Introduction

The 2019 ESC Guidelines on Diagnosis and Management of Acute Pulmonary Embolism (PE) suggest the use of percutaneous catheter-based ultrasound-assisted thrombolysis (UACDT) in patients with intermediate-high or high risk PE in whom systemic thrombolysis has failed or is contraindicated (IIa).

Methods

Between October 2017 and January 2020 we performed UACDT using the EkoSonic Endovascular System (EKOS). Over 15h 11,5 mg alteplase were continuously administered. Patients received unfractionated heparin for at least 48 hours and were then switched to vitamin K antagonists, direct anticoagulants or low molecular weight heparin.

Right ventricular stress was evaluated using transthoracic echocardiography before and after UACDT. Also cardiac biomarkers (cTNI, BNP) were followed up.

Results

UACDT was used in 51 patients (21 males, 30 females, age 63±17 years, mean cTNI initial 249,91 ± 86,26 pg/ml, mean BNP initial 481 ± 126,57 pg/ml) with intermediate-high or high risk PE that presented in our department. All patients had CT documented central PE and showed markers of right ventricular stress by transthoracic echocardiography and / or due to elevated biomarkers.

The EKOS cath was implanted in the right and / or left central pulmonary artery within 24 h after admission within cathlab without complications.

Mean cTNI increased from initial 249,81 ± 86,26 pg/ml to 391,23 ± 204,04 pg/ml (p = 0,144) during the first 24 hours after UACDT, mean BNP decreased from 481 ± 126,57 pg/ml to 400 ± 157,51 pg/ml (p = 0,05).

During initial hospitalization there was one death due to pneumonia associated sepsis and 6 major bleeding events BARC 3a resulting in transfusion. There was no stroke, myocardial infarction, right heart decompensation or recurrent PE.  So event free survival was 88%.

Another 4 patients developed minor bleeding events BARC type 2, one patient showed an aneurysma spurium which was successfully treated with ultrasound assisted manual compression.

RV/LV ratio measured by transthoracic echocardiography decreased from 1,15 ± 0,06 initial to 0,96 ± 0,06 (p = 0,0028) during the first 24 hours after UACDT and sPAP decreased from 47 ± 6,93 mmHg to 31 ± 2,67 mmHg (p = 0,0013).

30 patients (58,8%) could be discharged without any signs of right ventricular stress determined by transthoracic echocardiograpy, whereas 20 patients had still signs of right ventricular dysfunction.

Conclusion

UACDT is a safe and efficient method for treatment of patients with intermediate-high or high risk PE There were no life-threatening complications. The rate on severe complications was acceptable. More studies concerning outcomes and complications are needed.