SAN FRANCISCO, CA – SEPTEMBER 23, 2009 – Late-breaking data from SPIRIT IV, a large-scale multi-center study of nearly 4,000 patients in the U.S., shows that an everolimus-eluting stent demonstrated enhanced safety and efficacy in the treatment of de novo native coronary artery lesions when compared to a paclitaxel-eluting stent, and showed that "low late loss" may be achieved with drug-eluting stents without sacrificing safety.
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 results with the everolimus stent demonstrate enhanced safety and efficacy compared to the paclitaxel stent in this large-scale study without routine angiographic follow-up and sets a new standard for event-free survival after [implantation of a drug-eluting stent]," said principal investigator Gregg W. Stone, MD, immediate past chairman of CRF, professor of medicine at Columbia University Hospital and Director of Cardiovascular Research and Education at the Center for Interventional Vascular Therapy at NewYork-Presbyterian Hospital/Columbia University Medical Center.
Results of the study were presented at the 21st annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium, sponsored by the Cardiovascular Research Foundation (CRF).
The primary endpoint of the trial was target lesion failure (TLF) at one year, a composite measure of cardiac death, target vessel heart attack or ischemia-driven target lesion revascularization (TLR). Major secondary endpoints of the trial were TLR at one year, and a composite of cardiac death or target vessel heart attack at one year.
For the everolimus stent, TLF at one year was 4.2 percent, and for the paclitaxel-eluting stent, TLF was 6.8 percent, a significant 38 percent reduction.
At one-year, ischemia-driven TLR was 2.5 percent for the everolimus stent and 4.6 percent for the paclitaxel stent, a significant 45 percent reduction.
The composite rates of cardiac death or target vessel myocardial infarction through one year were not statistically different with the 2 stents (2.2 percent for the everolimus stent and 3.2 percent for the paclitaxel stent). The rates of stent thrombosis, however, were significantly reduced with the everolimus stent compared to the paclitaxel-eluting stent (0.3 percent vs. 1.1 percent respectively).
The results were consistent regardless of lesion length, vessel size and the number of lesions treated. However, in the diabetic-patient subgroup, the study found a comparable rate of TLF with both stents, whereas in patients without diabetes, the everolimus stent reduced TLF by 53 percent compared to the paclitaxel-eluting stent.
"Outcomes in patients with diabetes may still be improved, and should represent an area of focus for future development of novel drugs and enhanced stent design," Dr. Stone said.