Smartphone Measurement of Aortic Arch Pulse-Wave Velocity and Total Arterial Compliance: Accessible Local and Global...

Clinical studies have shown that aortic arch pulse-wave velocity (PWV_aa), a measure of local aortic stiffness, is a strong independent predictor of subsequent white matter hyperintensity volume and white matter integrity, both associated with cognitive decline, elevated stroke risk, vascular dementia, and neurodegenerative diseases. Total arterial compliance (TAC), a measure of global arterial stiffness, has been recognized as a marker of preclinical vascular disease. This study introduces a smartphone-based method for the noninvasive measurement of PWV_aa and TAC using carotid pressure waveforms acquired via smartphone.

This method uses intrinsic frequency analysis of smartphone-acquired (iPhone) carotid pressure waveforms to assess PWV_aa and TAC. The method was trained, validated, and blind-tested on a cohort of 132 participants aged 20 to 90 years, including both healthy individuals and those with cardiovascular disease, all of whom underwent cardiac magnetic resonance imaging, tonometry, and iPhone waveform measurements.

In the blind test set, our method achieved Pearson correlations of 0.81 and 0.80 for PWV_aa and TAC, with biases of -0.20 m/s and -0.06 mL/mm Hg and limits of agreement of -4.09 to 3.68 m/s and -0.52 to 0.40 mL/mm Hg, respectively. In the heart failure population, correlations were 0.81 for both, with a PWV_aa a bias of -1.07 m/s and TAC bias of -0.06 mL/mm Hg.

Our smartphone-based method enables accurate assessment of local and global arterial stiffness metrics (PWV_aa and TAC). It offers easy-to-use monitoring of vascular aging and arterial health, with important implications for identifying patients at higher risk of neurodegenerative and cardiovascular diseases.

URL: clinicaltrials.org; Unique Identifier: NCT02240979.