Q. A 65-year-old man presents to the emergency department complaining of recurrent episodes of dizziness and headache over the past three weeks. He has a history of hypertension and type II diabetes that is well-controlled with medications. Physical examination reveals a blood pressure of 170/100 mm Hg in the right arm and 140/90 mm Hg in the left arm. The patient has a 2+ bilateral femoral bruit. Laboratory testing shows elevated serum creatinine at 1.8 mg/dL. An ultrasound of the kidneys shows bilateral renal artery stenosis. Which of the following is the most appropriate next step in the management of this patient?