WASHINGTON, Oct. 22 -- Pitted head to head against the Taxus (paclitaxel-eluting) stent, the investigational Xience (everolimus-eluting) device had significantly fewer major adverse coronary events (MACE), reflecting a lower rate of peri-procedural myocardial infarction and a strong reduction in target lesion revascularization.
The one-year MACE rate was 43% lower in the Xience arm -- 5.8% versus 9.9% (P=0.01), said Gregg W. Stone, M.D., of the Center for Interventional Vascular Therapy of New York-Presbyterian Hospital at Columbia.
Action Points
- Explain to interested patients that this report describes data from a study of an investigational coronary stent that is not FDA approved.
- These findings were reported at a medical conference and should be considered preliminary until they have appeared in a peer-reviewed journal.
"This is the first time that an investigational stent had demonstrated superiority to an existing [drug-eluting] stent," Dr. Stone said during a press conference on the SPIRIT III results at the Transcatheter Cardiovascular Therapeutics meeting here.
The benefit, he said, represented fewer peri-procedural MIs and fewer target lesion revascularizations in the Xience group from six through 12 months.
Dr. Stone said peri-procedural MIs were adjudicated using World Health Organization criteria, which are the criteria required by the FDA. He said that if a universal MI definition just unveiled were applied to the SPIRIT III data, the MI rate would probably have been less because "that definition is more sensitive." (See: Troponin Elevation Key Element in Universal Definition of MI)
by Gregg W. Stone, M.D.
(Running time: apprx. 5 minutes)
The primary endpoint of the study was in-segment late-loss, and there was a clear advantage with Xience -- a reduction of 50% in late-loss compared with Taxus, Dr. Stone said.
The findings reported today were a follow-up to nine-month results reported at the American College of Cardiology meeting last March. (See: ACC: Xience Stent Better than Taxus on Visualized Lumen Loss but Not on Outcomes)
Moreover, one-year data found no significant increase in stent thrombosis compared with the Taxus stent. The rate by protocol definition was 0.8% (five of 647 patients implanted with Xience stents) versus 0.6% (two of 317 patients who received Taxus stents), Dr. Stone said.
Likewise there were no significant differences in the stent thrombosis rate at less than 30 days or at 30 days to one year. But more time is needed before any definite conclusions can be made about the stent thrombosis risk, said Ajay J. Kirtane, M.D., of Columbia.
Dr. Kirtane, who was not involved in the trial, pointed out the stent thrombosis risk with existing drug-eluting stents was not evident until nine months or longer after implant.
Subgroup analysis can often be problematic in trials such as SPIRIT III, and Dr. Stone confirmed that a the subgroup analysis provided an unexpected and thus far inexplicable finding -- the one year MACE rate was lowest in patients who were 63 or older -- 5.5% in the Xience stent group and 12.0% in the Taxus group, versus 6.4% and 8.6% respectively in younger patients.
But in the overall analysis there were no significant differences in the rate of death, MI, or stent thrombosis.
He said both stents performed well. "Taxus did what it was supposed to do," but the edge went to Xience.
| The Xience stent is being developed by Abbott Vascular, which funded the trial. Dr. Stone disclosed research support from Abbott Vascular and Boston Scientific. |
Primary Source
TCT-2007
Source Reference: Stone, G et al "Spirit III a Prospective, Randomized Trial Comapred an Everolimus-Eluting Stent with a Paclitaxel-Eluting Stent in Patients with Coronary Artery Disease One Year Follow-up and Subgroup Analysis" Late Breaking Clinical trials.