A 72-year-old man with a 50-pack-year smoking history and hypertension presents for routine abdominal ultrasound. The transverse image shows a dilated infrarenal aorta measuring 6.0 cm outer-to-outer diameter, as marked by **A** in the diagram. The patient is asymptomatic with no abdominal pain or back pain. Which of the following is the most appropriate next step in management?