Aortic Valve Calcification as an Incidental Finding at CT of the Elderly: Severity and Location as Predictors of Aortic Stenosis

The purpose of this study was to correlate the severity and location of aortic valve calcifications, as an incidental finding at chest CT of elderly persons, with pressure gradients across the valve. One hundred fifteen subjects who were 60 years old or older and who showed aortic valve calcification on chest CT (5-mm reconstructed section width, no IV contrast material) and who had also undergone transthoracic echocardiography within 3 months of the CT examination were identified retrospectively. Aortic valve calcification scores (Agatston and volumetric) and subjective calcification pattern scores (based on a 9-point scale) were calculated and correlated with echocardiographic gradients. Thirty patients (26%) (median age, 81 years) were identified who showed an increased pressure gradient across the aortic valve at echocardiography. Eighty-five subjects (74%), including 30 age-matched but otherwise randomly selected control subjects, showed no increase in pressure gradient. The severity of aortic valve calcification was greater for the 30 subjects with an increased gradient than for the control subjects (p < 0.0001). Increased mean and peak gradients across the aortic valve correlated with the subjective scores for aortic valve calcification (r = 0.69 and 0.65, respectively; p < 0.0001), with Agatston scores (r = 0.76 and 0.70, respectively; p < 0.0001), and with volumetric scores (r = 0.78 and 0.73, respectively; p < 0.0001). In terms of specific commissures, the greatest correlation with mean and peak gradients was for peripheral left-posterior commissural calcification (r = 0.71 and 0.65, respectively; p < 0.0001) and central right-left commissural calcification (r = 0.69 and 0.66, respectively; p < 0.0001). The severity of aortic valve calcifications on chest CT, as assessed either subjectively or objectively, correlated with increased pressure gradients across the aortic valve, particularly for calcification of the peripheral left-posterior commissure and the central right-left commissure. These results indicate that the severity and location of aortic valve calcifications on chest CT are associated with an increased pressure gradient across the aortic valve.