A 50-year-old man with a history of infective endocarditis has increasing fatigue. On physical examination, he is afebrile. His pulse is 80/min, respirations are 17/min, and blood pressure is 110/70 mm Hg. On aus cultation, diffuse rales are heard in the lungs. A chest radiograph shows bilateral pulmonary edema. An echocardiogram shows mitral regurgitation. He receives a bileaflet tilting disk mechanical mitral valve prosthesis. After surgery, he is stable, and an echocardiogram shows no abnormal valvular or ventricular function. Which of the following pharmacologic agents should he receive regularly after this surgical procedure? (A) Amiodarone (B) Ciprofloxacin (C) Warfarin (D) Cyclosporine (E) Digoxin (F) Propranolol