Pulse Wave Velocity Assessment by External Noninvasive Devices and Phase-Contrast Magnetic Resonance Imaging in the Obese

Carotid-femoral pulse wave velocity (PWV) is considered the gold-standard measurement of arterial stiffness. Obesity, however, can render inaccurate the measurement of PWV by external noninvasive devices. Phase-contrast MRI allows the determination of aortic PWV in multiple aortic locations with intra-arterial distance measurements, as well as the assessment of aortic mechanical properties. The purpose of this study was to assess the reliability of external carotid-femoral PWV values measured by well-validated external devices in comparison with MRI acquisitions of PWV and aortic mechanical properties in a population of obese subjects. PWV was measured with PulsePen and Complior II devices in 32 volunteers (18 men and 14 women), aged 46 to 65 years (mean: 55.7 +/- 5.1 years), presenting with isolated abdominal obesity, with a waist circumference > 102 cm for men and > 88 cm for women, and a body mass index between 27 and 35. These results were then compared with MRI PWV values and cross-sectional MRI thoracic aorta distensibility values. MRI PWV values were positively correlated with PWV measured by both PulsePen (r = 0.47; P = 0.005) and Complior (r = 0.43; P = 0.01). Aortic cross-sectional stiffness was positively correlated with PulsePen PWV (r = 0.42; P = 0.02). The same trend was also observed with Complior PWV (r = 0.33; P = 0.06). This is the first study comparing transcutaneous PWV measurements with MRI aortic elastic properties in obese subjects. Our results indicate that, for body mass index values <= 35 kg m(-2), PWV measured externally with Complior or PulsePen validly reflect values obtained directly in the thoracic aorta through MRI. (Hypertension. 2009; 54: 421-426.)