EXPRESS: Outcomes of Catheter-Directed Thrombolysis versus Standard Medical Therapy in a Retrospective Propensity Matched Cohort of Patients with Acute Submassive Pulmonary Embolism :

Background: Catheter-directed thrombolysis (CDL) is increasingly being used for the treatment of submassive and massive pulmonary embolism. Although this therapy has been shown to be effective at reducing right ventricle strain, the impact on clinical outcomes remains unclear. We therefore aimed to evaluate the outcomes of CDL compared to standard anticoagulation for submassive pulmonary embolism patients in a large cohort. Methods: We conducted a retrospective observational study of consecutive patients with a primary diagnosis of submassive pulmonary embolism admitted to an intensive care unit within our health system between June 2014 and April 2016. We compared the outcome of patients treated with systemic anticoagulation (medical therapy) vs. catheter-based delivery of tissue plasminogen activator (tPA) (CDL). CDL patients were matched with medical therapy controls using a propensity-score matching algorithm based on the components of the simplified pulmonary embolism severity index (sPESI) score. Results: Unadjusted mortality rates were 3.0% for CDL vs. 10.4% for medical therapy at 30 days and 8.1% for CDL vs. 22.9% for medical therapy at 1 year. In the propensity-score matched cohort, mortality rates were 3.1% for CDL vs. 6.1% for medical therapy at 30 days and 8.2% for CDL vs. 18.2% for medical therapy at 1 year. Length of stay was significantly shorter in the CDL group. The index admission bleeding and transfusion rates were not increased in the CDL group. Conclusions: In patients presenting with acute submassive pulmonary embolism who are admitted to an intensive care unit, the group treated with CDL experienced reduced mortality at 30 days and 1 year when compared to medical therapy without increase in bleeding. Further randomized studies are required to confirm these findings.