Introduction: Anticoagulation is the form of treatment for patients found to have a pulmonary embolism, choice of anticoagulation is often dependent on patient’s insurance, comorbidities, and risk factors. All forms of anticoagulation are often held when these patients present to the hospital with ischemic stroke due to increased risk of hemorrhagic conversion. There has been lack of evidence on the choice of anticoagulation to reduce the risk of hemorrhagic conversion of ischemic stroke in patient’s being treated for pulmonary embolism.
Methods: 1,299 acute stoke patients being treated for pulmonary embolism were studied. Patients were divided into three groups based on the form of anticoagulation used to treat pulmonary embolism: apixaban, rivaroxaban, and warfarin. Binary logistic regression was used to predict the likelihood of an outcome for a binary variable. The outcome measured in this study was incidents of hemorrhagic conversion and ICU admission. Using ANOVA, we also assess logtransformed length of stay as a secondary outcome.
Results: Patients taking warfarin for treatment of pulmonary embolism were more likely to have hemorrhagic conversion than patients taking apixaban/rivaroxaban when controlling other variables (Odds Ratio 2.438 [1.126, 5.279], p< 0.05). Due to limited sample size, apixaban and rivaroxaban were collapsed into one group. The use of warfarin was also significantly associated with a higher length of stay than apixaban/rivaroxaban (F(1,1283)=34.96, p < 0.0001). There was no significant association with the likelihood of mortality and ICU admission rates between the two groups.
Conclusions: The study suggests that hemorrhagic conversion risk is higher in the warfarin group, compared to apixaban/rivaroxaban. Warfarin was also associated with greater length of hospitalization. Because this is a retrospective study, we cannot conclude a causative relationship. The results of this study are however reasonable to consider alternatives to the use of warfarin, such as apixaban and rivaroxaban, for treatment of pulmonary embolism.
