White-Coat Hypertension: the Neglected Subgroup in Hypertension

The clinical prognostic importance of white coat hypertension (WCH), that is, the clinical condition characterized by an increase of office but a normal ambulatory or home blood pressure (BP) is since a long time matter of considerable debate. WCH accounts for a consistent portion of hypertensive patients (up to 30–40%), particularly when hypertension is mild or age is more advanced. Although scanty and inconsistent information is available on the response of office and out-office BP to antihypertensive treatment and the cardiovascular (CV) protection provided by treatment, an increasing body of evidence focusing on the association of WCH with CV risk factors, subclinical cardiac and extra-cardiac organ damage and, more importantly, with CV events indicates that the risk entailed by this condition is intermediate between true normotension and sustained hypertension. This review will address a number of issues concerning WCH with particular attention to prevalence and clinical correlates, relation with subclinical target organ damage and CV morbidity/mortality, therapeutic perspectives. Several topics covered in this review are based on data acquired over the past 20 years by the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study, a longitudinal survey performed by our group on the general population living in the surroundings of Milan area in the north part of Italy.