A 68-year-old man with a 40-year smoking history presents with a 3-month history of progressive claudication in the right lower limb. Duplex ultrasound reveals a 70% stenosis of the right superficial femoral artery (SFA). He is asymptomatic at rest and can walk 200 meters before claudication. His ankle-brachial index (ABI) is 0.65 on the right. What is the most appropriate initial management?