Arteries opened with angioplasty can become blocked again if the artery collapses. To reduce the risk of collapse, many angioplasties (at least 80 percent) are accompanied – or followed – by the insertion of a stent, a small stainless steel mesh tube that helps prop open the artery at the point where the blockage was opened.   Some arteries that can be treated successfully with angioplasty are not well suited to also receive a stent. These include arteries that are hardened or calcified and those in which blockages occur at points where arteries form a branch.

Your doctor may choose from two types of stents: bare metal and drug-coated (or drug-eluting). He or she may decide which type of stent to use to prop open your artery based on several factors, including the size of the artery and the location of the blockage and other factors specific to your case.

Bare metal stents. Arteries held open with bare metal stents may re-narrow, a condition called restenosis. The re-narrowing occurs when scar tissue grows inside the stent, reducing or blocking blood flow and causing a recurrence of chest pain, other symptoms or heart attack and increasing the likelihood that another procedure will be needed to re-open the artery. With a bare metal stent, the risk of scar tissue growing to re-block the flow of blood is approximately one in three.

Drug-coated, or drug-eluting, stents. Drug-coated, or drug-eluting, stents were developed to prevent or slow the growth of scar tissue at the site where the stent was placed. Coated with medications that are slowly released, the stents help block the body's ability to form scar tissue. Compared with bare metal stents, drug-coated stents dramatically reduce the likelihood that an artery will re-narrow - and that a repeat procedure will be needed to re-open an artery.