Which stents are safest? A comparison of the old and the new

This study compared the safety and efficacy of bare-metal stents, first-generation drug-eluting stents, and newer drug-eluting stents.

Patients with coronary artery disease often experience a narrowing or blockage of the arteries, which can be treated by placing small tubes (stents), inside the arteries to keep them open, allowing blood to flow easily. Stents were originally bare metal, but in recent years drug-eluting stents have come into use. These stents are coated with medications, such as sirolimus or paclitaxel, which help to keep the artery from becoming blocked again. However, drug-eluting stents are associated with higher rates of stent thrombosis (the formation of a blood clot that then blocks the artery). One possible cause is the coating used to contain the drug, which may lead to inflammation and delayed healing. Newer drug-eluting stents have incorporated bioabsorbable coatings, meaning they can be absorbed by the body, as well as newer drug treatments, such as cobalt-chromium everolimus-eluting stents (CoCr-EE), in an attempt to decrease the rate of stent thrombosis. The current analysis examines the outcomes of previous studies comparing the safety and efficacy of these newer stents to the earlier drug-eluting and bare metal stents.

This analysis reviewed 89 studies, including 85,490 patients, who received bare metal stents, sirolimus-eluting stents, paclitaxel-eluting stents, CoCr-EE stents, or bioabsorbable stents. Mortality, myocardial infarction (heart attack), the need for revascularization (re-stenting), and stent thrombosis rates were measured after 1 year, and then beyond 1 year.

Results showed that there was no difference among the different stents in 1-year mortality rates. Bioabsorbable stents were associated with a 30% decrease in myocardial infarction rates and a 70% decrease in the need for re-stenting compared to bare metal stents. However, bioabsorbable stents were more than twice as likely to lead to stent thrombosis as were CoCr-EE stents. 

There were no significant differences in long-term mortality rates among the different types of stents. However, beyond 1-year paclitaxel– and sirolimus-eluting stents had higher rates of stent thrombosis compared to bare metal, bioabsorbable, or CoCr-EE stents.