P5.4 Central Pressure Appraisal: Clinical Validation of a Subject-Specific Mathematical Model

Increased blood pressure represents a major cardiovascular risk factor for western populations. Usually blood pressure is measured peripherally, but current evidence suggested that central blood pressure better predicts cardiovascular events. However, central blood pressure measurement is not feasible in daily clinical practice. New instruments can estimate non-invasively central blood pressure from applanation tonometry at peripheral sites and transfer function. Accuracy of this evaluation has been questioned. Remarkable development in medical imaging and computation techniques granted the opportunity to explore mathematical models describing the cardiovascular functioning. Aim of the present study is the clinical validation of a mathematical model for appraisal of central blood pressure from subject-specific non-invasive measurements (i.e. brachial pressure, age, height, weight, ESV, EDV, etc.). A total of 52 healthy young male were selected for the present study. Central pressures were estimated with subject-specific model and compared with a common non-invasive technique (Sphygmocor). Model estimated systolic and diastolic blood pressure resulted to be significantly related to Sphygmocor central systolic (r 0.65 p <0.0001) and diastolic (r 0.84 p<0.0001) blood pressure. The model showed a significant over-estimation of systolic (+7.8 [−2.2;14] mmHg, p = 0.0003) and underestimation of diastolic (−3.2 [−7.5;1.6], p = 0.004) values. In conclusion, the proposed mathematical model allows non-invasive prediction of central aortic pressure with good accuracy in more than one half of this population. Both the systematic over-estimation of aortic systolic pressure and the under-estimation of diastolic values compare well with the error reported by large meta-analysis when Sphygmocor is used with non-invasive calibration.