Abstract 16422: Development and Validation of a Stent Thrombosis Risk Score in Patients With Acute Coronary Syndromes
Purpose: To personalize risk assessment for stent thrombosis (ST) after percutaneous coronary intervention (PCI) in acute coronary syndromes (ACS) through the development and validation of a ST risk score.
Methods: This study represents a patient-level pooled analysis of 6,139 patients undergoing PCI with stent implantation for ACS in the HORIZONS-AMI and ACUITY trials who were randomized to treatment with bivalirudin versus heparin plus a glycoprotein IIb/IIIa inhibitor. This cohort was randomly divided in a 2:1 fashion into a risk score development cohort (n=4093) and a validation cohort (n=2046). Cox proportional hazards methods were used to identify variables that were independently associated with ARC-defined definite/probable ST at 1-year follow-up. Clinical, angiographic and procedural characteristics associated with ST in prior investigations in the individual trials were included as covariates in the multivariate model. A stepwise variable selection procedure was used; p<0.05 was set as the level of significance for including variables in the model. Each covariate in this model was assigned an integer score based on the regression coefficients.
Results: At 1-year follow-up 106 ST events occurred in the development cohort (2.6%) and 50 ST events in the validation cohort (2.4%). Variables included in the risk score and the integer assignment for each one are shown in the Table. Drug-eluting stents as compared with bare metal stents were not associated with ST. Risk score 0-6 was considered low risk, 7-9 intermediate risk, and 10 or greater high risk for ST (figure 1). The c-statistic for this risk score was 0.66 in the development cohort and 0.65 in the validation cohort.
Conclusion: The individual risk of ST can be predicted with the use of a risk score based on clinical, angiographic and procedural variables. This risk assessment tool may be helpful in clinical practice by identifying pts at high risk for ST after ACS.
- © 2011 by American Heart Association, Inc.