A 62-year-old woman with hypertension and type 2 diabetes presents to the emergency department with 3 hours of substernal chest pressure radiating to her left arm. She is diaphoretic. Vital signs: blood pressure 88/54 mmHg, heart rate 118/min, respiratory rate 24/min, SpO2 94% on room air. ECG shows 3-mm ST elevations in leads II, III, and aVF with reciprocal changes in I and aVL. Which of the following is the most appropriate next step in management?