PROTECT: ZES Lowers Thrombosis Rates Over SES at 4 Years
San Francisco, CA—Large trial shows better outcomes with Endeavor over Cypher; results at 3 years were non-significant.
Zotarolimus-eluting stents (ZES) yielded a significantly reduced rate of definite or probable stent thrombosis (ST) four years after implantation compared with sirolimus-eluting stents (SES), according to results from the PROTECT trial presented Monday at TCT 2013.
Laura Mauri, MD, of Harvard Medical School in Boston, discussed results of the international randomized trial comparing the Endeavor ZES (Medtronic) and Cypher SES (Cordis). The 3-year results of the trial showed no significant difference, but the event rates diverged substantially between 3 and 4 years, she said. “This is the first time any DES has shown superiority over C-SES on hard clinical endpoints.”
PROTECT included 4,357 patients who received ZES and 4,352 patients who received SES; 96.8% (4,217 patients) of ZES patients and 96.9% (4,215 patients) of SES patients were available for the 4-year analysis of stent thrombosis. Dual antiplatelet therapy (DAPT) strategies were defined at each site prior to enrollment so as to ensure that stent thrombosis rates could be attributed to the stent rather than medical therapy; about 87% of both groups were still on DAPT after 1 year, though that fell to approximately 28% by 4-year follow-up.Significant difference in ST at 4 years
At 3 years, there was no significant difference in ARC-defined definite or probable stent thrombosis in the SES vs. ZES groups (P=.224). However, at 4 years, that endpoint had occurred at a higher rate in SES vs. ZES patients (see Figure).
All-cause mortality at 4 years was similar at 5.6% for ZES and 6.1% for SES (P=.33), though several other endpoints did favor the ZES group. For example, the cumulative incidence of the composite endpoint of all death/large MI was 8% in the SES group vs. 6.7% in the ZES group (HR 0.84; 95% CI, 0.71-0.98; P=.024). This 16% risk reduction was driven by a decrease in late, spontaneous Q-wave MI. Target lesion revascularization was lower in the SES group compared with ZES (4.5% vs. 6%; P=.002), while target vessel revascularization rates were not significantly different (P=.44).
Baseline characteristics of PROTECT patients were generally well matched between the two groups and included patients with an average age of 62 years and more than three-quarters male. About 25% of the cohort were current smokers, and about 20% had prior MI. Using a number of risk factors, patients were stratified by preserve or absence of elevated ST risk: 58% and 58.1%, respectively, for ZES and SES (P=.93).
“The reliable assessment of the efficacy and safety of any permanently implanted device such as a stent requires a well-powered, long-term study,” she observed.
Disclosures:
Mauri reports receiving consultant fees/honoraria from Biotronik, Medtronic CardioVascular, and St. Jude Medical; and that her institution has received grant/research support from several companies.
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