Abstract 3131: Characteristics and Outcomes of Patients Taking Warfarin Prior to Percutaneous Coronary Intervention
Background: Little is know about the characteristics, bleeding risks, and outcomes of patients taking warfarin prior to percutaneous coronary intervention (PCI).
Methods: Patients undergoing PCI in NCDR from 1/1/04 –3/31/06 were analyzed (n=307,443). Patients taking warfarin prior to PCI were compared with those not on warfarin, stratified by urgent PCI (PCI for cardiogenic shock, ST elevation MI, primary or rescue PCI) versus elective PCI. Multivariable modeling using the Generalized Estimating Equation was used to evaluate the association between warfarin use and the outcomes of in-hospital mortality and composite bleeding (requiring blood transfusion, and/or prolonging hospital stay, and/or hemoglobin drop > 3.0 gm/dl).
Results: Overall, 11,173 patients (3.6%) were taking warfarin prior to PCI. Patients taking warfarin were older, had more comorbidities, and were less likely to receive guideline indicated therapies (Table⇓). Unadjusted bleeding rates and in-hospital mortality were almost twice as high among patients taking warfarin versus patients not on warfarin. After adjustment for baseline characteristics and case complexity, patients taking warfarin no longer had a significantly increased risk of in-hospital mortality, both during elective [odds ratio (OR)=1.07, p=0.58] and urgent PCI (OR=0.90, p=0.47). However, the adjusted risk for excess bleeding persisted in patients receiving warfarin, for both elective (OR =1.26, p=0.002) and urgent PCI (OR=1.42, p=0.002).
Conclusions: Patients taking warfarin prior to PCI have substantially elevated rates of in-hospital mortality and bleeding. The increased risk of bleeding persists despite risk adjustment, whereas warfarin use appears to be a marker for comorbidities with regard to mortality risk. In light of these results, further evaluation of the optimal timing, periprocedural anti-coagulation and anti-platelet therapy use during PCI is needed for patients taking warfarin.