Patients age 65 and older with heart disease who receive stents coated with medicine to prevent blockages are more likely to survive and less likely to suffer a heart attack than people fitted with stents not coated with medication, according to a new study supported by the Agency for Healthcare Research and Quality (AHRQ) and the American College of Cardiology's National Cardiovascular Data Registry.
The comparative effectiveness study of 262,700 Medicare patients who received stents—spring-like tubes to keep heart vessels open—is the largest ever to compare drug-coated stents with bare metal ones. Researchers from Duke University, AHRQ, and Kaiser Permanente found that, compared with patients who received bare metal stents, those fitted with stents coated with medication (called drug-eluting stents) had an 18 percent better survival rate over the 30-month study period and were 16 percent less likely to suffer a heart attack.
The researchers found that 16.5 percent of the patients implanted with bare metal stents died within 30 months of implantation, compared with 13.5 percent of those with drug-eluting stents, after adjusting for population differences. They also found that 8.9 percent of the patients with bare metal stents suffered heart attacks during the period, compared with 7.5 percent of those with drug-eluting stents—a 16 percent higher rate. The researchers further found that patients fitted with drug-eluting stents in 2005 and 2006 had a lower risk of death than those given the stents in 2004.
According to AHRQ's Art Sedrakyan, M.D., Ph.D., a coauthor of the study, better outcomes found for patients with drug-eluting stents may be partially explained because those patients are required to take blood-thinning drugs, such as clopidogrel, for a long time after their procedure. Patients who receive bare metal stents are usually prescribed blood-thinner medications for a shorter period of time and may take them less often. In addition, patients with drug-eluting stents may visit their doctors more often after hospital discharge and may receive prescriptions for drugs and therapies to lower their cholesterol levels and manage other heart conditions more often than patients who received bare metal stents.
The researchers based their study on data from the American College of Cardiology's National Cardiovascular Data Registry on patients who underwent angioplasty with drug-eluting or bare metal stent implantation at 650 hospitals, together with Medicare national claims data to capture posthospital discharge information. The authors call for longer followup studies to further support the study's results and to confirm the possible effects of postimplantation treatment with blood-thinning drugs such as clopidogrel.
See "Clinical effectiveness of coronary stents in the elderly: Results from 262,700 Medicare patients in the American College of Cardiology-National Cardiovascular Data Registry," by Pamela S. Douglas, M.D., J. Matthew Brennan, M.D., Kevin J. Anstrom, Ph.D., and others in the 2009 Journal of the American College of Cardiology, available online at http://content.onlinejacc.org.
Editor's Note: This study was funded through AHRQ's DEcIDE (Developing Evidence to Inform Decisions about Effectiveness) research network, which is part of the Agency's Effective Health Care Program. The Effective Health Care Program sponsors the development of new scientific knowledge through studies on the outcomes of health care technologies and services. For more information about AHRQ's Effective Health Care Program and the DEcIDE Network, go to http://effectivehealthcare.ahrq.gov.