Selective Pulmonary-artery Intervention to Reduce Acute Right-heart tEnsion-I

Inclusion Criteria: 1. Age ≥ 18 years \< 80 years 2. Acute onset of symptoms ≤ 14 days consistent with the presence of pulmonary embolism. 3. CTA evidence (site determined) of proximal PE (filling defect in at least one main or interlobar pulmonary artery) 4. RV/LV ratio of \> 0.9 on CTA as assessed by investigator (site determined). 5. Systolic blood pressure ≥ 90 mmHg (initial SBP may be ≥ 80 mmHg if the pressure recovers to ≥ 90 mmHg with fluids) 6. Subject is willing and able to provide written informed consent prior to receiving any non-standard of care clinical investigation plan specific procedures 7. Subject is willing and able to comply with all clinical investigation plan required follow-up visits Exclusion Criteria: 1. Thrombolytic use within 30 days of baseline CTA 2. Pulmonary hypertension with peak pulmonary artery pressure \> 70 mmHg by right heart catheterization (site determined) 3. Vasopressor requirement after fluids to keep pressure ≥ 90 mmHg 4. Unstable heart rate \> 130 beats per minute prior to procedure 5. FiO2 requirement \> 40% or \> 6 LPM to keep oxygen saturation \> 90% 6. Hematocrit \< 28% 7. Platelets \< 100,000/µL 8. Serum baseline creatinine \> 1.8 mg/dL 9. International normalized ratio (INR) \> 3 10. Major trauma injury severity score (ISS) \> 15 within the past 14 days 11. Presence of intracardiac lead in the right ventricle or right atrium placed \<180 days prior to the index procedure 12. Cardiovascular or pulmonary surgery within last 30 days 13. Actively progressing cancer requiring chemotherapy 14. Known bleeding diathesis or coagulation disorder 15. Left bundle branch block 16. History of severe or chronic pulmonary arterial hypertension 17. History of chronic left heart disease with left ventricular ejection fraction ≤ 30% 18. History of decompensated heart failure 19. Patients on extracorporeal membrane oxygenation (ECMO) 20. History of underlying lung disease that is oxygen dependent 21. History of chest irradiation 22. History of heparin-induced thrombocytopenia (HIT) 23. Contraindication to systemic or therapeutic doses of heparin or anticoagulants 24. Known anaphylactic reaction to radiographic contrast agents that cannot be pretreated 25. Imaging evidence or other evidence that suggests, in the opinion of the Investigator, the Subject is not appropriate for mechanical thrombectomy intervention 26. Life expectancy of \< 365 days, as determined by Investigator 27. Female who is pregnant or nursing 28. Current participation in another investigational drug or device treatment study 29. Inability to lay flat for procedure 30. Known presence of right-to-left cardiac shunt 31. History of Hemorrhagic or Ischemic Stroke, including Transient Ischemic Attack, within last 90 days 32. Current or history of chronic thromboembolic pulmonary hypertension (CTEPH) or chronic thromboembolic disease (CTED) diagnosis