Ambulatory blood pressure monitoring in treated hypertensive patients--implications for clinical practice.

Studies involving patients receiving longterm antihypertensive therapy have demonstrated a high prevalence of a white coat effect both in the tertiary care setting and in the community. The likelihood of finding a white coat effect is greater in patients with higher office systolic blood pressures and in women. The possibility that some hypertensive patients in the community may be receiving unnecessary therapy is currently being investigated in a study involving 98 uncomplicated hypertensive patients who have had treatment withdrawn for up to three years. To date, it appears that at least 40% of such patients may remain off treatment without re-developing hypertension or exhibiting any increase in left ventricular mass. Physicians should follow existing recommendations on the use of ambulatory blood pressure recording in order to avoid over-diagnosis and unnecessary treatment of hypertension.