Phenotypes of Hypertensive Ambulatory Blood Pressure Patterns: Design and Rationale of the ECHORN Hypertension Study

Objective: To describe the rationale and design of a prospective study of ambula­tory blood pressure measurement (ABPM) combined with measurement of contextual factors to identify hypertensive phenotypes in a Caribbean population with high rates of HTN and cardiovascular disease. Design: Prospective, multi-center sub-study. Setting: Eastern Caribbean Health Outcomes Research Network Cohort (ECHORN) Study, with study sites in Puerto Rico, the US Virgin Islands, Trinidad and Tobago, and Barbados. Participants: Community-residing adults without a diagnosis of HTN and not taking antihypertensive medication. Intervention: Ambulatory BP patterns are assessed using 24-hour ABPM. Contextual factors are assessed with: ecological mo­mentary assessment (7-item survey of expe­riences, exposures and responses associated with daytime BP measurements); actigra­phy (capturing physical activity and sleep quality); and self-report surveys (assessing physical and social health, environmental and social stressors and supports). Main Outcome Measures: Phenotypes of contextual factors associated with hyperten­sive BP patterns (sustained HTN, masked HTN, and nocturnal non-dipping) Methods and Results: This study will enroll 500 participants; assessments of blood pressure and contextual factors will be conducted during Waves 2 and 3 of the ECHORN parent study, occurring 2 years apart. In Wave 2, we will assess the associa­tion between contextual factors and ABPM patterns. Using advanced analytic clustering methods, we will identify phenotypes of contextual factors associated with hyper­tensive ABPM patterns. We will then test the stability of these phenotypes and their ability to predict change in ABPM patterns between Waves 2 and 3. Conclusions: Assessment of ABPM, and the contextual factors influencing ABPM, can identify unique phenotypes of HTN, which can then be used to develop more preci­sion-based approaches to the prevention, detection and treatment of HTN in high-risk populations. Ethn Dis. 2019;29(4):535-544; doi:10.18865/ed.29.4.535