Scope of the Guideline These guidelines are intended to apply to adult patients with stable known or suspected IHD, including new-onset chest pain (ie, low-risk unstable angina [UA]), or to adult patients with stable pain syndromes (Figure 1). Patients who have ischemic equivalents, such as dyspnea or arm pain with exertion, are included in the latter group. Many patients with IHD can become asymptomatic with appropriate therapy. Accordingly, the follow-up sections of this guideline pertain to patients who were previously symptomatic, including those who have undergone percutaneous coronary intervention (PCI) or CABG. This guideline also addresses the initial diagnostic ap- proach to patients who present with symptoms that suggest IHD, such as anginal-type chest pain, but who are not known to have IHD. In this circumstance, it is essential that the practitioner ascertain whether such symptoms represent the initial clinical recognition of chronic stable angina, reflecting gradual progression of obstructive CAD or an increase in supply/demand mismatch precipitated by a change in activity or concurrent illness (eg, anemia or infection), or whether they represent an acute coronary syndrome (ACS), most likely due to an unstable plaque causing acute thrombosis. For patients with newly diagnosed stable angina, this guide- line should be used. Patients with ACS have either acute myocardial infarction (AMI) or UA. 