Clinical Outcomes of Patients with Intermediate-to-High-Risk Pulmonary Embolism Undergoing Ultrasound-Assisted Catheter-Based Fibrinolysis Therapy in a Mid-Term Follow-Up Period - A Retrospective Observational Study.

Objectives Endovascular therapy with ultrasound-assisted catheter-directed thrombolysis (UACDT) theoretically provides higher efficacy while reducing the bleeding risk compared with conventional systemic thrombolysis. The clinical outcomes of UACDT in treating intermediate-to-high-risk pulmonary embolism (PE) are lacking in an Asian population. Methods Forty-two patients who presented with intermediate-to-high-risk PE received UACDT. The patients were divided into two groups based on the incidence of procedure-related bleeding events, and baseline demographics were compared between the two groups. A paired-Student's t test was conducted to evaluate the efficacy of UACDT. Univariate and multivariate logistic regression analyses were conducted to identify independent risk factors for significant bleeding events. Results The average age was 58.93 ± 20.48 years, and 33.33% of the study participants were male. A total of 85.7% of the participants had intermediate-risk PE. Compared with pre-intervention pulmonary artery pressure, the mean pulmonary artery pressure decreased significantly (37.61 ± 9.57 mmHg vs. 25.7 ± 9.84 mmHg, p < 0.01) after UACDT. The cumulative total tissue plasminogen activator dosage and total infusion duration were 44.54 ± 20.55 mg and 39.14 ± 19.06 hours respectively. Overall, 21.43% of the participants had severe bleeding events during the endovascular fibrinolysis treatment period. Forward conditional multivariate logistic regression analysis revealed that the lowest fibrinogen level during thrombolysis was an independent factor associated with moderate-to-severe bleeding (odds ratio: 0.40, 95% confidence interval: 0.19-0.88, p = 0.02). Conclusions UACDT exhibited high efficacy, but resulted in a higher-than-expected bleeding rate in this real-world study of an Asian population. The lowest fibrinogen level during thrombolysis was an independent risk factor associated with procedure-related bleeding events.