Long-term outcomes following coronary drug-eluting- and bare-metal-stent implantation

Background

Although drug-eluting stents (DES) reduce restenosis rates relative to bare-metal stents (BMS), recent reports have indicated that the use of DES may be associated with an increased risk of stent thrombosis. Our study focused on the effect of stent type on clinical outcomes in a “real world” setting.

Methods

889 patients undergoing percutaneous coronary intervention (PCI) with either DES (Cypher or Taxus; n = 490) or BMS (n = 399) were enrolled in a prospective single center registry. The outcome analysis covered a period of up to 3.2 years (mean 2.7 years ± 0.5 years) and was based on 65 deaths, 27 myocardial infarctions, 76 clinically driven target lesion revascularizations (TLR), and 15 angiographically confirmed cases of definite stent thrombosis and was adjusted for differences in baseline characteristics.

Results

In total 1277 stents (613 BMS and 664 DES) were implanted in 1215 lesions. Despite a significantly different unadjusted death rate (10.1% and 5.1% in BMS and DES patients, respectively; p < 0.05), the patient groups did not differ significantly in the risk of myocardial infarction during 2.7 years of follow-up. After adjustment for differences in baseline characteristics between groups, the difference in the cumulative incidence of death did not remain statistically significant (p = 0.22). Target lesion revascularizations occurred significantly less frequently in patients with DES compared to individuals after BMS implantation (5.9% and 11.8% in patients with DES and BMS, respectively; p < 0.05). The rate of angiographically confirmed stent thrombosis was 2.1% in patients with DES and 1.1% in BMS patients (p = 0.31).There was a significantly lower unadjusted event rate (including deaths, myocardial infarction, target lesion revascularization, and stent thrombosis) in patients with drug-eluting stents than in those with bare-metal stents (16.4% and 25.8%, respectively), with 9.4 fewer such events per 100 patients (unadjusted hazard ratio HR], 0.64; 95% confidence interval CI], 0.46 to 0.87). After adjustment, the relative risk for all outcome events in patients with drug-eluting stents was 0.79 (95% CI, 0.67 to 0.95). However, the adjusted relative risk for death and myocardial infarction did not differ significantly between groups (adjusted relative risk in patients with drug-eluting stents 0.94 (95% CI, 0.77 to 1.37)).

Conclusions

In this real-world population, the beneficial effect of first generation DES in reducing the need for new revascularization compared with BMS extends to more than 2.5 years without evidence of a worse safety profile. The minor risk of stent thrombosis and myocardial infarction within this period after implantation of DES seems unlikely to outweigh the benefit of these stents.