Ground breaking discovery thanks to new heart and stroke machine
17 September 2019
University of Auckland researchers are uncovering crucial new information about strokes never documented before thanks to a unique machine gifted by the AH Somerville Foundation.
The Vevo 3100 has facilitated the research of Professor Julian Paton and Dr Fiona McBryde at the Faculty of Medical and Health Sciences to discover information that could play a critical role in how blood pressure levels are controlled in stroke patients.
Blood pressure often skyrockets during a stroke, but an ideal blood pressure for stroke patients hasn’t yet been scientifically determined.
Julian says blood flow and oxygen levels within the brain are key factors involved during a stroke. If blood pressure is too low, the brain could be starved of oxygen, making the stroke worse. If the blood pressure is too high, this could worsen the stroke, or trigger another one.
“In more than 80 percent of people when they have a stroke there is an immediate elevation of blood pressure. We’re asking is this harmful or protective? And what does one do about that change in pressure? Do you do nothing? Or do you treat the patient and return their blood pressure back to normal levels irrespective of whether they’ve got high blood pressure to start with? These are some of the questions we’ve been asking.”
Fiona adds: “Our clinical collaborators at Auckland City Hospital have pioneered a ground breaking new treatment where the blood clot causing the stroke can be physically removed to restore blood flow to the brain. However, this procedure requires patients to be anaesthetised, which causes blood pressure to fall. At the moment common practice for doctors is to keep blood pressure at a normal level in all patients.”
However early studies from using the machine indicate that blood pressure should be kept at a higher level.
The Vevo 3100 machine, which arrived in March, enables non-invasive imaging of internal organs. Unlike any other machine it provides anatomical, functional, physiological and molecular information in real time. Importantly for studying stroke, researchers are able to evaluate blood flow within the affected and non-affected parts of the brain at the same time.
Studies that Fiona has conducted with the machine show that decreasing the blood pressure to a normal level, rather than keeping it higher, results in worse outcomes for rats.
“Decreasing blood pressure during stroke seems to make it harder for blood to get around the blocked artery into the affected area. In particular we see that brain damage and mortality are greatly increased if blood pressure is lowered to a normal level in animals that were already hypertensive,” Fiona says.
Julian adds that following a stroke the animals that recover best have higher blood pressure.
“We believe that it is best to let the blood pressure stay high during stroke. We think this provides greater blood flow into the brain, which helps minimise damage. This is clinically quite important because the standard practice is to control the blood pressure to a normal level.”
He adds these findings are a first and could revolutionise how medical practitioners treat stroke patients.
“We are the first in the world to have shown this positive outcome and this has been made possible by the Vevo 3100. It allows us to do things we have only dreamt about and it’s so important.
“Clinicians around the world will be greatly interested in what we have found and we hope this may influence treatment of stroke patients in terms of where to control blood pressure. We have many exciting future studies planned where we will use the Vevo 3100 to look at whether we can further improve outcomes for patients using different anaesthetic drugs or cooling the brain down during stroke.”
On average someone in New Zealand has a stroke every hour, so it is vital that we are able to prevent strokes and treat stroke patients more effectively. Strokes are the country’s second-biggest killer and a major cause of adult disability according to the Stroke Foundation of New Zealand.
Julian and his team are grateful to the AH Somerville Foundation for gifting the state-of-the-art machine to the University, to a value just shy of $1 million.
The foundation was established after local Howick identity Archie Somerville died in 1992 when he was 60 years old. The Somerville family were among the first settlers to make Howick their home and Archie was well known in East Auckland - he often allowed locals to use his land for recreational purposes. In his mid-thirties Archie suffered a significant stroke, a significant blow for a farmer. As a result of the stroke, Archie's right arm became virtually useless and his speech was impaired.
Archie indicated during his lifetime that his primary objective was for his money to go towards helping people who had suffered strokes. The current trustees of the foundation are Archie's long time lawyer Jim Chamley and Anne Chamley, who is a lawyer in the same firm.
They say that since Archie died it has been hard to find good projects in this area and they are pleased that the Vevo 3100 is already showing such promise.
This is only the beginning of potential findings from the new machine and Julian says that researchers from across the country are queuing up to use it for their investigations into stroke, dementia, heart and kidney disease, hypertension and cancer.
With the establishment of the University’s new Manaaki Mānawa Centre for Heart Research, the Vevo 3100 machine will provide a platform for sustaining and developing new, world-leading research programmes across the region.
“It’s really exciting times and we are so grateful for the generosity of the AH Somerville Foundation,” says Julian.
“We can’t perform world-class research without acquiring the latest cutting edge equipment. The Vevo 3100 will ensure research excellence as we probe further into the enigma of stroke.”