The PEERLESS II Study

Inclusion Criteria:

1. Age at enrollment ≥ 18 years

2. Objective evidence of a proximal filling defect in at least one main or lobarpulmonary artery, as confirmed by CTPA, pulmonary angiography, or other imagingmodality

3. RV dysfunction, as defined as one or more of the following: RV/LV ratio ≥ 0.9 or RVdilation or hypokinesis

4. At least two additional risk factors, identified by at least one measure in twoseparate categories noted below: a. Hemodynamic: i. SBP 90-100mmHg ii. Resting heart rate > 100 bpm b. Biomarker: i.Elevated* cardiac troponin (troponin I or troponin T, conventional or highsensitivity) ii. Elevated* BNP or NT-proBNP iii. Elevated venous lactate ≥2 mmol/L *Elevated, meaning at or above the upper limit of normal, per local standards for theassay used c. Respiratory: i. O2 saturation < 90% on room air ii. Supplemental O2requirement ≥ 4 L/min iii. Respiratory rate ≥ 20 breaths/min iv. mMRC score > 0

5. Symptom onset within 14 days of confirmed PE diagnosis

6. Willing and able to provide informed consent

Exclusion Criteria:

1. Unable to be anticoagulated with heparin, enoxaparin or other parenteralantithrombin

2. Presentation with hemodynamic instability* that meets the high-risk PE definition inthe 2019 ESC Guidelines1, including ANY of the following

3. Cardiac arrest OR

4. Systolic BP < 90 mmHg or vasopressors required to achieve a BP ≥ 90 mmHgdespite adequate filling status, AND end-organ hypoperfusion OR

5. Systolic BP < 90 mmHg or systolic BP drop ≥ 40 mmHg, lasting longer than 15 minand not caused by new-onset arrhythmia, hypovolemia, or sepsis * Patients whoare stable at time of screening or randomization (i.e., SBP ≥ 90 mmHg andadequate organ perfusion without catecholamine or vasopressor infusion) may beincluded despite initial presentation including temporary, low-dosecatecholamines or vasopressors, or temporary fluid resuscitation.

6. Known sensitivity to radiographic contrast agents that, in the Investigator'sopinion, cannot be adequately pre-treated

7. Imaging evidence or other evidence that suggests, in the opinion of theInvestigator, the patient is not appropriate for catheter-based intervention (e.g.,inability to navigate to target location, clot limited to segmental/subsegmentaldistribution, predominately chronic clot)

8. End stage medical condition with life expectancy < 3 months, as determined by theInvestigator

9. Current participation in another drug or device study that, in the investigator'sopinion, would interfere with participation in this study

10. Current or history of chronic thromboembolic pulmonary hypertension (CTEPH) orchronic thromboembolic disease (CTED) diagnosis, per 2019 ESC Guidelines1

11. If objective testing was performed*, estimated RV systolic pressure > 70 mmHg onstandard of care echocardiography * If clinical suspicion of acute-on-chronic PE,chronic obstruction, or chronic thromboembolism, echocardiographic estimated RVSPmust be confirmed ≤70 mmHg to meet eligibility. Pressure assessment not required ifInvestigator attests to absence of such clinical suspicion

12. Administration of advanced therapies (thrombolytic bolus, thrombolyticdrip/infusion, catheter-directed thrombolytic therapy, mechanical thrombectomy, orECMO) for the index PE event within 30 days prior to enrollment

13. Ventricular arrhythmias refractory to treatment at the time of enrollment

14. Known to have heparin-induced thrombocytopenia (HIT)

15. Subject has any condition for which, in the opinion of the investigator,participation would not be in the best interest of the subject (e.g., compromise thewell-being or that could prevent, limit, or confound the protocol-specifiedassessments). This includes a contraindication to use of FlowTriever System perlocal approved labeling

16. Subject is currently pregnant

17. Subject has previously completed or withdrawn from this study