Associations between carotid-femoral and heart-femoral pulse wave velocity in older adults: the Atherosclerosis Risk In Communities study

BACKGROUND

Carotid-femoral pulse wave velocity (cfPWV) is widely used in epidemiological studies to assess central arterial stiffness. However, despite being superior to traditional risk factors in predicting cardiovascular outcomes, cfPWV is not routinely used in clinical practice. cfPWV assessments require applanation of the carotid artery, which can be cumbersome, and individual-level factors, including carotid artery plaque, may confound the measurements. Heart-femoral PWV (hfPWV) may be a suitable alternative measure of central arterial stiffness.

OBJECTIVES

The aim of this study was to estimate the strength of the agreement between hfPWV and cfPWV.

METHODS

We evaluated 4133 older-aged [75.2 (5.0) years] African-American and white adults in the community-based Atherosclerosis Risk in Communities (ARIC) Study. cfPWV and hfPWV were measured using an automated cardiovascular screening device. Agreement between the two measurements was determined using Pearson's correlation coefficient (r), standard error of estimate (SEE) and Bland-Altman analysis.

RESULTS

There was a strong (r > 0.7) agreement between hfPWV and cfPWV (r = 0.83, 95% CI: 0.82-0.84). Although the mean cfPWV [11.5 m/s (SD: 3.0)] and hfPWV [11.5 m/s (SD: 2.3)] were comparable, the SEE was 1.7 m/s. Inspection of the Bland-Altman plot revealed greater variability and bias for higher PWV values, with higher PWV further away from the regression line.

DISCUSSION

Findings suggest good agreement between hfPWV and cfPWV. hfPWV is a simpler alternative to cfPWV that is less likely to be confounded by individual-level factors. Considering the greater variability for higher PWV values, further work is warranted to determine the importance of local artery mechanics to both measures.

The aortic-femoral arterial stiffness gradient: an atherosclerosis risk in communities (ARIC) study

BACKGROUND

The aortic to femoral arterial stiffness gradient (af-SG) may be a novel measure of arterial health and cardiovascular disease (CVD) risk, but its association with CVD risk factors and CVD status, and whether or not they differ from the referent measure, carotid-femoral pulse-wave velocity (cfPWV), is not known.

METHOD

Accordingly, we compared the associations of the af-SG and cfPWV with (i) age and traditional CVD risk factors and (ii) CVD status. We evaluated 4183 older-aged (75.2 ± 5.0 years) men and women in the community-based Atherosclerosis Risk in Communities (ARIC) Study. cfPWV and femoral-ankle PWV (faPWV) were measured using an automated cardiovascular screening device. The af-SG was calculated as faPWV divided by cfPWV. Associations of af-SG and cfPWV with age, CVD risk factors (age, BMI, blood pressure, heart rate, glucose and blood lipid levels) and CVD status (hypertension, diabetes, coronary heart disease, heart failure, stroke) were determined using linear and logistic regression analyses.

RESULTS

(i) the af-SG and cfPWV demonstrated comparable associations with age and CVD risk factors, except BMI. (ii) a low af-SG was associated with diabetes, coronary heart disease, heart failure and stroke, whilst a high cfPWV was only associated with diabetes.

CONCLUSION

Although future studies are necessary to confirm clinical utility, the af-SG is a promising tool that may provide a unique picture of hemodynamic integration and identification of CVD risk when compared with cfPWV.

The aortic-femoral arterial stiffness gradient is blood pressure independent in older adults: the atherosclerosis risk in communities (ARIC) study

BACKGROUND

Aortic arterial stiffness is a strong independent predictor of cardiovascular disease (CVD); however, its dependence on mean arterial pressure (MAP) limits its clinical utility. The aortic-femoral arterial stiffness gradient (af-SG), a novel marker of CVD risk, may be a promising alternative, but its dependence on MAP is not known. The aim of this study was to determine the relationship between MAP and the af-SG in healthy older adults and those with established disease, including hypertension and diabetes.

METHOD

We evaluated the dependency of the af-SG on MAP in healthy older adults (n = 694, aged 74 ± 5 years), and adults with hypertension (n = 2040, aged 76 ± 5 years), and diabetes (n = 1405, aged 75 ± 5 years) as part of the community-based Atherosclerosis Risk in Communities (ARIC) Study. Carotid-femoral pulse-wave velocity (cfPWV), femoral-ankle PWV (faPWV) and blood pressure were measured using standardized protocols. The af-SG was calculated as faPWV divided by cfPWV. Multivariable regression analysis was performed to test the independent association of MAP with af-SG, with adjustments for known confounders, including age, sex, BMI, blood glucose and heart rate.

RESULTS

There was no significant relationship between the af-SG and MAP in healthy (β = 0.002, P = 0.301), hypertension (β = -0.001, P = 0.298) or diabetes (β = -0.001, P = 0.063) population groups, with MAP explaining less than 0.1, less than 0.1 and 0.2% of the variance in the af-SG, respectively.

CONCLUSION

These findings suggest that the af-SG may be regarded as a MAP independent index of arterial health and CVD risk in older adults.