Two-year data from SPIRIT IV, a large-scale multicentre study of nearly 4,000 patients in the USA, show that everolimus-eluting stents demonstrated enhanced safety and efficacy in the treatment of de novo native coronary artery lesions when compared to paclitaxel-eluting stents. The results were presented as a late breaking trial by Gregg W Stone, Columbia University Medical Center, New York and principal investigator of the SPIRIT IV trial at the 22nd annual TCT scientific symposium in Washington DC, USA.
Researchers randomised 3, 687 patients in a 2:1 ratio to treatment with the everolimus-eluting Xience V stent (Abbot Vascular) or the paclitaxel-eluting Taxus Express stent (Boston Scientific). Data showed that compared with the paclitaxel-eluting stent, the everolimus-eluting stent continued to reduce the primary composite endpoint of target lesion failure (a composite of cardiac death, target-vessel MI or ischaemia-driven target lesion revascularisation) as well as its individual components from one to two years. Academic Research Consortium- defined definite or probable stent thrombosis rates were also substantially lower with the newer stent, and mortality rates were similar between groups.
For the everolimus-eluting stent, target lesion failure at two years was 6.9%, and for the paclitaxel-eluting stent, target lesion failure was 9.9%, a significant 30% reduction. At two years, ischemia-driven target lesion revascularisation was 4.5% for the everolimus-eluting stent and 6.9% for the paclitaxel-eluting stent, a significant 34% reduction. In patients with diabetes there was a non significant difference in the rate of target lesion failure between the two stents, whereas target lesion failure was reduced by 41% with the everolimus-eluting stent compared to the paclitaxel-eluting stent in patients without diabetes. In addition to lowering target lesion failure and target lesion revascularisation, the everolimus-eluting stent compared to the paclitaxel-eluting stent also reduced the occurrence of heart attacks and stent thrombosis.
SPIRIT IV is the largest clinical trial to date comparing two drug-eluting stents. Unlike similar prior studies (SPIRIT FIRST, SPIRIT II and SPIRIT III), the SPIRIT-IV trial was powered for superiority for clinical endpoints without angiographic follow up. The trial also examined the differences in performance of the two stents in patients with diabetes. The primary endpoint of the trial was target lesion failure at one year, a composite measure of cardiac death, target vessel heart attack or ischemia-driven target lesion revascularisation. Most of the benefits of the everolimus-eluting stent were realized within the first year, with the results remaining robust at two years follow-up.
“The safety and efficacy of the everolimus-eluting stent compared to the paclitaxel-eluting stent, which were established at one year, are sustained at two years. These are significant findings that support the enhanced clinical outcomes achieved with the everolimus-eluting stent, which is the most commonly used drug-eluting stent,” concluded Stone.
As the trial design excluded left main or ostial disease and various complex lesion subsets, Stone stressed, “This was not an all-comers trial.”
Everolimus vs. sirolimus-eluting stents
Results from SORT OUT IV study, comparing Cordis’ Cypher sirolimus-eluting coronary stent and Abbott’s Xience V everolimus-eluting stent in the primary endpoint of major acute coronary events at nine months, were presented at the TCT conference in Washington, DC, USA.
In the all-comers SORT OUT IV trial, presented by Lisette Okkels Jensen, Odense University Hospital, Denmark, 2,774 patients with coronary artery disease were randomly assigned to Xience (n=1,390) or Cypher (n=1,384).
At nine months, the rate of the primary composite endpoint (cardiac death, myocardial infarction, definite stent thrombosis or clinically driven target vessel revascularisation), was 4.9% for the everolimus group vs. 5.2% for the sirolimus group, meeting criteria for non-inferiority (p=0.01). There was no difference between the two arms for secondary outcomes. However, a trend emerged in favour of the everolimus-eluting stent thrombosis which was 0.1% in everolimus and 0.7% in sirolimus (p=0.05).
The study took place between August 2007 and June 2009. Eligible patients were aged 18 or over, had chronic stable coronary artery disease or acute coronary syndromes or a coronary artery lesion requiring treatment with a drug-eluting stent.