First Use of an Ingestible Sensor to Manage Uncontrolled Blood Pressure in Primary Practice: The UK Hypertension Registry

Background: Primary care physicians used a CE-marked ingestible sensor in a real world setting to assess patients with persistent hypertension. The objectives were to (1) characterize the pattern of their medication use, (2) differentiate medication use from pharmacologic unresponsiveness as a potential underlying cause for uncontrolled hypertension; (3) categorize and summarize subsequent management decisions; and (4) assess the usability and acceptability of passive electronic monitoring for managing hypertension. Methods: There were 167 patients with uncontrolled hypertension whilst chronically prescribed 2 to 5 antihypertensives; 40% were chronically prescribed ≥ 3 antihypertensives. Patients were instructed to ingest a pharmacologically inert tablet containing the ingestible sensor whenever they took their prescribed medications. A wearable sensor on the patient's torso passively recorded the dates/times of tablet ingestion. Taking adherence (i.e., the total number passively detected divided by the total number prescribed) and timing adherence were determined for a period of two weeks with no change in therapy. Findings: Taking adherence ranged from 53-100%; timing adherence ranged from 21-100%. Systolic blood pressure decreased from 154 ± 13 to 145 ± 18 mmHg (mean -9.7 mmHg; 95% CI: -12.5, -7.0 mmHg, p<0.001). Diastolic blood pressure decreased from 85 ± 11 to 80 ± 12 mmHg (mean -5.0 mmHg; 95% CI: -6.5, -3.5 mmHg, p<0.001). Thirty-two percent (32%) of participants achieved their treatment goals using their existing therapy. Subsequent management included: medication reviews and/or adherence counseling with no anti-hypertensive changes in 81%, anti-hypertensive changes in 13%, referrals to specialists in 1%, and no additional actions were taken in 6%. Practitioners found the offering easy to utilise, and the majority of patients expressed a positive experience in using it. Conclusion: In patients with uncontrolled blood pressure, the inclusion of an ingestible sensor in everyday practice helped practitioners to identify potential factors contributing to persistent hypertension and to determine subsequent patient-specific interventions.