Patients with NSTE-ACS can be divided into risk groups on the basis of their initial clinical presentation. The TIMI, PURSUIT, and GRACE scores are useful tools for assigning risk to patients with NSTE-ACS. Risk stratification identifies patients who are most likely to benefit from subsequent revascularization. Patients with left main disease or multivessel CAD with reduced LV function are at high risk for adverse outcomes and are likely to benefit from CABG. Clinical evaluation and noninvasive testing aid in the identification of most patients at high risk because they often have 1 of the following high-risk features: advanced age (>70 years of age), prior MI, revascularization, ST devia- tion, HF, depressed resting LV function (ie, LVEF 0.40) on noninvasive study, or noninvasive stress test findings, includ- ing magnetic resonance imaging.348 Any of these risk factors or diabetes mellitus may aid in the identification of high-risk patients who could benefit from an invasive strategy. Some patients with NSTE-ACS are not in the very high- risk group and do not have findings that portend a high risk for adverse outcomes. They are not likely to receive the same degree of benefit from routine revascularization afforded to high-risk patients, and an invasive study is optional for those at lower risk and can be safely deferred pending further clinical evidence. Decisions about coronary angiography in patients who are not at high risk according to findings on clinical examination and noninvasive testing can be individualized on the basis of patient preferences and/or symptoms. 4.5. Risk Stratification Before Discharge for Patients With an Ischemia-Guided Strategy of NSTE-ACS: Recommendations Class I 1. Noninvasive stress testing is recommended in low- and intermediate-risk patients who have been free of ischemia at rest or with low-level activity for a mini- (Level of Evidence: B) 2. 