WASHINGTON — Data from a U.S. registry of drug-eluting stent use suggest that there is little difference between the two commercially available models, Charles Simonton, M.D., said at a symposium sponsored by the Cardiovascular Research Foundation.
Dr. Simonton reported on interim results of the Strategic Transcatheter Evaluation of New Therapies (STENT) registry, which aimed to track patterns of use and the comparative safety and efficacy of the Cypher, a sirolimus-eluting stent made by Cordis Corp., and the Taxus, a paclitaxel-eluting stent made by Boston Scientific.
The registry was supported by unrestricted grants from Boston Scientific, Cordis Corp., Possis Medical, and The Medicines Company. The two drugs have different mechanisms of action, but the STENT data “would suggest the actual clinical outcome for the patients is identical,” said Dr. Simonton, director of adult cardiology research at Carolinas Heart Institute (Charlotte, N.C.) and a principal investigator in the study.
The data for the registry were entered into a secure Web site by each of eight participating coronary interventional centers. The goal was to prospectively enroll between 8,000 and 10,000 consecutive cases per year. The data had to be entered within 60 days of each predetermined time period: in-hospital, 3- and 9-month data; and key events, such as stent thrombosis and target vessel revascularization (TVR), were adjudicated by physicians.
From May 2003 through September 2004, 8,013 patients who had primary coronary interventions were eligible for the registry, and 6,659 (83%) of those consented to inclusion. At 9 months, there was complete follow-up on 6,336. Not all the patients received drug-eluting stents; of those who did, there were complete data on 2,282 patients who received the Cypher and 1,476 who received the Taxus.
Among those who received stents, the major adverse cardiac events (MACE) rate was 7.9% for Cypher and 6.8% for Taxus. The death rate was 2.7% for Cypher and 2.1% for Taxus. Myocardial infarction rates were also similar, at 2.2% for Cypher and 1.8% for Taxus. Just under 4% of Cypher patients had a second procedure in the target vessel, compared with 2.8% of Taxus patients.
The TVR rates were very close, with 95 (4.2%) Cypher patients and 50 (3.4%) Taxus patients requiring revascularization. There was a low rate of subacute stent thrombosis: 0.7% for Cypher and 0.5% for Taxus.
There was no statistically significant difference between the two for time to TVR or MACE, said Dr. Simonton.
The Taxus group might have been at a slight disadvantage because it was a little older and had more incidents of acute coronary syndrome and a marginally lower preprocedure Thrombolysis in Myocardial Infarction Study Group (TIMI) grade flow, he said. But the majority of the baseline characteristics were similar between the two groups, and a risk-adjusted multivariable analysis for MACE and TVR showed no significant differences.
The results so far argue for both stents to stay in the catheterization lab, said Dr. Simonton. The choice on which one to use may in part be decided by price and deliverability, he said.
“If the clinical outcomes look the same, it comes down to deliverability—how easy [it is] to use the stent,” he said. But, he added, there are no objective ways to measure that deliverability.