Using a Fibrinolysis Delivery Catheter in Pulmonary Embolism Treatment for Measurement of Pulmonary Artery Hemodynamics

Abstract

What are the main findings? This study demonstrated that ultrasound-facilitated catheter-directed fibrinolysis for the treatment of 45 patients with intermediate high-risk pulmonary embolism was associated with significant improvements in hemodynamics and low major bleeding events as demonstrated in previous trials (Ultima and Seattle II). However, this protocol used a lower dose and shorter duration of t-PA. The third arm of Optalyse PE-Trial used the same regime (6 mg/6 h/lung) for the treatment of 24 patients. It focuses on pulmonary artery hemodynamics as a primary precise surrogate marker for therapy effectiveness in addition to RV/LV ratio that was used in previous trials (Ultima and Seattle II), which has a bias of interobserver variability. What is the implication of the main finding? It assessed pulmonary artery hemodynamics for the first time by fibrinolysis delivery catheter, without additional need for a right heart catheterization. The results matched the right heart catheter results in EKOS and Heparin arm of Ultima trial, thereby confirming the validity of these diagnostic tools. It’s a valid and precise diagnostic tool to assess therapy effectiveness and reduce additional procedure-related complications, hospital residency, and economics. It gives this therapy additional diagnostic potential. It stressed the importance of interdisciplinary teams in the management of PE and evaluated the quality of life of these patients. This protocol shortens ICU stay to 6 h. Highlights: Background: Ultrasound-facilitated and catheter-directed low-dose fibrinolysis (EKOS) has shown favorable hemodynamic and safety outcomes in intermediate- to high-risk pulmonary embolism (PE) cases. Objectives: This prospective single-arm monocentric study assessed the effects of using a delivery catheter for fibrinolysis as a novel approach for acute intermediate- to high-risk patients on pulmonary artery hemodynamics PE. Methods: Forty-five patients (41 intermediate–high and 4 high risk) with computer tomography (CT)-confirmed PE underwent EKOS therapy. By protocol, a total of 6 mg of tissue-plasminogen activator (t-PA) was administered over 6 h in the pulmonary artery (unilateral 6 mg or bilateral 12 mg). Unfractionated heparin was provided periprocedurally. The primary safety outcome was death, as well as major and minor bleeding within 48 of procedure initiation and at 90 days. The primary effectiveness outcomes were: 1. to assess the difference in pulmonary artery pressure from baseline to 6 h post-treatment as a primary precise surrogate marker, and 2. to determine the echocardiographic RV/LV ratio from baseline to 48 h and at 90 days post-delivery. Results: Pulmonary artery pressure decreased by 15/6/10 mmHg (p < 0.001). The mean RV/LV ratio decreased from 1.2 ± 0.85 at baseline to 0.85 ± 0.12 at 48 and to 0.76 ± 0.13 at 90 days (p < 0.001). Five patients (11%) died within 90 days of therapy. Conclusions and Highlights: Pulmonary artery hemodynamics were assessed using a delivery catheter for fibrinolysis, which is reproducible for identifying PE at risk of adverse outcomes. The results matched the right heart catheter results in EKOS and Heparin arm of Ultima trial, thereby confirming the validity of this potential diagnostic tool to assess therapy effectiveness and thereby reduce additional procedure-related complications, hospital residency, and economics. These results stress the importance of having an interdisciplinary team involved in the management of PE to evaluate the quality of life of these patients and this protocol shortens ICU admission to 6 h.