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Updated: May 27, 2026
A Methodological Approach to Non-invasive Assessments of Vascular Function and Morphology
Published on: February 7, 2015
Peripheral augmentation index as a biomarker of vascular aging: an invasive hemodynamics approach
Kevin S Heffernan1, Eshan A Patvardhan, Navin K Kapur
1Human Performance Laboratory, Department of Exercise Science, Syracuse University, Syracuse, NY, USA. KsHeffer@syr.edu
Insights
Two non-invasive vascular measures, augmentation index (AIx) and pulse wave amplitude-reactive hyperemia index (PWA-RHI), offer distinct insights into vascular aging. AIx reflects age-related changes and organ damage, while PWA-RHI indicates coronary atherosclerosis burden.
Area of Science:
- Cardiovascular Medicine
- Biomedical Engineering
- Gerontology
Background:
- Vascular aging is a complex process associated with increased cardiovascular risk.
- Assessing vascular function non-invasively is crucial for early detection of vascular damage.
- Digital volume waveform analysis offers novel approaches to evaluate systemic vascular health.
Purpose of the Study:
- To compare two digital volume waveform-derived measures of vascular function, augmentation index (AIx) and pulse wave amplitude-reactive hyperemia index (PWA-RHI), with invasive measures.
- To evaluate the relationship of AIx and PWA-RHI with target organ damage and vascular aging parameters.
- To determine the distinct contributions of AIx and PWA-RHI in assessing systemic vascular health.
Main Methods:
- Fifty-nine patients undergoing left heart catheterization provided data for invasive vascular function and coronary atherosclerosis assessment (Gensini score).
- Peripheral arterial tone (PAT) was used to capture digital volume waveforms, from which AIx and PWA-RHI were derived.
- Statistical analyses correlated AIx and PWA-RHI with age, estimated glomerular filtration rate, left ventricular hypertrophy, and invasive vascular parameters.
Main Results:
- AIx correlated with age, aortic pulsatility, estimated glomerular filtration rate, aortic pulse pressure amplification, and aortic form factor, and showed a trend towards association with left ventricular hypertrophy.
- AIx was not associated with the Gensini score, indicating no link to coronary atherosclerotic burden.
- PWA-RHI was inversely associated with the Gensini score but showed no significant association with age, estimated glomerular filtration rate, or other invasive vascular parameters.
Conclusions:
- AIx derived from PAT effectively reflects age-associated vascular changes and target organ damage, but not coronary atherosclerotic burden.
- PWA-RHI is associated with coronary atherosclerotic burden but does not reflect general vascular aging or target organ damage.
- AIx and PWA-RHI provide complementary information, offering distinct insights into systemic vascular aging and associated organ damage.
Abstract:
We compared two measures of vascular function obtained from digital volume waveforms with measures of target organ damage and novel invasive measures of vascular function as they relate to vascular aging. Aortic pulse pressure amplification, pulsatility, form factor and extent of coronary atherosclerosis (modified Gensini score) were obtained invasively in 59 patients undergoing left heart catheterization. Digital volume waveforms were captured via peripheral arterial tone (PAT) and used to derive augmentation index (AIx) and the pulse wave amplitude-reactive hyperemia index (PWA-RHI). AIx was associated with age (r = 0.50, p < 0.05) and aortic pulsatility (r = 0.45, p < 0.05) and inversely associated with estimated glomerular filtration rate (-0.29, p < 0.05) aortic pulse pressure amplification (r = -0.28, p < 0.05) and aortic form factor (r = -0.38, p < 0.05). AIx was slightly higher in patients with left ventricular hypertrophy (LVH) versus those without left ventricular hypertrophy (30 vs. 14%, p = 0.058). There was no association between AIx and Gensini score. PWA-RHI was not associated with age, estimated glomerular filtration rate or invasive vascular parameters and did not differ in patients with versus without LVH (p = ns). PWA-RHI was inversely associated with Gensini score (r = -0.32, p < 0.05). AIx derived from PAT is correlated with age-associated changes in vascular function and target organ damage but not coronary atherosclerotic burden. PWA-RHI is associated with coronary atherosclerotic burden but is not associated with target organ damage or other measures of vascular aging assessed in this study. Each parameter provides distinct insight into systemic vascular aging and target organ damage.
