A male who has been using multiple intravenous drugs for more than 10 years presents to the emergency department with complaints of fever, malaise, chest pain, and a skin rash. He says these symptoms appeared a few days ago. An examination reveals that he has petechiae, splinter hemorrhages, and Roth spot in the eye. Auscultation reveals an audible thrill in the 4th intercostal space on the left. The chest x-ray is unremarkable. Blood work reveals a CBC of 7, WBC 18, platelets 98, BUN 21, Cr 2.1, and blood glucose of 98. The patient undergoes an echocardiogram and is found to have an abscess beneath the cusps of the anterior aortic valve leaflet. If the abscess is left untreated, what will be the most common complication?