Surrogates of surrogates: the story of hypertension and 24 h blood pressure monitoring.

Ambulatory blood pressure (ABP) monitoring is emerging as a useful tool in the diagnosis and management of hypertension. It is particularly useful in certain settings, such as the identification of patients with 'white coat hypertension', the evaluation of patients with unexplained symptoms or end-organ damage, the study of circadian variations in BP and the management of patients with refractory hypertension (as assessed by office BP measurements), and as a guide to antihypertensive treatment. Recent data suggest that ABP monitoring may be superior to office BP measurements in the assessment of risk of hypertensive end-organ damage and clinical events. However, further evidence that the use of ABP monitoring can improve patients' clinical outcomes is needed and would make the use of this promising technique more compelling and more widely accepted.