A 52-year-old man from Delhi presents with progressive dyspnea on exertion and orthopnea for 3 months. On examination, he has an early diastolic decrescendo murmur best heard at the left sternal border. Echocardiography confirms severe aortic regurgitation with an ejection fraction of 55%. He is currently asymptomatic at rest and on no cardiac medications. What is the most appropriate next step in management?