MRCP2-0276

A 85-year-old man presents to the cardiology clinic with unstable angina and multiple coronary lesions that cannot be treated with stenting or bypass. His blood pressure is 106/45 mmHg, heart rate is 58 bpm, and ECG confirms atrial fibrillation. He is currently taking aspirin, bisoprolol, ramipril, isosorbide mononitrate, nicorandil, and simvastatin, but experiences chest pain with minimal exertion. What is the most appropriate medication to manage his angina?