Use of Apixaban after Lung Transplant for Atrial Fibrillation and Treatment of Venous Thromboembolism

Abstract

Purpose Guidelines recommend the use of direct oral anticoagulation (DOAC) therapy over warfarin for the treatment of venous thromboembolism and atrial fibrillation. However, there is uncertainty and lack of data supporting the safety and efficacy of DOACs in the lung-transplant population. Additionally, there are unique considerations that need to be made in this population, such as labile renal function, drug interactions, and the need to hold anticoagulation for routine biopsies and urgent procedures. The objective of this study is to evaluate the safety and efficacy of using apixaban in lung transplant patients for atrial fibrillation and the treatment of venous thromboembolism. Methods Data will be collected by a retrospective chart review of the electronic medical record. A list will be generated of patients who received apixaban orders from lung-transplant providers. These patients will then be evaluated for inclusion in the study. All adult patients who received a lung transplant at our institution and who were started on apixaban between January 1, 2018 and August 31, 2020 for atrial fibrillation or venous thromboembolism treatment post-lung transplant will be eligible for inclusion. Patients who were initiated on apixaban prior to lung-transplantation or who had a duration of apixaban for less than three days will be excluded. An estimation of 150 to 200 patients are expected to be included. Data on baseline characteristics will be collected in addition to anti-xa levels, apixaban dosing and dose adjustments, and drug-drug interactions. The protocol will be submitted to the Institutional Review Board for review and approval. Endpoints The primary efficacy outcome of the study will be the recurrence of a blood clot or the incidence of a stroke within 7 months from apixaban initiation. Safety outcomes will be determined by documentation of major and minor bleeding events, as defined by the ISTH score for each patient.