A preliminary evaluation of the mean arterial pressure as measured by cuff oscillometry

BACKGROUND The brachial artery (BA) mean blood pressure (MBIP) is now readily available using the oscillometric technique. In contrast to the auscultatory method where MBP is calculated from the systolic (SBP) and diastolic blood pressure (DBP), oscillometric MBP is measured separately from either SBP or DBP. Because the peripheral MBP is free of amplification, it is nearly the same throughout the entire arterial tree and could represent the corresponding aortic pressure. The oscillometric brachial MBP could therefore serve as a surrogate for aortic MBP and might be a valuable non-invasive risk predictor. METHODS This study compares the oscillometric BA pressures with simultaneously and directly recorded aortic pressures in 100 patients. RESULTS These results show that, over a wide range of cuff pressures, the oscillometric MBP, whether alone or with age in multiple regression, predicts aortic pressure better than the SBP or DBP do, with a better correlation coefficient (r = +0.91), low aortic-cuff MBP difference (-0.79 mm Hg) and the lowest s.d. of the individual differences (+7.2 mm Hg). CONCLUSIONS These results are preliminary and need to be confirmed by larger studies. If confirmed, the predicted aortic pressures should be calculated and displayed by the oscillometric BP devices, the goal being to develop better non-invasive cardiovascular (CV) risk predictors.