Xience V stent continues to demonstrate superior efficacy over the Taxus stent up to 2 years in the SPIRIT III trial

May 20, 2008 By Vijayalakshmi Kunadian MBBS MD MRCP [mailto:vkunadian@perfuse.org]

EUROPCR 08, Barcelona, Spain: Dr Gregg Stone presented the 2 years results of the SPIRIT III trial which demonstrated significant reduction in target vessel failure and major adverse cardiac events with Xience V stent vs. Taxus stent.

SPIRIT III trial is a prospective, randomized trial comparing an everolimus-eluting stent (Xience V) and a paclitaxel-eluting stent (Taxus) in patients with coronary artery disease. This study at one year demonstrated significant reduction in angiographic late-loss at 8 months, non-inferior 1-year rates of target vessel failure (TVF), reduced 1-year rates of major adverse cardiac events (MACE) and non-significant differences in the rates of protocol-defined and ARC stent thrombosis.

A total of 1002 patients from 65 US sites were enrolled in the trial and were randomized (2:1) to receive either Xience V or Taxus drug eluting stents. There were more patients with unstable angina in the Taxus group (p=0.02). Patients were treated with aspirin ≥80mg QD for 5 years and clopidogrel 75mg QD for ≥6 months. 2 year follow-up was available in 94.9% of patients. At 2 years, the primary endpoint of target vessel failure (TVF) occurred in 15.4% and 10.7% of cases in the Taxus and Xience V groups, [HR 0.68, 95%CI 0.48-0.98, p=0.04] respectively. Major adverse cardiac events occurred more frequently in the Taxus group rather than the Xience V group (12.8% vs. 7.3%, HR 0.55, 95% CI 0.36-0.83, p=0.004).

The 2 year binomial TVF and MACE favored Xience V compared with Taxus [RR 0.69, 95% CI 0.49-0.96, p=0.038 and RR 0.56, 95% CI 0.38-0.82, p=0.005]. There was a trend towards reduction in ischemia driven target lesion revascularization (TLR) with Xience V (4.3% vs. 6.9%, p=0.07). However, there was no difference in the occurrence of all cause death and cardiac death between the two groups (p=0.59 and p=0.79 respectively). There was a trend towards reduction in myocardial infarction with Xience V (3.2% vs. 5.6%, p=0.07). There was significant reduction in the combined all-cause death and myocardial infarction with Xience V (HR 0.60, 95% CI 0.35-1.01, p=0.052). At two years there was no significant difference in the incidence of stent thrombosis between the two groups (Xience V 0.9% vs. Taxus 1.6%, p=0.37). There was a trend towards reduction in stent thrombosis after discontinuation of clopidogrel at 6 months with Xience V (0.4% vs. 2.6%, p=0.10).

The SPIRIT III trial 2 year results demonstrate that the Xience V stent is associated with 32% and 45% reductions in the occurrence of TVF and MACE due to fewer peri-procedural and late myocardial infarctions and fewer TLR procedures through 2 years. Subsequent reduction in stent thrombosis after clopidogrel discontinuation requires further study.

Source

 * 1) EUROPCR Scientific Sessions, Barcelona 2008. Presented by Dr Gregg Stone.