The same multivariable model stratified by gender will be used to perform a pre-specified subgroup analysis (re-measuring the echocardiographic LVOT diameter on all subjects who are "re-classified" by CT). This will be done by remeasuring at the traditional LVOT diameter located 5-10 mm below the aortic annulus and also by measuring at the juncture of the aortic leaflets and LVOT in mid-systole (Mayo clinic way). The purpose of this analysis is to determine if the Mayo clinic method of LVOT measurement reduces the number of misclassifications compared to the traditional method. Finally, the investigators will also examine the CT data for threshold values which suggest erroneous or outlier values for echocardiography. Men and women will be assessed separately. For example, a value of 1.6 cm is often found on echocardiography but rarely on CT scanning in their subjective clinical experience.