Home Blood Pressure During Night-Time Sleep as a Better Treatment Target for Patients With Hypertensoin: A Proof-of-Concept Randomized Controlled Trial

Objective: Nocturnal blood pressure (BP) has been shown be a stronger predictor of cardiovascular disease and death compared to daytime, office, and 24-hour BP, the feasibility of implementing repeated measurement of nocturnal BP and treating it to target with medications has not been examined. This pilot randomized controlled trial (RCT) aimed to determine the feasibility of measuring home nocturnal BP and treating nocturnal systolic BP (SBP). Design and method: This RCT utilized blocked and stratified (sex/age) randomization to assign hypertensive patients in a 1:1 ratio to the control or intervention group. Participants were patients with daytime hypertension (SBP >=135mmHg) and nighttime hypertension (SBP >=120mmHg) based on a 24-hour ambulatory BP measurement (ABPM). In the intervention group, patients were instructed to measure their nocturnal BP for three days using the WatchBP home N device, measuring 3 BP readings per night during sleep (maximum possible nocturnal BP readings = 9) a week before the doctor’s visit. In the control group, patients were asked to measure their BP in the morning and evening for seven consecutive days using the same device before the consultation. Medications were adjusted every four weeks until respective BP targets (SBP <135mmHg for the control group and <120mmHg for the intervention group) were reached or until the study endpoint (6 months). Results: Within one year, we successfully recruited 78 patients, with a dropout rate of 5.1% (n=4). Both groups had similar baseline characteristics, including age, sex, and BP levels on ABPM. The feasibility of targeting home nocturnal BP measurements was confirmed, with patients in the intervention group providing >=6 nocturnal BP readings in 77.5% of the 160 follow-ups and had similar medication adherence to patients in the control group. At the 6-month, both groups showed similar 24-hour, daytime, and nighttime BP levels, office BP levels, lifestyle adherence, number of visits to primary care clinics, and hospitalizations. Conclusions: This proof-of-concept RCT demonstrates the feasibility of targeting home nocturnal BP as the primary treatment goal for patients with hypertension. A full RCT will examine whether nocturnal BP should be a primary treatment target for hypertension.