Early Intra-aortic Balloon Pump Use After Venoarterial Extracorporeal Membrane Oxygenation

Inclusion Criteria: 1. Age of ≥18 2. Cardiogenic shock(defined as a systolic blood pressure of less than 90 mm Hg for more than 30 minutes or the initiation of catecholamines to maintain a systolic pressure of more than 90 mm Hg, an arterial lactate level of more than 3 mmol per liter, and signs of impaired organ perfusion) 3. Successful implantation of VA-ECMO 4. Informed consent Exclusion Criteria: 1. SCAI shock stage A or B 2. Presence of moderate to severe aortic insufficiency or aortic dissection 3. Severe peripheral vascular disease 4. Post-cardiotomy cardiogenic shock(non-CABG procedure) or bridging to cardiac procedure(heart transplantation or LVAD). 5. VA-ECMO for definite non-cardiac causes 6. Isolated right ventricular failure 7. V-A ECMO usage confined to the period during surgery or other interventions 8. Ischemic mechanical complications(eg Ventricular septal defect, papillary muscle rupture) 9. Extracorporeal cardiopulmonary resuscitation 10. LVAD, Impella or IABP in situ. 11. Severe bleeding 12. Terminal malignancy 13. Irreversible neurologic injury 14. Pregnancy or lactation