CLINICAL TRIALS START FOR TREATING HYPERTENSION

British scientists believe they could cure millions of patients with hard-to-treat high blood pressure and hypertension.

A simple operation would involve removing a small cluster of nerves in the throat linked to blood pressure regulation.

Researchers from Bristol University are extremely hopeful the measures could help some 2.5 million individuals with hypertension that cannot be controlled by medication.

While scientists have already started a clinical trial on 20 people with high blood pressure – following successful laboratory tests on rats – if the trials prove to be successful and is given the go-ahead, the surgical procedure could be available within three years as a ‘relatively simple’ day treatment for adults. The novel approach successfully ‘cured’ the condition in laboratory rats.

The carotid body is one of the body’s smallest organs but acts as a sensor that detects changes in gas levels in the blood. Sometimes, however, it can become overactive.

Known as the silent killer, high blood pressure or hypertension affects a third of adults and significantly raises the odds of heart attacks, strokes and other potentially fatal conditions if left untreated.

At the moment, there is no effective remedy for individuals who do not respond to conventional drug therapies.

But scientists at Bristol’s School of Physiology and Pharmacology identified a key organ in the development of high blood pressure – the carotid body.

It consists of a tiny cluster of nerve cells that sit on the side of the two branches of the carotid artery in the neck, each the size of a grain of rice.

Despite being one of the body’s smallest organs, it has the highest blood flow of them all – reflecting its importance as an early warning device for the brain if there is any change to oxygen and carbon dioxide levels in the blood.

In some cases, it is thought the carotid body becomes overactive and sends a message to the brain to keep blood pressure high. Scientists involved in removing the organs in rats with hypertension found that blood pressure fell and remained low.

The study, which was funded by the British Heart Foundation, and first published in the journal Nature Communications, said the animals suffered no adverse side-effects either.

In human trials, only one carotid body would be removed in order to reduce blood pressure while maintaining the organ’s vital regulatory function.

Professor Julian Paton who is the lead researcher on the study, said:

… We know that these tiny organs behaved differently in conditions of hypertension, but had absolutely no idea that they contributed so massively to the generation of high blood pressure; this is really most exciting.

… It certainly has the potential to be a very novel interventional approach to drug-resistant hypertension (high blood pressure).

An estimated 16 million British adults have high blood pressure; a third of whom may be unaware they have the condition.

Patients are often at first advised to alter their lifestyle by taking more exercise, stopping smoking, cutting down on drinking and limiting the salt and fat in their diet.

GPs can also prescribe medication – often a combination of pills – but many patients skip doses because of the side-effects caused by most treatments. Up to 15 per cent of patients – 2.5 million people – also struggle to control their condition using drugs.

Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said:

… This potential new treatment has real promise to help this hard-to-treat group of patients … Many patients can control their blood pressure adequately by lifestyle change and medication so they would not be offered this kind of treatment.

… It is therefore unlikely this treatment will ever be tested as an alternative to standard medication – only as an extra procedure when current drug treatment fails.

A consultant cardiologist at Sheffield Teaching Hospital referred to the breakthrough as an ‘exciting and innovative approach’ and added that current treatments for high blood pressure have serious drawbacks, such as no-one likes taking multiple tablets and that medics are often guilty of not explaining properly why treatment is needed and what benefits might be expected.