P109 Reservoir-Excess Pressure Characteristics Help Identify People with High Intra-Arterial Aortic Systolic Blood Pressure

Abstract

Background

High aortic blood pressure (BP) predicts clinical outcomes beyond peripheral BP. Aortic BP may differ according to level of systolic BP (SBP)-amplification but these differences cannot be identified using current non-invasive BP measurement methods. In this study, we sought to determine if high intra-arterial aortic BP could be detected via reservoir-excess pressure characteristics.

Methods

Standard cuff BP, SphygmoCor-derived central BP (CBP), and intraarterial aortic and brachial waveforms were recorded in 160 participants (61 ±11 years, 68% male) during coronary angiography. SBP-amplification was defined as ≥5 mmHg increase in SBP across the aortic-to-brachial arteries, whereas no SBP-amplification was defined as 0.20 both). Aortic, but not brachial, reservoir pressure was significantly higher in participants with no SBP-amplification (2506 ± 662 versus 2239 ± 640 Pa/s, p = 0.011). This pattern was also observed for aortic excess pressure (718 ± 304 versus 624 ± 293 Pa/s, p = 0.049) and aortic diastolic rate constant (0.021 ± 0.08 versus 0.025 ± 0.09 s⁻¹, p = 0.002). All differences remained after adjustment for age, sex and intra-arterial aortic SBP.

Conclusions

Reservoir-excess pressure characteristics help identify people with high intra-arterial aortic BP that are otherwise missed using cuff BP or SphygmoCor-derived CBP. Thus, analysis of BP waveforms using reservoir-excess pressure characteristics could be used to refine accuracy of BP measurement.