IMPACT EU Post-Market Clinical Follow-Up Study

Inclusion Criteria: 1. Hemodynamically stable patients undergoing one (1) of the following cardiac surgery procedures on CPB including aortic cross-clamping and cardioplegic arrest * Isolated CABG * Isolated mitral valve repair or replacement (MVR) * Isolated aortic valve repair or replacement (AVR) * At lest two of the following: CABG, MVR, AVR, or tricuspid valve repair or replacement (TVR) 2. LVEF within 30 days before surgery of either: * ≤25% measured by echocardiogram or * LVEF ≤35% as above for patients with significant mitral regurgitation (MR 3+ or 4+; see definition) and planned corrective mitral valve surgery (including MV replacement or repair) 3. Age 18 years or older 4. Subject has signed informed consent form and is willing and able to attend all follow-up visits and to perform all tests. 5. Patient is eligible to receive the Impella 5.5 as per the current IFU. Exclusion Criteria: 1. Salvage operation (cardiac arrest within 24 hours prior to index surgery) 2. Unresponsive state within 24 hours of the time of surgery 3. Any inotrope within 72 hours of surgery 4. Any mechanical MCS device (such as IABP, ECMO, Impella®, CentriMag™ or TandemHeart®) in place prior to informed consent 5. RV dysfunction requiring mechanical or inotropic support preoperatively and/or likely to be needed postoperatively 6. Index procedures requiring total circulatory arrest (TCA), such as aortic arch replacement, planned durable LVAD, durable RVAD, planned right-sided temporary mechanical support of any kind, total artificial heart (TAH), cardiac transplantation, pericardiectomy, pulmonary thromboendarterectomy and septal myectomy 7. Restrictive or obstructive cardiomyopathy, constrictive pericarditis, restrictive pericarditis, pericardial tamponade or other conditions in which cardiac output is dependent on venous return 8. Ventricular septal defect (VSD) 9. Stroke within 30 days of the index cardiac surgical procedure 10. Prior mantle field chest irradiation 11. Prior solid organ or hematologic transplantation (heart, kidney, liver, lung, pancreas, bone marrow) or durable LVAD 12. History of chronic dialysis 13. Pre-existing liver dysfunction defined as Child-Pugh Class B or C 14. Pre-existing pulmonary disease requiring home oxygen, or "severe pulmonary disease" determined by enrolling investigator 15. Systemic active infection or evidence of systemic bacterial, fungal or viral infection within 72 hours before surgery (blood culture positive with leukocytosis) 16. Confirmed COVID-19 infection within two (2) weeks prior to operation 17. Pregnant or planning pregnancy within next 12 months. NOTE: Female patients of childbearing potential need to have a negative pregnancy test performed within 14 days prior to intervention. 18. Participation in the active treatment or follow-up phase of another interventional clinical trial of an investigational drug or device which has not reached its primary endpoint 19. Known contraindication to heparin; History of bleeding diathesis or known coagulopathy or will refuse blood transfusions 20. Inability to perform aortic cross-clamp, such as due to porcelain aorta 21. Any contraindication or condition that would prevent the ability to place Impella 5.5® (per current IFU), including LV thrombus and/or presence of a mechanical aortic valve 22. Any organ condition, concomitant disease (e.g., psychiatric illness, current severe alcoholism or current drug abuse, cancer, hepatic or kidney disease), with life expectancy of ≤2 years or other abnormality that itself or the treatment of which, could interfere with the conduct of the trial or that, in the opinion of the investigator would pose an unacceptable risk to the subject in the trial. 23. Subject has other medical, social or psychological problems that, in the opinion of the investigator, compromises the subject's ability to give written informed consent and/or to comply with trial procedures, including patients under guardianship 24. Any subject considered to be part of a vulnerable population (as per ISO 14155)