Macrovascular disease is a disease of any large (macro) blood vessels in the body.It is a disease of the large blood vessels, including the coronary arteries, the aorta, and the sizable arteries in the brain and in the limbs.This sometimes occurs when a person has had diabetes for a long time. Fat and blood clots build up in the large blood vessels and stick to the vessel walls.t is a disease of the large blood vessels, including the coronary arteries, the aorta, and the sizable arteries in the brain and in the limbs. This sometimes occurs when a person has had diabetes for a long time.