Background: Drug-eluting stents are thought to be more effective than bare-metal stents for small coronary arteries (less than 3.0 mm in diameter). However, it is unclear which type of stent is more effective for large-vessel stenting. Compared with bare-metal stents, first-generation drug-eluting stents (e.g., stents that release paclitaxel or sirolimus) have lower restenosis rates, but an increased risk of late stent thrombosis, which in turn may be associated with death from cardiac causes or nonfatal myocardial infarction. Kaiser and colleagues conducted a large, prospective, randomized, multicenter trial to evaluate the effectiveness of first-generation drug-eluting stents and bare-metal stents placed in large coronary arteries.

The Study: The authors randomly assigned 2,314 patients with acute or chronic coronary disease requiring stenting to receive bare-metal stents (n = 765), first-generation drug-eluting stents containing sirolimus (n = 775), or second-generation drug-eluting stents containing everolimus (n = 774). Patients were eligible if they required stents 3.0 mm or larger in diameter. All patients received aspirin in a daily dosage of 75 to 100 mg indefinitely and clopidogrel (Plavix) in a daily dosage of 75 mg for one year. The primary end point was death from cardiac causes or nonfatal myocardial infarction at two years.

Results: Two-thirds of patients presented with acute coronary syndromes, and one-half of those had myocardial infarction with ST-segment elevation. At two years, no significant differences were seen between groups with regard to the composite primary outcome of nonfatal myocardial infarction or death from cardiac causes, or when these factors were studied separately. The need for revascularization unrelated to myocardial infarction was significantly greater with bare-metal stents than with either drug-eluting stent group (8.9 percent for bare-metal, 3.7 percent for sirolimus, and 3.1 percent for everolimus), although rates with both drug-eluting stent groups were similar. No differences in thrombosis rates were noted between groups.

Conclusion: In patients who required large-vessel coronary artery stenting, no increased mortality risk was noted among those who received first- or second- generation drug-eluting stents compared with bare-metal stents. Both drug-eluting stent groups showed a reduced rate of target vessel revascularization compared with bare-metal stents; however, the risk of clinically relevant restenosis is lower among patients requiring only large-vessel stents than in those requiring small-vessel stents. Also, a nonsignificant reduction in death from cardiac causes or nonfatal myocardial infarction was noted in the drug-eluting stent groups.