Impact of sex and aortic valve morphology on the relationship between aortic valve calcification and mean transvalvular gradient in patients with aortic stenosis

A previous study in patients with aortic stenosis (AS) showed that the relationship between aortic valve calcification (AVC) and mean transvalvular gradient (MG) was different between bicuspid (BAV) and tricuspid aortic valve (TAV) patients, especially in younger patients. While TAV and older BAV patients had good AVC-MG correlation, no association was found in young BAV patients. This difference in young patients with BAV was particularly notable in women where the combination of high MG but no or minimal AVC was often present. We hypothesized that there might be a sex-related difference in the relationship between AVC and AS hemodynamic severity (MG) according to the aortic valve morphology (BAV vs TAV). Forty (40) BAV and 40 TAV patients with AS were matched for sex and for AVC indexed to the aortic annulus area (i.e. AVC density; AVCd). AVC by the Agatston method was measured by computed tomography and patients also underwent a Doppler-echocardiography to assess the AS hemodynamic severity (MG). The cohort consisted of 75% of men. As expected, TAV patients were older (70±11 vs 53±11, p < 0.0001) and had more risk factors (hypertension, dyslipidemia, diabetes, coronary artery disease) compared to BAV patients (all p < 0.02). AS hemodynamic severity and AVCd were similar in BAV and TAV patients (p>0.21). For the same level of AVCd, men harbored similar MG whether they had a BAV or TAV (P ancova=0.82). However, in women MG was higher in those with BAV versus those with TAV (P ancova=0.04) (Figure). After adjusting for AVCd, the aortic valve morphology did not correlate with MG in men (p=0.82) whereas it did in women (p=0.04). For the same burden of valve calcification, MG was higher in women with BAV compared to those with TAV, while there was no difference between BAV and TAV among men. Thus, AVCd assessed by computed tomography may underestimate AS severity in women with BAV and should then be interpreted cautiously. Further studies are needed to better determine the mechanisms underlying this sex-related difference between BAV and TAV aortic stenosis.