Although the treatment did not significantly lower blood pressure compared with a placebo device across all participants, researchers observed encouraging results in patients with more severe hypertension. The findings suggest that stimulating nerves in the ear could eventually help certain people whose blood pressure remains elevated despite taking medication.

The results come from the SCRATCH-HTN trial, published in Hypertension, a journal of the American Heart Association. Researchers emphasize that larger studies are needed to determine whether the approach can provide meaningful benefits and which patients might respond best.

How Ear Nerve Stimulation Could Lower Blood Pressure

The experimental treatment uses a technique called transcutaneous autonomic neuromodulation (tAN), which aims to influence the autonomic nervous system. This network of nerves automatically controls essential bodily functions, including heart rate, digestion, and blood pressure.

By delivering mild electrical signals to nerves in the ear, researchers hope to influence the body's natural mechanisms for regulating blood pressure without requiring an invasive procedure.

The handheld device, developed by Afferent Medical Solutions, uses two small clips positioned on the tragus, the small flap of cartilage located just in front of the ear canal. These clips deliver gentle electrical stimulation, allowing patients to administer the treatment themselves without visiting a clinic.

Clinical Trial Tests the Device in 63 Patients

The clinical trial, funded by the National Institute for Health and Care Research (NIHR), enrolled 63 people with uncontrolled hypertension. All participants were already taking at least one medication to lower their blood pressure, but their readings remained above recommended levels.

Researchers randomly divided the participants into two groups. One received active nerve stimulation, while the other used a sham device designed to serve as a comparison. This approach helped investigators assess whether the electrical stimulation produced benefits beyond those associated with using the device itself.

Participants used their assigned devices for 30 minutes daily during the first two weeks. For the following 10 weeks, they reduced their sessions to once per week.

The results showed that the treatment was safe and generally comfortable for participants. Most also followed the prescribed schedule, suggesting that the technology could be practical for regular use at home.

However, when researchers compared blood pressure changes across the entire study population, they found no statistically significant difference between patients receiving active stimulation and those using the sham device.

Promising Results in Patients With Severe Hypertension

Despite the lack of a significant overall benefit, the researchers identified a potentially important finding among participants who entered the trial with more severe hypertension.

A prespecified subgroup analysis, meaning the researchers had planned this comparison before examining the results, revealed a greater reduction in blood pressure among these patients when they received active nerve stimulation rather than the sham treatment.

This finding raises the possibility that the technique may work better for people with particularly difficult-to-control blood pressure. However, the trial was relatively small, and the subgroup results require confirmation in larger studies before any conclusions can be drawn about its effectiveness.

Dr. Ajay Gupta, Chief Investigator, Clinical Reader at Queen Mary University of London and Consultant Physician at Barts Health NHS Trust, said:

"This is an exciting, highly patient-acceptable technology that could ultimately provide a cheap, scalable solution for millions. 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.

"As the first and most thorough study of its kind, this points towards important new research directions that could help us understand whether non-invasive neuromodulation can benefit particular groups of patients with uncontrolled hypertension."

A Potential New Option for Hard-to-Control Blood Pressure

High blood pressure, also known as hypertension, is a major contributor to cardiovascular disease and increases the risk of heart attacks and strokes. It places additional strain on blood vessels and the heart, potentially causing serious damage over time.

Although medications help many patients manage their condition, a substantial number continue to have blood pressure readings above recommended targets even while receiving treatment.

This ongoing challenge has encouraged scientists to explore additional approaches that could complement existing therapies.

Ear nerve stimulation is one such possibility. Because the device is small, does not require surgery, and can be used at home, it could offer a convenient option if future research establishes that it reliably lowers blood pressure in certain patients.

For now, the findings represent an early step rather than proof of an effective new treatment. The researchers say larger clinical trials will be essential to confirm the encouraging results in patients with severe hypertension and identify which groups, if any, could benefit most from this approach.