Coronary angioplasty is a surgical procedure that is used to widen blocked or narrowed coronary arteries. Coronary angioplasty is performed by an interventional cardiologist, usually following a diagnostic coronary angiography. During PCI, a cardiologist places a tiny deflated cylinder-shaped balloon at the tip of a catheter under the X-ray control to the site of blockage in the coronary artery. The balloon is then inflated to crush the plaque into the walls of the artery. The procedure usually involves implantation of stents (“metallic mesh”) to the site of original narrowing or blockage to prop it open. Traditionally, drug-eluting stents (DES) which release drugs to prevent restenosis of the coronary artery.