Hypertension affects nearly 100% of adults over 75 years of age, and the recent Systolic Blood Pressure Intervention Trial (SPRINT) demonstrated that targeting lower clinic-based blood pressure (BP) measurements prevented cardiovascular disease (CVD) events in older adults. However, hypotension-related hospitalizations were among the most significant complications from intensive BP treatment, despite SPRINT's carefully executed BP measurement protocols. The inability of clinic-based BP to predict hypotensive complications has led many to question whether lower BP treatment goals based on clinic BP alone are safe in older adults, who are especially vulnerable to perceived consequences of hypotension, like falls and dementia. While guidelines recommend that BP treatment be informed by standing clinic-based BP measurements and 24-hour ambulatory blood pressure monitoring (ABPM) outside of clinic, the prevalence and long-term implications of (1) low BP upon standing (i.e. orthostatic hypotension [OH]) and (2) large discrepancies between clinic and home BP (?white coat effects? [WCE]) are under-characterized among older adults. In this study, we apply our unique expertise with OH assessments and 24-hour ambulatory blood pressure monitoring (ABPM) to one of the most long-standing and well-respected American cohorts of community-dwelling adults, the Atherosclerosis Risk in Communities Study (ARIC). Our proposal will assess OH and ABPM in 2,345 black and white adults over age 80 years, establishing possibly the largest prospective study of both OH and WCE among older adults in the United States.
Our aims are to quantify the prevalence of OH and WCE in this diverse population and determine the association of OH and WCE with longitudinal change in (1) physical function (balance, gait speed, gait pattern), (2) cognitive function (response time, visuospatial domains), and (3) highly sensitive markers of subclinical cardiac injury and strain, high sensitivity cardiac troponin T and N terminal b-type pro natriuretic peptide. Moreover, we will establish the association of OH and WCE with clinical events related to hypotension ? falls, dementia, and CVD ? over nearly four years of follow-up. Finding that OH and WCE in older adults are not associated with falls, dementia, and CVD would challenge current recommendations to screen for these BP patterns prior to BP treatment initiation or intensification, mitigating delays to treatment. However, finding that OH and WCE are prevalent and associated with falls, dementia, and CVD, particularly among those with elevated clinic BP, would confirm a greater role for these assessments prior to treatment initiation and intensification to avoid adverse events among vulnerable adults. This proposal will inform guidelines for BP management by filling critical gaps in knowledge related to two BP patterns that are often cited as reasons to defer intensive therapy in older adults. Ultimately, our proposal directly answers the call by NHLBI's 2017 expert panel on BP measurement for high impact research that determines: (1) ?the value of using orthostatic hypotension? and (2) ?the role of ABPM?[in the] treatment of hypertension.?
High blood pressure is the most prevalent modifiable risk factor for cardiovascular disease among older adults in the United States. However, unresolved concerns about low blood pressures (upon standing or at home) missed by seated, clinic-based assessments continue to curtail adoption of lower blood pressure treatment goals in older adults, predisposing them to greater risk of cardiovascular events. Our proposal will perform orthostatic hypotension and 24-hour ambulatory blood pressure monitoring assessments in over 2,300 community-dwelling adults, determining the prevalence and clinical implications of low blood pressure patterns on falls, dementia, and cardiovascular disease, thus informing blood pressure treatment strategies in this vulnerable population.
