Aortic Dilation at One Site Increases Risk for Dilation at Other Sites

The strongest predictor of an aortic dilation is the presence of a dilation in another aortic segment, according to study results published in the Journal of the American College of Cardiology.

Data for this study were sourced from the Danish Cardiovascular Multicenter Screening Trials I and II. The study population comprised 15,006 individuals aged 60 to 74 years who underwent cardiovascular screening at 5 hospitals between 2014 and 2018. Dilations were defined as more than 25% enlargement of normal diameters.

Participants were mostly men (n=14,235) with an average age of 68±4 years. Men and women differed significantly for all clinical characteristics (all P <.001) except for rates of stroke (P =.07), peripheral artery disease (P =.16), and familial disposition (P =.12).

Men had larger ascending aorta (mean, 37.5 vs 34.1 mm; P <.001), aortic arch (mean, 30.7 vs 28.1 mm; P <.001), descending aorta (mean, 28.5 vs 25.2 mm; P <.001), and abdominal aorta (mean, 20.5 vs 16.6 mm; P <.001) regions, respectively.

The predictive formulas of aortic dilations included sex, age, and body surface area. The formulas correlated with the ascending aorta (R², 0.09), aortic arch (R², 0.12), descending aorta (R², 0.17), and abdominal aorta (R², 0.13).

Increased risk for ascending aorta dilation was associated with atrial fibrillation (adjusted odds ratio [aOR], 1.9; P <.001), hypertension (aOR, 1.7; P <.001), and familial disposition (aOR, 1.6; P =.013). For aortic arch dilation, hypertension (aOR, 1.5; P =.043) increased dilation risk.

Risk for dilation in the descending aorta was increased with atrial fibrillation (aOR, 1.5; P =.013) and hypertension (aOR, 1.3; P =.021).

Abdominal aortic dilation risk was associated with current (aOR, 4.2; P <.001) and former (aOR, 2.0; P<.001) smoking status, acute myocardial infarction (aOR, 2.3; P <.001), familial disposition (aOR, 1.9; P <.001), men (aOR, 1.8; P =.003), peripheral artery disease (aOR, 1.5; P <.001), and hypertension (aOR, 1.2; P =.026).

Patients with dilation of the ascending aorta were at increased risk for all other dilations (OR range, 1.7-8.4) except for iliac artery dilation. For dilations of the aortic arch (OR range, 1.8-8.8), descending aorta (OR range, 1.9-6.2), and abdominal aorta (OR range, 1.8-9.9), risk for dilations in all other regions were increased.

The final model for predicting dilation risk had a receiver operating characteristic area under the curve (ROC-AUC) fit of 0.69 for the ascending aorta, 0.80 for the aortic arch, 0.73 for the descending aorta, and 0.74 for the abdominal aorta.

This study was limited by defining dilations on the basis of relative cutoffs.

The results of this study confirm the need to evaluate patients who present with aortic dilations for other coexisting dilations and provided prediction formulas for dilation risk.

Reference

Obel LM, Diederichsen AC, Steffensen FH, et al. Population-based risk factors for ascending, arch, descending, and abdominal aortic dilations for 60-74-year-old individuals. J Am Coll Cardiol. 2021;78(3):201-211. doi:10.1016/j.jacc.2021.04.094