LAUSR

Purpose Lung transplant recipients (LTRs) are at an increased risk for venous thromboembolism (VTE) after transplant, necessitating the use of anticoagulation. Guidelines recommend direct oral anticoagulants (DOACs) over warfarin for most patients and indications; however, many of the studies upon which these recommendations were made excluded high-risk patient populations, including transplant recipients. The purpose of this study was to compare rates of new or recurrent VTE and bleeding in patients receiving DOAC versus warfarin after lung transplant. Methods This retrospective cohort study was approved by the local institutional review board. Adult lung transplant recipients transplanted at a single center from 2010 - 2018 who received an oral anticoagulant for treatment of VTE were included. Re-transplants, patients with a diagnosis of atrial fibrillation/flutter, and those taking oral anticoagulation prior to transplant were excluded. The primary outcome was new or recurrent VTE within 1 year of starting oral anticoagulation, as determined by review of radiology reports. Safety was evaluated by assessment of 1-year rate of bleeding requiring emergency department visit or admission. Propensity matching in a 1:1 ratio using was used to control for confounders. Variables chosen for inclusion in the propensity score were sex, age, and chronic kidney disease. Clinical outcomes were assessed using chi-2 or Fisher's exact test. Results 366 LTRs met inclusion criteria. Of these, 68 received DOACs and 298 received warfarin. The analysis cohort included 132 LTRs who were successfully propensity matched, 66 in each group. After matching, patient demographics and comorbidities were similar at baseline. In the 1-year follow up period, 17 patients (12.9%) experienced new or recurrent VTE. There was no difference in the rate of VTE between the DOAC and warfarin groups (13.6% vs 12.1%, p=0.80). Six total bleeding events requiring hospital visits were observed, 4 in the DOAC group and 2 in the warfarin group (p=0.68). Conclusion No difference in the rates of new or recurrent VTE or bleeding for DOAC versus warfarin were observed in this propensity-matched, single-center retrospective cohort study of LTRs. DOACs appear to be safe and effective alternatives to warfarin in LTRs. Larger studies are needed to confirm these findings.