Ambulatory blood pressure as a predictor of target organ disease and outcome in the hypertensive patient.

Since the early 1980s, when Perloff and colleagues published their seminal report on awake ambulatory blood pressure as a predictor of cardiovascular outcomes, there have been several additional prospective ambulatory blood pressure studies that have been completed in five different countries. The basis for all of these investigations was to assess the predictive value of ambulatory blood pressure as a determinant of either cardiovascular morbidity (typically myocardial infarction, cerebrovascular accidents, and vascular surgical procedures) or mortality. With the exception of Syst-Eur, all of these studies have been uncontrolled for therapeutic interventions. Typically, the average follow-up period for each trial has been three to nine years. Despite these limitations, all of the studies have shown that ambulatory blood pressure is a far better predictor of cardiovascular events than the standard office or clinic blood pressure. Furthermore, the hypertensive patients whose nocturnal (or sleep) blood pressure remains high (i.e. non-dipper circadian blood pressure profile) have a much worse outcome compared with patients whose nocturnal blood pressure decline is over 10%.