Stents May Not Be the Ultimate Answer
Experts urge continued innovation as success rates flatten

(HealthDay News) -- Has the bloom gone off the rose, so to speak? The value of using stents to open blocked heart arteries -- once the subject of considerable fanfare -- is now being questioned by some heart experts.

Stents, which are flexible tubes, are used mostly in smaller arteries, where blockages generally are less difficult to handle.

After the introduction of bare-metal stents in the mid-1990s, there was a dramatic rise in the success rate of keeping heart arteries open. However, those improvements have since leveled off, even after doctors started using newer drug-coated stents.

In one study, researchers at the Mayo Clinic in Rochester , Minn. , analyzed 1,262 open-heart procedures done over 25 years to treat arteries that were nearly or totally blocked. Data was divided into four periods: 1979-1989, before stents were available; 1990-1996, when they were first used; 1997-2003, when the use of stents became routine; and 2003-2005, when drug-coated stents had been introduced.

The success rate of artery-opening procedures increased from 51 percent in the pre-stent period to 72 percent in the early 1990s, when the first stents were introduced. Since then, however, the success rates leveled off to 73 percent and 70 percent, respectively, in the latter two periods, the study found.

These stagnated success rates "highlight the need for continued development of new techniques and devices" for opening blocked heart arteries, the study authors noted. Blocked heart arteries account for about 10 percent of all procedures done to open blocked arteries. The findings were published in the Journal of the American College of Cardiology .

"There have been some improvements but significantly less than for other arteries," study senior researcher Dr. David R. Holmes Jr., professor of medicine at Mayo, told HealthDay .

"Stents, once a heart artery has been open, are very good," Holmes noted. "The problem is that you can't get a wire to the blockage, and you can't get a balloon through it. The problem is simply to get through the occlusion in the first place."

Once the heart artery is open, clinical trials show that drug-coated stents are better than bare-metal stents, he said.

In addition, a trio of studies published in the British journal BMJ concluded that coronary bypass surgery had fewer complications and was more cost-effective than angioplasty and stents for people with blocked heart arteries.

Dr. Deepak Bhatt, associate director of the Cleveland Clinic's cardiovascular coordinating center, stressed that surgery might be better in some cases, but the choice of treatment depends on the condition of the patient. Surgery is considered more risky than angioplasty/stent treatment, which is riskier than medication.

"Medical therapy might be enough for someone with a completely blocked artery," Bhatt told HealthDay . "If just one artery is blocked, it might be reasonable to try angioplasty. If there are a lot of problems with circulation, enough disease in other arteries, the decision could be to go ahead and do a bypass. If there are lots of other blockages, then surgery might make sense."

He noted that the Mayo Clinic study on stents found a dramatic reduction in the rate of complications -- such as closing of the treated artery, heart attack and death -- even though more people who got that treatment had such health problems as diabetes, obesity and high blood pressure.

On the Web

To learn more about stents, visit the U.S Food and Drug Administration.

SOURCES: HealthDay News ; David R. Holmes Jr., M.D., professor of medicine, Mayo Clinic, Rochester, Minn.; Deepak Bhatt, M.D., associate director, Cardiovascular Coordinating Center, Cleveland Clinic, Cleveland; April 17, 2007, Journal of the American College of Cardiology ; March 24, 2007, BMJ
Author: Robert Preidt
Publication Date: April 30, 2008
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