No association between the novel international classification of bicuspid aortic valve anatomy and performed surgery of the valve or aorta
Authors: Wulffeld S , Schmiegelow M D S , Raunso J , Norager B , Bundgaard H , Iversen K K , Oksjoki R , Eske Bruun N , Procida K 
Published: October 2024

Abstract

Introduction
In 2021, international experts introduced a new classification of the diverse anatomy of bicuspid aortic valves (BAV). This classification identifies three BAV types: Fusion, 2-sinus, and Partial-fusion BAV, which may be further subdivided into specific phenotypes according to orientation of the commissure and the presence of a raphe. However, it remains uncertain whether this new BAV classification can identify subgroups of patients with an unfavorable long-term prognosis.

Purpose
To assess whether the BAV anatomy according to the new classification is associated with the risk of surgery of the aortic valve or aorta.

Methods
A multicenter case-control study of all current patients with BAV from the outpatient clinics of three major cardiology departments in Denmark in the years 2018, 2019 and 2022. We excluded patients with more than minor concomitant heart defects, uncertain BAV anatomy, and genetic syndromes. Due to the novelty of the concept at the time of study, we excluded 15 patients with Partial-Fusion BAV. Because echocardiography examinations performed prior to January 1 2006 were unavailable, we excluded patients diagnosed prior to this date to ensure comparability between cases and controls. Cases were all patients with BAV, who had had surgery of the aortic valve and/or surgery of the ascending aorta at the end of their accrual year. All other patients with BAV were controls. We assessed BAV anatomy by review of routinely performed echocardiography examinations and compared patients according to BAV type: Fusion or 2-sinus BAV. Secondarily, we compared patients with specific phenotypes: Right-Left Fusion, Right-Non-Coronary Fusion, Left-Non-Coronary Fusion, Latero-Lateral 2-sinus, and Antero-Posterior 2-sinus BAV.

Results
We included 931 patients (237 cases, 694 controls). Table 1 displays clinical characteristics in BAV phenotype subgroups. In the primary analysis, we found no significant difference in the odds of surgery between the Fusion versus 2-sinus BAV: unadjusted OR 0.65, 95% CI [0.41-1.03]. This did not change after adjusting for age and sex in a logistic regression model: OR 0.72, 95% CI [0.45-1.15]. Results were similar when comparing phenotypes; no difference in odds of surgery between phenotypes in both unadjusted and age- and sex-adjusted analyses (see Fig. 1). In exploratory analyses, we compared patients according to the orientation of the BAV commissure (latero-lateral versus antero-posterior) and a more complex definition of the fusion phenotype that incorporates the visibility of a raphe. Findings were similar; no significant difference in the odds between subgroups. In all models, increasing age and male sex were associated with higher odds of surgery.

Conclusion
In this study, we did not find any association between BAV anatomy as defined by the new international consensus classification, and performed surgery of the valve or aorta.