Uncontrolled out-of-office blood pressure (BP), measured by either home BP monitoring (HBPM) or ambulatory BP monitoring, has been shown to predict higher cardiovascular risk. However, HBPM could not identify daytime BP surge, which leads to underestimation of future risk among treated hypertensive individuals.

HeartGuide provides validated out-of-office BP measurements, along with activity/sleep recordings. The present study is designed to examine whether BP monitoring with the HeartGuide could identify masked uncontrolled hypertension in controlled hypertensive patients based on office BP. We will enroll hypertensive patients with controlled office BP according to their cardiovascular risk profile. We will also examine prevalence of post-prandial BP changes and BP variability using HeartGuide.

Recent hypertension guidelines stressed the importance of out-of-office BP monitoring. Ambulatory BP (ABPM) and home BP monitoring (HBPM) both predict future cardiovascular events better than office BP. Masked hypertension is an important issue. As revealed by recent studies, daytime BP surge can result in greater target organ damage for high-risk hypertensive individuals.

Previous trials such as TASMINH2 and TASMINH-SR study showed positive effects of HBPM on BP control in hypertensive patients. However, several issues preclude perfect applications of HBPM. For example, HBPM could not provide BP recordings during activity or at night-time. In addition, the currently recommended time schedule for HBPM may be insufficient for detecting daytime surge especially among high-risk individuals. Wearable BP devices seem to fill in this gap as a novel approach of out-of-office monitoring.

HeartGuide, the new watch BP monitor, was recently validated to provide accurate BP measurements. It could provide incremental knowledge with potentially larger numbers of recordings. The primary objective of this study is to unveil uncontrolled masked hypertension with HeartGuide, particularly for those undetected with current office BP and HBPM. A second objective is to assess diurnal BP trends and BP variability.

Inclusion Criteria:

• Willing to sign informed consent form
• Currently taking anti-hypertensive therapy for more than 3 months
• Drugs are unchanged during the study period
• Office BP below 140/90 mmHg at least one visit

Exclusion Criteria:

• Diagnosed with terminal illness
• End-stage renal disease requiring lifelong dialysis treatment
• Patients with impaired performance status (ECOG >= 2)
• Women undergoing or expecting pregnancy during the study period
• Resistant hypertension (taking more than 4 kinds of anti-hypertensive drugs)
• Known atrial or ventricular arrhythmia
• Wrist circumference out-of range between 13.5 to 21.5 cm

Participants routinely treated at out-patient clinics for hypertension are to be enrolled after informed consent.