Delays in sponsorship and funding necessitate a stop in the study set up.

Hypertension, or high blood pressure, is a major cause of preventable illness and premature death, affecting millions in the UK. Despite effective treatments, many patients struggle to achieve adequate blood pressure control. This study evaluates the effectiveness of the OptiZ. OptiZ is a mobile phone application ("app") intended to be installed on a mobile device as part of a treatment for hypertension for use by patients prescribed Zestril (lisinopril). The OptiZ app helps patients record blood pressure, dose-related side effects, and medication adherence, send reports to healthcare professionals for dose adjustments, set reminders to log their medication and blood pressure readings, and access information about high blood pressure and health tips.

This is a real-world observational study involving adults diagnosed with essential hypertension who are eligible for Zestril treatment. Recruitment will occur at selected GP practices across England over six months, with participants followed for 12 months. The study aims to enrol 113 participants. Using the OptiZ app, participants will record daily blood pressure readings, track medication adherence, record dose-related side effects, and access educational content on hypertension management. Healthcare professionals will use reports generated by the app to personalise Zestril dosing.

The main objective is to evaluate the OptiZ app's impact on reducing systolic blood pressure during the dose adjustment phase. Secondary objectives include adherence to Zestril, how often patients log blood pressure readings onto the OptiZ app and other patient-reported outcomes. Participants will also complete electronic questionnaires to provide feedback on their experience using the OptiZ app and their perceptions of hypertension treatment.

This study is funded by Closed Loop Medicine Ltd and Atnahs Pharma UK Ltd. The findings aim to improve hypertension care by using digital tools to enhance adherence, optimise dosing, and potentially reduce cardiovascular risks while guiding future digital solutions for chronic conditions.

Inclusion Criteria:

1. Participants must be 18 years or older.
2. Participants must have a diagnosis of essential hypertension.
3. Participants must be eligible for Zestril prescription as part of their hypertension treatment plan, in line with the NICE stepwise approach, based on the clinical judgment of the responsible healthcare professional
4. Participants need to be willing to self-monitor, must be able to use a smartphone (iOS 16+ or Android 11+). A carer aged 18+ can use the app on their behalf if needed.
5. Participants must provide written informed consent to participate in the study, including agreeing to adhere to the study procedures.

Exclusion Criteria:

1. Participants with the following comorbidities: heart failure, a history of acute myocardial infarction, renal complications associated with diabetes mellitus, known clinically significant renal impairment (eGFR < 60 ml/min/1.73 m2). Participants with a strongly activated renin-angiotensin- aldosterone system (such as those with renovascular hypertension, salt and/or volume depletion, cardiac decompensation, or severe hypertension).
2. Participants with severe cognitive impairment or severe visual impairment/blindness that would prevent effective use of the smartphone app or self-monitoring using a blood pressure monitor (applies only if no carer is available).
3. Clinically significant abnormal blood results as judged by the responsible healthcare professional (including but not limited to, known abnormal serum potassium and/or blood urea nitrogen/serum creatinine renal).
4. Failure to satisfy the responsible healthcare professional of fitness to participate for any other reason.

Uncomplicated primary hypertension cohort in England