Impact of home warfarin use on treatment patterns and bleeding complications for patients with non-ST-segment elevation acute coronary syndromes: observations from the CRUSADE quality improvement initiative.

Abstract

To examine treatment patterns and outcomes of patients with non-ST-segment elevation acute coronary syndrome (NSTE ACS) receiving long-term warfarin anticoagulation. We examined acute medication and invasive cardiac procedure use and in-hospital outcomes among 101,078 patients with NSTE ACS included in the CRUSADE registry. On admission, 7201 patients (7%) were on home warfarin therapy. Compared with non-anticoagulated patients, these patients were older and had more comorbidities, but were less likely to receive acute antiplatelet and antithrombin medications. Patients on warfarin were also less likely to undergo coronary angiography (adjusted OR 0.77, 95% CI 0.70-0.86) and percutaneous coronary intervention (adjusted OR 0.80, 95% CI 0.75-0.86), and had longer waiting times for these procedures when performed. Although patients on warfarin had higher rates of death and major bleeding compared with non-anticoagulated patients, these differences were no longer significant after multivariable adjustment [ORs 0.90 (95% CI 0.80-1.02) and 1.02 (95% CI 0.93-1.11)]. Among patients on warfarin, however, early use of antiplatelet medications was associated with increased transfusion risk. Despite higher-risk characteristics, warfarin-anticoagulated patients are often more conservatively managed, as early use of antithrombotic therapies may be associated with increased bleeding. Further investigation is needed to determine the optimal choice of therapies for this population.