Cardiologists at The Nebraska Medical Center have recently introduced the use of drug-eluting stents to their arsenal of defenses against heart disease. Drug-eluting stents are an innovative approach to treating patients with occluded arteries that provides renewed hope to heart disease patients who have minimal success with traditional treatments. The new technique involves using medicated stents in conjunction with angioplasty to open narrowed arteries. The stents have been been highly successful at preventing renarrowing of the vessels through restenosis or the redevelopment of scar tissue after an angioplasty procedure. The renarrowing rate of blood vessels after angioplasty is about 50 percent. The introduction of stents reduced renarrowing of vessels to 25 percent. Medicated stents has dropped the incidence down to less than 10 percent after six to eight months.

The Nebraska Medical Center performs the largest volume of interventional cardiac procedures in Omaha which includes procedures like angioplasties, stents and the use of other advanced devices.

How is the procedure performed?

Stents are inserted after an angioplasty, a procedure in which a balloon is inflated inside the artery to remove an obstruction. The stents are then threaded inside the artery and expanded to keep it open. The stents are coated with a drug that is slowly released into the vessel walls over several weeks, discouraging scar tissue from forming.

As a preventive measure, patients are administered an anti blood-clotting medication called Plavix for three months after the stent has been implanted. The medication is typically administered for one month with standard stents.

Who is a candidate for the procedure?

Whether a patient will benefit from the drug-eluting stent depends on the size of the artery in question, the length of the lesion and the number of occlusions. Currently, the procedure is limited to patients who have a high risk for restenosis such as diabetics and those with medium to smaller-size vessels. The procedure is also proving effective for patients with multiple blockages who are normally candidates for bypass surgery. With the new medicated stents, renarrowing is less likely to occur. Without the medicated stents, these patients often have up to a 50 percent restenosis rate. The medicated stents are projected to result in a 15 to 20 percent reduction in the need for bypass surgery.

At present, the use of the drug-eluting stents has not been approved for patients who have experienced restenosis after the first administration of the stent. However, on-going trials are investigating use of the device for restenosis.

The major impediments to using the drug-eluting stent are cost, availability and insurance coverage. Drug-eluting stents cost nearly three times more than traditional stents. In addition, coverage for the stents and the number of stents that will be covered per procedure, varies among insurance companies.

What are the potential complications?

Potential complications include the formation of blood clots. Studies show that blood clots have occurred in less than one percent of patients who receive the stents which is about the same risk as standard stents.

What types of advancements are in the future?

Advancements in the current drug-eluting stent are in progress. A new version of the stent, which is expected to be more flexible, less costly and will increase the availability of drug-eluting stents, is expected to be approved and introduced in early 2004. It has recently received approval for use by the Canadian government. The new stent uses a drug called paclitaxel, and in one study performed better than the current version.