A device implanted in one of the major blood vessels in the neck has been shown to significantly lower dangerously high blood pressure in a trial group of patients, according to research published in The Lancet.
One of the research team, BRC Director Professor Bryan Williams, will now lead the global pivotal study of this new technology, which is about to start recruiting patients at UCLH.
The first-in-man study tested MobiusHD, a small, four-sided titanium implant, and reported data from the results of the first 30 patients implanted with the device in Europe. Results showed that the majority of the patients saw their blood pressure reduced towards normal levels within just a few months.
MobiusHD works by controlling hypertension using the body’s natural hypertension control mechanism. The implant is positioned in a branch of one of the carotid arteries – major blood vessels that run up either side of the neck, supplying the head; and applies a tiny amount of force to baroreceptors – nerves that help regulate blood pressure. The baroreceptors sense changes in blood pressure and send signals to the brain to keep blood pressure at safe levels.
Ordinarily, the carotid arteries are stretched by untreated hypertension and the baroreceptors signal to the brain to bring the blood pressure back to a normal level. As a result, the heart rate changes, causing blood vessels to dilate or contract. In drug-resistant patients however, long-term raised blood pressure causes the baroreceptors to malfunction and set the body’s resting blood pressure at a dangerously high level. MobiusHD is designed to exert pressure on these nerves, duping the brain into thinking blood pressure is consistently raised. It then signals to the body to lower the heart rate and widen the blood vessels.
To implant MobiusHD, clinicians make a tiny incision in an artery in the groin and a fine catheter, carrying the implant, is inserted. The catheter is then eased through the circulation system and into the carotid artery, where it is left in an area known as the carotid sinus, where the baroreceptors are situated. This is carried out under local anaesthetic and MobiusHD is left in the carotid artery permanently.
The Lancet study provides proof of concept for the pivotal CALM-2 (Controlling and Lowering Blood Pressure with MobiusHD) study which will involve researchers from the UK, the Netherlands, Germany and the US. CALM-2 is a pivotal global trial to investigate drug-resistant hypertension treatment using MobiusHD further, which will take place at UCLH with Professor Williams as Global Chief Investigator; Professor Greg Stone from Columbia University; and US medical device company Vascular Dynamics in California as collaborating industry partner.
Hypertension was recently identified by the WHO as the leading cause of preventable death globally, accounting for about 10 million deaths per year. There are approximately 12 million people living with hypertension in the UK. When blood pressure is uncontrolled or untreated hypertension it can result in stroke, heart attacks and vascular dementia. Resistant hypertension affects approximately 500,000 patients in the UK, whose blood pressure remains uncontrolled despite conventional drug treatment.
Visit The Lancet to read Endovascular baroreflex amplification for resistant hypertension: a safety and proof-of-principle clinical study.
