Renin-angiotensin-aldosterone system dynamics after targeted blood pressure control using angiotensin II or norepinephrine in cardiac surgery: mechanistic randomised controlled trial

What Was Tested

This randomized controlled trial paper looks at Angiotensin II in the context of low blood pressure and orthostatic hypotension.

The role of the renin-angiotensin-aldosterone axis in vasoplegia after cardiac surgery remains unclear.

The researchers tested the hypothesis that, compared with norepinephrine, infusion of angiotensin II titrated to achieve similar mean arterial pressure (MAP) would suppress plasma renin concentration (PRC) while maintaining aldosterone levels.

Who Took Part

PubMed indexes the participants as older adults, both men and women.

In a double-blind, randomised controlled trial, subjects received either an infusion of angiotensin II or norepinephrine to maintain MAP 70-80 mm Hg from induction of anaesthesia.

The researchers compared PRC, aldosterone, dipeptidyl peptidase-3, and angiotensin-converting enzyme 2 activity between treatment groups, before surgery, on ICU admission, and 24 h after surgery.

How the Study Was Run

In design terms this was a randomized and double-blind study.

Random assignment meant chance, not the researchers, decided who got Angiotensin II and who got the comparison, which limits bias.

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

What Was Measured

The researchers tested the hypothesis that, compared with norepinephrine, infusion of angiotensin II titrated to achieve similar mean arterial pressure (MAP) would suppress plasma renin concentration (PRC) while maintaining aldosterone levels.

The subject headings attached to it are Renin-Angiotensin System, Angiotensin II, Blood Pressure, Angiotensin-Converting Enzyme 2, Renin, Norepinephrine and Aldosterone.

Author keywords: cardiac surgery, noradrenaline, vasoplegia and vasopressor.

What This Means in Plain Language

The paper is a randomized and double-blind study of Angiotensin II in people with low blood pressure and orthostatic hypotension.

Its findings take up roughly 7 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2023 (British journal of anaesthesia), a journal based in England.

More context: the Angiotensin II compound page, Low blood pressure and orthostatic hypotension research.