A novel approach to determine aortic valve area with phase-contrast cardiovascular magnetic resonance

Journal of Cardiovascular Magnetic Resonance

Johannes Schwaiger¹  Axel Bauer²  Ivan Lechner²  Gert Klug²  Martin Reindl²  Christina Tiller²  Bernhard Metzler²  Magdalena Holzknecht²  Sebastian J. Reinstadler²  Christian Kremser³  Mathias Pamminger³  Felix Troger³  Agnes Mayr³ 

[1] Department of Internal Medicine, Academic Teaching Hospital Hall in Tirol, Hall in Tirol, Austria;University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria;University Clinic of Radiology, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria;

关键词: Aortic stenosis;    Cardiac magnetic resonance imaging;    Phase-contrast-CMR;    Valvular heart disease;   

DOI  :  10.1186/s12968-021-00838-w

来源: Springer

【 摘 要 】

BackgroundTransthoracic echocardiography (TTE) is the diagnostic routine standard for assessing aortic stenosis (AS). However, its inaccuracies in determining stroke volume (SV) and aortic valve area (AVA) call for a more precise and dependable method. Phase-contrast cardiovascular magnetic resonance imaging (PC-CMR) is a promising tool to push these boundaries. Thus, the aim of this study was to validate a novel approach based on PC-CMR against the gold-standard of invasive determination of AVA in AS compared to TTE.MethodsA total of 50 patients with moderate or severe AS underwent TTE, cardiac catheterization and CMR. AVA via PC-CMR was determined by plotting momentary flow across the valve against flow-velocity. SV by CMR was measured directly via PC-CMR and volumetrically using cine-images. Invasive SV and AVA were determined via Fick-principle and Gorlin-formula, respectively. TTE yielded SV and AVA using continuity equation. Gradients were calculated via the modified Bernoulli-equation.ResultsSV by PC-CMR (85 ± 31 ml) correlated strongly (r: 0.73, p < 0.001) with cine-CMR (85 ± 19 ml) without significant bias (lower and upper limits of agreement (LLoA and ULoA): − 41 ml and 44 ml, p = 0.83). In PC-CMR, mean pressure gradient correlated significantly with invasive determination (r: 0.36, p = 0.011). Mean AVA, as determined by PC-CMR during systole (0.78 ± 0.25 cm2), correlated moderately (r: 0.54, p < 0.001) with invasive AVA (0.70 ± 0.23 cm2), resulting in a small bias of 0.08 cm2 (LLoA and ULoA: − 0.36 cm2 and 0.55 cm2, p = 0.017). Inter-methodically, AVA by TTE (0.81 ± 0.23 cm2) compared to invasive determination showed similar correlations (r: 0.58, p < 0.001 with a bias of 0.11 cm2, LLoA and ULoA: − 0.30 and 0.52, p < 0.001) to PC-CMR. Intra- and interobserver reproducibility were excellent for AVA (intraclass-correlation-coefficients of 0.939 and 0.827, respectively).ConclusionsOur novel approach using continuous determination of flow-volumes and velocities with PC-CMR enables simple AVA measurement with no bias to invasive assessment. This approach highlights non-invasive AS grading through CMR, especially when TTE findings are inconclusive.

【 授权许可】

CC BY