An Updated Wearable Magnetic Flux Device to Optimize Blood Pressure Control

Hypertension is significant public health problem locally as well as internationally. Untreated hypertension results in much morbidity and mortality. In Singapore, there is a significant proportion of poorly controlled hypertensives, with its attendant risks. The compliance to antihypertensive medications has been reported at about only 50%. Several pertinent factors have been brought up including dislike of oral medications, having too many medications, cost of chronic medications and side effects of medications. Several studies have also pointed out the importance of combining various components (e.g. regimen simplification, patient behavioural modification, communication and education by health professionals) in order to improve antihypertensives adherence.

This project aims to study the impact of static magnetic flux on blood pressure control. If efficacious, this may potentially provide an effective, non-invasive, non-pharmacological option for blood pressure control. In addition, the project aims to incorporate this static magnetic flux into a wearable, portable device to increase its availability and uptake. This may potentially increase compliance amongst patients who may be non-compliant to oral medications, and help reduce the attendant mortality and morbidity associated with hypertension.

In this double-blind randomized control trial, 200 participants (140 hypertensive, 60 normotensive) will be recruited. Participants will be randomized into 2:1:1 to receive the original strength magnetic device vs half strength magnetic device (half the strength of the original magnetic device) vs the sham device respectively. The half strength arm will allow us to evaluate the dose-response effect of the magnetic field. The magnetic and sham devices will be made identical in appearance and numbered for assignment purposes during the period of the trial. Study team and participants will be blinded to whether they are receiving the magnetic device or sham device.

The study participation will consist of 2 visits, an initial visit and device return visit. The participants will wear a 24hr ambulatory blood pressure (ABP) monitor for 24 hours, whereas the study device will be worn only for 8 hours. Prior to that, a blood pressure measurement will be taken at rest to confirm eligibility. Baseline ABP measurement will be taken for 3-4 hours, followed by the additional study device to be worn for the next 8 hours. Subsequently, participants will remove the study device leaving only the ABP monitor for the rest of the remaining hours. The first 3-4 hours will give an indication of the subject's baseline blood pressure. The next 8hr will give an indication of the effect of the device. The remainder 12-13hr will allow us to see the impact on blood pressure after the device is removed. The subjects will be required to complete a hardcopy questionnaire on their baseline demographics, characteristics, experience with the device, and any side effects.

Inclusion criteria

• For normotensive patients, Systolic Blood Pressure 100-139mmHg/ Diastolic Blood Pressure 50-89mmHg
• For hypertensive patients, SBP 140-180mmHg, DBP 90-110mmHg (no change in blood pressure medications in last one month) OR Hypertensive patients with stable blood pressure (SBP not <100, DBP not <50) well controlled on medication

Exclusion criteria

• SBP <100mmHg, DBP<50mmHg
• SBP>180mmHg, DBP >110mmHg
• Recent change (<1month) in blood pressure medications
• Prior stroke
• Prior ischemic heart disease
• Prior peripheral vascular heart disease
• Prior carotid stenosis or bruit
• Presence of metallic implants (e.g. ICD, pacemaker, etc)
• Pregnancy
• Breast feeding
• Allergy to device material/skin allergy