How well does ambulatory blood pressure predict target-organ disease and clinical outcome in patients with hypertension?

Abstract

For many years, it has been evident that ambulatory blood pressure monitoring is superior to the measurement of office blood pressure as a predictor of target-organ involvement in patients with hypertension. Until recently, there were far fewer data on the relationship between 24 h ambulatory blood pressure and cardiovascular outcomes such as myocardial infarction, stroke, and cardiovascular death. In 1983, Perloff et al. published their seminal report on awake ambulatory blood pressure as a predictor of cardiovascular outcomes. During the 16 years that have passed since that publication, several additional prospective ambulatory blood pressure studies have been completed, in five different countries. The basis for all these investigations has been to assess the predictive value of ambulatory blood pressure as a determinant of either cardiovascular morbidity (myocardial infarction, cerebrovascular accidents, and vascular surgical procedures) or mortality. With the exception of the Systolic Hypertension in Europe (Syst-Eur) trial, all these studies have been uncontrolled for therapeutic interventions. Typically, the average follow-up period for each trial has been 3-9 years. All these studies have shown that ambulatory blood pressure is a much better predictor of cardiovascular events than the standard office or clinic pressure. In addition, hypertensive patients whose nocturnal (or sleep) blood pressure remains high (that is, those who have a 'non-dipper' circadian blood pressure profile) have a worse outcome than patients whose nocturnal blood pressure decline is at least 10%. These data all support the desirability of increased utilization of 24 h ambulatory blood pressure monitoring in clinical trials of antihypertensive drugs and in the management of hypertensive patients in clinical practice.