A 54-Year-Old Man Comes to the Clinic 6 Weeks After

A 54-year-old man comes to the clinic 6 weeks after being discharged from the hospital for treatment of aortic valve endocarditis.  He has no concerns and says that he feels "fine."  The patient's endocarditis was caused by Enterococcus and occurred following cystoscopic evaluation of hematuria.  Transesophageal echocardiography during hospitalization showed moderate aortic regurgitation and a 5-mm vegetation on the non-coronary cusp of the aortic valve.
The patient had an uncomplicated hospital stay and completed a full course of intravenous antibiotics as an outpatient.  His other medical problems include peptic ulcer disease, kidney stones, and gout.  He does not use tobacco.  His father had a stroke at age 72.
Temperature is 36.7 C (98 F) , blood pressure is 124/78 mm Hg, and pulse is 78/min.  The lungs are clear to auscultation.  No murmurs are present.
ECG shows normal sinus rhythm and nonspecific T-wave changes.  Transthoracic echocardiogram shows normal left ventricular size, a left ventricular ejection fraction of 65%, and moderate eccentric aortic regurgitation.
Which of the following is the next best step in management of this patient?

A) Angiotensin II receptor blocker therapy
B) Education on antibiotic prophylaxis
C) Exercise stress testing
D) Long-term anticoagulation therapy
E) Transesophageal echocardiogram