Thromboembolic safety and efficacy of prothrombin complex concentrates in the emergency reversal of warfarin coagulopathy

Background

There is uncertainty regarding the efficacy and incidence of thromboembolic events in patients treated with prothrombin complex concentrates (PCC) for the emergency reversal of warfarin effect.

Methods

During 2002 to 2010 we prospectively included 160 patients treated with PCC for emergency reversal of warfarin either for bleeding or because of the need of emergency surgery. A possible relationship to PCC was considered if objectively verified thromboembolism occurred within 7 days of PCC administration. Efficacy was adjudicated as good if the bleeding was controlled promptly or if the surgeon did not report excessive perioperative bleeding.

Results

We included 160 patients; 72% received PCC for bleeding. The median international normalized ratio (INR) before and after treatment with PCC was 3.5 (interquartile range IQR] 2.6-5.4) and 1.4 (IQR 1.2-1.6). The mean dose of PCC was 1800 IU (IQR 1200-2000). In addition to PCC, 74% of the patients received vitamin K and 34% received plasma. Six patients (3.8%; 95% confidence interval CI], 1.4-8.0%) developed thromboembolic events (3 strokes, 1 myocardial infarction, 1 deep vein thrombosis, 1 splenic infarction), possibly related to PCC. The clinical efficacy was good in 146 (91%), moderate in 6 (4%), poor in 4 (2.5%) and non-evaluable in 4 patients.

Conclusion

The administration of PCC for the emergency reversal of warfarin may be associated with a low risk of thromboembolism. The contribution of an unmasked thrombotic process by cessation of anticoagulation or of activation of coagulation by the hemorrhagic event should also be considered.