How to Measure 24-hour Central Blood Pressure and Its Potential Clinical Implications.

The evaluation of 24-hour central blood pressure (24h cBP) combines the cBP non-invasive assessment with the 24-h ambulatory BP measurement. The major strength of the 24-h cBP evaluation is the ability to assess the degree of circadian changes between central and peripheral BP, namely 24-h BP amplification. This allows an accurate quantification of the degree of spatial and temporal BP variability in each single individual. BP amplification depends from a number of factors, such as the interaction between pressure and flow pulsatile motions, vasomotor tone, arterial tapering and other physiological and anthropometrical determinants. The assessment of 24-h BP amplification, a relatively pressure-independent parameter, may be helpful in better refining the risk of organ damage and future CV events over traditional measures of office and 24-h brachial BP. Currently, only few devices enable the assessment of 24-h cBP. These devices are based on peripheral (brachial or radial) BP waveform detection, and reconstruction of central BP waveform through mathematical models. The estimation of 24-h cBP imputed from multivariate regression equations was also proposed. Clinical data are still scarce and, although suggesting a possible superiority of 24-h cBP over brachial BP in the association with markers of organ damage, they are limited by methodological and technical aspects. There is urgent need of a standardized methodology and rigorous validation protocols for the 24-h cBP assessment. The field of 24-h cBP measurement still requires significant advancements of scientific knowledge before its introduction into clinical practice.