Value of cardiac multislice spiral CT for the assessment of degenerative aortic stenosis:: Comparison with echocardiography

Objective: To non-invasively assess the severity of aortic valve stenosis (AS) by the determination of aortic valve calcification (AVC) using multislice spiral computed tomography (MSCT). Materials and Methods: Forty-one consecutive patients (17 male, 24 female, mean age 71.0 +/- 7.9 years) with a history of AS and an aortic valve area less than or equal to 2 cm(2) underwent retrospectively ECG-gated 4-slice MSCT and echocardiography. The AVCs were quantitatively assessed using the score described by Agatston as well as by calculating the calcium mass. The echocardiographically determined aortic valve area (AVA) and the severity of AS according to the ACC/AHA guidelines were compared to the degree of aortic valve calcifications. Pearson's correlation coefficient, cut-off values, kappa test and F-test with post hoc Bonferroni t-tests were calculated. Results: Calcium scores were significantly higher in patients with severe AS, when compared to mild or moderate AS (p < 0.001). In patients suffering from severe AS, the mean Agatston score was 4125.5 +/- 1168.9 (calcium mass 904.1 +/- 263.3) while in patients with moderate and mild AS the corresponding values were 1596.3 +/- 987.0 (319.1 +/- 208.3) and 785.9 +/- 390.1 (149.1 +/- 90.2), respectively. Pearson's correlation coefficients were r = 0.75 for the Agatston score and r = -0.72 for the calcium mass. There was a moderate agreement between severity of AS according to the ACC/AHA guidelines and the degree of AS determined from AVC scores with kappa = 0.6091 and kappa = 0.6985, respectively. Conclusion: Severe AS may be differentiated from moderate or mild AS using cardiac MSCT. Extensive calcifications of the aortic valve presenting with an Agatston-Score 2824 (calcium mass greater than or equal to 611) indicate a severe AS and should be taken as an indication for further diagnostic workup.