Adapted with permission from Dehmer et al.352 gram [ECG] changes, elevated troponin, high Global Registry of Acute Coronary Events score), recurrent symptoms, threat- ened viable myocardium, CKD, and larger ischemic burden (Appendix 4E). For choice of revascularization technique, the anatomical considerations are generally those used for stable CAD, although PCI may initially be performed in the index lesion to stabilize the patient (Section 2). Contemporary studies variably comparing strategies of very early (within hours of admission), early (within 24 hours of admission), and delayed (1 to 7 days after admission) cardiac catheterization and revascularization support a strat- egy of early angiography and revascularization to reduce the risk of recurrent ischemia and MI, particularly among those at high risk (eg, Global Registry of Acute Coronary Events score 140),367,369,370 whereas a delayed approach is reason- able in low-intermediate risk patients (based on clinical course). There is no evidence that incremental benefit is derived by angiography and PCI performed within the first few hours of hospital admission.207,367,371 378 5.2.2. ST-Elevation Myocardial Infarction 5.2.2.1. Coronary Angiography Strategies in STEMI: Recommendations Class I 1. A strategy of immediate coronary angiography with intent to perform PCI (or emergency CABG) in patients with STEMI is recommended for a. Patients who are candidates for primary PCI.351,379 382 (Level of Evidence: A) b. Patients with severe heart failure or cardiogenic shock who are suitable candidates for revascular- ization.383,384 (Level of Evidence: B) Class IIa 1. A strategy of immediate coronary angiography (or transfer for immediate coronary angiography) with intent to perform PCI is reasonable for patients with STEMI, a moderate to large area of myocardium at risk, and evidence of failed fibrinolysis.385,386 (Level of Evidence: B) 2. 