Short summary

Earlier work derived percentile curves for the Agatston score of coronary calcification by using nonparametric lowess smoothing on age and using the distribution of residuals. Adding a second explanatory variable (body surface area, BSA), we intend to apply fractional polynomial regression of aorta diameter measurements on age and BSA and identify the final regression model as best fractional polynomials fit. We will use the distribution of the residuals to derive 3D percentile hyperplanes.

Rationale

An ectatic or aneurysmal (dilated) ascending aorta is a potentially lethal condition in which there is a risk of dissection or rupture. Early identification and appropriate surveillance in patients with a dilated aneurysmal ascending aorta are therefore important. There are various options for imaging assessment of aorta diameters, including computed tomography (CT). Earlier investigations have pursued a multivariable regression approach to explain aorta diameter growth, some of which have aimed for parsimonious models regressing aorta diameter (stratified by sex) on age and body surface area (BSA) alone. The Danish Cardiovascular Screening Trial (DANCAVAS) comprises low-dose non-contrast CT scanning to detect coronary artery calcification and aortic/iliac aneurysms. Five dimensions have been measured for aorta diameters: Aorta, abd., AP [mm]; Aorta, abd., trans [mm]; Aorta, arcus [mm]; Aorta ascendens [mm]; and Aorta descendens [mm]. We aim to derive percentile hyperplanes for aorta diameter measurements using age and BSA as explanatory variables. Our project serves setting a reference frame for aorta diameter measurements. An individual patient's measurements can be visually illustrated in relation to our percentile hyperplanes for age and BSA. Given a patient's age and BSA, his or her measurement for Aorta ascendens can be placed on the closest percentile (e.g. 68th, meaning above average and close to ¾ for all patients at the same age and with a similar BSA).

Description of the cohort

Danish men and women aged 65-74 years living on the Island of Funen, or in the surrounding communities of Vejle and Silkeborg. No exclusion criteria are used. The citizens were invited to cardiovascular seven-faceted screening examinations (DANCAVAS).

Data and biological material

demographic and clinical baseline characteristics; aorta measurements derived from CT scans

Collaborating researchers and departments

Dept. of Cardiology, OUH

• Axel Cosmos Pyndt Diederichsen

Dept. Cardiothoracic and Vascular Surgery, OUH

• Jes Sanddal Lindholt
• Lasse Møllegaard Obel

Publications associated with the project

Diederichsen AC, Rasmussen LM, Søgaard R, Lambrechtsen J, Steffensen FH, Frost L, Egstrup K, Urbonaviciene G, Busk M, Olsen MH, Mickley H, Hallas J, Lindholt JS. The Danish Cardiovascular Screening Trial (DANCAVAS): study protocol for a randomized controlled trial. Trials. 2015;16:554.

Gerke O, Lindholt JS, Abdo BH, Lambrechtsen J, Frost L, Steffensen FH, Karon M, Egstrup K, Urbonaviciene G, Busk M, Mickley H, Diederichsen ACP. Prevalence and extent of coronary artery calcification in the middle-aged and elderly population. Eur J Prev Cardiol. 2022;28(18):2048-2055.

Gerke O, McClelland RL. Nonparametric percentile curve estimation for a nonnegative marker with excessive zeros. MethodsX. 2022;9:101757.

Obel LM, Lindholt JS, Leetmaa TH, Dahl JS, Møller JE, Steffensen FH, Frost L, Lambrechtsen J, Busk M, Urbonaviciene G, Egstrup K, Karon M, Gerke O, Diederichsen ACP. Individual, expected diameters of the ascending aorta and prevalence of dilations in a study-population aged 60-74 years: a DANCAVAS substudy. Int J Cardiovasc Imaging. 2021;37(3):971-980.

Obel LM, Diederichsen AC, Steffensen FH, Frost L, Lambrechtsen J, Busk M, Urbonaviciene G, Egstrup K, Karon M, Rasmussen LM, Gerke O, Bovling AS, Lindholt JS. 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.