Sex-Specific Differences in Aortic Valve Calcification Between Bicuspid and Tricuspid Severe Aortic Stenosis

Sex-specific thresholds of aortic valve calcification (AVC) correlate with aortic stenosis (AS) and may complement echocardiography to determine AS severity. Importantly, current guideline-recommended thresholds of AVC scores derived by multislice computed tomography do not distinguish between bicuspid and tricuspid aortic valves. The objective of this study was to evaluate the sex-specific differences in the amount of AVC in patients with severe AS and tricuspid (TAV) versus bicuspid (BAV) aortic valve morphologies, retrospectively evaluated by 2 tertiary care institutions. The inclusion criteria comprised patients with severe AS and a left ventricular ejection fraction ≥50% and suitable imaging examinations. The study included 1,450 patients (723 men; 49.9%) with severe AS, including 1,335 patients with TAV (92.1%) and 115 with BAV (17.9%). The calculated Agatston score was higher in BAV patients (men: BAV 4,358 [2,644 to 6,005] AU vs TAV 2,643 [1,727 to 3,794] AU, p <0.01; women: BAV 2,174 [1,330 to 4,378] AU vs TAV 1,703 [964 to 2,534] AU, p <0.01), also when indexed for valve dimensions and body surface area (men: BAV 2,227 [321 to 3,105] AU/m² vs TAV 1,333 [872 to 1,913] AU/m², p <0.01; women: BAV 1,326 [782 to 2,148] AU/m² vs TAV 930 [546 to 1,456] AU/m², p <0.01). Differences between the BAV- and TAV-derived Agatston score was more prominent in concordant severe AS. In conclusion, sex-specific Agatston scores in severe AS were approximately 1/3 higher in patients with BAV than in patients with TAV for both women and men. Optimal AVC thresholds should be adjusted for BAV, also respecting considerable prognostic implications.