ORLANDO, Fla.—Drug-eluting stents (DES) are better than bare-metal stents (BMS) at protecting patients against serious cardiovascular events, and are equally safe, according to research presented during the i2 Summit at the American College of Cardiology (ACC) 58th annual scientific sessions. The real-world study found that during three years of follow-up, DES significantly reduced the risk of heart attack, death and additional heart procedures when compared to BMS, while provoking no increased risk of stroke or major bleeding.
"Some previous studies have suggested that drug-eluting stents are associated with an excess long-term death rate, whereas others have not," said Pamela S. Douglas, MD, Geller professor of medicine at Duke University. "The biggest take home message of our study is: Drug-eluting stents are safe."
For the study, Douglas and colleagues analyzed data from the American College of Cardiology's National Cardiovascular Data Registry (ACC-NCDR) on patients over the age of 65 who had a stenting procedure performed from 2004 to 2006. Of these, 217,675 were treated with DES (46 percent Cypher, 55 percent Taxus) and 45,025 were treated with BMS. Follow-up information for each patient was obtained from Medicare claims data. The combination of these two data sets created a novel and powerful resource for assessment of post-marketing stent performance in a community setting, Douglas said.
Equally important, randomized controlled trials are very selective about the types of patients they enroll. "Few patients who currently require stenting would be considered eligible for a randomized controlled trial-only about 20 percent in our population," Douglas said. "Real-world data are required to assess stent safety and performance in the other 80 percent."
Researchers adjusted the data for 102 patient characteristics such as sex, age and co-existing medical conditions. They found that patients who received DES had significantly lower rates of death (hazard ratio [HR], 0.75), nonfatal heart attack (HR, 0.76) and repeat heart procedures (HR, 0.91) when compared to patients who received BMS. In addition, there were essentially no differences in rates of stroke (HR, 0.96) or major bleeding (HR 0.91). The benefits for DES held true across all subgroups.
The investigators were not able to directly assess rates of stent thrombosis. However, data that Douglas characterized as "suggestive" showed that after one year, ST-elevation MI, which is associated with stent thrombosis, was no more common with DES than BMS. In addition, the long-term hazard ratio favored DES for both STEMI and non-STEMI heart attacks.
The Cardiovascular Consortium of the Agency for Healthcare Research and Quality (AHRQ), a federal agency in the Department of Health and Human Services, funded the study, with additional support from ACC-NCDR.