Relationship between the level, pattern and variability of ambulatory blood pressure and target organ damage in hypertension.

Certain forms of preclinical cardiovascular disease are critical to the transition between hypertension and the development of cardiovascular morbid events. The level of the echocardiographic left ventricular mass is a stronger predictor of death or non-fatal events than arterial pressure or any other risk factor except advancing age. While the evidence shows a closer relationship between ambulatory compared with clinic blood pressure measurements and left ventricular mass or other measures of hypertensive disease, it is not clear which measures of ambulatory blood pressure are the most important. Present evidence weakly favors systolic over diastolic ambulatory pressure and daytime over night-time pressures. Further studies of large, well defined populations with standardized components of ambulatory blood pressure and well validated measures of hypertensive target organ damage are needed.