Assessment of Temporary Warfarin Reversal in Patients With Left Ventricular Assist Devices: the KVAD Study

•Patients with left ventricular assist devices (LVADs) require warfarin anticoagulation.•The traditional approach to prevent bleeding during surgery is to stop warfarin 5–6 days before and to use intravenous heparin or subcutaneous injections of heparin before and after surgery, when warfarin is restarted, until therapeutic levels of anticoagulation are reached.•After 4-factor prothrombin complex concentrate (4F-PCC) immediately reverses warfarin, therapeutic anticoagulation levels are recovered at 48 hours if warfarin is continued.•By using titrated dosages of 4F-PCC on the day of surgery to immediately, but temporarily, reverse warfarin, we can continue warfarin and avoid the need for traditional heparin-bridging treatments for 10–14 days. Patients with left ventricular assist devices (LVADs) require interruption of warfarin for invasive procedures, but parenteral bridging is associated with many complications. Four-factor prothrombin complex concentrate (4F-PCC) can temporarily restore hemostasis in patients undergoing anticoagulation with warfarin. This pilot study evaluated the strategy of using variable-dose 4F-PCC to immediately and temporarily reverse warfarin before invasive procedures without holding warfarin in patients with LVADs. The duration of effect of 4F-PCC on factor levels and time to reestablish therapeutic anticoagulation post procedure were assessed. Adult patients with LVADs and planned invasive procedures were enrolled from a single center. Warfarin was continued uninterrupted. The 4F-PCC dose administered immediately pre-procedure was based on study protocol. International normalized ratio (INR)- and vitamin K-dependent factor levels were collected before and during the 48 hours after 4F-PCC administration. The use of parenteral bridging, International Society for Thrombosis and Haemostasis major and clinically relevant nonmajor bleeding (CRNMB) and thromboembolic events at 7 and 30 days were collected. In 21 episodes of 4F-PCC reversal, median baseline INR was 2.7 (IQR 2.2–3.2). The median dosage of 4F-PCC administered was 1794 units (IQR 1536–2130). At 24 and 48 hours post 4F-PCC administration, median INRs were 1.8 (IQR 1.7–2.0) and 2.0 (IQR 1.9–2.4). Two patients required postoperative bridging. One patient experienced major bleeding within 72 hours, and 2 experienced CRNMB within 30 days. There were no thromboembolic events. Baseline and post 4F-PCC vitamin K-dependent factor levels corresponded with changes in INR values. The