The investigation is intended to evaluate the safety and effectiveness of the AlphaReturn Blood Management System when used in conjunction with the cleared AlphaVac MMA F1885 System for the treatment of acute pulmonary embolism.

This is a prospective, multicenter, single-arm investigational device study evaluating safety and effectiveness.

Inclusion Criteria:

A potential subject will be included in the study if he/she meets all the following inclusion criteria:

1. Provision of signed and dated informed consent form.
2. Subject is 18 years of age and older.
3. Subject presents clinical signs and symptoms consistent with acute intermediate-risk pulmonary embolism for less than or equal to 14 days.
4. Subject has a diagnosis of pulmonary embolism detected from computed tomography angiography (CTA).
5. Subject has a RV/LV ratio of 0.9 or higher.
6. Subject has a systolic blood pressure (SBP) of 90mmHg or higher.
7. Subject has a heart rate of 130 beats per minute (BPM) or less prior to the procedure.
8. Subject is deemed medically eligible for interventional procedure(s) per institutional guidelines and/or clinical judgment.

Exclusion Criteria:

A potential subject will be excluded from the study if he/she meets any of the following exclusion criteria:

1. Subjects who are or may be pregnant as determined by a positive pregnancy test or who are breastfeeding.
2. Subjects who have any contraindication to systemic or therapeutic doses of heparin or anticoagulants.
3. Subjects who have used thrombolytics in the 30 days prior to the baseline CTA.
4. Subjects who have pulmonary hypertension with peak pulmonary artery pressure (PAP) > 70 mmHg.
5. Subjects who have FiO2 requirement > 44% or > 6 LPM to keep oxygen saturations > 90%.
6. Subjects with hematocrit < 28% within 6 hours of index procedure.
7. Subjects with platelets count < 100,000/μL.
8. Subjects with serum creatinine > 1.8 mg/dL.
9. Subjects with International Normalized Ratio (INR) > 3.
10. Subjects who have undergone a major trauma within the past 14 days of the index procedure and have Injury Severity Score (ISS) > 15.
11. Subjects with the presence of cancer requiring active chemotherapy.
12. Subjects with known bleeding diathesis or coagulation disorder.
13. Subjects who have had a cardiovascular or pulmonary surgery within the past 7 days of index procedure.
14. Subjects with a history of severe or chronic pulmonary hypertension, uncompensated heart failure, chest irradiation, underlying lung disease that is oxygen dependent, heparin-induced thrombocytopenia (HIT) and/or chronic left heart disease with left ventricular ejection fraction ≤ 30%.
15. Subjects with known anaphylactic reaction to radiographic contrast agents that cannot be pretreated.
16. Subject requires vasopressor after fluids to keep pressure ≥ 90mmHg.
17. Subjects with left bundle branch block.
18. Subjects who have intracardiac lead in the right ventricle or atrium.
19. Evidence such as imaging or other that suggest the subject is not appropriate for this procedure.
20. Subjects that have life expectancy < 90 days, in the opinion of the investigator at the time of enrollment.
21. Subjects dependent on extracorporeal life support such as extracorporeal membrane oxygenation (ECMO).
22. Participation in another investigational study.