Restenosis Rate With Drug-eluting Stents Less Than 10 Percent

The longest term data yet available on the sirolimus-eluting stent (Cypher, Johnson and Johnson) shows that it has an event-free survival rate of more than 90%. Studies of a number of other drug-eluting stents, presented Tuesday at the American Heart Association’s Scientific Sessions 2002, are also yielding promising results.

Dr. Alexandre Abizaid of the Institute Dante Pazzanese in Sao Paulo, Brazil, presented the three-year data from the First in Man trial, which involves 45 patients. Half received a fast drug-release stent and half received a slow-release stent. Sirolimus had cleared by 14 days in the fast-release formulation and the drug was gone in 30 days in the slow-release version.

There have been no deaths in the study, Dr. Abizaid reported. There has been one non-Q wave MI that was proximal to the stent and therefore not related to it, one CABG and one angioplasty in the group. One patient developed stenosis at the edge of the stent that Dr. Abizaid believes is the result of the stent not being long enough to start with. There has been “essentially no intimal hyperplasia,” he notes. “There has been no significant scar tissue over time with the slow release formulation.”

Dr. Abizaid also presented 6-month data from a study of 30 patients who received 17-beta estradiol-eluting stents. He reported that there has been 0.5 mm late lumen loss, compared with 0.1 to 0.2 with sirolimus and 9.1 with bare stents.

There have been no deaths, no myocardial infarctions and one case of revascularization. “Close to 95% of patients are free of any events,” said Dr. Abizaid.

The Brazilian researcher also presented early data in a subset of the First in Man trial on a mycophenolic acid-eluting stent being tested in 150 patients in a case-control study. Results appear to show efficacy similar to that of sirolimus, but “the only thing I can say now is that the drug is safe,” Dr. Abizaid said.

Use of other types on drugs may have potential, Dr. Abizaid told Reuters Health. “An anti-inflammatory might be better for unstable plaques…There may be a subset of patients with a genetic predisposition to hyperplasia that may need a different formulation.”

“These are remarkable results,” said panel moderator Dr. Donald LaVan of the University of Pennsylvania in Philadelphia. “This is really dramatic research showing the safety and efficacy of these stents.”