Optimizing Precision of Hypertension Care to Maximize Blood Pressure Control (OPTI-BP): A Pilot Study Utilizing a Smartphone App

Background: About half of patients with hypertension (HTN) respond to any given antihypertensive drug. Discordance in pathophysiologic pathways underlying HTN and anti-HTN mechanism of action are major contributors. Personalizing anti-HTN therapy could optimize blood pressure (BP) control. The objective of OPTI-BP was to assess the pragmatic implementation of a smartphone app used to guide physiologically optimal HTN treatment based on plasma renin activity (PRA). Methods: The smartphone app (PRA-HTN) and PRA testing was implemented in three primary care clinics. Patients with untreated or treated but uncontrolled HTN, aged 18-65 years, were recruited. BP and PRA were measured at baseline (and again as often as needed) with final BP measured at 6 months. PRA level and current anti-HTN meds are entered into the app and recommendations to optimize volume- and RAS blocking meds returned. Providers were at liberty to follow or disregard app recommendations. The primary outcome was BP change from baseline to 6 months. Independent t-test was used to compare BP responses of patients whose clinicians followed the app recommendations vs. those who did not. A multivariable linear regression analysis adjusting for baseline BP, age and sex was also conducted. Results: This analysis includes 29 white patients, including 11 (37.9%) women, with a mean age of 52 ± 9 years and a median baseline PRA of 1.3 ng/mL/hr (IQR 0.5-3.1 ng/mL/hr). Mean baseline BP between patients whose clinicians followed the app recommendations (n=16, 55%) vs. those who did not (n=13, 45%) was not statistically different ( P >0.05). After 6 months, the average BP change among patients whose clinicians followed the app recommendations was -14 ± 20/-7 ± 9 mmHg vs. -5 ± 21/-2 ± 9 mmHg among those who did not. In regression analysis, use of app recommended therapy was associated with greater mean BP difference of -13±8/-9±4 mmHg ( P =0.1/0.02). Conclusion: This pilot study demonstrates that PRA testing and implementation of recommendations from a smartphone app that utilizes PRA to optimize anti-HTN therapy was associated with good BP lowering among a relatively small cohort of patients. Future studies using larger sample sizes are warranted to confirm these preliminary findings.