally, although echocardiographic, radionuclide, and CMR stress imaging can have complementary roles for estimating patient prognosis, there is rarely a reason to perform multiple tests in the same patient, unless the results of the initial imaging test are unsatisfactory for technical reasons or the findings are equivocal or require confirmation. 2.2.1.3. Exercise Versus Pharmacological Testing When a patient is able to perform routine activities of daily living without difficulty, exercise testing to provoke ischemia is preferred because it often can provide a higher physiolog- ical stress than would be achieved by pharmacological testing. This can translate into a superior ability to detect ischemia as well as providing a correlation to a patient s daily symptom burden and physical work capacity not offered by pharmacological stress testing. In addition, exercise capacity alone is a very strong prognostic indicator.118,119 The goal of exercise testing for suspected SIHD patients is 1) to achieve high levels of exercise (ie, maximal exertion), which in the setting of a negative ECG generally and reliably excludes obstructive CAD, or 2) to document the extent and severity of ECG changes and angina at a given workload (ie, demand ischemia) so as to predict the likelihood of underly- ing significant or severe CAD. 