Determinants of Cardio-Ankle Vascular Index and Heart-Thigh β Index in a US Cohort: The MESA

The cardio-ankle vascular index (CAVI) and heart-thigh β index (htβ) assess arterial stiffness by correcting pulse wave velocity for blood pressure to achieve less dependency on blood pressure variations. Normative data for these markers among US communities are lacking. We aimed to assess the determinants and normative values of CAVI and htβ. MESA (Multi-Ethnic Study of Atherosclerosis) participants with CAVI and htβ measurements were included (n=2950). A subgroup selected to define normative values included only participants without previous cardiovascular disease, diabetes, smoking, antihypertensive use, and with blood pressure <140/90 mm Hg, body mass index <35 kg/m2, and creatinine <1.5 mg/dL. Associations were assessed by multivariable linear regressions. All continuous variables were standardized. Among 2950 participants (mean age, 73.6 years; 47.2% male), older age (β for CAVI=0.39, P<0.001 and htβ=0.41, P<0.001), and male sex (β for CAVI=0.30, P<0.001 and htβ=0.11, P<0.001) were associated with higher arterial indices. Participants with higher blood pressure, height, and diabetes exhibited higher CAVI and htβ. A higher waist circumference was associated with lower CAVI and htβ. Among the normative value subgroup (n=676), the mean CAVI was 8.7 (2 Z score range, 6.5-11.2), and the mean htβ was 8.9 (2 Z score range, 4.3-13.6). Among participants without cardiovascular disease, higher CAVI and htβ were associated with higher predicted 10-year cardiovascular risk estimated by pooled cohort equations (per SD of CAVI=3.6%, P<0.001 and htβ=3.3%, P<0.001). We report determinants and normative values of CAVI and htβ in a multiethnic community-based US population. Future studies should focus on the prognostic utility of CAVI and htβ.