Wertigkeit der kardialen Mehrschicht-Spiral-CT zur Beurteilung der degenerativen Aortenklappenstenose: Vergleich zur Echokardiographie

Zusammenfassung

Ziel: Korrelation der mit kardialer Mehrschicht-Spiral-CT (MSCT) bestimmten Kalzifikationen der Aortenklappe mit dem Schweregrad der Aortenklappenstenose (AS). Material und Methode: 41 konsekutive Patienten (17 Männer, 24 Frauen, Durchschnittsalter 71,0 ± 7,9 Jahre) mit anamnestisch bekannter AS und einer Klappenöffnungsfläche ≤ 2 cm² wurden mittels nativer 4-Schicht-MSCT mit retrospektivem EKG-Gating und Echokardiographie untersucht. Kalzifikationen der Aortenklappe wurden mit Agatston-Score und Massenscore quantifiziert. Echokardiographisch bestimmte Klappenöffnungsfläche (EKÖF) und Schweregrad der AS wurden mit dem Ausmaß der Klappenkalzifikationen verglichen. Ergebnisse: Agatston-Score und Massenscore waren bei einer hochgradigen AS signifikant höher (p < 0,001) als bei geringer oder mittelgradiger AS. Bei hochgradigen AS betrug der mittlere Agatston-Score 4125,5 ± 1168,9 (Massenscore: 904,1 ± 263,3) während die korrespondierenden Werte für mittelgradige AS bei 1596,3 ± 987,0 (319,1 ± 208,3) und für geringgradige AS bei 785,9 ± 390,1 (149,1 ± 90,2) lagen. Pearson’s Korrelationskoeffizient war r = - 0,75 für den Agatston-Score und r = - 0,72 für den Massenscore. Die Übereinstimmung mit dem Schweregrad einer AS war mit κ = 0,6091 bzw. κ = 0,6985 moderat. Schlussfolgerung: Die kardiale MSCT hat das Potenzial, hochgradige AS von gering- oder mittelgradigen AS zu unterscheiden. Ausgeprägte Kalzifikationen der Aortenklappensegel mit einem Agatston-Score ≥ 2824 (Massenscore ≥ 611) weisen auf eine hochgradige AS hin und können als Indikation für eine weitergehende Diagnostik angesehen werden.

Abstract

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 ≤ 2 cm² 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 κ = 0.6091 and κ = 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 ≥ 611) indicate a severe AS and should be taken as an indication for further diagnostic workup.

Key words

Computed Tomography (CT) - multidetector row - heart, CT - heart, US - heart, calcification - aortic valve

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