Diagnostic thresholds for the clinical use of ambulatory blood pressure monitoring.

The technique of noninvasive ambulatory blood pressure monitoring is now well established as an instrument in clinical research and as a diagnostic tool in clinical practice. Diagnostic thresholds for ambulatory monitoring were derived by averaging the 95th percentiles of the ambulatory blood pressure measurements in the normotensive subjects enrolled in various large-scale studies. Subjects normotensive on conventional sphygmomanometry, in the absence of other risk factors, have a low cardiovascular risk profile in comparison with their hypertensive counterparts. The evidence from prospective outcome studies also supports the proposed thresholds. More outcome studies are still ongoing. However, their results are unlikely to change the proposed thresholds, which are in line with the recommendations of the JNC VI (the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure) and those of many other national expert committees.