Drug-eluting stents boost survival in patients with coronary stenosis

Coronary artery stenosis patients age 65 and older have better survival chances when they are treated with drug-coated stents than with bare metal stents, according to findings of a study involving more than a quarter million Medicare recipients.

The study, sponsored by the Agency for Healthcare Research and Quality and the American College of Cardiology, is the largest to date comparing the safety and effectiveness of drug-coated and bare metal stents. Its findings provide important new evidence for decision making by heart disease patients and their physicians, said AHRQ director Dr. Carolyn M. Clancy.

"These results should help resolve many lingering questions regarding the safety of drug-eluting stents in recent years," Clancy said.

The investigators found that patients treated with drug-coated stents during the 30-month study period had a nearly 20% better survival rate and were 16% less likely to suffer a heart attack compared with patients who received bare metal ones. Researchers also found that patients fitted with drug-eluting stents in 2005 and 2006 had a lower mortality risk than those who received them in 2004.

The findings were presented at the 2009 ACR meeting in Orlando.

Before now, studies of drug-eluting stents have produced mixed results. The FDA approved the first drug-eluting stent in this setting in 2003 but issued an advisory warning only three years later after reports of serious complications, including thrombosis and sometimes death. A prospective study of more than 5000 patients published in 2007 showed that drug-eluting stents correlated with a high rate of short-term complications in patients with coronary stenosis. It also noted, however, that these complications affected mostly severely ill patients undergoing off-label indications.

In the current study, lead investigator Dr. Pamela S. Douglas from Duke University and colleagues at AHRQ and Kaiser Permanente reviewed files from 262,700 Medicare patients. Cases were enrolled under the ACC's National Cardiovascular Data Registry of patients who underwent angioplasty with drug-eluting or bare metal stents at 650 hospitals.

The researchers found no significant differences in the percentages of drug-eluting and bare metal stent patients who required a repeat angioplasty or coronary artery bypass surgery or who suffered strokes or major bleeding. Factors such as age, gender, race, or ethnicity did not significantly influence results.

Patients who receive bare metal stents usually take blood-thinning medications for a shorter period of time and less often than patients with drug-eluting stents. Patients with drug-eluting stents, on the other hand, may visit their doctors after discharge and undergo further management more often than patients with bare metal stents. That may account, at least partly, for better outcomes, said coauthor Dr. Art Sedrakyan, an AHRQ researcher.

Longer follow-up studies are needed to confirm trial results and the possible effects of post-implantation treatment with blood-thinning drugs such as clopidogrel, the researchers said.

For more information from the Diagnostic Imaging and SearchMedica archives:

Drug-eluting stents reduce repeat treatment in peripheral arterial diseaseOff-label use of drug-eluting stents leads to higher rate of complicationsResearch determines timing, tools for optimal coronaryinterventions