Coronary Artery Disease USMLE Step 1 Practice Question

A 55-year-old woman with a 10-year history of type 2 diabetes mellitus and hyperlipidemia (LDL 156 mg/dL despite atorvastatin) presents to the emergency department with acute substernal chest pain radiating to her left arm and associated dyspnea. Vital signs show blood pressure 92/58 mmHg, heart rate 102 bpm, and respiratory rate 22/min. Troponin I is 3.2 ng/mL (normal <0.04). A 12-lead ECG demonstrates new ST-segment elevation in leads V1-V4 with reciprocal ST depression in leads II, III, and aVF. She is immediately anticoagulated with heparin and taken for urgent cardiac catheterization. Coronary angiography reveals a critical LAD occlusion with TIMI 0 flow, severe (90%) RCA stenosis, and severe (85%) LCx stenosis. Hemodynamic assessment shows a cardiac output of 3.8 L/min with pulmonary capillary wedge pressure of 28 mmHg. Left ventriculography demonstrates global hypokinesis with an ejection fraction of 28%. Which of the following findings most strongly supports mechanical revascularization via percutaneous coronary intervention or coronary artery bypass grafting rather than medical management alone?