African-Americans At Risk From Drug-Coated Stents

A new study suggests that African-Americans have almost three times the risk of having a heart attack after having a drug-coated stent placed to treat their chest pain, compared to other races. Bare metal stents seem to be safer options. The medical journal Circulation: Journal of the American Heart Association published the study on August 30.

What Is the Doctor's Reaction?

A stent is a small metal tube inserted into an artery. When used in a heart artery, a stent can widen the artery and reduce chest pain.

There are two kinds of stents — "drug-coated" and "bare metal." Usually, a heart doctor (cardiologist) decides which to use. The decision is not obvious, because there are complications unique to each type of stent.

Both types have a risk of closing. Bare metal stents can become clogged with scar tissue (called "restenosis"). Drug-coated stents can be clogged by a blood clot.

A study published today suggests that African-Americans have almost three times the risk of having a heart attack after having a drug-coated stent placed, compared with other races. Bare metal stents seem to be a safer option.

This news is the latest chapter in a slowly unfolding story about stents and safety. As a doctor and as a daughter of someone who has heart disease, I have followed the story closely.

Five years ago, my dad was having chest pain during his daily walks up his driveway to get the newspaper. His cardiologist told him he needed to have a stent placed.

"Dad," I said, "make sure you get a drug-coated stent. These are new, so not every cardiologist has them. But you shouldn't accept anything else." That was in 2005. My dad got a drug-coated stent, and at that time we felt lucky.

Back then, we knew that "bare" stents and the new drug-coated stents could open arteries. However, about one-third of the people who got bare stents had their arteries close up again within the first few months after treatment. A layer of tissue heals over the surface of the stent. When too much tissue narrows the opening the stent provided, the problem is called restenosis. This seldom occurs for people with drug-coated stents. In the first several months after a stent is placed, people with drug-coated stents are about half as likely to have their chest pain symptoms return.

My dad and his stent got along famously for the first year. But in his second year, a small parade of studies appeared and suggested that drug-coated stents may cause a heart attack or death. A blood clot could form on the metal surface of the stent that was not healed over by tissue.

The drug-free coils that had been known as "bare" metal stents are eventually covered with a new artery lining, while the drug-coated stents can stay "bare." Studies showed that heart attack risk is increased from about 1% per year to as much as to 5% per year for people who have the drug-coated type of stent.

The following year, my dad had to have an elective surgery. In the middle of surgery, his drug-coated stent clotted, and he had a large heart attack. He was lucky to survive.

What Changes Can I Make Now?

Doctors still use drug-coated and bare metal stents. The Food and Drug Administration (FDA) says drug-coated stents may be good choices under these conditions:

• If the narrowed artery is a short segment

• If the artery does not fork into two branches where the stent will be placed

• If you do not have any complicating illnesses, such as diabetes

In light of today's research, we would have to add:

• If you are not African-American

Some experts recommend that people with drug-coated stents take strong blood thinners for 12 months or longer after getting a stent. Options are clopidogrel (also called Plavix) or ticlopidine (Ticlid). But if you take Plavix, stay away from the anti-acid medication omeprazole (Prilosec) and the antidepressant fluoxetine (Prozac). They can both weaken the effects of Plavix.

What Can I Expect Looking to the Future?

Medicine is becoming more and more personalized. Research that points to a preferred treatment based on race is a clear example of this. The race difference in stent safety probably relates to the enzyme that activates Plavix. In the future, we may have a test that can measure the function of this enzyme. This will let us be even more specific about who is at increased risk for stent clotting complications.