A new 10-minute scan may significantly improve treatment for millions of people with high blood pressure, according to a study led by researchers at University College London (UCL).
An estimated quarter of individuals with hypertension have overactive adrenal glands that produce excess aldosterone. Yet this issue often goes undetected because the diagnostic process is complicated, requires several tests, and relies on an invasive procedure that is not always reliable.
The new scan, developed at UCL and described in a research letter in the New England Journal of Medicine, identifies adrenal overactivity that conventional tests miss, pinpointing exactly where excess aldosterone is produced. This precision may help clinicians select the most effective treatment, either surgically removing the overactive adrenal gland or prescribing targeted medications that block aldosterone production.
Study researchers believe this innovation has the potential to transform the diagnosis of aldosterone excess as an important and previously hidden cause of hypertension in many of our patients. It offers huge potential to completely change the way clinicians make this diagnosis and enable them to provide better targeted treatment for patients.
Excess aldosterone causes the body to retain too much salt, raising blood pressure and contributing to primary aldosteronism, a condition linked to higher risks of heart disease, stroke, and kidney disease. Even people who do not fully meet diagnostic criteria for the condition may have clinically meaningful aldosterone excess.
Current diagnostic pathways start with a blood test, followed by a confirmatory assessment. Treatment decisions require adrenal vein sampling, threading two catheters through the veins in the groin to measure aldosterone levels from each adrenal gland. The procedure is complex, not widely available, and can yield uncertain results.
To create a more accurate alternative, UCL researchers used PET-CT imaging, combining detailed 3D CT images with PET scans that track a radioactive tracer. They developed a new tracer designed to bind specifically to aldosterone synthase, the enzyme responsible for producing aldosterone. The tracer accumulated only in overactive regions of the adrenal gland, which then “lit up” on the scan.
In the first global use of this technique, 17 patients were scanned at UCLH. The team identified the source of aldosterone overproduction in every case, with no observed side effects.
This is the first time clinicians have been able to visualise this disease as it can be lit up on the scan. The intensity of the signal reflects the level of aldosterone overproduction. This might allow clinicians, in future, to more precisely target these over-producing areas.
The study, funded by the MRC and the NIHR University College London Hospitals Biomedical Research Centre, was conducted at UCL and UCLH. A phase 2 clinical trial is now underway to collect the data needed for NHS approval of the test.
Source: University College London
Image Credit: iStock
