The Efficacy of XIENCE V Stent over Taxus Stent Decreases with Time: Results from the SPIRIT II study

March 31, 2008 By Alexandra M. Palmer [mailto:apalmer@perfuse.org]

 SCAI-ACCi2 08-Chicago, IL: The 2-year results of the SPIRIT II study demonstrate no significant difference between the outcomes obtained from implantation of the XIENCE V everolimus-eluting stent or the TAXUS paclitaxel-eluting stent.

The SPIRIT II study was a prospective, randomized, single-blind, multicenter study which enrolled 300 patients at 28 centers in Europe, New Zealand and India. Included patients presented with no more than 2 new native coronary artery lesions between 2.5 mm and 4.25 mm in diameter and ≤28 mm in length. 223 patients were randomized to implantation of the XIENCE V Everolimus Eluting Coronary Stent System and 77 to the TAXUS Paclitaxel-Eluting stent.

Previously reported angiographic results of SPIRIT II compared 6-month in-stent late loss between XIENCE V everolimus-eluting stents and TAXUS paclitaxel-eluting stents. In these findings, XIENCE V was favored over TAXUS (0.17 ± 0.32 mm vs. 0.33 ± 0.32 mm, p = 0.0037).

The 1-year clinical results also favor XIENCE V implantation for greater reduction in the total rate of major adverse cardiac events (MACE), including myocardial infarction, cardiac death, and repeat treatment of the culprit lesion (2.7% vs. 9.2%, p = 0.04).

The new 2-year follow-up data were presented by Dr. Patrick W. Serruys at today’s SCAI-i2 summit Annual Scientific Sessions in Chicago.

At 2 years, the pre-specified primary endpoint of angiographic in-stent late loss was not significanttly different between XIENCE V and TAXUS stents (0.33 ± 0.37 mm vs. 0.34 ± 0.34 mm, p = 0.6026). There was no difference between the rate of ≥50% restenosis (2.1% vs. 2.9%) and the rate of stent thrombosis either.

Also at 2 years, the clinical superiority of XIENCE V (n=211) over TAXUS (n=73) was no longer statistically significant. The rate of MACE was 11.0% in the TAXUS group and only 6.6% in patients treated with XIENCE V (p=0.3077). Furthermore, 6.8% of patients with TAXUS stents underwent ischemia driven target lesion revascularization, in comparison to only 3.8% of patients with XIENCE V stents. Myocardial infarction and cardiac death rates tended to be lower in the XIENCE V arm as well (2.8 vs. 5.5% and 0.5 vs. 1.4%).

The results suggest that with time, the superiority of XIENCE V declines. It will be interesting to continue to follow this study as there are still results to come from the 3, 4, and 5-year clinical follow-ups.