Association of aortic wall thickness with stiffness in the Multi-Ethnic Study of Atherosclerosis (MESA)

Methods 423 studies by 1.5-T whole-body MRI were analyzed. CMRI protocol included cardiac function and late gadolinium enhancement. Only participants with no findings of myocardial scar were included. AWT images were obtained using a double inversion recovery black-blood fast spin-echo sequence and phase contrast cine gradient echo sequence was used to evaluate aortic stiffness. Aortic sagittal oblique plane with black blood sequence was acquired to position the aortic imaging and allowed for the measurement of the distance between the ascending and descending aorta. Images of the ascending and descending aorta were obtained in the transverse plane at the level of the right pulmonary artery perpendicular to the vessel lumen. The thickness of the midthoracic descending aortic wall was measured using electronic calipers at 4 standard positions: 12, 3, 6, and 9 o’clock (QMASS 7.2). The average value of these 4 measurements was calculated. Distensibiliy of the ascending aorta and PWV were performed using validated automated software (ARTFUN. INSERM U678). Results Table 1 lists demographics, AWT, distensibility and PWV stratified by hypertension status. AWT was not different (p = 0.35) but distensibility was lower (p < 0.001) and PWV was higher (p = 0.012) in hypertension. Linear regression analyses (Table 2) demonstrate distensibility was significantly correlated to AWT in the cohort without hypertension. AWT was a predictor for PWV with the basic adjustment (Model 1) in the hypertension group, but this correlation diminished after adjusting for more variables (Model 2, only systolic blood pressure and black race were positively correlated to PWV significantly).