The purpose of this research is to evaluate the use of Angiotensin II in patients with low blood pressure post-surgery. Your information will be collected for 28 days post the procedure and initiation of the study drug to assess for safety events and complications.

Inclusion Criteria:

• Adult patients ≥ 18 years of age undergoing cardiac surgery requiring CPB
• Patients must have clinical features of vasodilation as determined by a MAP < 65 mmHg that is non-transient in the opinion of the treating physician
• Patients must be adequately volume resuscitated in the opinion of the treating physician
• Systemic Vascular Resistance index (SVRi) < 1970 dynes·sec/cm⁵/m² to support the clinical diagnosis of vasodilation; if no pulmonary artery catheter is in place, vasodilatory hypotension diagnosis according to the judgement of the critical care team
• Biventricular systolic function is at or greater than pre-cardiopulmonary bypass baseline as demonstrated by echocardiographic evaluation, or the patient is concomitantly treated with

Exclusion Criteria:

• Bleeding as primary etiology of hypotension, as determined by > 4 units RBC transfusion in 24 hours.
• Patients on ECMO
• Patients with active endocarditis
• Patients already on renal replacement therapy or creatinine of > 4 mg/dl within 2 weeks of surgery
• Patients with contraindications to Angiotensin II including women who are pregnant or breastfeeding or have active coronary ischemia, mesenteric ischemia, limb ischemia, or high potassium (> 5.5 meq/L) while receiving Angiotensin II