Findings from Abbott's Spirit IV trial, one of the largest randomized clinical trials comparing two drug eluting stents, with 3,690 US-based patients, shows that its market-leading Xience V Everolimus Eluting Coronary Stent System reduces adverse events comparatively, according to the study published in The New England Journal of Medicine.
The published study results show that one year after a stenting procedure, patients treated with Abbott's market-leading Xience V Everolimus Eluting Coronary Stent System were significantly less likely to have a major adverse event such as a heart attack, repeat procedure or cardiac death, compared to patients treated with a Taxus Express2 Paclitaxel-Eluting Coronary Stent System (Taxus), manufactured by Boston Scientific.
The Spirit IV trial also showed that patients treated with Xience V were considerably less likely to experience a blood clot (stent thrombosis) compared to patients treated with Taxus. These results were originally presented during the September 2009 Transcatheter Cardiovascular Therapeutics (TCT) conference.
In the Spirit IV trial's primary endpoint of target lesion failure (TLF), Xience V demonstrated a statistically superior 38 per cent reduction compared to Taxus at one year (4.2 per cent for Xience V vs. 6.8 per cent for Taxus, p-value=0.001). TLF is defined as a composite measure of important efficacy and safety outcomes for patients and includes cardiac death, heart attack attributed to the target vessel (target vessel myocardial infarction), and ischemia-driven target lesion revascularization (TLR). The Spirit IV trial also found that the one-year rate of blood clots (stent thrombosis) with Xience V is among the lowest reported to date with any drug eluting stent (0.29 per cent per Academic Research Consortium definition of definite/probable stent thrombosis).
In a subgroup analysis of more than 1,100 patients with diabetes, who typically are sicker and have more challenging artery disease, Xience V demonstrated a numerically lower TLF rate compared to Taxus at one year (6.4 per cent for Xience V vs. 6.9 per cent for Taxus, p-value=0.80). In the critical safety endpoint of stent thrombosis as presented during TCT 2009, Xience V demonstrated a 40 per cent reduction compared to Taxus in patients with diabetes (per ARC definition of definite/probable stent thrombosis, 0.80 per cent for Xience V vs. 1.33 per cent for Taxus, p-value=0.52).
"With more than 3 million stent procedures being performed annually worldwide, determining the safety and efficacy differences between various drug eluting stents has important implications for societal health," said Gregg W Stone professor of medicine at Columbia University Medical Center; immediate past chairman of the Cardiovascular Research Foundation in New York; and principal investigator of the Spirit IV trial. "With nearly 4,000 patients studied, Spirit IV represents the largest randomized trial of two drug eluting stents completed to date, and found that the everolimus-eluting stent significantly reduces a patient's risk of experiencing a heart attack, stent thrombosis, or the need for a repeat procedure within one year, compared to the paclitaxel-eluting stent. Based on these results, and results from the 1,800-patient Compare study conducted in the Netherlands, the everolimus-eluting stent has set a new standard for patient safety and efficacy."
Separately, in a recent retrospective cost-effectiveness analysis of Spirit IV data, researchers found that the clinical benefits offered by Xience V translated into lower overall medical costs at one year after the stenting procedure. The Spirit IV cost-effectiveness analysis, presented by David Cohen, of St Luke's Mid America Heart Institute in Kansas City, Mo., in March 2010 at the Optimizing PCI Outcomes symposium sponsored by the Cardiovascular Research Foundation, found that one-year total medical costs (initial hospitalization plus follow-up) were approximately US$ 150 lower for patients treated with Xience V than those treated with Taxus. When costs not related to the original treated vessel (non-target-vessel-revascularization) were excluded, the one-year medical costs were approximately US$ 450 lower with Xience V than Taxus. The Xience V and Taxus stents are competitively priced.
"The cost-effectiveness analysis of Spirit IV shows that a stent designed to deliver outstanding clinical benefits can deliver economic benefits as well," said Dr Cohen, who is the lead investigator of the Spirit IV cost-effectiveness analysis. "Since the findings were derived from a multicenter, comparative trial with only clinical follow-up, these results may be generalizable to most US practice settings."
"The Spirit IV data, published today in The New England Journal of Medicine, have changed clinical practice as more and more physicians around the world have embraced the Xience V drug eluting stent. With the additional Spirit IV cost-effectiveness analysis, we have observed favorable economic data based upon the strong clinical results. These findings should prove valuable as hospitals evaluate different treatment options for coronary artery disease patients," said Charles A. Simonton, M.D., FACC, FSCAI, divisional vice president, Medical Affairs, and chief medical officer, Abbott Vascular.
Abbott's market-leading Xience V is used to treat coronary artery disease by propping open a narrowed or blocked artery and releasing the drug, everolimus, in a controlled manner to prevent the artery from becoming blocked again following a stent procedure.