Ascending aortic dimensions and risk of aortic surgery in bicuspid aortic valve patients with and without concomitant aortic coarctation

Abstract Introduction Bicuspid aortic valve (BAV) disease is associated with dilatation of the ascending aorta as well as aortic coarctation (coarctation). Both aortic conditions increase the risk of acute aortic dissection. Therefore, current guidelines suggest prophylactic surgery of aortic dilatation at lower diameter thresholds in BAV patients with coarctation. It is unclear whether coarctation influences development of aortic dilatation and if it is associated with an increased risk of aortic surgery in BAV patients. Purpose To compare ascending aortic diameters and the risk of aortic surgery in BAV patients with and without coarctation. Methods An observational study of adult BAV patients attending clinical check-up in one of three outpatient clinics in Denmark in the period 2018-2022. Exclusion criteria: prior surgery of the ascending aorta or aortic valve, genetic syndromes, or other cardiovascular malformations. We measured cross-sectional aortic diameters on transthoracic echocardiograms using the leading-edge-to-leading-edge method in end-diastole. We compared mean diameters at the level of sinus of Valsalva and the broadest part of the tubular ascending aorta across 10-year age intervals. The association between aortic diameters and coarctation was assessed using multiple linear regression. The age-adjusted risk of surgery of the ascending aorta with or without aortic valve intervention was visualized using age-based cumulative incidence taking competing risks of death and valve surgery into account. We used Cox regression to compare cause-specific hazards of adverse aortic events according to the presence of coarctation. Results We included 1002 patients of whom 119 (12%) had coarctation. The majority (85.7%) of patients with coarctation had undergone previous repair. Patients with coarctation were younger (median age: 38 vs. 54 years, p 0.0001). Mean aortic diameters in 10-year age intervals, were similar at the aortic root but diameters of the tubular ascending aorta tended to be lower in those with coarctation (Figure 1). In linear regression, absence of coarctation was significantly associated with a 2.2 mm increase in the mean aortic diameter at the tubular level (95% CI: 0.9-3.6 mm) after adjusting for age, sex, and BSA. Median follow-up was 1.5 years, during which we observed one case of aortic dissection and 61 cases of prophylactic surgery of the ascending aorta of which 45 had concomitant valve surgery performed. Estimated age-based cumulative incidence of aortic surgery appeared higher in patients without coarctation, but there was no difference in the cause-specific hazard (Figure 2). Conclusions In patients with a bicuspid aortic valve, concomitant aortic coarctation was associated with smaller diameters of the tubular ascending aorta but similar aortic root diameters. During follow-up, we observed no difference in the age-specific risk of aortic surgery according to the presence of aortic coarctation.Figure 1 Figure 2