Clinical benefits of consistent reduction in the daily blood pressure of hypertensive patients.

Mean 24-hour blood pressure (BP) values are more closely associated with cardiovascular events and target organ damage than are clinic measurements, and therefore may be more useful for assessing drug efficacy. Clinically important information may also be contained in other data derived from ambulatory BP measurement. For example, both daytime and nighttime BPs are correlated with organ damage and cardiovascular events. BP variability is also correlated with organ damage and events. This observation is important because BP variability may differ greatly among individuals and may increase markedly in hypertension. A large increase in BP variability may also occur with some antihypertensive drugs, particularly those whose efficacy declines as they are metabolized. The most important aim of antihypertensive therapy should be the dynamic control of BP-lower BP and lower BP variability.