A year after safety questions about drug-coated heart stents prompted doctors to change treatment for hundreds of thousands of cardiac patients, many physicians say the medical community overreacted and should reverse course.
The alarm was caused by studies suggesting drug-coated stents might be causing deadly blood clots. But with benefit of additional data and further analysis, many doctors say drug-coated stents may not be so risky after all, at least compared with various alternatives that each entail drawbacks that may outweigh the risks of clotting.
Because the safety fears were widespread, however, even those rooting hardest for a rebound - the companies that make stents - are not expecting a quick resurgence for the drug-coated devices. Worldwide, stent sales have fallen by about $1 billion since last year, to $5 billion this year.
In the United States, stenting procedures, whether using drug-coated stents or older bare-metal versions, have declined by about 10 percent in the last year. And within that smaller pie the share of drug-coated stents has shrunk even more, to about 64 percent in recent months, down from about 88 percent in spring 2006.
"It takes a lot longer to regrow a forest than to cut it down," said Dr. Donald Baim, chief medical officer for Natick-based Boston Scientific, the market leader in stents.
Studies showing good results in patients relying solely on drugs have also contributed to the decline.
Stents are among the most extensively studied products in the history of the medical device industry. But the torrent of performance data reflects the largely uncoordinated and piecemeal way that medical research is gathered and publicized, and the medical uncertainty than can result.
Drug-coated stents are the newest and most popular form of the tiny mesh cylinders, which are used to keep coronary arteries propped open after plaque blockages have been cleared through the procedure known as angioplasty. The drug coatings reduce the risk of reclogging at the stent site, as frequently happens with the bare-metal versions. But the studies last year indicated the drug-coated versions could cause blood clots months or even years after they are implanted.
The medical reports of blood clots were amplified by sometimes alarmist media coverage, as when one cable news network described drug-coated stents as "tiny time bombs." And federal regulators issued cautionary statements.
Doctors responded by prescribing long-term use of a potent anti-clotting medicine for drug-coated stent patients, a course that raised costs and the risks of various side effects. Many patients avoided the stents altogether in favor of alternative treatments, including bypass operations, with their own attendant risks.
Now, though, for drug-coated stents "there really is a turnaround in the texture and the direction of the data," said Dr. Eric J. Topol, a cardiologist at the Scripps Clinic in La Jolla, Calif. He was chosen by the Food and Drug Administration to serve on a panel on stent safety, which concluded the clotting hazard was real. While none of last year's concerns have been proved unfounded, Topol said, newer data indicate a return to higher use of drug-coated stents is appropriate.
Some experts still contend all but the sickest patients should think twice about getting any form of stent. The first effort, they say, should be making changes in diet and exercise, and taking drugs like statins to reduce cholesterol and beta-blockers to control hypertension and heart rhythm.