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The William Harvey Research Institute - Faculty of Medicine and Dentistry


Sham controlled Randomized Control Trial evaluating the Safety, Acceptability and Efficacy of Autonomic neuromodulation using trans-cutaneous auricular sensory stimulation in uncontrolled hypertensive patients: a pilot study evaluating a novel non-invasive device-based strategy (SCRATCH–HTN).

About the study

SCRATCH-HTN aims to explore a new way of managing high blood pressure (BP), specifically in people who have raised BP despite being on antihypertensive medications. Participants will use an external self-administered device, which is like a TENS machine, which produces a small electrical current and which may result in a decrease in BP.

The aim of the study is to see how effective the device is in the treatment of uncontrolled hypertension, and to see if it is comfortable and safe to use.

This study is conducted in accordance with the ethical standards of the institutional research ethics committee (REC number: 21/WS/0157) and is a registered clinical trial on (NCT05179343) and ISCRTN (ISRCTN14509154).

Please see Patient Information Sheet [PDF 368KB] (PIS) for more information about the study.

Why is it important?

High BP is the leading risk factor for death and illness from a cardiovascular event, and managing high BP is a key focus of treatment for cardiovascular diseases. Antihypertensive drugs are widely available, however a high number of people with high BP fail to achieve a healthy BP value despite receiving 1 or more anti-hypertensive medications. For uncontrolled hypertensive patients, including drug-resistant patients, the lack of an effective therapy is a major health challenge and an urgent unmet clinical need. One potentially highly effective strategy to improve BP control in hypertension is via redressing the nervous system imbalance, which is linked with the development of hypertension; the brain controls the cardiovascular system by sending commands through the nervous system. In this study, we will use a device that produces a very small electrical current to the nerves at the front area of the ears (the tragus). With this strategy, we aim to correct the nervous system imbalance, and treat hypertension.

Who can participate?

Patient Information Sheet [PDF 368KB] to view the participant information sheet

You can participate if you are aged ≥18 years and <80 years and:

  • You are taking between 1 to 4 antihypertensive medications
  • Have a confirmed diagnosis of hypertension

Have one or more of the following associated conditions:

  • Obesity
  • Type 2 diabetes
  • Increased heart rate
  • High glycated haemoglobin or fasting glucose AND low high density lipoprotein cholesterol or high triglyceride
  • Diagnosed polycystic ovarian syndrome

If you’re a female, you should be post-menopausal or surgically sterile or willing to use contraception during the period of the trial.

What happens next

If you decide to take part in the study, we will first carry out a screening assessment to make sure you are suitable for the trial. If you are suitable, we will train you to use the device. You will be asked to use the device for 30 minutes for 14 days, and once a week thereafter for 10 weeks. Please see the following video showing the device and how to use it.

Watch the SCRATCH-HTN Video

During the trial you will be asked to remain on your medication and not change it throughout the trial. You will be asked to come to the clinical facility at least five times in a period of 4 months.

Please note that all information provided and collected is confidential, and we will only use the anonymised data (data where all personally identifiable information has been removed )for the purpose of analysis and research publications.


For further information about the SCRATCH-HTN study, please email our research personnel at 

Address: William Harvey Clinical Research Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry Queen Mary University of London, Charterhouse Square, London EC1M 6BQ

Tel: 0800 471 4683

Chief Investigator: Dr Ajay Gupta
Co-investigators: Dr David Collier, Dr Manish Saxena

Additional resources for participants and others interested


This trial is funded by the National Institute for Health Research.

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