Factors associated with bleeding after ultrasound-assisted catheter-directed thrombolysis for the treatment of pulmonary embolism

Ultrasound-assisted catheter directed thrombolysis (US-CDT) is frequently used for the treatment of pulmonary embolism. Due to the variety of thrombolytic and anticoagulant dosing utilized in practice, patients with pulmonary embolism who undergo US-CDT may be at an increased risk of bleeding. The primary objective of this study was to determine factors associated with major bleeding occurring with US-CDT. Secondary outcomes included in-hospital mortality and ventilator-free days. This multicentre retrospective cohort study evaluated inpatients diagnosed with pulmonary embolism and treated with US-CDT and systemic anticoagulation. A total of 173 patients were included. Most patients receiving US-CDT had a submassive pulmonary embolism with a median Pulmonary Embolism Severity Index (PESI) score of 85. Major bleeding events occurred in 37 of the 173 patients (21%). In-hospital mortality occurred in four (11%) of the patients who experienced major bleeding and three (2%) patients who did not experience major bleeding (P = 0.04). Factors associated with a higher risk of major bleeding included female sex and anticoagulation strategy. The odds of major bleeding were 3.3 times higher for women than for men (odds ratio = 3.32, 95% confidence interval 1.29-8.54). In addition, for each second increase in goal aPTT the odds of major bleeding increased by 5% (odds ratio = 1.05, 95% confidence interval 1.02-1.09). In patients with pulmonary embolism treated with US-CDT, major bleeding may be underestimated. In this analysis, major bleeding was associated with female sex and higher goal aPTT levels. In addition, bleeding with US-CDT was associated with a higher risk of in-hospital mortality.