The initial technique of percutaneous coronary intervention, coronary angioplasty, was to widen narrowed coronary arteries by inflating a small balloon catheter at the site of the narrowing. The current standard of care usually results in the placement of a metal tube called a stent at the site of the narrowing. The stent functions to keep the artery open. Many stents now are coated with drugs to help prevent scar tissue formation and therefore reduce the need for repeat procedures. Because of...