Outcomes Following Coronary Stenting in the Era of Bare-Metal vs the Era of Drug-Eluting Stents
Stents are commonly used to treat coronary disease, and drug-eluting stents are considered a technological advance over bare-metal stents. Soon after their introduction in 2003, more than 60 percent of stents used in the Medicare population were drug-eluting. The FDA, however, raised concerns that drug-eluting stents may contribute to the risk of stent thrombosis (ST). Despite several large studies, uncertainty remains concerning the trade-offs between safety and effectiveness of drug-eluting stents.
To shed light on this issue, this study compares outcomes in Medicare patients receiving stents before (38,917 patients) and after (28,086 patients) the introduction of drug-eluting stents. Outcome measures in the study were percutaneous coronary revascularization (a procedure necessitated by continued coronary problems), ST-elevation myocardial infarction (STEMI, a type of heart attack), and survival through two years of follow up. The authors hypothesized that decreased rates in STEMIs and re-stenosis would compensate for small increases in STs attributable to the newer stents.
Results indicated that after the introduction of drug-eluting stents, relative risk of repeat revascularizations decreased by 16.7 percent, the actual number decreased by 3.8 percent, and there was no discernable increase in death or STEMI incidence. Survival did not change pre- and post-introduction. This study has several significant limitations. The true rate of ST could not be assessed because of the nature of data collected; and, differences in patient selection, in procedural practices or in medical management may have played a role in differences observed. The authors conclude that if there is an increased risk of ST due to the use of drug-eluting stents, it is more than offset by the other benefits of this technology.