Sex differences in aortic valve calcification in severe aortic valve stenosis: association between computer tomography assessed calcification and valvular calcium concentrations

Aims The aims of this study were to investigate the correlation and sex differences between total valve calcium, valve calcium concentration, and aortic valve calcification (AVC) in explanted valves from patients with severe aortic valve stenosis undergoing aortic valve replacement (AVR). Methods and results Sixty-nine patients with severe aortic stenosis (AS) scheduled for elective AVR underwent echocardiography and cardiac computed tomography (CT) prior to surgery (AVC(in vivo)) and CT of the explanted aortic valve (AVC(ex vivo)). Explanted valves were prepared in acid solution, sonicated, and analysed with Arsenazo III dye to estimate total valve calcium and valve calcium concentration. Median AVC(ex vivo )was 2082 (1421-2973) AU; mean valve calcium concentration was 1.43 +/- 0.42 mu mol Ca-2(+)/mg tissue; median total valve calcium 156 (111-255) mg Ca2+, and valve calcium density 52 (35-81) mg/cm(2). AVC displayed a strong correlation with total valve calcium (R-2 = 0.98, P< 0.001) and a moderate correlation with valve calcium concentration (R-2 = 0.62, P< 0.001). Valvular calcium concentration was associated with sex, aortic valve area, and mean gradient. After adjusting for age and estimated glomerular filtration rate, sex and mean gradient remained associated with valve calcium concentrations. Conclusion AVC score provides a strong estimate for total valve calcium but to a lesser degree calcium concentration in the valve tissue of patients with severe AS. Females presented lower valvular calcium concentrations than males irrespective of AS severity, adding evidence and providing support to the important point that sex differences in valvular calcium concentration in AS does not reflect valvular size.

Automated summary

This study aimed to investigate the correlation and sex differences between total valve calcium, valve calcium concentration, and aortic valve calcification in explanted valves from patients with severe aortic valve stenosis. The results showed that the AVC score provides a strong estimate for total valve calcium, but to a lesser degree calcium concentration in the valve tissue. Females had lower valvular calcium concentrations than males regardless of AS severity.