Abstract 2560: Stent Thrombosis Predictors in Everyday Practice: Insights from the 7000-Patient TAXUS ARRIVE Registry Program
Background: Risk factors associated with stent thrombosis (ST) of drug-eluting stents (DES) include acute coronary syndrome, stented length, and thienopyridine non-compliance. Predictive analyses for ST>30 days can be limited by low event numbers. The objective of this study was to identify baseline ST predictors at 1 and 2 years (yr) using a pooled analysis of >7000 registry patients (pts) to help guide individual pt therapy.
Methods: Analysis included consecutively-enrolled pts (N=7307; 99 US sites) who received the TAXUS®Express2 paclitaxel-eluting stent (Boston Scientific, Natick, MA) DES and were prescribed long-term aspirin and minimally 6 months (M) thienopyridine therapy per the product label. Events were adjudicated by an independent Clinical Events Committee using Academic Research Consortium (ARC) ST definitions. Over 30 baseline characteristics were assessed as potential predictors of ST using backward step-wise Cox proportional hazards regression.
Results: Predictors for ST<1 yr and very late ST (VLST) differed except for discontinuation of thienopyridine before 6M, which was a strong predictor in both time intervals. For ST<1 yr predictors were based on lesion characteristics (calcification, long lesions, multiple stents in a vessel, and small vessels) as well as pt-related factors such as smoking at baseline and congestive heart failure. Predictors of VLST>1 yr included more biologic factors such as prior myocardial infarction and age. At time of event, 31% of VLST pts were on dual antiplatelet therapy; in contrast, 59% of ARRIVE pts overall continued thienopyridine therapy at 2 yrs.
Conclusions: Differences in predictors for ST before and after 1 year suggest differences in pathophysiology. Dual antiplatelet therapy may be useful during year 2 after DES. Determination of DES baseline predictors may help identify pts at highest risk for late ST and VLST. Predictor analyses for high-risk subgroups in ARRIVE will be available in November.