Absolute assessment of aortic valve stenosis by planimetry using cardiovascular magnetic resonance imaging: comparison with transesophageal echocardiography, transthoracic echocardiography, and cardiac catheterisation

OBJECTIVE: The aims of this study were to investigate absolute assessment of aortic valve area (AVA), before surgery for aortic stenosis, using cardiovascular magnetic resonance (CMR) in comparison with transesophageal echocardiography (TEE) and with effective AVA indirectly obtained by routine techniques i.e. transthoracic echocardiography (TTE) and cardiac catheterisation. MATERIALS AND METHODS: Absolute AVA planimetry was performed by TEE and CMR steady state free precession sequences obtained through the aortic valvular plane. Effective AVA was calculated by the continuity equation in TTE and by cardiac catheterisation (Gorlin formula). RESULTS: Thirty-nine patients with aortic valve stenosis, mean age 71.7 +/- 7.6 years, with a mean AVA of 0.93 +/- 0.31 cm2 as measured by TEE, were enrolled in the study. Mean differences were: between CMR and TEE planimetry: d = 0.01 +/- 0.14 cm2, between CMR and cardiac catheterisation: d = 0.05 +/- 0.13 cm2, between CMR and TTE: d = 0.10 +/- 0.17 cm2, between TTE and TEE: d = 0.10 +/- 0.18 cm2, between TTE and cardiac catheterisation: d = 0.06 +/- 0.16 cm2, and between TEE and cardiac catheterisation: d = 0.07 +/- 0.13 cm2. Mean intraobserver and interobserver differences of CMR planimetry were d = 0.02 +/- 0.07 cm2 and d = 0.03 +/- 0.14 cm2, respectively. CONCLUSION: CMR planimetry of the AVA is a noninvasive and reproducible technique to evaluate stenotic aortic valves and can be used as an alternative to echocardiography or cardiac catheterisation.