High blood pressure affects millions worldwide, yet identifying the underlying cause can be a diagnostic odyssey for patients and physicians. Now, a breakthrough imaging technique developed by University College London researchers offers a perhaps faster and more accurate path to diagnosis, notably for a frequently missed hormonal contributor. The novel scan-detailed in a study published Wednesday in the New England journal of Medicine-could substantially improve treatment strategies and reduce the risk of serious cardiovascular complications for those with difficult-to-control hypertension.
High blood pressure, a widespread health concern globally, can be difficult to manage for many patients despite treatment. A new imaging advancement may help doctors more quickly identify a frequently overlooked hormonal cause and select the most appropriate treatment.
A novel scan, taking just ten minutes to complete, could improve care for millions living with hypertension, according to a study led by researchers at University College London (UCL). The findings were published Wednesday in the New England Journal of Medicine. Identifying the root cause of high blood pressure is crucial for effective treatment and preventing serious complications like heart disease and stroke.
Approximately one in four individuals with high blood pressure may have adrenal glands that produce too much aldosterone, a hormone that regulates the body’s salt balance. Excess aldosterone raises blood pressure by causing the body to retain sodium and water, potentially leading to primary hyperaldosteronism – also known as Conn’s syndrome – a condition linked to an increased risk of heart disease, stroke, and kidney damage.
Researchers emphasize that many patients likely don’t meet the traditional criteria for primary hyperaldosteronism, yet still have elevated aldosterone levels contributing to their hypertension.
Currently, diagnosing this cause is complex. Initial screening involves a blood test, followed by a confirmatory test, and typically requires an invasive procedure called adrenal vein sampling to determine the best course of treatment.
Adrenal vein sampling involves inserting two catheters through the groin veins to measure aldosterone levels from each adrenal gland, aiming to pinpoint whether the excess hormone originates from one or both glands. The procedure is technically challenging, available at limited centers, and doesn’t always provide definitive results, leading to many cases remaining undiagnosed.
The new test utilizes PET-CT, a technique combining computed tomography (CT) scans with positron emission tomography (PET) to create detailed 3D images and track the distribution of a radioactive tracer injected intravenously.
The UCL team developed the new substance, designed to selectively bind to aldosterone synthase, the enzyme responsible for producing aldosterone.
During the scan, the tracer accumulates in areas of the adrenal glands that are overproducing the hormone, making them visible even when standard tests fail to detect the issue.
In the first clinical study using this method, conducted at UCLH, 17 patients were investigated, and the source of excessive aldosterone production was identified in each case, with no observable adverse reactions.
Researchers say this direct visualization of hormonal “hot spots” would greatly simplify treatment decisions: either through surgical removal of the responsible adrenal gland when the problem is localized to one side, or with targeted medication to block aldosterone production when both glands are involved.
Professor Bryan Williams, clinical lead of the study and head of the Department of Medicine at UCL, said that a test like this has been anticipated for decades and could substantially change how excess aldosterone – a significant and often unidentified cause of hypertension – is diagnosed. The findings offer hope for more personalized and effective treatment strategies for patients with difficult-to-control blood pressure.
The intensity of the signal on the scan appears to correlate with the level of hormone overproduction, potentially allowing for even more precise treatments in the future, targeting the hyperactive areas directly.
The innovation follows more than ten years of research by the UCL team, who developed and patented the method for producing the radioactive tracers. They adapted a molecule with a drug-like structure, replacing a single atom with a radioactive variant, allowing the compound to be tracked using PET-CT.
The team is now preparing a Phase 2 clinical trial to gather the data needed for approval of the test for routine use within the National Health Service (NHS).
In the United Kingdom, over 14 million people – approximately one in three adults – have high blood pressure. Rapidly identifying a treatable hormonal cause could significantly impact disease control and reduce the risk of cardiovascular and kidney complications.
