Special scan may reveal a treatable reason for high blood pressure

A specialized scan can help detect small adrenal tumors that drive high blood pressure by producing too much hormone. In selected patients, identifying the source can lead to surgery that improves blood pressure and may even eliminate the need for medication.

The technique is used for primary aldosteronism, a disorder in which the body makes too much aldosterone. This hormone causes the kidneys to hold on to salt and water, which raises blood pressure.

Research published in Nature Medicine compared the scan with an established test that measures blood from the veins draining the adrenal glands. The scan performed similarly, suggesting a less invasive way to find patients who could benefit from surgery.

The adrenal glands are located above the kidneys. A nodule in one gland that produces aldosterone can create a problem that differs from the more common type of high blood pressure, which usually has several contributing causes.

Standard imaging can reveal a nodule, but its appearance does not prove that it is producing excess hormone. Some growths are inactive, and hormone production may also come from both glands.

The study used PET-CT, which combines a scan of chemical activity with an anatomical image. After a preparation process, a short-lived radioactive tracer called carbon-11 metomidate helps highlight the relevant adrenal tissue.

This method can show which gland is responsible, helping distinguish patients who may benefit from surgery from those who are better treated with medicines. It is not intended as a screening scan for everyone with high blood pressure.

The trial included 143 people with primary aldosteronism, and 128 completed the main follow-up assessment. Among them, 78 had surgery and 50 were treated medically.

Researchers compared how well the scan and adrenal-vein sampling predicted correction of the hormone disorder and improvement in blood pressure. The scan met the study’s standard for being no worse than the established test within a predefined margin.

That does not mean the scan was clearly better. Rather, it supports the test as a useful alternative without exaggerating the result.

Fixing excess aldosterone and fully resolving high blood pressure are also not the same outcome. A patient may have the hormone source treated successfully and still need blood-pressure medicine for other reasons.

As a result, the findings do not show a universal cure for high blood pressure. They apply to a specific hormonal subtype and to identifying patients for whom surgery may provide substantial benefit.

The scan also depends on specialist equipment and an appropriate radioactive tracer, so its use will vary according to local resources and expertise. Careful biochemical testing remains part of the process rather than being replaced by an image alone.

The advance offers a more accessible way to look for a potentially reversible cause. Finding the reason for high blood pressure can sometimes reveal a treatment option that simply adding another blood-pressure pill would miss.

If you are interested in this topic, please read articles about What should know about high blood pressure drugs and their side effects, and The DASH diet is a simple way to lower high blood pressure.

For more information, please see articles about Salt and heart health: does less really mean more?, and Prebiotic fiber could manage high blood pressure.

Source: Queen Mary University of London; Barts Health NHS Trust; Cambridge University Hospitals.