Use of phase-contrast MRI to measure aortic stiffness in young-onset hypertension: a pilot study

Abstract

Background: Young-onset hypertension is defined as hypertension diagnosed before the age of 40 years. Aortic pulse wave velocity is an indication of aortic stiffness. MRI assessment has been well verified compared to invasive pressure recordings for evaluating aortic pulse wave velocity. In this study, we aimed to determine whether aortic stiffness played a role in the aetiology of young-onset hypertension by calculating pulse wave velocity using MRI. Methods: We enrolled 20 patients diagnosed with young-onset hypertension and 20 volunteers without hypertension. Aortic pulse wave velocity was measured by cardiac MRI and protocol for the pulse wave velocity measurement involved the use of a 1.5 T scanner to acquire velocity-encoded, phase-contrast transverse aortic cine images. Sagittal oblique images used to measure the distance (ΔX) between the ascending aorta and descending aorta for the calculation of pulse wave velocity. The aortic flow versus time curves of ascending aorta and descending aorta were automatically obtained from the phase-contrast MRI images. Using these curves, the temporal shift (ΔT) was measured by Segment Medviso. Findings: The mean pulse wave velocity was 8.72 (SD 2.34) m/second (range: 7–12.8 m/second) for the patient group and 5.96 (standard deviation 1.86) m/second (range: 4.8–7.1 m/second) for the control group. The pulse wave velocity values were significantly higher in the patient group compared to the control group (p < 0.001). Interpretation: Aortic stiffness may play a role in the aetiology of young-onset hypertension and serve as a non-invasive and reliable screening tool when measured by MRI.