Treatment of Masked Hypertension

To date, most observational and all intervention studies have defined hypertension on the
basis of clinic blood pressure (BP). Measurement of BP outside the clinic with home or
ambulatory BP provides a better estimate of the risk of cardiovascular disease and all-cause
mortality. Using clinic and ambulatory BPs, patients can be categorized as normotensive
(normal clinic and ambulatory BPs), white-coat hypertension (elevated clinic BP with normal
ambulatory BP), masked hypertension (normal clinic BP with elevated ambulatory BP), and
sustained hypertension (elevated clinic and ambulatory BP). Approximately one third of
patients with chronic kidney disease (CKD) with normal clinic BP have elevated ambulatory BP
(masked hypertension). We demonstrated that, among participants from the Chronic Renal
Insufficiency Cohort (CRIC) study, low estimated glomerular filtration rate (eGFR) and
elevated proteinuria are associated with increased odds of masked hypertension. Additionally,
participants with masked hypertension had increased risk for target organ damage as assessed
by left ventricular mass and pulse wave velocity. These results in participants with CKD are
consistent with prior studies in patients with normal renal function that demonstrated a
two-fold increased risk for cardiovascular events in patients with masked hypertension
compared to patients with normal clinic and ambulatory BP. Despite this elevated risk for
adverse outcomes, patients with masked hypertension have been excluded from hypertension
trials because of their normal clinic BP. Therefore, it is unknown whether the reduction in
target organ damage and adverse cardiovascular outcomes associated with treatment of
hypertension extends to patients with masked hypertension. To address this important gap in
knowledge, we are planning a randomized, controlled trial to evaluate whether
antihypertensive treatment can modify BP patterns in patients with masked hypertension, that
is, convert them to controlled clinic and ambulatory BP. We will also evaluate the effect
antihypertensive treatment on target organ damage in patients with masked hypertension. The
current study is a pilot randomized controlled trial to evaluate the feasibility of the
planned trial and the effect of antihypertensive therapy on clinic and ambulatory BP,
proteinuria, and target organ damage in patients with masked hypertension.