Aortic regurgitation in bicuspid aortic valve: know to decide

Abstract Funding Acknowledgements Type of funding sources: None. Chronic aortic regurgitation (AR) is the second cause of valve surgery in patients with bicuspid aortic valve (BAV) and has distinctive characteristics of trileaflet regurgitation. The quantification variables of aortic regurgitation do not take into account the unique characteristics of bicuspid regurgitation. Recognition of the mechanisms that lead to bicuspid AR is relevant as it allows correct treatment planning and valve repair in candidate patients. Objective a prospective study was designed to identify the mechanisms of AR and the factors (clinical and anatomical) associated with the development of significant AR (moderate/severe) in adult patients with BAV. Materials and methods We included consecutive adult patients with a confirmed diagnosis of BAV evaluated between 2014 and 2021 with at least 3 years of follow-up by the Structural Heart Disease group of our institution. Valve disease was evaluated by echocardiography and complementary methods. It was classified as mild, moderate (Mod), and severe (Sev) aortic regurgitation, according to current criteria (integral approach with quantitative and semi-quantitative criteria). The prevalence of regurgitation mechanisms, the progression of aortic regurgitation, and predictive variables of significant AR and major cardiovascular events (death, surgery) were analyzed using univariate and multivariate analyses. A p<0.05 was considered significant. Surgery was indicated following international recommendations (ESC guidelines): symptoms development or ventricular dysfunction. Results We included 300 patients (39.7 ± 14.9 years, 72.6% men). Regarding valvular phenotype 84% (257p) presented fused BAV (coronary leaflets) and the majority with raphe (87.5%). 71.7% of the patients had some degree of aortic regurgitation at the start of follow-up (24.1% Mod/Sev AR). Among the patients with significant AR, 50% had cusp prolapse (86% prolapse of the fused leaflet), 39.18% dilatation of the aortic root, 26.6% significant calcification of the valve, 1.3% valve perforation and 29.4% restriction of valve movement. 43% with Mod/Sev AR had mixed mechanisms of regurgitation and the combination, half represented by the combination of aortic root dilatation and cusp prolapse (Fig 2). During follow-up 18–6% of patients with Mod AR showed progression to Sev AR and 4.7% underwent surgery. On the other hand, 34.1% of patients with baseline Sev AR required aortic valve surgery (p<0.01). Conclusions In our cohort, AR was highly prevalent: 1 out of 4 patients had significant AR at the start of follow-up. Eccentric jets and the presence of valve prolapse were frequent in patients with significant AR. 43% of BAV patients with Mod/Sev AR exhibited mixed regurgitating mechanisms. Because mechanism affects the choice of surgical technique, comprehensive mechanism description is critical in patients with BAV and AR.