Growth Rates of the Normal, Subaneurysmal, and Aneurysmal Ascending Aorta: A 5-Year Follow-up Study from the Population-Based Randomized DANCAVAS Screening Trials

Objective: Sub-aneurysmal abdominal aortas are of current interest as more than 50% progress to aneurysms within 5–10 years (1–3). However, little is known regarding expansion rates of the ascending aorta. Thus, this study aimed to report 5-year follow-up growth rates of the normal, sub-aneurysmal, and aneurysmal ascending aorta.

Methods: Data stem from the two randomized, population-based, Danish Cardiovascular Screening Trials (DANCAVAS I+II). At baseline, participants underwent electrocardiogram-gated non-contrast CT scans measuring anterior-posterior aortic diameters (4). All participants from the pilot-study (n = 1,422) and selected participants with baseline ascending aortic dilations from the main trials were re-invited to follow-up CT scans. Data were stratified by baseline diameters <45 mm (Group A), 45–49 mm (Group B), 50–54 mm (Group C), and ?55 mm (Group D). Annual ascending aortic growth rates were estimated from multivariate linear regression analyses adjusted for sex and age.

Results: A total of 14,989 participants were screened (95.0% men) with a mean age of 68 ± 4 years. Distribution of baseline ascending aortic diameters for Group A, B, C, and D was 14,402 (96.1%), 494 (3.3%), 80 (0.5%), and 13 (0.1%), respectively. Of these, 2,012 participants underwent one or more follow-up CT scans measuring the ascending aortic diameter after exclusions ([Fig. 1]). The overall mean scan-interval was 4.1 ± 1.2 years. The adjusted mean annual growth rates for Group A-D were 0.07 mm (95% CI: 0.02?0.12), 0.00 mm (95% CI: -0.08?0.08), 0.11 mm (95% CI: -0.04?0.25), and 0.02 mm (95% CI: -0.46?0.50), respectively ([Fig. 2]). Amongst the sub-aneurysmal ascending aortas (Group B+C), 2.0% (95% CI: 0.6–4.5) developed into full-grown aneurysms ?55 mm ([Fig. 1]).

Conclusions: Growth rates of the ascending aorta were close to none within 5 years regardless of baseline diameters. Hence, clinical benefits from re-CT-scans of the sub-aneurysmal ascending aorta are sparse considering psychological costs and impaired cost-effectiveness.

Fig. 1 Flowchart illustrating the distribution of participants from the DANCAVAS trials undergoing non-contrast follow-up CT scans measuring the ascending aortic diameter.

Fig. 2 Growth rates of the ascending aorta stratified by baseline diameters. Growth rates are in this figure estimated by univariate linear regression analyses stratified by baseline ascending aortic diameters. Group A: baseline diameters.

References

1. Oliver-Williams C, Sweeting MJ, Turton G, et al; Gloucestershire and Swindon Abdominal Aortic Aneurysm Screening Programme. Lessons learned about prevalence and growth rates of abdominal aortic aneurysms from a 25-year ultrasound population screening programme. Br J Surg 2018;105(1):68–74 PubMed

2. Svensjö S, Björck M, Wanhainen A. Editor's choice: five-year outcomes in men screened for abdominal aortic aneurysm at 65 years of age: a population-based cohort study. Eur J Vasc Endovasc Surg 2014;47(1):37–44 PubMed

3. Wild JB, Stather PW, Biancari F, et al. A multicentre observational study of the outcomes of screening detected sub-aneurysmal aortic dilatation. Eur J Vasc Endovasc Surg 2013;45(2):128–134 PubMed

4. Diederichsen AC, Rasmussen LM, Søgaard R, et al. The Danish Cardiovascular Screening Trial (DANCAVAS): study protocol for a randomized controlled trial. Trials 2015;16:554 PubMed

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
10 June 2022