Heart disease patients 65 and older who receive drug-eluting stents are more likely to survive and less likely to suffer a heart attack than people fitted with bare metal stents, according to a new study supported by the Health and Human Services’ 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 is the largest ever to compare drug-eluting with bare metal ones. It was presented on 28 March, 2009 at the American College of Cardiology’s 58th Annual Scientific Session in Orlando, USA.
A team of researchers from Duke University, AHRQ and Kaiser Permanente found that, compared with patients who received bare metal stents, those fitted with drug-eluting stents had an 18% better survival rate over the 30-month study period and were 16% less likely to suffer a heart attack.
“The 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.”
The researchers in the AHRQ-funded study found that 16.5% of the patients implanted with bare metal stents died within 30 months of implantation, compared with 13.5% of those with drug-eluting stents, after adjusting for population differences. They also found that 8.9% of the patients with bare metal stents suffered heart attacks during the period, compared with 7.5% of those with drug-eluting stents – a 16% 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.
“Some previous studies have suggested that drug-eluting stents are associated with an excess long-term death rate, whereas others have not,” said the study’s lead author, Dr Pamela S Douglas, Duke University.
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 graft surgery (roughly 23%) and in the percentages of patients who suffered strokes or major bleeding (about 3% and 3.5%, respectively). The results were not affected by age, gender, race, ethnicity or other factors.
According to AHRQ’s Dr Art Sedrakyan, a co-author of the study, the better outcomes found for patients with drug-eluting stents may be at least 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 authors call for longer follow-up studies to further support the study’s results and to confirm the possible effects of post-implantation treatment with blood-thinning drugs such as clopidogrel.