Association of arterial stiffness with aortic calcification and tortuosity

Abstract

Impact of arterial stiffness on aortic morphology has not been well evaluated. We sought to investigate the association of brachial-ankle pulse wave velocity (baPWV) with aortic calcification and tortuosity.A total of 181 patients (65.4 ± 10.4 years, males 59.7%) who underwent computed tomographic angiography and baPWV measurement within 1 month of study entry were retrospectively reviewed. Aortic calcification was quantified by the calcium scoring software system. Aortic tortuosity was defined as the length of the midline in the aorta divided by the length of linear line from the aortic root to the distal end of the thoraco-abdominal aorta. In simple correlation analyses, baPWV was correlated with aortic calcification (r = 0.36, P < .001) and tortuosity (r = 0.16, P = .030). However, these significances disappeared after controlling for confounders in multivariate analyses. Factors showing an independent association with aortic calcification were age (β = 0.37, P < .001), hypertension (β = 0.19, P = .003), diabetes mellitus (β = 0.12, P = .045), smoking (β = 0.17, P = .016), and estimated glomerular filtration rate (β = -0.25, P = .002). Factors showing an independent association with aortic tortuosity were age (β = 0.34, P < .001), body mass index (β = -0.19, P = .018), and diabetes mellitus (β = -0.21, P = .003).In conclusion, baPWV reflecting arterial stiffness was not associated with aortic calcification and tortuosity. Traditional cardiovascular risk factors were more influential to aortic geometry. Further studies with a larger sample size are needed to confirm our results.

Figure 1

Measurement of aortic calcifications. Three-dimensional volume rendering image of thoracoabdominal CT angiography shows multiple atherosclerotic wall calcifications in the aorta, which are depicted as white patches. (A) Post-processing in the dedicated work stations enables the automated detection of bone and aortic calcifications. Semi-automated identification of aortic calcification was necessary for defining the aortic calcifications to differentiate the aortic calcium from the bone or calcified lymph nodes. Axial image obtained at the level of aortopulmonary window shows the red-colored aortic calcifications. (B) The total amount of aortic calcification measured 30,539.

Figure 2

Measurement of aortic tortuosity. Three-dimensional volume rendering image of thoracoabdominal CT angiography shows that the distance between the aortic root and the aortic bifurcation is 221.5 mm. (A) Curved multiplarnar reconstruction image shows the centerline of the whole aortic lumen from the aortic root to the aortic bifurcation. (B) Straightened multiplanar reconstruction image shows that the length of the center line is 473.2 mm. Aortic tortuosity was estimated at 0.47 (= 221.5/473.2).

Figure 3

(A) Aortic calcification and (B) aortic tortuosity increased with age.

Figure 4

Relative importance for (A) aortic calcification and (B) aortic tortuosity. baPWV = brachial-ankle pulse wave velocity, eGFR = estimated glomerular filtration rate.

Figure 5

Comparison of aortic tortuosity between patients with and without diabetes mellitus. DM = diabetes mellitus.

Figure 6

Linear correlation between BMI and aortic tortuosity. BMI = body mass index.