[White-coat hypertension].

Abstract

White-coat hypertension may be broadly defined by the coexistence of normal ambulatory, or self-measured, blood pressure (BP) with persistently increased clinic BP. White-coat hypertension should not be considered as a separate clinical entity, but, rather, as a low-risk stratum of essential hypertension which may be identified using ambulatory BP monitoring or self-measured BP. One possible cause of white-coat hypertension may be a conditioned response to the clinical visit, with consequent alerting reaction and rise in BP. Specifically, white-coat hypertension may be defined by an average daytime ambulatory BP ideally less than 130 mm Hg systolic and 80 mm Hg diastolic (or, at least, 134 mm Hg systolic and 90 mm Hg diastolic) in untreated subjects with essential hypertension and clinic BP above 140 mm Hg systolic or 90 mm Hg diastolic for at least three visits. Several cross sectional studies have shown that hypertensive target organ damage (TOD) is not dissimilar between clinically normotensive subjects and subjects with white-coat hypertension but this finding is still controversial. Moreover, nearly all studies have shown that TOD is lesser in subjects with white-coat hypertension than in those with higher levels of ambulatory BP. Evidence is accumulating that white-coat hypertension is a condition of low cardiovascular risk. In this setting, a prospective study from our center and preliminary data from another center suggest that the incidence of serious cardiovascular complications of hypertension (myocardial infarction, sudden death, stroke, etc) is lower in subjects with white-coat hypertension than in those with ambulatory hypertension, and not dissimilar between subjects with white-coat hypertension and clinically normotensive subjects. Further prospective studies are needed to clarify the very-long term history of white-coat hypertension and to test the hypothesis that antihypertensive drug treatment may not be necessary, as unable to improve an already good prognosis, in uncomplicated subjects with white-coat hypertension and absence of concomitant risk factors.