Comparing vasopressin and norepinephrine for treating low blood pressure after heart surgery

Inotropic Effects of Vasopressin Versus Noradrenaline In Patients With Vasoplegic Syndrome After Cardiac Surgery

PHASE4 · University of Sao Paulo · NCT06934798

This study is testing whether vasopressin or norepinephrine works better to treat low blood pressure in patients who develop complications after heart surgery.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment350 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of Sao Paulo (other)
Locations1 site (São Paulo)
Trial IDNCT06934798 on ClinicalTrials.gov

What this trial studies

This clinical trial is a randomized, double-blind investigation comparing the effects of vasopressin versus norepinephrine in patients who develop vasoplegic syndrome shortly after cardiac surgery. Vasoplegic syndrome leads to severe low blood pressure despite adequate fluid resuscitation, and this study aims to determine which vasopressor is more effective in improving cardiac output and hemodynamic stability. Eligible patients will receive either vasopressin or norepinephrine, with their responses monitored through various echocardiographic and hemodynamic parameters. The findings could help refine treatment protocols for managing this serious postoperative complication.

Who should consider this trial

Good fit: Ideal candidates are adults over 18 undergoing coronary artery bypass grafting or valve surgery who develop vasoplegic syndrome within 24 hours postoperatively.

Not a fit: Patients who have undergone aortic surgery, heart transplants, or emergency surgeries, or those with certain postoperative complications, will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved management of vasoplegic syndrome, enhancing patient outcomes after cardiac surgery.

How similar studies have performed: While norepinephrine is the standard treatment, the exploration of vasopressin as an alternative is relatively novel, and previous studies have shown mixed results regarding its efficacy.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age over 18.
* Patients undergoing coronary artery bypass grafting, valve surgery or both, with a diagnosis of vasoplegic syndrome in the immediate postoperative period (\<24 hours), defined as mean arterial pressure \< 65 mmHg (measured using an invasive blood pressure catheter) and resistance to fluid replacement - at least 1000ml of crystalloids.

Exclusion Criteria:

* Pregnancy or breastfeeding.
* Aortic surgery.
* Surgeries to correct congenital heart disease.
* Heart transplants.
* Emergency surgery.
* Use of vasopressor therapy in the preoperative period.
* Presence of a ventricular assist device other than an intra-aortic balloon in the postoperative period.
* Severe hyponatremia in the postoperative period (serum sodium less than 130mEq/l).
* Postoperative acute coronary syndrome.
* Mesenteric ischemia in the postoperative period.
* History of Raynaud's disease.
* History of neoplasia.

Where this trial is running

São Paulo

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Vasoplegic Syndrome of Cardiac Surgery, Shock Cardiogenic, Postoperative Complications, Cardiac Surgical Procedures

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.