Prevalence and clinical importance of aortic valve calcification detected incidentally on CT scans: comparison with echocardiography

Abstract

Purpose: To evaluate retrospectively the prevalence and grade of aortic valve calcification incidentally detected on chest multi-detector row computed tomographic (CT) scans and to compare the grade of calcification with the severity of aortic valve disease as assessed with echocardiography.

Materials and methods: Patient informed consent was waived by the institutional board on medical ethics that approved this study. The authors identified 402 patients (231 men and 171 women; mean age, 62.5 years +/- 12.1) of 1820 patients who underwent chest multi-detector row CT between July 2001 and August 2004 and also underwent echocardiography. Aortic valve calcification at multi-detector row CT was visually graded on a scale ranging from 0 to 4 (0 = no calcification, 4 = severe calcification). CT findings were correlated with hemodynamic data obtained at echocardiography. Patients without aortic stenosis were compared with patients with aortic stenosis. The Student t test, Spearman correlation coefficient, chi(2) analysis, and an unweighted kappa test were used to compare results.

Results: Aortic valve calcification was noted on multi-detector row CT scans in 72 of the 402 patients (18%). Twelve of 20 patients (60%) with grade 3 or grade 4 calcification on CT scans had aortic stenosis at echocardiography, compared with only nine of 382 patients (2.4%) with grade 0-2 calcification (P < .001). Significant correlations were observed between the grade of aortic valve calcification and the echocardiographically determined mean (r = 0.45, P = .03) and peak transvalvular gradient (r = 0.47, P = .03). There was substantial agreement between the grade of valve calcification at multi-detector row CT and the severity of aortic valve disease at echocardiography (kappa = 0.67).

Conclusion: Aortic valve calcification was an incidental finding on 18% of multi-detector row CT scans. The grade of aortic valve calcification is correlated with the hemodynamic severity of aortic valve disease as determined with echocardiography.