Silver lining for Sunshine Heart

A new Australian developed device that boosts failing hearts while they repair themselves has won a silver medal in the Far Eastern Economic Review's annual Asian Innovation Awards.

The new device, called the Sunshine Heart, was conceived by New Zealand heart surgeon Dr William Peters, and the first prototype was designed and constructed by engineers at the University of Technology, Sydney.

The heart of the device is a hydraulically inflatable cuff that fits around the ascending aorta, the major artery leading from the heart to the abdomen and legs.

The Sunshine Heart represents a radically different, life-saving approach to treating congestive heart failure when conventional drug therapy fails.

Where highly-publicised 'artificial hearts' like the US-developed Jarvik Heart, have been designed to take the place of failing hearts, and require risky invasive surgery to install, the Sunshine Heart simply wraps around the aorta, and a coin-sized pacemaker device tuned to the heart's own electrical activity produces contractions that alternate with the natural heart -- precisely when the heart relaxes after its own beat.

As the cuff is squeezing blood into the aorta, it also forces blood through dangerously occluded coronary arteries, perfusing the heart muscle with oxygen and nutrients.

These combined actions reduce the load on the patient's own heart and enhance its own activity, allowing it to recover and repair itself -- particularly in younger patients.

The Sunshine heart is being developed and marketed by Sunshine Heart Co Pty Ltd, which Peters founded and of which he is its managing director.

Sunshine Heart's executive chairman, Crispin Marsh, described the Asian Innovation Award Silver Medal as "a great win for Australian innovation and research".

Researchers at the UTS Faculty of Engineering designed and built the Sunshine Heart, while University of Sydney researchers manufactured the housing for its fluid compressor, and the cuff that wraps around the heart.

Design and development was assisted by a $2 million AusIndustry R&D Start grant.

Internal use

Marsh said the cuff was made of a biocompatible synthetic polymer and is secured by a sawn Dacron wrap that directs the inflation pressure inwards -- the cuff is filled with a special oil.

The device has so far been tested only as a prototype, on three patients with congestive heart failure -- the pump and pacemaker were kept outside the body.

The commercial device will be worn internally, with an external controller. Marsh said the design specification called for a device that will work for at least three years without failing.

It will be used primarily on Class 4 patients, who are suffering from severe congestive heart failure that makes even the smallest physical activity exhausting .

With donor hearts in critically short supply, the Sunshine Heart could treble the life expectancy of these patients.

Marsh said that without a heart transplant, Class 4 patients had an average life expectancy of 12 months. In younger patients suffering from debilitating viral infections of the heart muscle, the Sunshine Heart may provide sufficient respite to eliminate the need for a new heart.

He said the Sunshine Heart was unique because it unlike the current generation of artificial hearts, it would have no contact with the blood.

So-called left ventricular assistance devices, or LVADs, like the Jarvik, Novacor, TCI Heartmate, Thoratec artificial pumps, are sewn into the left ventricle and actively pump blood.

The Sunshine Heart will avoid this invasive surgery, minimising the risk of bleeding around the connection points, bacterial infections in the bloodstream, and clotting.

Marsh said Peters estimated that surgery to insert the Sunshine Heart would take only an hour and a half, compared with at least six hours for an LVAD. Patients will require only one day's intensive care, compared with six for LVAD patients, and should be able to go home in two weeks, versus four to eight weeks for LVAD recipients.

The price of the Sunshine Heart is like to be comparable with that of LVAD devices, but these reductions in surgery and hospital time should result in huge savings.

Marsh said the global market for heart-assistance devices had been estimated at between $US2 billion and $US10 billion.

The recent Rematch study, conducted by a scientific committee of the US Food and Drug Administration, had concluded that artificial hearts prolonged the lives of patients with congestive heart failure patients, and offered a better quality of life.

But the committee had also found that there were serious adverse consequences on health, which restricted LVADs to being used as a bridge to a heart transplant.

That meant many elderly patients who were not fit enough to qualify for a heart transplant did not qualify for an artificial heart device either.

The committee had recently recommended to the FDA that it approve heart devices as an end-therapy in their own right, but had been critical of available LVAD devices because of the risks involved.

Marsh said such a change could create a big opportunity for the company if the Sunshine Heart could fulfil this specification.