Researchers at Baker IDI Heart and Diabetes Institute in Melbourne will this week publish the results of a world-first trial of a new minimally invasive procedure for the treatment of difficult-to-treat high blood pressure by using radio waves.
In the first international randomized controlled trial of the technology, sympathetic nerves leading into and out of the kidneys were silenced using radio frequency energy emitted by a catheter device inserted into the renal arteries through the groin.
The Symplicity® Catheter System - the device used to perform renal denervation - has now received TGA approval in Australia and it is anticipated that it will be available for routine clinical application within the next 12 months.
Known as 'renal denervation', this minimally invasive day procedure has been proven to be extremely effective in reducing blood pressure in patients with uncontrolled blood pressure - that is, blood pressure that is not responsive to medication.
Research has shown that each incremental 20/10 mmHg increase of blood pressure above normal levels is associated with a doubling of cardiovascular mortality over a 10 year period and that reducing systolic blood pressure by as little as 5 mmHg can reduce the risk of stroke by almost 30 per cent.
Professor Murray Esler, Associate Director, Cardiovascular Neurosciences at Baker IDI, was the Chief Investigator for the international trial, which involved 106 randomized patients in Europe and Australia across 24 separate sites.
In a presentation to the American Heart Association this week, Professor Esler will discuss the results of the trial. The key finding, which will be published simultaneously in The Lancet, was that the procedure resulted in an average blood pressure reduction of 33/11mmHg when compared to the control group that did not undergo the procedure.
The procedure is highly effective with 84 per cent of patients who underwent renal denervation experiencing a reduction in systolic blood pressure by more than 10 mmHg. The study also found that the therapy was safe, with no serious device or procedure-related events, no cardiovascular complications and no kidney-related complications.
Hypertension is the biggest killer worldwide with around 7.1 million deaths per year directly attributed to uncontrolled blood pressure. In Australia, between 25 to 30 per cent of the adult population is affected by high blood pressure and about half of those patients' blood pressure is not controlled to target through medication.
Commenting on the trial, Professor Esler said, "Combined with findings from the earlier Symplicity HTN-1 study, which demonstrated the safety and durability of the therapy out to two years, these results show that this procedure has the potential to become a truly revolutionary treatment with the scope to significantly impact the standard of care for the large number of patients suffering from uncontrolled blood pressure."
Principle Investigator Professor Markus Schlaich of Baker IDI said, "Hypertension often has no symptoms yet significantly increases a patient's risk of heart attack, stroke or death.
"We know the renal sympathetic nerves play a crucial role in blood pressure elevation and this study proves they can be specifically targeted with our novel approach. Renal denervation is a safe, quick and minimally invasive procedure that leads to a substantial and sustained blood pressure reduction without major side effects."
In addition to hypertension, the therapy may hold promise for treating heart failure, diabetes and chronic kidney disease, conditions also characterised by elevated sympathetic nerve activity.
