Drug Coated Stents

Drug Coated Stents

About six years ago, a friend of mine named Helen underwent an angioplasty procedure to insert a stent in a narrowed artery. Her doctor assured her that this was routine stuff – not a day at the beach, of course, but relatively simple and common.

Helen was nearly 80 when her stent was inserted, so she had qualms about undergoing surgery, no matter how minor. I expect her doctor understood that some reassurance was needed, so his characterizing of the procedure as routine was probably intended to calm her fears.

But I’m not a doctor, and you’re not my patient, so I’ll just come right out and tell you that the insertion of a stent should not be taken lightly, because while it may treat one problem, it often leads to new complications that are not easily solved.

Reading the fine print

You may have heard about the new stents that are coated with medication. They’re called drug-eluting stents. The first were introduced in 2003, and in just three years they’ve more or less become the standard.

When I first heard of drug-coated stents I wondered what they might be coated with: A blood-thinning medication or maybe even a cholesterol-lowering statin? Good guess, but it turns out the medication is there to help prevent restenosis, which is the renarrowing of an artery prompted by scarring and inflammation that may occur when stents are inserted.

That’s right: The drug treats a problem caused by the stenting procedure.

Previous to the medicated stent era, the American College of Cardiology estimated that renarrowing occurred in about 30 percent of patients who received stents. And in most restenosis cases, an additional angioplasty or even bypass surgery is required.

Unfortunately, drug-coated stents are not quite trouble-free. According to presentations made at the World Congress of Cardiology in Barcelona, Spain (as reported in a recent issue of Forbes), clinical trials sponsored by stent manufacturers show that drug-eluting stents sometimes cause blood clots. Which is not exactly what you’re looking for in a treatment for a narrowed artery.

This problem may only occur in about six cases per every thousand, but it’s enough of a concern that cardiologists are resorting to blood-thinning drugs more then they used to with non-medicated stents. One doctor told Forbes that he prescribes Plavix (a blood thinner) for patients who receive drug-eluting stents. He adds that his stent patients may need to use Plavix for up to three years, and in some cases for the rest of their lives.

Post-stent protection

Studies have shown that folate, combined with other B vitamins, may be effective in preventing restenosis.

I told you about one of those studies in the e-Alert “B & E My Valentine” (9/3/02). As reported in the Journal of the American Medical Association, 533 patients who had undergone coronary angioplasty were divided into two groups. Half received a supplement of folic acid, vitamin B6 and B12, while the other half received a placebo. Six months later, the researchers found that folate treatment not only slowed the development of plaque build up in the arteries, but in some cases also prevented it from occurring.

For some patients, chelation therapy provides a safe and considerably less expensive alternative to stent angioplasty. Chelation contains vitamins, minerals, and a synthetic amino acid called ethylene diamine tetracetic acid (EDTA) that binds with calcium deposits in the arteries and eliminates them from the body.

For more information about chelation, see the e-Alert “Passing on the Bypass” (1/23/03)

Sources:
“Stent Safety Concerns Near Boiling Point” Matthew Herper, Forbes, 9/8/06, forbes.com
“Folate Therapy and In-Stent Restenosis after Coronary Stenting” Vol. 350, No. 26, New England Journal of Medicine, 6/24/04, content.nejm.org