Development and Validation of a Novel Method to Derive Central Aortic Systolic Pressure From the Radial Pressure Waveform Using an N-Point Moving Average Method

Abstract

We show that an NPMA with a denominator of one-quarter of the tonometer sampling frequency accurately defines CASP when applied to noninvasively acquired RAPWFs in man. These novel findings have important implications for the simplification of noninvasive CASP measurement and its wider application in clinical trials and clinical practice.

Comparison of two measuring instruments, B-pro and SphygmoCor system as reference, to evaluate central systolic blood pressure and radial augmentation index

“…To this we may add the slight underestimation of CASP with SphygmoCor vs. the invasive method, as has already been reported by other authors 22,23 -a situation that does not appear to occur with B-Pro. 12 Williams et al 12 The correlation found between the two measurements of CASP (r¼0.94, Po0.01) was also similar to that reported by Williams et al, depending on the method employed (r¼0.95 or r¼0.99). However, the intraclass correlation in this study was intermediate between the two (r¼0.97, 95%CI: 0.96-0.98)-thus indicating that the measures may be inter-exchangeable.…”

“…Central blood pressure was measured with Pulse Wave Application Software (B-Pro+A-Pulse software; HealthSTATS International) using tonometry attached to a wrist (like a wristwatch) to record the radial pulse with the patient in the sitting position and resting the arm on a firm surface, using an equation to estimate CASP. 12 The increases in central blood pressure, mean blood pressure and rAIx were estimated as well. rAIx was calculated from the radial wave pulse as follows: (second peak SBP (SBP2)ÀDBP)/(first peak SBPÀDBP)Â100, 13 as seen in Figure 1.…”

“…7,11 Recently, a new system has been developed that estimates derived aortic pressure using an n-point moving average method (B-Pro device s + A-pulse software). 12 This device has been validated in some sub-populations, particularly in the high-risk hypertensive individuals and in the Asian populations, but it has not been validated to date in healthy Caucasians without drug treatment. The morphology of the radial pulse can also be used to estimate the peripheral or radial augmentation index (rAIx), as a parameter assessing vascular structure and function.…”

Effect of angiotensin receptor blockade on central aortic systolic blood pressure in hypertensive Asians measured using radial tonometry: an open prospective cohort study

“…This tonometric method has been validated against the gold standard of direct aortic root measurement during cardiac catheterisation, with excellent correlation (r = 0.99). (9) A recent study involving patients with type I diabetes mellitus also showed that there was good agreement between the CASP readings measured using both the SphygmoCor and BPro devices; (10) i.e. any differences observed were within the acceptable limits recommended by the Association for the Advancement of Medical Instrumentation (AAMI) and the European Society of Hypertension (ESH).…”

Changes in the practice of cardiology: therapies at the forefront of science

“…(7) The BPro watch, developed by Dr Ting Choon Meng, a Singaporean doctor and an inventor of medical devices, was validated to accurately measure CASP. (8) This study is important to the cardiology community, as CASP has been shown to predict cardiovascular events better than brachial blood pressure. (9) Moreover, ARBs are thought to act more favourably on CASP than other classes of antihypertensive drugs, albeit only in Western populations.…”