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A magnetic resonance perspective of the pulse wave transit time by the Arteriograph device and potential for improving aortic length estimation for central pulse wave velocity

BackgroundSimple reproducible methods of measuring arterial stiffness, a powerful index of prognosis, are becoming available. AimTo compare the pulse wave transit time (TT) and pulse wave velocity (PWV) between MRI and an arm cuff-based oscillometric method, the Arteriograph. Materials and methodsMRI phase-contrast data were acquired at the aortic arch and just above the aortic bifurcation in 49 men (age 53±6 years). Supine left-arm Arteriograph measurements were made after MRI using the surface sternal notch to symphysis pubis pathway length. ResultsMRI TT and PWV covered 86% of aortic root-bifurcation length omitting a mean 4.7 cm of proximal ascending aorta. Arteriograph TT (71±9 ms) was 6.6 ms [95% confidence interval (CI) 3.9–9.4] or 10% higher than MRI (64±10 ms). Arteriograph PWV (7.9±1.3 m/s) was 1.33 m/s (95% CI 0.95–1.70) higher than MRI (6.6±1.2 m/s), primarily because the surface aortic length was 70 mm (95% CI 59–81) longer than MRI. Arteriograph–MRI PWV difference decreased to 0.31 m/s (95% CI 0.01–0.61) when Arteriograph PWV was calculated using the MRI aortic path length and to 0.25 m/s (95% CI −0.05 to 0.55) after correcting for the aortic segments omitted in the MRI method. After similar TT corrections for MRI, the Arteriograph–MRI difference in TT reduced to 3.2 ms (95% CI 0.2–6). ConclusionTT estimations by Arteriograph and MRI are close. More accurate length estimation from MRI-derived models improves Arteriograph PWV measurement.