Central blood pressure measurement and validation: What is still needed?

Abstract

Accurate measurement of blood pressure (BP) is a critical goal for appropriate diagnosis and management of high BP. The measurement reference standard is brachial cuff BP, but recent large-scale meta-analyses show major deficiencies in the accuracy of this method. Indeed, irrespective of cuff technique (e.g. mercury auscultation or oscillometry) brachial cuff BP measures lack precision for representing the BP within both the brachial artery and the central aorta. These data clearly indicate the need to refine and improve methods to measure BP accurately, whether at the brachial or central aortic level, with preference towards the latter as the best representation of pressure loading experienced by the organs at risk from hypertension. The current focus to improve measurement of central aortic BP is on better calibration methods, with mean arterial pressure (MAP) and diastolic BP (DBP) proposed as the best solution. However, the ability to accurately estimate central aortic BP using this calibration method appears to be device-specific and related to the capacity of different devices to accurately measure MAP/DBP using conventional cuff BP. Beyond this, even if we can accurately measure MAP/DBP using non-invasive cuff methods, this does not necessarily provide a final solution because characteristic waveform features and the level of systolic BP amplification still influence accuracy. Thus, altogether, manufacturers of devices purporting to measure central aortic BP need to provide robust evidence about accuracy performance; preferably according to ARTERY Society recommendations.