Is local stiffness, as measured by radio frequency, more sensitive than intima-media thickness?

The aim of our study was to explore the changes in common carotid arterial intima-media thickness (CCA IMT) and local arterial stiffness to evaluate, non-invasively, early vascular disease in patients with cardiovascular (CV) risk factors and "normal" carotid IMT (<0.9 mm).

We studied 50 patients (mean age 42 years±14), with no history of cardio-cerebrovascular events and "normal" IMT. We assessed the traditional cardiovascular risk factors, the CCA IMT, and the local stiffness with Quality Arterial Stiffness technology, based on Radio frequency signal (RFQAS-ESAOTE, Italy). CCA distensibility coefficient (DC), compliance coefficient (CC), pulse wave velocity (PWV) and β parameter were measured in patients, with and without traditional cardiovascular risk factors. 25 subjects with risk factors (mean age 49±13) were compared with 25 controls (mean age 36±12).

We did not find any significant differences in the IMT measurement between subjects with CV risk factors compared to controls (0.530±0.99 mm vs. 0.626±0.127 mm; P=5.68). The mean DC (0.030±0.014 1/kPa vs. 0.0221±0.016 1/kPa; P<0.05) and CC (1.087±0.47 mm²/kPA vs. 0.864±0.41 mm²/kPA; P<0.05), were significantly lower, while PWV (6.21±1.74 m/s vs. 7.68±2.07 m/s; P<0.05) and β (7.67±4.09 m/s vs. 10.45±5.58 m/s; P<0.05) were significantly higher in subjects with CV risk factors. ROC curves showed that PWV>6.05 m/s better identified, among patients with IMT <0.9 mm, those with cardiovascular risk factors (sensitivity 82.0% specificity 62.0%; AUC 0.73).

Increased stiffness is a result of change both in quantity and quality of the arterial wall. Arterial functional changes and distention alterations may herald the onset of vascular disease before manifestation of symptoms or detection of preclinical atherosclerotic lesions.