Twelve-Month Outcome of Patients with an Established Indication for Oral Anticoagulation Undergoing Coronary Artery Stenting and Stratified by the Baseline Risk of Bleeding. Insights from the Warfarin and Coronary Stenting (War-Stent) Registry

Purpose: To evaluate the outcome of patients with an established indication for oral anticoagulation (OAC) undergoing coronary stent implantation (PCI-S) and stratified by the baseline risk of bleeding. Material and methods: The database of the prospective, multicentre, observational WAR-STENT registry (ClinicalTrials.gov identifier NCT00722319) was analyzed and patients with atrial fibrillation and CHA2DS2-VASc score ≥2, mechanical heart valve, prior cardiac embolism, intra-cardiac thrombus and recent venous thromboembolism who were treated with either triple (warfarin, aspirin and clopidogrel) or dual (warfarin and clopidogrel) or dual antiplatelet (aspirin and clopidogrel) therapy, identified. Patients were then sorted into two groups at non-low and low risk of bleeding, as defined by an ATRIA score >3 and ≤3 respectively, and compared regarding major adverse cardiac and vascular events (MACVE) and bleeding. Results: At 12-month follow up, MACVE were comparable in the two groups, whereas total, major and minor bleeding, as well as combined MACVE and total bleeding, were significantly more frequent in the non-low bleeding risk group. Upon Cox univariate and multivariable analysis, non-low bleeding risk category confirmed as an independent predictor of major bleeding. The choice of antithrombotic therapy however, appeared not to be influenced by the bleeding risk category at baseline. Conclusions: In patients with an established indication for OAC undergoing PCI-S, non-low bleeding risk category is the most potent independent predictor of major bleeding. Stratification of the bleeding risk at baseline should therefore be regarded as an indispensable process to be carried out before selection of the antithrombotic therapy.