CT scan enables detection and cure of the commonest cause of high blood pressure

Doctors at Queen Mary University of London, Barts Hospital, and Cambridge University Hospital led research that used a novel form of CT scan to identify microscopic nodules in a hormone gland and remove them to correct high blood pressure. One in every twenty patients with high blood pressure has nodules.

The study, published today in Nature Medicine, tackles a 60-year-old challenge of detecting hormone-producing nodules without a rigorous catheter study that is only offered in a few institutions and frequently fails. The study also discovered that when paired with a urine test, the scan reveals a subset of patients who discontinue all blood pressure medications following therapy.

128 participants took part in a new scan research after physicians discovered that their hypertension (high blood pressure) was caused by a steroid hormone called aldosterone. The scan discovered that two-thirds of individuals with increased aldosterone secretion have a benign lesion in only one of the adrenal glands, which may be safely removed. The scan employs a low-dose of metomidate, a radioactive tracer that adheres solely to the aldosterone-producing nodule. The scan was just as accurate as the traditional catheter test, but it was faster, less painful, and technically effective in every patient.

The catheter test could not determine which individuals will be entirely cured of hypertension by surgical excision of the gland until today.

By contrast, the combination of a ‘hot nodule’ on the scan and urine steroid test detected 18 of the 24 patients who achieved a normal blood pressure off all their drugs.

The research, conducted on patients at Barts Hospital, Cambridge University Hospital, and Guy’s and St Thomas’s, and Universities of Glasgow and Birmingham, was funded by the National Institute for Health and Care Research (NIHR) and Medical Research Council (MRC) partnership, Barts Charity, and the British Heart Foundation.

Professor Morris Brown, co-senior author of the study and Professor of Endocrine Hypertension at Queen Mary University of London, said: “These aldosterone-producing nodules are very small and easily overlooked on a regular CT scan. When they glow for a few minutes after our injection, they are revealed as the obvious cause of Hypertension, which can often then be cured. Until now, 99% are never diagnosed because of the difficulty and unavailability of tests. Hopefully this is about to change.”

Professor William Drake, co-senior author of the study and Professor of Clinical Endocrinology at Queen Mary University of London, said:”This study was the result of years of hard work and collaboration between centres across the UK. Much of the ‘on the ground’ energy and drive came from the talented research fellows who, in addition to doing this innovative work, gave selflessly of their time and energy during the national pandemic emergency. The future of research in this area is in very safe hands.”

The aetiology of Hypertension (high blood pressure) is unclear in the majority of cases, and the illness need long-term pharmacological therapy. Previous study by the Queen Mary University group found that a gene mutation in the adrenal glands causes an excess of the steroid hormone aldosterone to be generated in 5-10% of persons with hypertension. Aldosterone increases salt retention in the body, raising blood pressure. Patients with high aldosterone levels in their blood are resistant to treatment with routinely used hypertension medicines, and they are at a higher risk of heart attacks and strokes.