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EKOS™ Endovascular System

Higher-risk Pulmonary Embolism Thrombolysis Study

Patients now enrolling!​

​“We are pleased to see the official start to the HI-PEITHO trial with the first patient enrollment. HI-PEITHO is the largest, most rigorous trial in the PE space intended to address critical gaps in PE clinical evidence. This trial reflects Boston Scientific’s investment and commitment to providing the highest level of scientific evidence to ultimately help guide clinical practice.”

-Dr. Michael R. Jaff

Key Resources

HI-PEITHO – The Higher-Risk Pulmonary Embolism Thrombolysis Study​

Hear from the Principal Investigators

 HI-PEITHO: Higher-risk Pulmonary Embolism Study Video


HI-PEITHO is a joint research study led by Boston Scientific, in partnership with the PERT Consortium and the University Medical Center of Mainz in collaboration with PEITHO International Study Network.

Trial Overview


The HI-PEITHO study has been designed to address a critical gap in clinical evidence in PE by comparing the clinical benefit of intervention with EKOS vs. the current standard of care – anticoagulation. This trial is the largest and first of its kind in PE. It is designed to generate the most rigorous, highest level of data, contributing to the body of evidence for the treatment and outcomes in acute, intermediate-high risk PE. In addition, HI-PEITHO aims to advance the understanding of intermediate-high risk PE and risk stratification, to better identify patients who may clinically benefit from intervention, expanding access to care for these patients. 


Mult-center Prospective Randomized Controlled Transatlantic menu
HI-PEITHO is a multi-center, prospective, randomized, controlled trial in the U.S. and Europe that will compare the outcomes of ultrasound-facilitated, catheter-directed, thrombolysis plus anticoagulation vs. anticoagulation alone for the treatment of acute, intermediate-high risk pulmonary embolism (PE).


EKOS™ Endovascular System + Anticoagulation vs. Anticoagulation Alone

Evaluate if treatment with EKOS is associated with a significant reduction in the acute composite outcome of the measures below compared to anticoagulation alone –​

  • PE-Related Death
  • Cardiorespiratory decompensation or collapse, and
  • Non-fatal symptomatic and objectively confirmed recurrence of PE 

Trial Methodology


  • Estimated enrollment: 406-544 participants​
  • Acute intermediate high-risk pulmonary embolism
  • ​RV/LV > 1.0, elevated troponin, & risk of early death/hemodynamic collapse​

Trial Design


Trial End Points & Assessments

Checkmarks  - Independent Review Blinded outcome adjudication Long-term

End Points

7-day composite of –

  • PE-related mortality
  • PE recurrence (non-fatal symptomatic and objectively confirmed)
  • Cardiorespiratory decompensation or collapse

Cardiorespiratory decompensation or collapse, defined as at least one of the following:

  • Cardiac arrest or need for CPR​
  • Signs of shock: new onset arterial hypotension with end-organ hypoperfusion​
  • ECMO placement
  • ​Intubation or noninvasive mechanical ventilation​
  • National Early Warning Score (NEWS) of 9 or higher

Long Term Follow-Up

Additional follow-ups at 30-days, 6 months, and 1-Year 

National Early Warning Score (NEWS)

Earlier Warning Standardizing Assessment Objectify patient experience menu
National Early Warning Score (NEWS) Chart
Reproduced from: Royal College of Physicians. National Early Warning Score (NEWS): Standardising the assessment of acute-illness severity in the NHS. Report of a working party. London: RCP, 2012

The NEWS is an early warning system score for clinical deterioration in hospitalized patients – it standardizes the assessment of acute-illness severity.

The score aims to objectify how the patient is doing at the bedside.

The NEWS is based on an aggregate scoring system based on physiological measurements – respiration rate, oxygen saturations, supplemental oxygen need, temperature, systolic blood pressure, heart rate, and level of consciousness.

Key Additional Assessments

Functional & QOL measures Two bleeding measurements Health Economic Assessment menu
  • Individual primary outcome components
  • GUSTO major (moderate and severe) bleeding within 7 days
  • International Society on Thrombosis and Haemostasis (ISTH) major bleeding
  • Ischemic or hemorrhagic stroke within 7 days and 30 days
  • All-cause mortality
  • Symptomatic PE recurrence within 30 days and 6 months
  • Change from baseline in RV dysfunction on echocardiography at 6 months
  • Chronic thromboembolic pulmonary hypertension (CTEPH) diagnosis within 12 months
  • Health economic assessments
  • Functional status and quality of life measures
  • Cardiopulmonary Exercise Testing (CPET) at select sites