A 48-year-old man is evaluated for tightness in his calves. His symptoms are exacerbated with walking and resolve with rest. His medical history is significant for hypertension, type 2 diabetes mellitus, and chronic kidney injury. Medications are hydrochlorothiazide, lisinopril, metformin, glyburide, and atorvastatin. He was a cigarette smoker with a 30-pack-year tobacco use history but quit 6 months ago.
On physical examination, blood pressure is 138/74 mm Hg, pulse rate is 68/min and regular, and respiration rate is 16/min. BMI is 32. No abdominal or femoral bruit is present. No skin changes are noted in the lower extremities. The remainder of the physical examination is unremarkable.
Laboratory studies are significant for a serum creatinine level of 1.9 mg/dL (168 µmol/L), normal electrolyte levels, and a hemoglobin A1c value of 6.4%.
Right systolic brachial pressure | 140 mm Hg |
Left systolic brachial pressure | 132 mm Hg |
Right posterior tibialis pressure | 200 mm Hg |
Left posterior tibialis pressure | 130 mm Hg |
Right dorsalis pedis pressure | Not detected |
Left dorsalis pedis pressure | 140 mm Hg |
Which of the following is the most appropriate diagnostic test to perform next?