Much has been written, but little is known, about the long-term outcomes after drug-eluting stent (DES). The introduction of DES has extended the use of stents from a passive platform for vessel wall scaffolding to an active biotechnology vehicle for local delivery of antiproliferative pharmacotherapy. Like any other therapy or medical technology, no treatment is perfect and free of potential adverse effects or complications. Nonetheless, DES have been the most significant progress in the field of interventional cardiology, drastically reducing the rates of restenosis and need for revascularizations.^1-6

Recent publications of registries and meta-analyses have raised concerns among healthcare providers and the lay public regarding the long-term safety of DES.^7-13 However, these publications have been criticized as being inconclusive because of an insufficient number of patients, the absence of concurrent controls, a limited duration of follow-up, or a lack of access to original source data.¹⁴ Some common terms need to be clarified for better understanding of the subject, including the new expanded definitions of stent thrombosis, randomized clinical trials (RCTs) versus registries, on- and off-label use of stents, and the role of long-term antiplatelet therapy.

To address the limitations of the trial-level meta-analyses, Stone et al. performed a patient-level pooled meta-analysis of data from nine doubleblind trials in which patients were randomly assigned to receive DES or bare-metal stents (BMS) in single, previously untreated coronary lesions through four years of follow-up. Data were used from the original databases, as defined and adjudicated by the clinical events committees for each study. Both stent types were associated with marked reductions in revascularization, an advantage that was maintained through four years of follow-up. Compared with BMS, target lesion revascularization (TLR) rates were 7.8% versus 23.6% (p<0.001) with Cyper, and 10.1% versus 20.0% (p<0.001) with Taxus. The rates of death or myocardial infarction (MI) were not significantly different between the groups with DES at any point during the four years of follow-up, and correspond to previously published natural histories of patients with coronary artery disease (CAD) treated by percutaneous coronary revascularization. Stone's findings differ from those of some other analyses mentioned above, which suggested that overall rates of stent thrombosis and death are higher with DES than with BMS.^10,11 These discrepancies may be explained by the fact that Stone et al. included only randomized double-blind studies and had full access to the complete patient-level data of the trials compared with the triallevel meta-analyses, and thus their results are more accurate. The triallevel eta-analyses relied on estimations of event rates from limited published results, abstracts, and online summaries, and therefore are not as accurate as patient-level analyses.