Late Clinical Events After Drug-Eluting Stents The Interplay Between Stent-Related and Natural History-Driven Events

Objectives We evaluated the relative contributions of drug-eluting stent-specific and background natural history-driven causes for adverse clinical events between 1 and 5 years, in the paclitaxel-eluting stent (PES) and bare-metal stent (BMS) cohorts of the TAXUS randomized clinical trial program. Background Prior studies have demonstrated that clinical events in the first year after BMS are predominantly stent-related but thereafter tend to be driven more by atherosclerotic activity outside the stented segment. It is not known whether the same is true for PES. Methods Annualized hazard rates (HRs) were calculated for major adverse events in 1,400 TAXUS and 1,397 BMS patients from the randomized and blinded TAXUS I, II, IV, and V trials (median 4.8-year follow-up). Results Although target vessel revascularization (TVR) during the first year was driven by target lesion revascularization (TLR), TVR after 1 year involved similar numbers of TLR and non-TLR events. Moreover, the annualized HR for non-target lesion TVR and other major adverse events (including death, myocardial infarction, and stent thrombosis) were relatively constant beyond 1 year and not significantly different between PES and BMS. Conclusions The low and similar late HR for many of the observed late events after BMS and PES suggests that many of the late events after PES reflect background disease activity outside the stented segment rather than stent-related events per se. Analyses of long-term drug-eluting stent outcomes should recognize and attempt to correct for this background event rate by using suitable BMS control subjects. (J Am Coll Cardiol Intv 2009;2:504-12) (c) 2009 by the American College of Cardiology Foundation