Single vs Serial Assessments of Arterial Hemodynamics to Predict Thoracic Aortic Aneurysm Expansion

Thoracic aortic aneurysm (TAA) is a highly morbid disease. We have previously shown that baseline hemodynamic measures reflecting aortic function are associated with future TAA expansion. However, whether serial arterial hemodynamic assessment further improves TAA growth assessment remains unknown. Therefore, we aimed to compare single vs serial arterial hemodynamic assessments in the evaluation of future TAA growth.

Eighty-six unoperated participants with TAA underwent noninvasive arterial hemodynamic assessment using arterial tonometry and echocardiography at baseline and after 1 year. Aortic diameter was measured serially with the use of standard imaging modalities. Stepwise multivariable linear regression was used to assess associations of baseline and 1-year change (Δ) in arterial hemodynamic measures with TAA growth.

Mean age was 62.7 ± 11.0 years; 79% were male. Mean aneurysm growth was 0.48 ± 0.54 mm/year after a follow-up of 2.96 ± 1.03 years. Yearly changes in arterial hemodynamic measures ranged from -3.2% to +4.2%. Linear regression results showed that while baseline arterial hemodynamic measures were independently associated with aneurysm growth (carotid-femoral pulse wave velocity: β ± SE = 0.038 ± 0.013; aortic characteristic impedance: β ± SE = 0.002 ± 0.001; proximal aortic compliance: β ± SE = -0.011 ± 0.006; forward pressure wave amplitude: β ± SE 0.009 ± 0.002; reflected pressure wave amplitude: β ± SE = 0.017 ± 0.006; P < 0.05 for each), the 1-year Δ in these measures did not incrementally add to aneurysm growth assessment (P > 0.05 for each Δ).

Although baseline measures of aortic function independently predict TAA expansion, 1-year changes in these measures do not improve this prediction. Thus, for TAA risk assessment purposes, a baseline assessment of aortic function may suffice, which simplifies its use for potential predictive algorithms.