Targeted Thermal Therapy could transform management of common cause of high blood pressure

Doctors at Queen Mary University of London, Barts Health NHS Trust, and University College London have led the development of a simple, minimally invasive Targeted Thermal Therapy (Triple T) that has the potential to transform medical management of a common, but commonly overlooked, cause of high blood pressure.

This breakthrough, published today in The Lancet, could, after further testing, help millions of people worldwide who currently go undiagnosed and untreated.

In the UK, Triple T, known scientifically as endoscopic ultrasound-guided radiofrequency ablation, was rigorously tested, in collaboration with researchers from University College London, University College Hospital NHS Trust, Cambridge University NHS Trust, and the University of Cambridge.

A hidden cause of high blood pressure

High blood pressure affects one in three adults, of whom a hormonal condition called primary aldosteronism accounts for one in twenty cases. However, fewer than one percent of those affected are ever diagnosed.

The condition occurs when tiny benign nodules 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 attacks, strokes, and kidney failure.

A game-changing alternative to surgery

Until now, the only effective cure for primary aldosteronism has been surgical removal of the entire adrenal gland, requiring general anaesthesia, a two-to three-day hospital stay, and weeks of recovery. As a result, many patients go untreated.

Triple T offers a faster, safer alternative to surgery, by selectively destroying the small adrenal nodule without removing the gland. This is made possible by recent advances in diagnostic scans, using molecular dyes that accurately identify and locate even the smallest adrenal nodules. Those in the left adrenal gland are seen to be immediately adjacent to the stomach, from where they can be directly targeted.

The new treatment harnesses the energy of waves, adapting two well-established medical techniques: radiofrequency or microwaves generate heat in a small needle placed into the malfunctioning tissue, causing a controlled burn; ultrasound uses reflected sound waves to create a real-time video of the procedure.

In Triple T, as in routine endoscopy, a tiny internal camera—in this case using ultrasound as well as light—is passed by mouth into the stomach. The endoscopist visualises 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.

Successful trial shows promise

The study is called FABULAS, the name being an acronym for Feasibility study of radiofrequency endoscopic ABlation, with ULtrasound guidance, as a non-surgical, Adrenal Sparing treatment for aldosterone-producing adenomas.

FABULAS tested Triple T in 28 patients with primary aldosteronism, whose molecular scan had pinpointed a hormone-producing nodule in the left adrenal gland. 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.

It is 70 years since the discovery in London of the hormone aldosterone, and, a year later, of the first patient in USA with severe hypertension due to an aldosterone-producing tumour. This patient's doctor, Jerome Conn, predicted, with perhaps only minor exaggeration, that 10-20% of all hypertensions might one day be traced to curable nodules in one or both glands. We are now able to realise this prospect, offering 21st-century breakthroughs in diagnosis and treatment."

Professor Morris Brown, co-senior author of the FABULAS study and Professor of Endocrine Hypertension at Queen Mary University of London

One of the trial participants, Michelina Alfieri, shared her experience:

"Before the study, I suffered from debilitating headaches for years despite multiple GP visits. As a full-time worker and single parent, my daily life was severely affected. This non-invasive treatment provided an immediate recovery—I was back to my normal routine straight away. I'm incredibly grateful to the team for giving me this choice."

What's next?

The success of FABULAS has led to a larger randomised trial called 'WAVE', which is comparing Triple T with traditional adrenal surgery. 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, added: "With appropriate training, this less invasive technique could be widely offered in endoscopy units across the UK and internationally."

Clinical Endocrinology Lead at Addenbrooke's Hospital and Professor of Clinical Endocrinology at the University of Cambridge, Professor Mark Gurnell, said: "This breakthrough was made possible thanks to the collaborative development of novel PET tracer molecules, which enable non-invasive diagnosis by allowing us to precisely locate and treat adrenal nodules for the first time.

"Thanks to this work, we may finally be able to diagnose and treat more people with primary aldosteronism, lowering their risk of developing cardiovascular diseases and other complications, and reducing the number of people dependent on long-term blood pressure medication," he added.

A major step forward for hypertension treatment

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 and Cambridge Biomedical Research Centres (BRCs), and the British Heart Foundation.

It is being followed by a larger randomised trial, called 'WAVE', which will compare TTT to traditional surgery in 120 patients. The results are expected in 2027.