Bare-metal and drug-eluting stents yield similar cardiac event risks, according to pooled analysis

A pooled analysis involving 1,748 patients in 4 randomized trials contradicts the results of recent trials that have demonstrated that the risks for death and myocardial infarction (MI) are potentially higher in patients receiving drug-eluting stents (particularlysirolimus-eluting stents) compared with patients receiving bare-metal stents.

Key Points

A pooled analysis published in the New England Journal of Medicine (NEJM) involving 1,748 patients in 4 randomized trials contradicts the results of recent trials that have demonstrated that the risks for death and myocardial infarction (MI) are potentially higher in patients receiving drug-eluting stents (particularly sirolimus-eluting stents) compared with patients receiving bare-metal stents.

The trials included in this study were the Sirolimus-Coated Bx Velocity Balloon-Expandable Stent in the Treatment of Patients with De Novo Native Coronary Artery Lesions (RAVEL) study, the Sirolimus-Eluting Balloon-Expandable Stent in the Treatment of Patients with De Novo Native Coronary-Artery Lesions (SIRIUS) trial, the European SIRIUS (ESIRIUS) trial, and the Canadian SIRIUS (C-SIRIUS) trial. Each of these double-blinded trials randomized patients (1:1) to receive either a sirolimus-eluting stent or a bare-metal stent implanted into previously untreated lesions in a single, native coronary artery.

The primary safety end point in this study was all-cause mortality. After 4 years of patient follow-up, there was no statistically significant difference in the risk of death between the sirolimus-coated stent group (57 of 878) and the bare-metal stent group (46 of 870) (HR=1.24; 95% CI, 0.84–1.83; P=.28). In addition, the risk of MI or stent thrombosis was demonstrated to be similar between groups (HR=1.03; 95% CI, 0.71–1.51; P=.86 and HR=1.07; 95% CI, 0.64–1.79; P=.80, respectively). Sirolimus-eluting stents were associated with a greater percentage of complex lesions compared with bare-metal stents (22.5% vs 18.5%; P=.04). A greater percentage of patients with bare-metal stents had diabetes than patients with sirolimus-eluting stents (26.8% vs 22.2%; P=.02).

An estimated 664,000 percutaneous coronary intervention (PCI) procedures were performed in 2003 in the United States; drug-eluting or bare-metal stents were used in 84% of the procedures.

With regard to the previous studies that have demonstrated increased risk with drug-eluting stents, the authors stated: "The divergence of the Kaplan–Meier survival curves over time could be interpreted as a growing trend toward a lower survival rate among patients treated with sirolimus-eluting stents as compared with those treated with bare-metal stents, although a larger number of patients, a longer follow-up period, or both would be necessary to confirm this interpretation."

SOURCES

Spaulding C, Daemen J, Boersma E, Cutlip DE, Serruys PW. A pooled analysis of data comparing sirolimus-eluting stents with bare-metal stents. New Engl J Med. 2007;356:989–997.

Heart disease and stroke statistics-2007 update. A report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. http:// http://www.americanheart.org/statistics/. Accessed July 10, 2007.