Implantation of the Cypher Sirolimus-eluting coronary stent to treat completely blocked coronary arteries led to substantial reductions in recurrent blockage and the need for repeat treatment compared to bare metal stents in a study presented at the Transcatheter Cardiovascular Therapeutics 2007 meeting (TCT 2007).
Researchers reported that the approaches to chronic occlusions with sirolimus-eluting Stents (Across-Cypher Trial) study met its primary endpoint, which was the assessment of angiographic restenosis at six-month follow-up. Among 200 patients treated with the Cypher Stent following successful reopening of a completely blocked coronary artery (chronic total occlusion), the likelihood of renarrowing of the treated segment (angiographic restenosis) was reduced by 65.6 per cent compared with a pre-specified cohort of patients treated with a bare metal stent in the earlier Total Occlusion Study of Canada (TOSCA-1) trial. In the entire segment treated with balloon angioplasty and stents, the restenosis rate for the Cypher Stent was 19.0 per cent while the restenosis rate for the bare metal stent was 55.2 per cent. Following risk adjustment, these differences translated into an 84 per cent reduction in the primary endpoint (p<0.0001). Further, restenosis occurring only within the Cypher Stent-treated area was 7.5 per cent.
"Chronic total occlusions remain one of the most challenging lesions to treat, especially because rates of restenosis and reocclusion have remained high despite treatment with bare metal stents. These data, combined with the results of the PRISON II Randomized Controlled Trial, which showed similar positive results for the Cypher Stent in chronic total occlusions, add to the unsurpassed volume of clinical evidence on the use of the Cypher Stent in a variety of patients and lesion subsets, including these very complex, chronically occluded vessels," said David E. Kandzari, M.D., F.A.C.C., F.S.C.A.I., chief medical officer, Cordis Corporation, while presenting the results.
Among patients treated with the Cypher Stent, at six months, there were no deaths, and myocardial infarction and target lesion revascularization occurred in 1.0 percent and 6.0 percent of patients, respectively. Overall major adverse cardiac events were similarly low, at 6.5 per cent.
The reported stent thrombosis rate for the Cypher Stent was 0.0 per cent within 24 hours after stent implantation, 0.0 per cent between one and 30 days after stent implantation; and 0.5 per cent beyond 30 days after stent implantation.
The Across-Cypher Trial is a prospective, multi-centre, open-label, single-arm study designed to demonstrate the safety and efficacy of the Cypher Stent in non-acute chronic total occlusions. The study included patients from 15 medical centres in the United States and Canada.
Dr. Kandzari is one of the principal investigators of the Cordis-sponsored study. Enrolment and six-month follow-up were completed before Dr. Kandzari joined Cordis. At the time, Dr. Kandzari was part of the faculty at Duke University Medical Centre.
In the United States, the Cypher Stent is indicated for de novo lesions less than 30 mm in length in native coronary arteries between 2.5 mm and 3.5 mm in diameter. It does not have an approved indication for patients with chronic total occlusions.
The Cypher Stent is the most studied drug-eluting stent in history and has been chosen by cardiologists worldwide to treat more than three million patients with coronary artery disease. The safety and efficacy of the device is supported by a robust clinical trial program that includes more than 70 studies that examine the performance of the Cypher Stent in a broad range of patients.
The Cypher Stent 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 a 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 United States.
Cordis, a Johnson & Johnson company, is a worldwide leader in the development and manufacture of interventional vascular technology. Through the company's innovation, research and development, Cordis partners with interventional cardiologists worldwide to treat millions of patients who suffer from vascular disease.