The clinical significance of white-coat and masked hypertension

Self-measured blood pressure (BP) and 24-hour ambulatory blood pressure (ABP) monitoring are used to define the arbitrary clinical categories of masked hypertension (MH) and white-coat hypertension (WCH). Severity of target organ damage and incidence of major cardiovascular events are greater in patients with MH than in patients whose BP is normal both inside and outside the doctor's office.

We reviewed studies that addressed the prognostic impact of MH and WCH.

Overall, WCH was associated with a better outcome and MH to a poor outcome. We, however, need the criteria to identify the clinically normotensive patients at elevated pretest probability of MH in whom a broad use of self-measured home BP and 24-hour ambulatory BP as screening tests may be appropriate and cost effective. Clinical management of patients with MH should continue to be based on current guidelines and mostly related to target organ damage and associated clinical conditions because of the normal values of clinic BP in these patients. WCH is generally defined by the coexistence of persistently high office BP with normal daytime or 24-hour ABP. Daytime ABP normalcy has been defined by values<135/85 mmHg. Data, however, suggest that incidence of cardiovascular events tends to increase consistently above the cut-off value of 130/80 mmHg for daytime BP.

The long-term outcome of patients with WCH remains uncertain. Data suggesting an increased risk of stroke need to be confirmed in wide-scale studies.