New scan Offers Hope for Diagnosing Difficult-to-Treat High Blood Pressure
High blood pressure, affecting over 14 million people in the UK – roughly one in three adults – can sometimes stem from an overproduction of aldosterone, a hormone that regulates salt and water balance. While often overlooked, this hormonal imbalance can significantly contribute to hypertension and increase the risk of serious health problems like heart disease, stroke, and kidney damage. The condition, known as primary hyperaldosteronism or Conn’s syndrome, is often linked to sodium retention.
Currently, diagnosing the root cause of aldosterone-related hypertension is a complex process. initial screening involves a blood test, followed by a confirmatory test. However, pinpointing the source of excess aldosterone often requires adrenal vein catheterization – an invasive procedure involving the insertion of catheters through the groin to measure aldosterone levels on each side of the adrenal glands. This technique is technically challenging, limited to specialized centers, and doesn’t always yield definitive results, leaving many cases undiagnosed.
Researchers at University College London (UCL) have developed a possibly groundbreaking new diagnostic tool utilizing PET-CT (Positron Emission Tomography-Computed Tomography) scanning. This technique combines detailed 3D imaging with the tracking of a newly developed radioactive tracer. The tracer is specifically designed to bind to aldosterone synthase, the enzyme responsible for aldosterone production.
In the scan, the tracer accumulates in areas of the adrenal gland that are overproducing aldosterone, effectively highlighting these “hot spots” even when customary tests fail to detect the issue. A recent initial clinical trial at UCLH involving 17 patients successfully identified the source of excessive aldosterone production in every case, with no reported side effects.
This direct visualization method promises to streamline treatment decisions.If the overproduction is localized to one adrenal gland, surgical removal becomes a viable option. When both glands are involved, targeted drug therapy to block aldosterone production can be implemented.
Professor Bryan Williams, clinical coordinator of the study and chair of the Department of Medicine at UCL, stated that this test has been eagerly anticipated for decades and has the potential to fundamentally change the diagnosis of excess aldosterone, a frequently unidentified cause of hypertension. Moreover, the intensity of the signal on the scan appears to correlate with the degree of hormonal overproduction, potentially enabling more precise and tailored treatments in the future.
The innovation is the culmination of over ten years of research by the UCL team, who developed and patented the method for creating these radioactive tracers. They adapted a drug-like molecule that binds to aldosterone synthase, substituting a single atom with a radioactive variant to allow for tracking via PET-CT.
The team is now preparing for a phase 2 clinical trial to gather the necessary data for approval for routine use within the British National Health Service (NHS). Successfully implementing this test could have a significant impact on managing high blood pressure and reducing the risk of cardiovascular and kidney complications for millions.
