News:Drug Eluting Stents Continue to Demonstrate Superiority over Bare Metal Stents in Reducing the Need for Repeat Revascularization

June 25, 2008 By Vijayalakshmi Kunadian MBBS MD MRCP [mailto:vkunadian@perfuse.org]

Malenka and colleagues in a new study published in JAMA this week compared the outcomes of Medicare beneficiaries who underwent non-emergent percutaneous coronary intervention (PCI) before and after the drug eluting stents (DES) became available for routine use. Patients who were enrolled in the fee-for-service Medicare programs who had received a coronary stent from 2002 to 2005 were included in this study. Patients who had suffered an acute myocardial infarction (MI) and CABG patients were excluded. The historical control for this study consisted of patients who underwent bare metal stent (BMS) implantation from October 1, 2002 and March 31, 2003. The outcome measure consisted of the rate of repeat revascularization defined as any PCI whether or not a stent was used or crossed over to CABG. Other outcome measures were ST elevation myocardial infarction (STEMI) and death.

A total of 38, 917 patients underwent PCI using BMS in the BMS era and 17,275 out of the 28,086 patients (61.5%) had DES implantation in the DES era. There were no significant differences in the baseline characteristics between the two study groups except there were more diabetics in the DES era and around 18% of patients had multivessel PCI. Repeat PCI rates were significantly reduced in the DES era compared with BMS era at 6 months (9.7% vs. 10.8%, p<0.001), 12 months (13.1% vs. 15.2%, p<0.001) and 2 years (17.1% vs. 20%, p<0.001).

Likewise the rate of CABG was significantly reduced in the DES era compared with BMS era at 3 months (0.5% vs. 0.7%, p<0.001), 6 months (1% vs. 1.9%, p<0.001), 12 months (1.7% vs. 2.9%, p<0.001) and 2 years (2.7% vs. 4.2%, p<0.001). The rate of PCI or CABG was also significantly reduced in the DES era compared with BMS era at 2 years (19% vs. 22.8%, p<0.001). The adjusted hazard of repeat revascularization was significantly lower in the DES era compared with the BMS era in subgroup analysis consisting of men, women, patients aged 75 years or older, those younger than 75 years, African Americans, non-African Americans, those with and without diabetes.

There was however no difference in the incidence of death at two years between the DES era and BMS era at two years (8.4% in both groups, p=0.98). There was a difference in the rate of STEMI at two years (2% vs. 2.4%, p<0.001) which resulted in a significant difference in the two year composite of death and MI between DES and BMS eras (9.6% vs. 10.1%, p=0.04). However, the adjusted hazard ratio for the composite of death and MI was not significant between the two groups [HR 0.96; 95% CI 0.92 to 1.01] at two years. The adjusted hazard of death or STEMI was non-significantly lower in the DES era compared with the BMS era in a subgroup analysis consisting of women, men, patients aged 75 years or older, those younger than 75 years, African Americans, non-African Americans, those with and without diabetes. In a landmark analysis, the adjusted cumulative hazard by 2 years demonstrated that the outcomes were comparable between the DES era and the BMS era (HR 0.97; 95% CI 0.92 to 1.03). The investigators concluded that the use of DES was associated with a significant reduction in the incidence of repeat revascularization procedures without significant difference in the 2 year risks of death and myocardial infarction compared with the bare metal stents.

The authors report several limitations with this study including the fact that the true rate of stent thrombosis was not assessed and the information on the impact of dual antiplatelet therapy on the outcomes was not available. This study is limited to sirolimus eluting stents and the outcomes among STEMI patients are not available as they were excluded from this study.

Source

 * 1) http://jama.ama-assn.org/cgi/content/full/299/24/2868