Non high-risk patients with non high-risk lesions require no additional precautions. Best scenario for PCI without on-site surgery. CTO indicates chronic total occlusion; CVA, cerebrovascular accident; LVEF, left ventricular ejection fraction; PCI, percutaneous coronary intervention; and SCAI, Society for Cardiovascular Angiography and Interventions. Adapted with permission from Dehmer et al.352 Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e597 mias) not treated initially with primary PCI, a strategy of immediate coronary angiography with intent to perform PCI is implemented unless invasive management is considered futile or unsuitable given the clinical circumstances.383,384 In stable patients treated with fibrinolytic therapy and clinical suspicion of reperfusion failure, a strategy of imme- diate coronary angiography followed by PCI improves out- come in those at high risk.385,386 Such a strategy is also implemented in patients with evidence for infarct artery reocclusion (Table 9). The clinical diagnosis of failed fibri- nolysis is difficult but is best made when there is 50% ST-segment resolution 90 minutes after initiation of therapy in the lead showing the greatest degree of ST-segment elevation at presentation. Given the association between bleeding events and adverse cardiac events, a reasonable approach is to select moderate- and high-risk patients for PCI and treat low-risk patients with medical therapy. ECG and clinical findings of anterior MI or inferior MI with right ventricular involvement or precordial ST-segment depression, as well as ongoing pain, usually predicts increased risk and the greatest potential benefit.392 Conversely, patients with symptom resolution, improving ST-segment elevation, or inferior MI localized to 3 ECG leads probably gain little benefit. 