Outcomes of urgent warfarin reversal with frozen plasma versus prothrombin complex concentrate in the emergency department.

BACKGROUND Physicians reverse patients' warfarin anticoagulation with frozen plasma or prothrombin complex concentrate. Our objective was to determine adverse event frequency after urgent reversal with frozen plasma versus the prothrombin complex concentrate Octaplex. METHODS AND RESULTS This natural before-after retrospective cohort study in 2 tertiary care emergency departments compared anticoagulation reversal with frozen plasma (September 2006-August 2008) and with Octaplex (September 2008-August 2010), without other system changes. We included adult patients on warfarin with an international normalized ratio ≥1.5 who received frozen plasma or Octaplex. Our primary outcome was serious adverse events (death, ischemic stroke, myocardial infarction, heart failure, venous thromboembolism, or peripheral arterial thromboembolism) within 7 days. Secondary outcomes included time to international normalized ratio reversal, hospital length of stay, and red blood cells transfused within 48 hours. We included 149 patients receiving frozen plasma and 165 receiving Octaplex. The incidence of serious adverse events for the frozen plasma group was 19.5% compared with 9.7% for the Octaplex group (P=0.014; relative risk, 2.0; 95% confidence interval, 1.1-3.5). This remained significant after adjustment for baseline history and reason for treatment (P=0.038; adjusted relative risk, 1.85; 95% confidence interval, 1.03-3.3) in multivariable regression analysis. Median international normalized ratio reversal was 11.8 hours with frozen plasma and 5.7 hours with Octaplex (P<0.0001). Mean red cell transfusion was 3.2 with frozen plasma and 1.4 with Octaplex (P<0.0001). CONCLUSIONS Octaplex for urgent reversal of warfarin resulted in faster reversal and lower red cell transfusion requirement with fewer adverse events than frozen plasma.