A new meta-analysis showed that cobalt-chromium everolimus-eluting stents have much lower short- and long-term rates of stent thrombosis than both bare metal stents and all other drug-eluting stents.
Although drug-eluting stents outperform bare metal stents in terms of efficacy, the cobalt-chromium everlimus-eluting stent is the first to have lower thrombosis rates than bare metal stents during follow-up, according to a press release.
Researchers identified 49 randomized controlled trials comprising more than 50,000 patients that compared currently approved drug-eluting stents or drug-eluting with bare metal stents. Data extracted included study design, inclusion and exclusion criteria, sample characteristics and clinical outcomes.
Analysis showed that the 1-year rate of definite stent thrombosis was significantly lower with cobalt-chromium everolimus-eluting stents (Xience V, Abbott Vascular) than with bare metal stents (OR=0.23; 95% CI, 0.13-0.41). This was the primary endpoint of the trial.
According to the researchers, there were significant differences in stent thrombosis between cobalt-chromium everolimus-eluting stents and bare metal stents as early as 30 days (OR=0.21; 95% CI, 0.11-0.42). The difference was also significant between 31 days and 1 year (OR=0.27; 95% CI, 0.08-0.74).
Rates of 1-year stent thrombosis were also significantly lower with cobalt-chromium everolimus-eluting stents when compared with paclitaxel-eluting stents (Taxus Express and Taxus Liberté, Boston Scientific; OR=0.28; 95% CI, 0.16-0.48), permanent polymer-based sirolimus-eluting stents (Cypher, Cordis; OR=0.41; 95% CI, 0.24-0.70), phosphorylcholine-based zotarolimus-eluting stents (Medtronic; OR=0.21; 95% CI, 0.10-0.44) and zotarolimus-eluting stents (Resolute, Medtronic; OR=0.14; 95% CI, 0.03-0.47).
At 2 years, the cobalt-chromium everolimus-eluting stent was still associated with significantly lower rates of definite stent thrombosis vs. bare metal stents (OR=0.35; 95% CI, 0.17-0.69) and paclitaxel-eluting stents (OR=0.34; 95% CI, 0.19-0.62). At 2-year follow-up, no other drug-eluting stent had lower definite thrombosis rates vs. bare metal stents.
“The low rate of stent thrombosis in the first 2 years after deployment of [cobalt-chromium everolimus-eluting stents] is very reassuring,” the researchers wrote. “On this basis, [cobalt-chromium everolimus-eluting stents] should be regarded as the standard against which future design improvements are compared. These findings might also give pause to those who are developing stents with resorbable coatings with the thought that a so-called bare metal-equivalent stent would be less thrombogenic.”
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Disclosure: The study was funded by the Cardiovascular Research Foundation. See the study for a full list of disclosures.