Ear Nerve Stimulation Fails to Beat Placebo for Blood Pressure, but Hints at Help
A small handheld device that gently stimulates nerves in the ear could eventually offer a new way to treat stubborn high blood pressure, but a clinical trial found no significant benefit across all participants. The results of the SCRATCH-HTN trial were published in Hypertension, a journal of the American Heart Association.
The trial included 63 patients who were already taking blood pressure medication. The treatment proved safe, easy to use at home and well tolerated.
How the device works
The experimental treatment is called transcutaneous autonomic neuromodulation (tAN). It aims to influence the autonomic nervous system, the network of nerves that automatically controls heart rate, digestion and blood pressure. The device, made by Afferent Medical Solutions, uses two small clips placed on the tragus, the small flap of cartilage just in front of the ear canal. They deliver mild electrical signals, so patients can treat themselves at home without a clinic visit and without any invasive procedure.
What the trial found
Participants generally found the treatment comfortable, and most followed the prescribed schedule, which suggests it could be practical for regular home use. However, when the researchers compared blood pressure changes across the whole study population, they found no statistically significant difference between patients receiving active stimulation and those using a sham device, a look-alike that gives no real treatment.
A prespecified subgroup analysis, a comparison planned before the results were seen, showed a greater drop in blood pressure among participants who entered the trial with more severe hypertension when they received active stimulation instead of sham. The trial was relatively small, and the researchers say this subgroup result needs confirmation in larger studies before any conclusions can be drawn about effectiveness.
"This is an exciting, highly patient-acceptable technology that could ultimately provide a cheap, scalable solution for millions," said Dr. Ajay Gupta, chief investigator, clinical reader at Queen Mary University of London and consultant physician at Barts Health NHS Trust. "Although the trial did not achieve significance across the broad unselected group, those with more severe hypertension exhibited a clear blood pressure reduction in the active group compared to sham."
Why it matters
High blood pressure, or hypertension, is a major contributor to cardiovascular disease and raises the risk of heart attacks and strokes. Medications help many patients, but a substantial number still have readings above recommended targets despite treatment. Ear nerve stimulation is one approach that could complement existing therapies if future research shows that it reliably lowers blood pressure in certain patients.
For now, the authors describe the findings as an early step rather than proof of an effective treatment. Larger trials are needed to confirm the result in severe hypertension and to identify who might benefit. More on this topic is in our health section.