A comparison of drug-eluting stents

This study compares the effectiveness of zotarolimus-eluting stents and sirolimus-eluting stents for patients undergoing percutaneous coronary revascularization.

Coronary artery disease is often treated by the insertion of stents (small wire mesh tubes) into clogged and narrowed arteries in order to maintain normal blood flow, a treatment known as percutaneous coronary revascularization. Bare-metal stents were originally the only type of stent used, but these are associated with high rates of occlusions (known as restenosis) due to scar tissue formation at the site of implantation. Drug-eluting stents prevent restenosis by slowly releasing over time drugs which prevent scar tissue formation. However, clot formation at the site of the stent (known as stent thrombosis) remains a problem for many patients, a complication which may lead to additional heart attacks and death. New drug-eluting stents, such as the zotarolimus-eluting stent, are being developed to decrease the risk of this complication. However, whether the zotarolimus-eluting stent is as effective as the older drug-eluting stents, such as the sirolimus-eluting stent, is still unclear. This analysis examines the results of clinical trials comparing zotarolimus-eluting stents and sirolimus-eluting stents.

This study analyzed the results of seven studies, including 5983 patients, comparing the zotarolimus-eluting and sirolimus-eluting stents. Outcomes measured included the rate of restenosis, the need for revascularization after restenosis, the number of major adverse coronary events such as heart attacks or deaths, and stent thrombosis.

The need for revascularization was significantly higher in the zotarolimus-eluting stent patient group (6.02%) compared to the sirolimus-eluting stent patient group (2.3%). Zotarolimus-eluting stent patients also experienced a significantly greater rate of restenosis and major adverse coronary events compared to sirolimus-eluting stent patients. The rate of stent thrombosis was not significantly different between treatment groups, with 0.74% of zotarolimus-eluting stent patients experiencing a clot versus 0.55% of sirolimus-eluting stent patients.

This study concluded that sirolimus-eluting stents are more effective than zotarolimus-eluting stents at reducing restenosis, the need for revascularization, and major adverse cardiac events. Zotarolimus-eluting stents do not effectively reduce the rate of stent thrombosis as compared to sirolimus eluting stents.