Heart Attack Risk and Medicated Stents

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Is There Increased Risk of a Heart Attack with the New Medicated Stents?

The importance of screening people for coronary artery disease before they develop symptoms is brought to light by the recent condition of ex-president George W. Bush. While he was active and not having cardiac symptoms, a screening stress test as part of his annual physical detected a severe underlying blockage, and he was able to receive a stent and likely prevent a possibly life-threatening heart attack.

Metal stents, devices placed into an artery to keep the vessel open, have been used in lieu of balloon angioplasty to treat patients with coronary artery disease (CAD) for about 15 years, due to their better long-term patency. Nonetheless, with conventional ("bare metal") stents, there may be a disease recurrence rate of at least 20% to 30% due to scar tissue formation within the stent. Much research has been done to try to prevent this scar tissue formation. In the past decade, newer metal stents coated with medication to prevent scar tissue formation have become widely available. These stents have reduced the recurrence ("restenosis") rate of coronary artery disease to well under 10%.

A major concern with use of stents is that the stainless steel they are composed of may promote the formation of blood clots, which may occlude the stent and result in heart attack or even death. When a stent is placed in a coronary artery, the body naturally coats the stent with a protective lining called "endothelium," which serves as a barrier that prevents blood clotting. This process generally is complete within 3 weeks, so patients generally take a regimen of dual antiplatelet therapy (DAPT) for 4 weeks, until the protective lining is in place. This consists of aspirin and a second agent. Traditionally, the second agent was clopidogrel (Plavix), but some patients lack a certain enzyme and are nonresponders to clopidogrel; this can be determined with a simple blood test. In lieu of clopidogrel, two newer agents are often used which don't require enzymatic activation; these are prasugrel (Effient) and ticagrelor (Brilinta).

Medically Reviewed by a Doctor on 9/13/2013