Cypher versus taxus: are there differences?

Abstract

Today, drug-eluting stents (DES) are the standard stenting procedure in the USA and in Switzerland. The objective of this analysis is to answer the two questions: what clinically relevant data regarding DES have been published, and is there a clinically relevant difference between the Cypher and the Taxus stents? Twenty-two randomized, controlled studies with a total of 11,118 patients were identified: 18 randomized studies compared a DES to a bare metal stent of identical design in 8,301 patients, and 4 randomized studies compared the Cypher and the Taxus stents in 2,817 patients. Three studies regarding Paclitaxel-releasing stents without polymer (1,235 pats) and five studies regarding Paclitaxel released from a polymer (3,513 pats) were analyzed. Sirolimus released from a polymer was investigated in five studies (2,070 pats). Everolimus released from a polymer was investigated in three studies (166 pats), Biolimus A9 released from a polymer in one (120 pats), and Zotarolimus (ABT-578) released from a polymer in also one (1,197 pats) trial. Thirteen studies chose either a surrogate primary endpoint (angiographic or IVUS) or a clinical endpoint insufficient for a power calculation. A primary clinical endpoint with an adequate sample size for a power calculation was chosen in three trials for the Taxus stent (TAXUS-IV, TAXUS-V, TAXUS-VI; 2,916 patients), in one trial for the Cypher stent (SIRIUS; 1,058 patients), and in one trial for the Endeavor stent (ENDEAVOR-II; 1,197 patients). In all these trials, the primary clinical endpoint was reached. Of the four studies comparing Cypher stents to Taxus stents, one did not define the primary endpoint (TAXi), two assumed superiority of the Cypher stent (REALITY with a surrogate endpoint and SIRTAX, a single-center study), and one was designed as a non-inferiority trial (ISAR-Diabetes, single-center study with a surrogate endpoint). Based on the European Society of Cardiology established strict criteria with a clinical primary endpoint as a prerequisite to recommend a DES, only three DES have thus far had proven positive effects on clinical outcome: the Cypher-stents, Taxus-stents, and Endeavor-stents. A trial proving the superiority of one DES over another would require a multicenter study with a clinical primary endpoint at an adequate power. As long as such a trial does not exist, Cypher and Taxus are regarded as being equivalent.