A pooled analysis of data comparing sirolimus-eluting stents with bare-metal stents

Although randomized studies have shown a beneficial effect of drug-eluting stents in reducing the risk of repeated revascularization, these trials were underpowered to compare rates of death and myocardial infarction. The long-term safety of drug-eluting stents has been questioned recently.

We performed a pooled analysis of 1748 patients in four randomized trials evaluating the safety of sirolimus-eluting stents as compared with bare-metal stents. Patient-level data were obtained and analyzed by independent statisticians at two academic institutions. The primary safety end point was survival at 4 years. We tested for heterogeneities in treatment effect in patient subgroups.

The survival rate at 4 years was 93.3% in the sirolimus-stent group, as compared with 94.6% in the bare-metal-stent group (hazard ratio for death, 1.24; 95% confidence interval [CI], 0.84 to 1.83; P=0.28). In the 428 patients with diabetes, a significant difference in the survival rate was observed in favor of the bare-metal-stent group over the sirolimus-stent group (95.6% vs. 87.8%; hazard ratio for death in the sirolimus-stent group, 2.9; 95% CI, 1.38 to 6.10; P=0.008). The lower survival rate among patients with diabetes who were treated with sirolimus-eluting stents was due to increased numbers of deaths from both cardiovascular and noncardiovascular causes. No difference in survival rate was detected among the patients without diabetes. Rates of myocardial infarction and stent thrombosis were similar in the two groups.

In a pooled analysis of data from four trials comparing sirolimus-eluting stents and bare-metal stents, no significant differences were found between the two treatments in rates of death, myocardial infarction, or stent thrombosis. (ClinicalTrials.gov numbers, NCT00233805 [ClinicalTrials.gov] , NCT00381420 [ClinicalTrials.gov] , NCT00232765 [ClinicalTrials.gov] , and NCT00235144 [ClinicalTrials.gov].)