A minimally invasive therapy that has the potential to transform treatment of a common cause of high blood pressure, has been developed by researchers at UCL, Queen Mary University of London and Barts Health.
High blood pressure affects around one in three adults in the UK, with estimates suggesting that at least one in twenty cases are caused by a hormonal condition called primary aldosteronism. However, only a small percentage of those affected by primary aldosteronism are ever diagnosed.
The condition occurs when tiny benign nodules (abnormal tissue growths) in one or both adrenal glands produce excess aldosterone, a hormone that raises blood pressure by increasing salt levels in the body. Patients with primary aldosteronism often do not respond well to standard blood pressure medications and face higher risks of heart attack, stroke, and kidney failure.
Findings from the FABULAS study, published in The Lancet, describe initial results for Targeted Thermal Therapy (Triple T), which was tested in 28 patients with primary aldosteronism, whose molecular scan had pinpointed a hormone-producing nodule in the left adrenal gland.
Triple T offers a faster, safer alternative to surgery, by selectively destroying the small adrenal nodules without removing the gland. This is made possible by recent advances in diagnostic scans, using molecular dyes that accurately identify even the smallest nodules.
The new treatment harnesses the energy of waves, adapting two well-established medical techniques. Microwaves generate heat in a small needle placed into the abnormal tissue, causing a controlled burn, while ultrasound uses reflected sound waves to create real-time imaging of the procedure.
In Triple T, as in routine endoscopy, a tiny internal camera that uses ultrasound as well as light is passed by mouth into the stomach.
The endoscopist visualizes the adrenal gland and guides a fine needle from the stomach precisely into the nodule. Short bursts of heat destroy the nodule but leave the surrounding healthy tissues unharmed. This minimally invasive approach takes only 20 minutes and eliminates the need for internal or external incisions.
The new procedure was found to be safe and effective, with most patients having normal hormone levels six months later. Many participants were able to stop all blood pressure medications, with no recurrence of the condition.
Triple T, known scientifically as endoscopic ultrasound-guided radiofrequency ablation, was rigorously tested in collaboration with researchers from University College Hospital (UCLH), Cambridge University NHS Trust and the University of Cambridge, and Queen Mary University of London.
After further testing, Triple T could help millions of people worldwide who currently go undiagnosed and untreated for high blood pressure.
Professor Morris Brown, co-senior author of the FABULAS study and Professor of Endocrine Hypertension at Queen Mary University of London, said: "It is 70 years since the discovery in London of the hormone aldosterone, and a year later the first patient with severe hypertension due to an aldosterone-producing tumor in the USA.
This patient's doctor, Jerome Conn, predicted, with perhaps only minor exaggeration, that 10-20% of all hypertension cases might one day be traced to curable nodules in one or both adrenal glands. We are now able to realize this prospect, offering 21st-century breakthroughs in diagnosis and treatment."
Morris Brown, Professor, Queen Mary University of London
Until now, the only effective cure for primary aldosteronism has been surgical removal of the entire adrenal gland, requiring general anesthesia, a two-to three-day hospital stay and weeks of recovery. As a result, many patients go untreated.
The adrenal glands, which are located on top of each kidney, help to control important bodily functions like blood pressure and metabolism. They also make the activity hormones cortisol, adrenaline and noradrenaline, which are important for wellbeing and boost organ function in response to stress.
The success of FABULAS has led to a larger randomized trial called 'WAVE', which is comparing Triple T with traditional adrenal surgery in 120 patients. The results are expected in 2027.
Professor Stephen Pereira, Chief Investigator of FABULAS and Professor of Hepatology & Gastroenterology at UCL Institute for Liver and Digestive Health, said: "With appropriate training, this less invasive technique could be widely offered in endoscopy units across the UK and internationally and become standard practice if these initial results, which show that Triple T is safe and effective, are confirmed by the ongoing WAVE study."
For the millions of people suffering from undiagnosed primary aldosteronism, this research offers new hope. Safely targeted thermal therapy, delivered by mouth, could replace major surgery, allowing faster recovery and better outcomes.
With further studies underway, this breakthrough treatment could soon become a standard procedure worldwide, transforming care for patients with this curable form of hypertension.
The research was primarily supported by Barts Charity, National Institute for Health and Care Research (NIHR) through the Barts, Cambridge and UCLH Biomedical Research Centres (BRCs), and the British Heart Foundation.
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