Factor Xa inhibition and sPESI failure in intermediate-high-risk pulmonary embolism

We report the case of a 61-year-old man who presented at the Emergency Department (ED), complaining of sudden-onset dyspnea and chest pain after a long flight from Tokyo to Houston. Considering his clinical stability and sPESI 0, enoxaparin 1 mg/kg BID was started for 24 h, and the patient was then considered for early discharge with apixaban 10 mg BID. Direct-factor Xa inhibition did not improve extensive thrombus burden and right ventricular dysfunction despite D-dimer measurement reduction. Because of the treatment failure, we considered thrombolysis. Currently, recommendations to use thrombolysis in patients under non-vitamin K antagonist oral anticoagulants (NOACs) do not exist. Hence, the one dose of apixaban was stopped, and 12 h later, we performed successful thrombolysis. A systematic review from 2007 to 2017 did not identify any cases related to NOACs failure to reduce thrombus burdens in patients with PE and persistent right ventricular dysfunction. We also did not find any evidence of cases that reported strategies for urgent thrombolysis in PE patients on NOACs. To the best of our knowledge, apixaban's failure to reduce thrombus burden, persistent right ventricular dysfunction, and a NOACs-thrombolysis bridge in patients with PE on apixaban has not been previously described. Both the bedside risk stratification and the therapeutic failures should alert clinicians in the ED to the potential limitations of low-molecular-weight heparin, NOACs therapy, and sPESI in the setting of intermediate-high-risk PE.