Drug-Coated Stents Reduce Repeat Artery Procedures

By Ed Edelson
HealthDay Reporter
Wednesday, June 25, 2008; 3:00 AM

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TUESDAY, June 24 (HealthDay News) -- Heart patients who got drug-coated stents did better than those who received the bare-metal kind of stent, a major study found.

But it isn't a simple either-or issue, the study authors said.

The researchers compared the experience of almost 39,000 Medicare recipients who underwent non-emergency stenting between October 2002 and March 2003, when only bare-metal stents were available, with that of more than 28,000 patients who got stents from September through December 2003. During the later time period 61.5 percent of patients received drug-coated stents.

A stent is a tiny tube placed into an artery or blood vessel to keep the vessel open.

Only one coated stent -- Cordis Corp.'s sirolimus-coated Cypher -- was available in 2003. Over a two-year follow-up period, 22.8 percent of the people in the bare-stent era required a repeat procedure to open a blocked coronary artery. In comparison, just 19 percent of those in the coated-stent era required a second procedure, an 18 percent reduction, the researchers noted.

The overall two-year death rate in both periods was the same, 8.4 percent, but there was a reduction in the number of heart attacks (formally called ST-elevation myocardial infarctions) from 2.4 percent to 2.0 percent.

But, the overall survival of bare-metal stent recipients declined when the coated-stent era began, the study found. "Why should having a coated stent available affect the survival of bare-metal stent patients?" asked lead researcher Dr. David J. Malenka, a cardiologist at Dartmouth Medical School. "The reason is that somehow sicker patients were getting bare-metal stents."

So the study's results were affected by "selection bias," Malenka said. "Patients who got drug-eluting stents somehow were healthier and more likelier to survive," he said. In many cases, it was a matter of anatomy, he added. Patients with complex artery problems got bare-metal stents, while those with simpler anatomy got drug-coated stents.

But the bottom line is that drug-coated stents did decrease the need for new procedures when an artery became blocked again, the study found. Drug-coated stents might increase the incidence of such blockages, "but when you compare the increased risk of late thrombosis [clotting] associated with drug-eluting stents, that risk is more than counterbalanced by reducing the adverse events associated with revascularization [artery-reopening procedures]," Malenka said.