Drug-Coated Stent May Revolutionize Heart Surgery

For more than a year, physicians at the Texas Heart Institute and St. Luke’s Episcopal Hospital have been testing a new breed of stents coated with drugs.

Stents are structures that are inserted into arteries obstructed by plaque. The stents are put into place after a balloon angioplasty has been performed to open the blocked artery. Acting as scaffolding, the stents help “prop” the artery open. Traditionally, bare metal stents have been used. Depending on where the stent was placed, between 15 percent and 40 percent of patients developed restenosis.

The Texas Heart Institute is testing a new type of stent coated with drugs designed to prevent scar tissue from building up inside the stent, a condition known as in-stent restenosis. One drug in particular, sirolimus, is showing positive results.

The institute was the first heart center in Texas to participate in the SIRIUS clinical trials to evaluate a sirolimus-coated stent. Sirolimus is an immunosuppressant drug used for preventing organ rejection after kidney transplantation. Coating the stent with sirolimus and a noneroding polymer allows for direct drug application at a site where restenosis occurs. Sirolimus has been associated with a generally low incidence of side effects and toxicity, much lower than that of other medications previously tested for coated stents.

“If this new breed of stent proves successful, it could revolutionize interventional cardiology,” says Emerson Perin, M.D., cardiologist and director of New Cardiovascular Interventional Technology at the Texas Heart Institute.

“In previous studies, patients had simple lesions in the arteries,” explains Perin. “The SIRIUS study includes patients with long lesions, hard-to-treat areas, and those with small vessels. It really is more representative of the difficult cases we see every day.”

Patient enrollment in the trial concluded last April and preliminary results from the first 400 SIRIUS patients reported 2 percent restenosis using the sirolimus-coated stent.

“Given the good results so far, we hope the Food and Drug Administration will approve this stent for everyone. We anticipate it will become the new standard of care for every angioplasty,” says Perin.

Adding fuel to the growing excitement surrounding the device, federal Medicare officials have already approved a payment plan for the stent – an unprecedented move for a device that has yet to win FDA approval. That approval is expected by the second quarter of this year.

“Patients at St. Luke’s will be among the first in the country to have this available,” says Perin. “As we continue to establish the safety and long-term efficacy of this device, we could see a significant impact on traditional open-chest bypass surgery.”

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©2006 Texas Medical Center

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