P060 a Novel Non-Invasive Method for Estimating Central Systolic Blood Pressure Using Ambulatory Blood Pressure Monitoring

Background and Objective: Central blood pressure (BP) holds superior prognostic value compared to peripheral BP in predicting cardiovascular events. Despite its significance, measuring central BP in outpatient settings is impractical. To address this limitation, our research group devised a novel non-invasive method for estimating central systolic blood pressure (cSBP) using peripheral data based on the equation proposed by Chemla et al. However, its validity remains uncertain. The objective was to assess the validity of our new non-invasive method for estimating cSBP by comparing it to a validated brachial oscillometric method. Methods: A cross-sectional study was conducted, involving 132 patients who underwent 24-hour ambulatory blood pressure monitoring (24-h ABPM). A total of 8,112 BP records were obtained. The cSBP was measured during 24-h ABPM using a Custo Screen 310 device (Custo, Ottobrunn, Germany), which has been validated. The cSBP was estimated using the formula: cSBP= MAP2/DBP, where MAP2 represents the estimated mean arterial pressure using the equation: MAP2=(Ts/T) × SBP + (Td/T) × DBP, where T, Ts, and Td denote the cardiac, systolic, and diastolic periods, respectively. The SBP indicate systolic blood pressure and DBP denote diastolic blood pressure. Ts was calculated as: Ts=0.2061+ (Age/2244) + (T/8.17). Results: Among the participants, 53.8% were men, with an average age of 55±16 years. The average height was 1.65±0.1 m, weight 74±12 kg, heart rate 71±12 bpm, SBP 125±19 mmHg, DBP 79±12 mmHg, and cSBP 120±19 mmHg. The agreement of cSBP between the new method and the brachial oscillometric method was very good. Bland-Altman plots revealed that the differences between the methods were randomly distributed along the mean difference line (Figure). Conclusions: The new non-invasive method to estimate cSBP from peripheral BP data, using MAP2 and cardiac periods, has been demonstrated to be valid. The equation, which allows for the estimation of cSBP without a pulse wave, could be easily implemented in conventional 24-h ABPM systems.