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.