A 32-year-old man from Delhi presents to the emergency department with a 3-day history of fever, chills, and a new cardiac murmur. Blood cultures are pending. On examination, he has splinter hemorrhages on his nails and petechiae on his trunk. A transthoracic echocardiogram shows a 1.2 cm vegetation on the mitral valve. What is the most appropriate immediate next step in management?