Individualized estimation of the central aortic blood pressure waveform: a comparative study

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Hemodynamics

Background:

• Accurate estimation of central aortic blood pressure (BP) waveforms is crucial for cardiovascular assessment.
• Current methods for deriving central aortic BP from peripheral measurements vary in their degree of individualization.
• Understanding the performance differences between individualized and non-individualized approaches is essential for clinical application.

Purpose of the Study:

• To comparatively evaluate the performance of different strategies for estimating individualized central aortic blood pressure (BP) waveforms.
• To assess the impact of individualization in transfer functions on BP waveform estimation accuracy.
• To determine the optimal transfer function approach under varying physiological conditions.

Main Methods:

• Construction of fully individualized (ITF 1), partially individualized (ITF 2, ITF 3), and non-individualized (NITF) transfer functions based on a transmission line model.
• Utilizing experimental data from nine swine subjects for transfer function development.
• Comparison of estimated central aortic BP waveforms against gold standard measurements using root-mean-squared error and absolute errors for systolic and pulse pressures.

Main Results:

• A modest but statistically significant advantage was observed for individualized transfer functions over the non-individualized approach.
• The performance benefit of individualized methods became more pronounced under non-nominal or extreme physiological conditions.
• Partially or fully non-individualized transfer functions showed acceptable performance under nominal physiological conditions.

Conclusions:

• Fully individualized transfer functions (ITF 1) are strongly recommended for estimating central aortic BP waveforms, particularly in non-nominal physiological states.
• Partially individualized (ITF 2, ITF 3) or non-individualized (NITF) transfer functions may provide acceptable accuracy under nominal physiological conditions.
• The degree of individualization in transfer functions impacts the accuracy of central aortic BP waveform estimation, with greater benefits in non-ideal scenarios.