Computed tomography calcium scoring in aortic stenosis: bicuspid versus tricuspid morphology.

Objective: CT aortic valve calcium score (AVC _score ) and density (AVC _density ) thresholds have been recommended for aortic stenosis (AS) severity assessment in tricuspid aortic valve (TAV). We aimed to compare AVC _score and AVC _density in bicuspid aortic valve (BAV) versus TAV.
Methods: Retrospective single-centre study of patients with echocardiographic AS-severity and CT-AVC assessments within 6 months, and left ventricular ejection fraction ≥50%, all referred for clinical AS evaluation.Severe AS was defined as aortic valve area (AVA) ≤1 cm ² or indexed AVA ≤0.6cm ² /m ² plus mean gradient ≥40 mm Hg or peak velocity ≥4 m/s. AVC was assessed by Agatston method.
Results: Of the 1957 patients, 328 had BAV and 1629 had TAV, age 65±11 vs 80±9 years (p<0.001), men 65% vs 56% (p=0.006), respectively. BAV morphology was associated with higher AVC _score and AVC _density independent of age, comorbidities and AS severity (p<0.001) in men only (sex and BAV interaction p<0.001). In patients with severe AS, mean AVC _score and AVC _density were higher in BAV-men than that in TAV-men (both p<0.001), but similar in BAV-women and TAV-women (both p≥0.4). Such patterns remained the same after adjustment for clinical covariates and AS severity. Best thresholds for severe AS diagnosis in BAV-men were 2916 AU by AVC _score and 600 AU/cm ² by AVC _density which were higher than the guideline-recommended thresholds, while thresholds in BAV-women (1036 AU and 282 AU/cm ² ) were similar to guideline-recommended ones.
Conclusion: Valve calcification in AS differs according to valve morphology and sex. BAV-men with severe AS exhibit greater AVC _score and AVC _density than TAV-men. This presents a diagnostic challenge to the current guidelines, which needs confirmation in larger studies.
Competing Interests: Competing interests: None declared.
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