A 63-year-old woman comes to the physician for a 6-month history of increasing calf pain bilaterally while walking. The pain is relieved with rest. She has a history of hypertension and hypercholesterolemia. Cardiopulmonary examination shows no abnormalities. Peripheral pulses are reduced. Which of the following is the next best step in diagnosis?
Ankle-brachial indices
Arteriography
Cilostazol
Dipyridamole
Duplex ultrasonography
Exercise stress test
