Computed tomography calcium scoring in aortic stenosis: bicuspid versus tricuspid morphology
Zi Ye, Marie‐Annick Clavel, Thomas A. Foley, Philippe Pîbarot, Maurice Enriquez‐Sarano, Héctor I. Michelena
Abstract
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.