March 5, 2009 - In the first six-year follow-up of a pivotal study of any drug-eluting stent, the clinical benefits of the CYPHER Sirolimus-eluting Coronary Stent compared to a bare-metal stent (BMS) were sustained according to data presented at the Cardiovascular Revascularization Therapies conference.
In addition, the study found no differences between the CYPHER and the BMS in the safety measures of myocardial infarction (heart attack), death or stent thrombosis (blood clots).
At six -year follow-up, patients in the CYPHER arm of the SIRIUS trial experienced significantly lower rates of target vessel failure (TVF), the primary endpoint of the trial, than those who received the BMS (26.1 percent for the CYPHER stent versus 39.9 percent for the BMS; p<0.0001). TVF was defined as a composite of cardiac death, myocardial infarction and target vessel revascularization (TVR, or re-treatment of the blocked vessel).
In this long-term six-year follow-up, the CYPHER stent also demonstrated lower rates of TLR and major adverse cardiac events (MACE), which include myocardial infarction and death, compared to the BMS. The TLR rate for the CYPHER was 11.9 percent versus 27.9 percent for the BMS (p<0.0001), and the MACE rate for the CYPHER was 22.6 percent versus 37.2 percent for the BMS (p<0.0001). These six-year outcomes support the previously reported results of the trial and showed no signs of late “catch-up.”
In addition, there was no significant difference in the mortality or the myocardial infarction rates between the CYPHER stent and the BMS at six-year follow-up. The mortality rate was 8.9 percent for those receiving the CYPHER, compared to 9.4 percent for those receiving BMS (p=0.974). The myocardial infarction rate for the CYPHER Stent was 6.4 percent, compared to 7 percent for the BMS (p=0.774).
There was no significant difference in the overall rate of stent thrombosis between the CYPHER and the BMS, regardless of the definition of stent thrombosis employed. The definitions include the original SIRIUS Trial protocol definition and the Academic Research Consortium (ARC) definition. At six years, the protocol definition identified a rate of 1.2 percent stent thrombosis for the CYPHER, versus 0.8 percent for the BMS (p=0.536). The definite/probable ARC definition identified a stent thrombosis rate of 1.2 percent for the CYPHER, versus 2.1 percent for the BMS (p=0.304). There was no trend for an increase in ARC-defined definite or probable very late stent thrombosis rates between one and six years (0.8 percent in CYPHER stent arm vs. 1 percent in the BMS arm).
The SIRIUS (Sirolimus-coated BX VELOCITY Balloon-Expandable Stent in Treatment of Patients with De Novo Coronary Artery Lesions) Trial, sponsored by Cordis Corp., served as a pivotal study for the U.S. approval of the CYPHER stent in 2003 and is the longest running U.S.-based study for a drug-eluting stent. In the double-blinded, multi-center randomized trial, patients were divided into two treatment groups: 533 patients received the CYPHER and 525 patients received a BMS. Of the original 1,058 participants, approximately 50 percent of patients (271 patients receiving the CYPHER and 255 patients receiving a BMS) participated in the six-year follow up.
The CYPHER stent has been used worldwide to treat about 3 million patients with coronary artery disease. Developed and manufactured by Cordis Corp., the CYPHER is currently available in more than 80 countries and has the broadest clinical experience and longest-term clinical follow-up of any drug-eluting stent. The next version of sirolimus-eluting stent, the CYPHER SELECT Sirolimus-eluting Coronary Stent, was launched in Europe, Asia Pacific, Latin America and Canada in 2003. The CYPHER SELECT Plus Stent, the third version of a sirolimus-eluting coronary stent, received CE Mark in 2006 and is currently available in many markets outside the U.S.
For more information: www.cypherstent.com