Calcification of aortic valve detected incidentally on CT scans: prevalence and clinical significance.

Abstract

Aortic valve calcification that is visualized on chest radiographs is considered a marker for clinically significant aortic stenosis, but the clinical importance of this finding on CT is unknown. Accordingly, we studied the prevalence and clinical relevance of aortic valve calcification found incidentally on CT scans of the chest. After comparing computer records of chest CTs and echocardiograms, we identified 109 patients who underwent both studies during a 2-year period. Two thoracic radiologists reviewed the CT scans to identify and quantify aortic valve calcification. The quantity of aortic valve calcification was graded on a scale of 1 to 3, with grade 3 indicating the most severe calcification. The prevalence of calcification was correlated with patient age and sex. The findings on CT were correlated with hemodynamic data from echocardiography. At echocardiography, a peak aortic valve gradient of greater than 25 mm Hg was defined as abnormal. Aortic valve calcification was noted on CT scans in 33 (30%) of the 109 patients. Aortic valve calcification shown by CT was significantly more common in patients more than 65 years old (p < .01). Five (15%) of 33 patients with aortic valve calcification shown by CT had abnormal aortic valve gradients at echocardiography. In contrast, none of 76 patients without aortic valve calcification shown by CT had abnormal aortic valve gradients (p < .01). All five patients with abnormal aortic valve gradients had moderate quantities of aortic valve calcification seen on CT scans. Two of the five were younger than 55 years old. Aortic valve calcification is a common finding on CT scans and is usually clinically insignificant. Nevertheless, some patients with aortic valve calcification on CT have aortic stenosis, particularly those younger than 55 years old and those with moderately dense aortic valve calcification shown by CT. These patients may benefit from hemodynamic assessment of the aortic valve by echocardiography.