Discovery could lead to novel treatment for heart failure

Researchers at the University of Auckland have made a groundbreaking discovery that could lead to new therapies for a debilitating heart condition. 

Approximately 90,000 New Zealanders suffer from heart failure, with an estimated 50 percent affected by a specific type called Heart Failure with Preserved Ejection Fraction (HFpEF). This condition occurs when the heart muscle becomes stiff and struggles to relax and fill with blood, reducing the supply of oxygenated blood that the body needs for optimal function. Particularly common in older women, it causes crippling symptoms like severe breathlessness and fatigue.

“Getting breathless in day-to-day life – going up stairs, carrying shopping bags, playing with grandkids – is really life-limiting,” says Dr Julia Shanks, Senior Research Fellow in Physiology at Manaaki Manawa, the Centre for Heart Research.

“Our aim is to develop new therapies that reduce the symptom burden of HFpEF and help people with the condition live better lives.”

HFpEF does not respond to current heart failure medications, and while it has shown some success with an existing diabetes drug, targeted therapies are needed. Julia and her team hope to transform treatment options and have been exploring how nerves regulate the heart, with a particular focus on the vagal system. Through early pre-clinical testing, they made a significant finding: cardiac vagal nerves innervate the heart and can improve how it relaxes and how blood flows through the muscle.

“These nerves help the heart function in situations where it needs to work harder,” she explains. “We are looking at ways to target the nerves to improve heart function for people living with HFpEF.”

Specifically, they are exploring ways to target the nerves electronically using specialised implants. These devices would stimulate the vagal nerves, increasing their activity and supporting blood flow through the heart. Julia says the concept is similar to a pacemaker, which is implanted under the skin and sends electrical impulses to the heart to regulate its rhythm.

If the implant is successful, it would be the first effective treatment for HFpEF through an entirely new mechanism. The long-term goal would be to create a device that functions proactively without requiring manual activation.

“Can we build it into some sort of biofeedback loop? Can we build something a patient doesn’t have to turn on and off when they need help, but that works natively in the body? The impact would be huge.”

The research is supported by a significant bequest from the Estate of Bob and Barbara Dawn. Bob and Barbara Dawn were siblings who chose to support heart and stroke research with a gift in their wills. Julia says the generous gift has been essential in enabling this vital early work to occur.

“Legacy gifts to research are hugely important. They really enable us to do this early evidence testing and allow us the freedom to explore potentially high-impact novel ideas prior to being at a stage where work is more viable for bigger grants.”

She and her team are now focused on scaling up their research and conducting longer-term testing of the vagal nerve stimulator. Julia is excited for the potential implications of their work and what it could mean more broadly:

“What excites me most is that the parasympathetic nervous system is gaining interest globally now, when historically it has been overlooked as a therapeutic target. It has opened up a whole avenue of therapies that didn’t exist.”