10.7 NON-INVASIVE ESTIMATION OF CENTRAL SYSTOLIC PRESSURE: A COMPARISON BETWEEN RADIAL ARTERY TONOMETRY AND A NEW DIRECT CENTRAL BLOOD PRESSURE ESTIMATION METHOD (DCBP)

Background: We have developed a new proprietary method (DCBP® Direct Central Blood Pressure) to estimate central systolic blood pressure (cSBP) directly from peripheral pressure. In a previous meta-analysis of published high-fidelity pressure studies with simultaneous aortic and brachial pressure recordings, negligible mean difference between DCBP and cSBP has been documented (1). The accuracy and precision of DCBP against arterial tonometry measurements remain to be documented. Methods: The cSBP was estimated from radial artery tonometry and a transfer function using a SphygmoCor® system (AtCor Medical, Australia) in 100 subjects (mean age+/-SD = 57+/-10 years). Pressure waveforms were calibrated from the brachial systolic and diastolic pressures, measured just prior to tonometric measurement with an oscillometric cuff system (Omron 705CP Omron, Japan). DCBP and cSBP were compared using the Bland and Altman method and subgroups were compared using unpaired Student’s t test. Results: The difference between DCBP (129.2+/−16.8 mmHg) and cSBP (129.4+/−16.4 mmHg) was −0.2+/−2.6 mmHg. The difference was not influenced by the mean (DCBP + cSBP / 2). Similar results were obtained in men (n=60) and women (n=40), and in subjects with/without hypertension (n=51/49), with/without diabetes (26/74), and with/without dyslipidemia (36/64). Conclusions: The new DCBP® method and the transfer function applied to radial tonometry method were interchangeable in estimating central SBP. These results pertained strictly to the studied population (patients aged 57 years on average, and displaying a high percentage of cardiovascular risk factors). Further studies are needed to confirm our results.