‘Coin’ in the wrist cuts high blood pressure
DIscs the size of 10p coins are being implanted into patients’ wrists to control high blood pressure. The discs emit pulses of electricity to stimulate nerves in the arm — these then transmit signals to the blood pressure control centres in the brain.
Initial results from a study involving nearly 50 patients show the discs led to significant drops in blood pressure compared with a placebo.
More than 300 patients across the U.s. are taking part in a new trial.
High blood pressure, or hypertension, affects more than one in four adults in Britain, but many are unaware of it because the condition doesn’t always cause noticeable symptoms.
However, left untreated, hypertension increases the risk of serious problems, including heart attacks and strokes.
Hypertension can be controlled with pills such as AcE inhibitors or calcium channel blockers to widen blood vessels, but many patients don’t respond to drug treatment, or can’t tolerate side-effects, which can include dizziness, an upset stomach and dry cough.
Doctors have been working on new approaches to the problem, with some success with treatments involving the nervous system, which plays a key role in the control of blood pressure.
In one new procedure, renal denervation, tiny nerves in the lining of the arteries of the kidney are destroyed to stop faulty signals from the brain to these nerves.
This has been shown to reduce the kidneys’ production of hormones that raise blood pressure. However, this involves invasive surgery and doesn’t work for everyone.
THE coins are another way to treat the problem via the nervous system. They are implanted under the skin in each forearm, a couple of inches above the wrist and over the median nerve, which runs along the length of the arm.
The nerve transmits signals to the various brain areas that control blood pressure — stimulating it is thought to ‘reset’ the brain’s blood pressure signals.
The implants, named ecoin, are inserted in a 20-minute procedure under local anaesthetic. Once in place, the devices send pulses of electricity automatically once a week for 30 minutes at a time.
A study of 48 patients with hypertension in New Zealand, Taiwan and canada last year suggested that the implant led to an average drop in blood pressure of 16.7mmHg, much higher than in a placebo group, according to the Journal of the American society of Hypertension.
A larger trial with 306 patients with hypertension is about to start in hospitals across the U.s., with results expected next year.
commenting on the ecoin, Neil Poulter, a professor of preventive cardiovascular medicine at Imperial college london, says: ‘several devices are undergoing investigation, with a view to replacing or supplementing drug therapy for the treatment of difficult hypertension.
‘The ecoin is in the early stages of development but, if the blood pressure changes demonstrated to date are replicated in larger studies over the next few years, and the device is cheap and welltolerated, it may have an interesting future in helping to combat the burden of disease that high blood pressure causes.’
MEANWHILE, a commonly prescribed blood pressure medication may reduce the risk of Alzheimer’s. In a trial at Emory University in the U.s., 72 people with early evidence of the disease will be prescribed candesartan or a placebo pill for a year.
Effects on mental functioning and thinking skills of the groups will be compared.
Previously, a study of 3,000 elderly people taking the blood pressure medication suggested that candesartan was associated with a 50 per cent drop in the risk of developing Alzheimer’s.
One theory is that the drug prevents inflammation in nerve cells and may also stop the buildup of a protein called amyloid, long thought to be a main feature of Alzheimer’s.