A 60-year-old male patient is receiving aspirin, atorvastatin, isosorbide mononitrate, and a beta-blocker for chronic stable angina. He presents to the ER with episodes of unusually severe and long-lasting anginal chest pain each day over the past 3 days. His ECG and cardiac enzymes are normal. Which of the following is the best course of action?
Admit the patient and add intravenous digoxin Admit the patient and begin low-molecular-weight (LMW) heparin and clopidogrel Admit the patient for thrombolytic therapy Admit the patient for observation with no change in medication