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Prospective Cohort: 3-Month Data

Vascular Surgery / EKOS Endovascular System Overview / Clinical Evidence / KNOCOUT PE



The Largest Data Set in the Interventional Treatment of PE Just Got Bigger

Study Objective

To understand the impact of the EKOS™ Endovascular System low-dose, short treatment duration OPTALYSE PE study on various ultrasound-accelerated thrombolysis (USAT) protocols being used as the standard of care in the treatment of acute pulmonary embolism and associated long-term outcomes including quality of life outcomes.

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489 patients in the prospective cohort
Blue circle with illustration of brain.  Safety 0ICH
Zero intracerebral hemorrhagic events
RV Reduction LV Efficacy 23%
23% RV / LV reduction post-procedure


With 489 patients, the prospective KNOCOUT cohort represents the largest prospective body of evidence in the interventional PE space to-date. The registry included a wide range of patients with intermediate-high and high-risk PE, making it an accurate representation of patients with PE treated with EKOS every day. In addition, KNOCOUT captures the largest breadth of contemporary clinical practices with 83 centers enrolled across the United States and Europe between 2018 and 2020.


Results from KNOCOUT PE reflect contemporary clinical practice and demonstrated effective treatment of PE with EKOS with lower r-tPA dose and shorter infusion duration, and low major hemorrhagic complications and zero intracerebral hemorrhagic events.




Major Bleeding within 30 days​

12 (2.5)​*
Anemia​ 1 (0.2)​
Gastrointestinal Hemorrhage​ 1 (0.2)​
Peritoneal Hemorrhage​ 1 (0.2)​
Procedural Hemorrhage​ 1 (0.2)​
Laceration​ 1 (0.2)​
Compartment Syndrome​ 1 (0.2)​
Hematoma​ 1 (0.2)​
Lower Gastrointestinal Hemorrhage​ 1 (0.2)​
Retinal Hemorrhage​ 1 (0.2)​
Retroperitoneal Hemorrhage​ 1 (0.2)​
Subdural Hematoma (pre-existing)​ 1 (0.2)​
Vascular Access Site Hematoma​ 1 (0.2)​

* Out of a pool of 489


Recurrent VTE Within 30 Days

Pulmonary Embolism ​ 4 (0.8)
Confirmed Post-Procedure DVT 1 (0.2)*
* 34 DVTs were reported, however; 33 of the 34 reported DVTs were identified on duplex ultrasound within 1-2 days of the USCDT procedure and were not differentiated from preexisting DVTs. 30 of the 34 DVTs were reported from one center
Procedural Prospective Cohort bar graph & Efficacy Change in RV/LV Prospective Cohort line graph


KNOCOUT shows that contemporary clinical practices are moving to low-dose, short duration OPTALYSE protocols. It adds to the growing evidence that EKOS is effective at treating intermediate-risk and high-risk PE with lower lytic doses and shorter infusion durations compared to other thrombolytic therapies.

Bar chart titled Duration and dose by therapy.  EKOS Knocout PE 10.4 hrs

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Indications, Safety and Warnings

1. KonstantinidesS, GeibelA, HeuselG, et al. Heparin plus alteplase compared with heparin alone in patients with submassivepulmonary embolism. N EnglJ Med. 2002;347:1143–1150.
2. Kuo W et al. CHEST 2015; 148(3):667 673.
3. Piazza G et al. A Prospective, Single-Arm, Multicenter Trial of Ultrasound-Facilitated, Catheter-Directed, Low-Dose Fibrinolysis for Acute Massive and Submassive Pulmonary Embolism. The SEATTLE II Study. J Amer Coll Cardiol: Cardiovasc Interventions 2015; 8(10):1382-1392.
4. 3-Month Prospective KNOCOUT Data Presentation at VIVA 2021.
5. TapsonVF, Sterling K, Jones N, et al. A randomized trial of the optimum duration of acoustic pulse thrombolysis procedure in acute intermediate-risk pulmonary embolism: the OPTALYSE PE trial. JACC Cardiovasc Interv. 2018;11:1401-1410. doi: 10.1016/j.jcin.2018.04.008