A ortic stenosis (AS) is common in elderly people, affecting 2% of the population ≥65 years old and 4.6% of population ≥75 years old based on Doppler echocardiographic or community studies.1,2 Nowadays, the most common cause of AS is degenerative, and aortic valve calcification (AVC) is the intrinsic mechanism of valvular stiffening and obstruction. [3][4][5][6] Although degenerative AS has long been considered age related, recent studies have demonstrated that it is an active process involving biological pathways with many similarities to atherosclerosis. 7,8 Epidemiological studies identified similar risk factors for calcific AS and coronary atherosclerosis such as age, smoking, elevated cholesterol levels, diabetes mellitus, metabolic syndrome, hypertension, and increase in lipoprotein-a levels. 9 Male sex was also touted as an independent risk factor for AS similar to atherosclerosis, 9 but studies linking valve tissue alterations 10,11 and calcification to AS 12 have not differentiated between men and women. Moreover, studies of aortic valve weight as a surrogate for calcification load showed discordant results with regard to sex, 13,14 and clinically, guidelines do not differentiate between men and women for AS pathophysiology and management. 6 However, the analogy to atherosclerosis suggests that there may be important, yet thus far undefined, sex-related differences in the development of AVC and the transition to AS. This issue can now be analyzed because cardiac computed tomography (CT) provides accurate and reproducible quantification of AVC load, 15 and multidetector CT (MDCT) may prove to be a useful adjunct tool for the evaluation of AS severity. However, previous studies suggested a single set of cutoff values for detecting severe AS regardless of sex, 16 so the impact of sex on the relation between aortic cusp calcification measured by MDCT and hemodynamic severity of AS remains uncertain. The aim of the present study was to determine the differential physiological relationship between AVC Background-Aortic valve calcification (AVC) is the intrinsic mechanism of valvular obstruction leading to aortic stenosis (AS) and is measurable by multidetector computed tomography. The link between sex and AS is controversial and that with AVC is unknown. Methods and Results-We Conclusions-In Aggarwal et al Aortic Valve Calcification in Women 41load and AS hemodynamic severity between men and women. We hypothesized that women reach thresholds for severe AS for lower calcification loads than men and that when MDCT is used for the diagnosis of AS severity, criteria of AVC load would need to be adjusted specifically for each sex. Methods Study PopulationWe prospectively enrolled patients with at least mild calcific AS in whom we performed noncontrast MDCT scan for the evaluation of AVC and comprehensive transthoracic echocardiography within 90 Creatinine Clearance age k gPatients from the Bichat Hospital were enrolled in 2 ongoing prospective studies on aortic valve calcification/stenosis (COFRASA; www.clinica...