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

What Was Tested

This registered phase 4 trial tested Vasopressin.

This is a randomized, double-blind clinical trial designed to compare the inotropic effects of vasopressin versus norepinephrine in patients who develop vasoplegic syndrome in the immediate postoperative period following cardiac surgery.

Vasoplegic syndrome is characterized by severe hypotension due to systemic vasodilation, despite adequate fluid resuscitation and preserved or elevated cardiac output.

Vasopressors are essential in restoring hemodynamic stability in this context; however, their impact on myocardial performance remains uncertain.

It had two arms (groups): Vasopressin (experimental) and Noradrenaline (active comparator).

The registry classes the interventions as drug.

More on the Plan

This prospective, randomized, double-blind clinical trial investigates the inotropic effects of vasopressin versus norepinephrine in patients who develop vasoplegic syndrome (VS) in the immediate postoperative period following cardiac surgery.

Vasoplegic syndrome is characterized by severe hypotension with low systemic vascular resistance despite adequate cardiac output, often unresponsive to standard fluid resuscitation and catecholamine vasopressors.

In recent years, vasopressin has been explored as an alternative or adjunctive treatment due to its different mechanism of action and potentially fewer adverse effects compared to catecholamines.

Eligible patients (≥18 years) undergoing coronary artery bypass grafting or valve surgery, who develop vasoplegic syndrome within 24 hours postoperatively, will be randomized in a 1:1 ratio to receive vasopressin or norepinephrine.

Who Took Part

The registry lists 350 planned participants were the target.

It was open to people of any sex aged from 18 years with no upper age limit.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: Age over 18.

The full record lists 2 inclusion and 12 exclusion criteria; among the exclusions: pregnancy or breastfeeding; aortic surgery; surgeries to correct congenital heart disease.

How the Study Was Run

It was run as a randomized, parallel-group and quadruple-blind study.

The participants were allocated by chance, so the Vasopressin group and the comparison group should start out alike.

The Vasopressin group and the comparison group ran side by side rather than switching.

Neither the participants nor the staff measuring them knew who was on Vasopressin, so expectations could not easily colour the readings.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2024-04-01 with completion listed for 2025-07-30.

It ran at 1 site in Brazil.

Its stated primary purpose is treatment.

What Was Measured

Researchers chose this as the main measure: Change in inotropic function assessed by cardiac output between T0 and T1 (time frame: Up to 1 hour after initiation of vasopressor therapy).

It also tracked 7 secondary outcomes, for example Change in left ventricular ejection fraction (LVEF) between T0 and T1, Time to achieve target mean arterial pressure (MAP ≥65 mmHg), Change in heart rate (HR) between T0 and T1, Change in arterial lactate levels between T0 and T1, Change in central venous oxygen saturation (SvO₂) and Change in CO₂ gap (central venous-to-arterial CO₂ difference).

What This Means in Plain Language

Put simply, this is a phase 4, randomized trial of Vasopressin in 350 people.

It is still recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Vasopressin compound page, all human trials.