Background Measurement of the degree of aortic valve calcification (AVC) using electron beam computed tomography (EBCT) is an accurate and complementary method to transthoracic echocardiography (TTE) for assessment of the severity of aortic stenosis (AS). Whether threshold values of AVC obtained with EBCT could be extrapolated to multislice computed tomography (MSCT) was unclear and AVC diagnostic value in patients with low ejection fraction (EF) has never been specifically evaluated.
Methods Patients with mild to severe AS underwent prospectively within 1 week MSCT and TTE. Severe AS was defined as an aortic valve area (AVA) of less than 1 cm2. In 179 patients with EF greater than 40% (validation set), the relationship between AVC and AVA was evaluated. The best threshold of AVC for the diagnosis of severe AS was then evaluated in a second subset (testing set) of 49 patients with low EF (≤40%). In this subgroup, AS severity was defined based on mean gradient, natural history or dobutamine stress echocardiography.
Results Correlation between AVC and AVA was good (r=−0.63, p<0.0001). A threshold of 1651 arbitrary units (AU) provided 82% sensitivity, 80% specificity, 88% negative-predictive value and 70% positive-predictive value. In the testing set (patients with low EF), this threshold correctly differentiated patients with severe AS from non-severe AS in all but three cases. These three patients had an AVC score close to the threshold (1206, 1436 and 1797 AU).
Conclusions In this large series of patients with a wide range of AS, AVC was shown to be well correlated to AVA and may be a useful adjunct for the evaluation of AS severity especially in difficult cases such as patients with low EF.
- Aortic valve disease
- CT scanning
- Accepted 1 July 2010
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Funding CC was supported by a grant from the Fédération Française de Cardiologie, DM-Z was supported by a contrat d'interface INSERM. The COFRASA and GENERAC studies are supported by a grant from the Assistance Publique, Hôpitaux de Paris (PHRC national 2005 and PHRC regional 2007, respectively).
Competing interests AV and DH are consultants for Edwards Lifesciences. BI received speaker's fees from Edwards Lifesciences and Sanofi-Aventis.
Patient consent Obtained.
Ethics approval This study was conducted with the approval of the Comité de Protection des Personnes, Hotel-Dieu Paris, France.
Provenance and peer review Not commissioned; externally peer reviewed.
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