Drug-eluting Stents Found Safe And Effective In Study On Cardiac Patients

David O. Williams, MD, director of Rhode Island Hospital's cardiovascular laboratory and interventional cardiology, is the national principle investigator of the DEScover study, a registry of 7,752 patients in 140 hospitals across the country who received a coronary intervention treatment (stent or percutaneous coronary interventions (PCI)) in 2005. The one-year follow-up of those patients indicates that DES are safe and effective. The results of this study were reported in the November 14 issue of Circulation.

Of the patients enrolled in the study, 7,420, or 96 percent, received at least one stent while the remaining 325 received angioplasty alone. Of those patients with stents, the results of the study show some differences in DES (6509 patients) versus bare metal stents (BMS" 397 patients) outcomes. At one-year of follow-up, death occurred in 5.9 percent of BMS patients and 3.1 percent of DES patients. The rate of myocardial infarction (MI) was 3.5 percent for BMS and 2.4 percent for DES. Stent thrombosis, or clotting of the stent, showed no significant difference between BMS and DES (0.8 percent versus 0.6 percent respectively). Importantly, the need for additional procedures such as a repeat PCI or bypass surgery was substantially less among DES patients.

Earlier this week at the annual meeting of the American Heart Association, Williams also presented findings of a second study, the Dynamic Registry, a National Institutes of Health supported clinical investigation comparing outcomes of another large group of DES- and BMS-treated patients. Williams, the chair of the steering committee for the study, reported that the data from this study coincides with the results of the DEScover and indicated no excess complications in patients who received DES compared to BMS.

The Dynamic Registry study included 3,223 patients -- 1,460 who received at least one DES in 2004 and 1,763 who received at least one BMS in 2001-2002. Each patient was followed for at least one year. Differences in baseline characteristics of the patients were noted, in that patients who received DES had more cardiovascular risk factors and prior PCI or coronary artery bypass graft (CABG). While more elective procedures were done in the DES group, more complex lesions were attempted. In the comparison of the two groups, in-hospital mortality was 0.5 percent of DES cases versus 1.1 percent BMS of cases. At one year, mortality rates were comparable but rates of repeat revascularization by either PCI or CABG were again higher in the BMS group.

Williams notes that as the medical community continues to treat more patients with DES and has had the opportunity to follow those patients, some concerns about their safety have been raised, as some patients have experienced clotting in the stents that may result in a heart attack. Based on these new findings, however, Williams comments, "To this point in time, the available information reassures us that DES are not only an effective treatment in reducing the need for repeat interventions, but appear are as safe as bare metal stents and should be used in routine clinical practice." He also acknowledges that patients who receive DES also require supplemental long-term antiplatelet therapy, that is they do need to take aspirin and clopidogrel (Plavix).