Balloon angioplasty: Coronary angioplasty is accomplished using a balloon-tipped catheter inserted through an artery in the groin or arm to enlarge a narrowing in a coronary artery. Coronary artery disease occurs when cholesterol plaque builds up (atherosclerosis) in the walls of the arteries to the heart. Angioplasty is successful in opening coronary arteries in 90% of patients. 40% of patients with successful coronary angioplasty will develop recurrent narrowing at the site of balloon inflation. This is now only rarely performed without also placing a stent in the artery.