P5.13 Estimation of Central Systolic Pressure: Are Peripheral Waveforms and Transfer Function Necessary?

Background and aim The degree of systolic pressure amplification (SPamp) from aorta to brachial artery depends on a number of variables including age, gender, heart rate and arterial stiffness. It is admitted that central systolic blood pressure (cSBP) cannot be predicted with sufficient accuracy from brachial blood pressure and thus needs to be estimated using peripheral waveform analysis and transfer functions. We have developed a proprietary method for direct central blood pressure (DCBP) estimation, which challenges this paradigm. In the present preliminary study, our DCBP method was applied to a meta-analysis of published studies with invasive, high-fidelity pressure tip data of both aortic and brachial artery pressures. Methods and results Five studies were found fulfilling our criteria. There were 282 subjects (77.3% male), with known or suspected coronary artery diseases. Mean age was 63.3±13.2years and heart rate was 67.1±11.3bpm. Invasive brachial systolic, diastolic and mean BP were 137.9±19.9mmHg, 70.9±10.2mmHg and 97.1±11.7mmHg, respectively. The measured invasive cSBP was 131.1±19.9mmHg and the mean SPamp was 6.8mmHg. The cSBP estimated with DCBP method was 132.9mmHg and the mean difference with invasive measures was 1.8mmHg. Conclusion The meta-analysis of studies documenting invasive high-fidelity pressure at aortic and brachial artery level indicates that our DCBP method can predict cSBP from brachial blood pressures with good accuracy in relatively old subjects with established or suspected coronary diseases. Further studies are needed to document the precision of the DCBP method in healthier and younger subjects as well as its sensibility to peripheral BP measuring method.