Assessment Of Aortic Valve Stenosis Research Articles

Comparative assessment of aortic valve stenosis using two-dimensional, three-dimensional transesophageal echocardiography, computed tomography and cardiac catheterization

Aim. To compare effectiveness of ultrasound, radiological and invasive methods for assessing aortic valve (AV) stenosis.Material and methods. This study included 33 patients with AV stenosis. The mean age of the patients was 71,8±6,8 years. All patients underwent standard and three-dimensional echocardiography, computed tomography, and cardiac catheterization.Results. According to two-dimensional echocardiography, the AV area averaged 0,58±0,21 mm2, according to cardiac catheterization — 0,61±0,17 mm2, according to three-dimensional transesophageal echocardiography — 1,13±0,42 mm2, and according to multislice computed tomography 0,88±0,48 mm2. The difference between the values was significant (p<0,05).Conclusion. For routine diagnosis of AV stenosis, two-dimensional echocardiography is the optimal research method. With indications for radical treatment methods, three-dimensional echocardiography or multislice computed tomography should be performed.

Computed tomography and magnetic resonance imaging assessment of aortic valve stenosis: an update

Computed tomography and magnetic resonance imaging assessment of aortic valve stenosis: an update

Clinical assessment of aortic valve stenosis: Comparison between 4D flow MRI and transthoracic echocardiography.

BackgroundThe prevalence of valvular aortic stenosis (AS) increases as the population ages. Echocardiographic measurements of peak jet velocity (Vpeak), mean pressure gradient (Pmean), and aortic valve area (AVA) determine AS severity and play a pivotal role in the stratification towards valvular replacement. A multimodality imaging approach might be needed in cases of uncertainty about the actual severity of the stenosis.PurposeTo compare four‐dimensional phase‐contrast magnetic resonance (4D PC‐MR), two‐dimensional (2D) PC‐MR, and transthoracic echocardiography (TTE) for quantification of AS.Study TypeProspective.PopulationTwenty patients with various degrees of AS (69.3 ± 5.0 years).Field Strength/Sequences4D PC‐MR and 2D PC‐MR at 3T.AssessmentWe compared Vpeak, Pmean, and AVA between TTE, 4D PC‐MR, and 2D PC‐MR. Flow eccentricity was quantified by means of normalized flow displacement, and its influence on the accuracy of TTE measurements was investigated.Statistical TestsPearson's correlation, Bland–Altman analysis, paired t‐test, and intraclass correlation coefficient.Results4D PC‐MR measured higher Vpeak (r = 0.95, mean difference + 16.4 ± 10.7%, P <0.001), and Pmean (r = 0.92, mean difference + 14.9 ± 16.0%, P = 0.013), but a less critical AVA (r = 0.80, mean difference + 19.9 ± 20.6%, P = 0.002) than TTE. In contrast, unidirectional 2D PC‐MR substantially underestimated AS severity when compared with TTE. Differences in Vpeak between 4D PC‐MR and TTE showed to be strongly correlated with the eccentricity of the flow jet (r = 0.89, P <0.001). Use of 4D PC‐MR improved the concordance between Vpeak and AVA (from 0.68 to 0.87), and between PGmean and AVA (from 0.68 to 0.86).Data Conclusion4D PC‐MR improves the concordance between the different AS parameters and could serve as an additional imaging technique next to TTE. Future studies should address the potential value of 4D PC‐MR in patients with discordant echocardiographic parameters. Level of Evidence: 2 Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2020;51:472–480.

Recommendations on the echocardiographic assessment of aortic valve stenosis: a focused update from the European Association of Cardiovascular Imaging and the American Society of Echocardiography.

Echocardiography is the key tool for the diagnosis and evaluation of aortic stenosis. Because clinical decision-making is based on the echocardiographic assessment of its severity, it is essential that standards are adopted to maintain accuracy and consistency across echocardiographic laboratories. Detailed recommendations for the echocardiographic assessment of valve stenosis were published by the European Association of Echocardiography and the American Society of Echocardiography in 2009. In the meantime, numerous new studies on aortic stenosis have been published with particular new insights into the difficult subgroup of low gradient aortic stenosis making an update of recommendations necessary. The document focuses in particular on the optimization of left ventricular outflow tract assessment, low flow, low gradient aortic stenosis with preserved ejection fraction, a new classification of aortic stenosis by gradient, flow and ejection fraction, and a grading algorithm for an integrated and stepwise approach of artic stenosis assessment in clinical practice.

EComment. Re: Is cardiac magnetic resonance imaging as accurate as echocardiography in the assessment of aortic valve stenosis?

Aortic stenosis (AS) is the most frequent degenerative valvular heart disease in Western countries and its prevalence increases with an ageing population [1]. Interestingly, Wong and colleagues [2] have analysed a very common clinical scenario of a 72-year old man with an incidental diagnosis of AS on routine transthoracic echocardiography to answer the question: “Is cardiac magnetic resonance (CMR) imaging as accurate as echocardiography in the assessment of aortic valve stenosis?” They selected and level-headedly examine 12 out of more than 200 papers to reach the answer and they conclude that CMR is as accurate as echocardiography in the evaluation of patients with aortic valve stenosis, and that CMR has better interand intraobserver reliability and demonstrates an advantage over echocardiography in the detection of severe AS with greater specificity and sensitivity. It must also be emphasized that dobutamine stress echocardiography may help to differentiate between severe AS and pseudo severe AS and to assess the presence of LV contractile or flow reserve, which has been associated with better prognosis in patients undergoing surgical aortic valve replacement [3]. The advent of new echocardiographic techniques, such as speckle tracking echocardiography has also enabled the detection of eventually associated early myocardial damage in the left ventricle and have a good correlations with the extent of myocardial scar assessed found at MR late gadolinium enhancement (LGE) [4]. The contrast enhanced CMR with the LGE evaluation or better still, the new technique of T1 mapping could evidence the presence of scar, replacement focal fibrosis or interstitial diffuse fibrosis that are associated with worse prognosis [5]. Overall, the final conclusion of the authors that “the final choice, however, is as likely to be influenced by the availability of magnetic resonance imaging and expertise in interpreting the results as on accuracy and reliability” clearly represent the everyday real-life scenario.

Is cardiac magnetic resonance imaging as accurate as echocardiography in the assessment of aortic valve stenosis?

A best evidence topic was written according to a structured protocol. The question addressed was: is cardiac magnetic resonance (CMR) imaging as accurate as echocardiography in the assessment of aortic valve stenosis? Altogether 239 papers were found using the reported search. Only 12 demonstrated the best evidence to answer the clinical question. Nine of these 12 papers found CMR to correlate well with transthoracic echocardiography (TTE) or transoesophageal echocardiography (TOE) in the evaluation of aortic valve stenosis. When aortic valve areas were measured with cardiac tomography (CT) or cardiac catheterization (CC), four papers found CMR to be more accurate than TTE. Eight of 12 papers found CMR to have excellent reliability and reproducibility, as demonstrated by the low inter- and intraobserver variability. Four papers did not estimate intra- or interobserver variability. One paper noted a sensitivity and specificity of 96 and 100%, respectively, when using CMR to detect severe aortic stenosis (AS) that had been diagnosed during CC. A second paper noted a lower sensitivity and specificity of 78 and 89%, respectively, but this was still better than the sensitivities and specificities found when using TOE or TTE to detect severe AS, as noted on CC. We conclude that current evidence finds echocardiography and CMR to be equally reliable in assessing aortic stenosis. CMR has better inter- and intraobserver reliability and demonstrates an advantage over echocardiography in the detection of severe AS with greater specificity and sensitivity. The final choice, however, is as likely to be influenced by the availability of magnetic resonance imaging and expertise in interpreting the results as by accuracy and reliability.

Cardiovascular magnetic resonance imaging and transthoracic echocardiography in the assessment of stenotic aortic valve area: a comparative study

Magnetic resonance (MR) imaging and echocardiography both allow assessment of aortic valve stenosis. In MR the aortic valve area (AvA) is measured using planimetry while in transthoracic echocardiography (TTE) AvA is usually calculated by applying the continuity equation. To compare the measured stenotic aortic valve areas using five different MR-acquisition alternatives with the corresponding area values calculated by TTE. The aortic valve was imaged in 14 patients, with diagnosed aortic valve stenosis, using balanced steady state free precession (bSSFP) gradient echo (GE) and phase contrast imaging (PC). Three adjacent slices were planned to encompass the aortic valve and the aortic valve area was measured using planimetry. The two sets of complex valued images generated by the PC sequence formed three kinds of images that could be used for aortic valve area measurements: the magnitude image (PC/Mag), the modulus (PCA/M), and phase difference (PCA/P) between the two complex images, respectively. The valve area from TTE was calculated using the continuity equation. A cut-off of <1.0 cm(2) was used as a criteria for severe stenosis. The mean area differences between the different MR acquisitions and TTE method were -0.05 ± 0.37 cm(2) (GE), -0.18 ± 0.46 cm(2) (bSSFP), 0.27 ± 0.43 cm(2) (PC/Mag), 0.15 ± 0.32 cm(2) (PCA/P), and 0.26 ± 0.27 cm(2) (PCA/M). The valve area was significantly overestimated using PCA/M that, in turn, implied a significant underestimation of the aortic valve stenosis severity compared to the assessments using TTE. The smallest area valve difference between TTE and an MR-acquisition alternative is obtained with gradient echo images. The use of PCA/M leads to significant differences in planimetry measurements of the aortic valve orifice and the gradation of the stenosis severity compared to TTE.

Aortic valve stenosis: CT contributions to diagnosis and therapy

As populations in Western civilizations are aging, the prevalence of degenerative aortic valve stenosis is increasing. CT imaging provides information on aortic valve pathology in many ways: In nonenhanced scans, aortic valve calcification can be quantified accurately, which helps to understand the pathogenesis and progression of aortic sclerosis and stenosis. After contrast injection, CT allows excellent visualization of aortic valve structure and, through measurement of the aortic valve area, is capable to serve as a "backup method" for the assessment of aortic valve stenosis, especially if other imaging methods are difficult to interpret. Importantly, CT tends to overestimate aortic valve opening areas in comparison to transthoracic echocardiography, which relies on the continuity equation for quantifying aortic stenosis, based on flow velocities and the estimated area of the left ventricular outflow tract. It has recently been shown that the oval rather than round shape of the left ventricular outflow tract is the most likely factor behind this systematic difference between functional compared with anatomic assessment of aortic valve stenosis. In fact, the ability to provide superbly accurate anatomic imaging of the aortic valve and entire aortic root makes CT a uniquely useful tool for the planning of transcatheter aortic valve implantation. Hence, CT imaging spans a wide range of applications in aortic valve disease, from basic research to diagnosis and treatment planning. This review aims to summarize the current state of the art concerning imaging of the aortic valve by CT and the potential clinical applications.

Real-time three-dimensional transoesophageal echocardiography in the assessment of aortic valve stenosis

To determine the feasibility of real-time three-dimensional transoesophageal echocardiography (3D-TOE) in the evaluation of aortic valve stenosis, to study its reliability, and to test the concordance of this new method when compared with transthoracic two-dimensional echocardiography (2D-TTE) as the diagnostic standard. Fifty-nine consecutive patients with moderate-to-severe aortic valve stenosis were assessed by means of 2D-TTE and 3D-TOE by independent blinded observers. Aortic valve planimetry was possible in 94.9% of patients. Inter-observer intraclass correlation coefficients (ICC) were 0.892 (CI 95% 0.818-0.936; P < 0.001), and 0.871 (CI 95% 0.780-0.925; P < 0.001) for 2D-TTE and 3D-TOE, respectively. Bland-Altman plot showed a mean difference in aortic valve area (AVA) of 0.040 cm(2), with 2D-TTE yielding larger values than 3D-TOE. ICC of both methods was 0.724 (CI 95% 0.530-0.839; P < 0.001). Assessment of AVA by means of 3D-TOE is feasible in most patients with aortic valve stenosis. Reliability of the measurement is good. However, there is some disagreement with standard 2D-TTE that needs further investigation.

Critical impact of pressure recovery on assessment of aortic valve stenosis

Critical impact of pressure recovery on assessment of aortic valve stenosis

Selection of percutaneous aortic valve replacement candidates: CMR assessment of aortic valve stenosis and aortic root morphology in comparison with echocardiography and cardiac catheterization

Percutaneous aortic valve replacement in patients presenting high risk for surgery is a promising new interventional treatment modality. The potential role of non-invasive imaging techniques in patient selection needs further validation.

Direct measurement of left ventricular outflow tract by transthoracic real-time 3D-echocardiography increases accuracy in assessment of aortic valve stenosis

Background Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter. Methods We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from systolic LVOT areas. These results were compared to area values obtained by M-mode LVOT-diameters (area = π ⁎ ( d / 2) 2). In addition, the calculated aortic valve orifices were compared to invasive measurements or direct planimetry in the transthoracic or transesophageal examination. Results Two independent observers found a reduction in LVOT area during systole ( p < 0.001). Often a more ellipsoid-like shaped LVOT resulted at end-systole which was shown by a reduction ( p < 0.001) of the LVOT longitudinal to oblique axis ratio. 3D-TTE determination of aortic valve orifice areas (mean difference: − 0.04 ± 0.09 cm 2) showed a lesser deviation from the invasively or planimetrically measured areas than conventionally calculated LVOT areas (mean difference: − 0.1 ± 0.1 cm 2) using the continuity equation ( p < 0.001). Conclusions The tested transthoracic 3D-echocardiography technique offers non-invasive measurement of the LVOT and aortic valve area based on the continuity equation during systole and thus improves accuracy and, additionally, agreement of aortic valvular area determination with invasive and direct measurements.

Evaluation of Bicuspid Aortic Valve and Aortic Coarctation With 4D Flow Magnetic Resonance Imaging

Time-resolved, 3D, phase-contrast magnetic resonance imaging (4D flow) is an effective means of evaluating dynamic multidirectional blood flow in the thoracic aorta.1 We have used the technique for characterization of abnormal flow features in a 14-year-old boy with aortic coarctation and bicuspid aortic valve (BAV) but without evidence of aortic stenosis or regurgitation. In addition to the expected flow disturbance in the region of the juxtaductal coarctation (Figure 1), we show an unusual flow feature in the ascending aorta that has not been previously reported in this clinical setting and that may be unique to BAV: 2 discrete nested helices of midsystolic blood flow in a nonaneurysmal aorta (Figure 2). Figure 1. Fourteen-year-old boy with BAV and aortic coarctation. A, Three-dimensional contrast-enhanced magnetic resonance angiography that demonstrates a focal juxtaductal coarctation and prominent internal mammary and …

Absolute assessment of aortic valve stenosis by planimetry using cardiovascular magnetic resonance imaging: Comparison with transœsophageal 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 transœsophageal 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 cm 2 as measured by TEE, were enrolled in the study. Mean differences were: between CMR and TEE planimetry: d = 0.01 ± 0.14 cm 2, between CMR and cardiac catheterisation: d = 0.05 ± 0.13 cm 2, between CMR and TTE: d = 0.10 ± 0.17 cm 2, between TTE and TEE: d = 0.10 ± 0.18 cm 2, between TTE and cardiac catheterisation: d = 0.06 ± 0.16 cm 2, and between TEE and cardiac catheterisation: d = 0.07 ± 0.13 cm 2. Mean intraobserver and interobserver differences of CMR planimetry were d = 0.02 ± 0.07 cm 2 and d = 0.03 ± 0.14 cm 2, 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.

Accuracy of Multislice Computed Tomography in the Preoperative Assessment of Coronary Disease in Patients With Aortic Valve Stenosis

To evaluate multislice computed tomography (MSCT) as an alternative to coronary angiography, we prospectively studied its diagnostic accuracy for the detection of significant coronary artery lesions in patients with significant aortic valve stenosis undergoing valve surgery. In patients with aortic valve stenosis, coronary angiography is still recommended before surgery. Multislice computed tomography is a promising noninvasive technique for the detection of significant coronary artery lesions. Fifty-five consecutive patients scheduled for coronary angiography in the preoperative assessment of aortic valve stenosis underwent 16-slice MSCT 24 h before coronary angiography. We analyzed coronary lesions, image quality, and arterial calcium score. The sensitivity of the MSCT-based strategy in detecting significant stenosis was 100%, and its specificity 80%. The positive and negative predictive values were respectively 55% and 100%. For calcium scores <1,000 (77% of patients), MSCT detected all patients without coronary artery disease, enabling conventional coronary angiography to be avoided in 35 of 55 cases (80%). For calcium scores >1,000, MSCT enabled conventional coronary angiography to be avoided in only 6% of cases, either because significant stenosis was found with a possible indication of revascularization, or because the examination was not interpretable. The results of this initial experience in relatively few patients suggest that MSCT-based coronary angiography may serve as an alternative to invasive coronary angiography to rule out significant coronary artery disease in patients scheduled for elective aortic valve replacement. Larger studies are necessary to fully explore the potential of coronary MSCT to improve preoperative risk stratification.

838 Direct measurement of left ventricular outflow tract by newly developed transthoracic real-time-3D-echocardiography increases accuracy in assessment of aortic valve stenosis

Background: Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter. Methods: We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from systolic LVOT areas. These results were compared to area values obtained by M-mode LVOT-diameters (area= π ⁎(d/2) 2 ). In addition, the calculated aortic valve orifices were compared to invasive measurements or direct planimetry in the transthoracic or transesophageal examination. Results: Two independent observers found a reduction in LVOT area during systole (pb0.001). Often a more ellipsoid-like shaped LVOT resulted at end-systole which was shown by a reduction (pb0.001) of the LVOT longitudinal to oblique axis ratio. 3D-TTE determination of aortic valve orifice areas (mean difference: −0.04±0.09 cm 2 ) showed a lesser deviation from the invasively or planimetrically measured areas than conventionally calculated LVOT areas (mean difference: −0.1±0.1 cm 2 ) using the continuity equation (pb0.001). Conclusions: The tested transthoracic 3D-echocardiography technique offers non-invasive measurement of the LVOT and aortic valve area based on the continuity equation during systole and thus improves accuracy and, additionally, agreement of aortic valvular area determination with invasive and direct measurements. © 2008 Elsevier Ireland Ltd. All rights reserved.

Magnetic resonance to assess the aortic valve area in aortic stenosis: How does it compare to current diagnostic standards?

ObjectivesThe purpose of the present study was to evaluate whether magnetic resonance (MR) planimetry of the aortic valve area (AVA) may prove to be a reliable, non-invasive diagnostic tool in the assessment of aortic valve stenosis, and how the results compare with current diagnostic standards. BackgroundCurrent standard techniques for assessing the severity of aortic stenosis include transthoracic and transesophageal echocardiography (TEE) as well as transvalvular pressure measurements during cardiac catheterization. MethodsForty consecutive patients underwent cardiac catheterization, TEE, and MR. The AVA was estimated by direct planimetry (MR, TEE) or calculated indirectly via the peak systolic transvalvular gradient (catheter). Pressure gradients from cardiac catheterization and Doppler echocardiography were also compared. ResultsBy MR, the mean AVAmaxwas 0.91 ± 0.25 cm2; by TEE, AVAmaxwas 0.89 ± 0.28 cm2; and by catheter, the AVA was calculated as 0.64 ± 0.26 cm2. Mean absolute differences in AVA were 0.02 cm2for MR versus TEE, 0.27 cm2for MR versus catheter, and 0.25 cm2for TEE versus catheter. Correlations for AVAmaxwere r = 0.96 between MR and TEE, r = 0.47 between TEE and catheter, and r = 0.44 between MR and catheter. The correlation between Doppler and catheter gradients was r = 0.71. ConclusionsMagnetic resonance planimetry of the AVA correlates well with TEE and less well with the catheter-derived AVA. Invasive and Doppler pressure correlated less well than those obtained from planimetric techniques. Magnetic resonance planimetry of the AVA may provide an accurate, non-invasive, well-tolerated alternative to invasive techniques and transthoracic echocardiography in the assessment of aortic stenosis.

Pressure recovery in aortic valve stenosis.

Pressure recovery is the variable increase in lateral pressure downstream from a stenotic orifice. The magnitude and clinical significance of pressure recovery in aortic valve stenosis are poorly defined. We obtained high-fidelity pressure and velocity recordings in 11 patients with isolated significant aortic valve stenosis at the time of diagnostic cardiac catheterization. Systematic catheter pullback from the left ventricular cavity revealed a consistent although variable subvalvular gradient. Further pullback across and distal to the region of the stenosed aortic valve revealed a consistent and progressive increase in the ascending aortic pressure. This increase in lateral pressure occurred pari passu with a diminution in amplitude of the velocity pulse. The extent of pressure recovery was directly related to systemic blood flow and transvalvular flow but inversely related to the Gorlin-derived aortic valve area. These findings have potentially important implications for the hemodynamic evaluation of mild to moderately severe aortic valve stenosis. The extent of pressure recovery may be of additional utility in the assessment of aortic valve stenosis under varying physiological states.

Color-Guided Doppler Echocardiographic Assessment of Aortic Valve Stenosis

Color-Guided Doppler Echocardiographic Assessment of Aortic Valve Stenosis

Color-guided Doppler echocardiographic assessment of aortic valve stenosis

The severity of valvular aortic stenosis was assessed by Doppler color flow mapping in 100 consecutive patients who underwent successful cardiac catheterization within 2 weeks of the Doppler study. The maximal width of the aortic stenosis jet seen in 61 of these patients (Group A) was measured at the aortic valve. Color-guided continuous wave Doppler examination was used to measure the mean transaortic pressure gradient, and the aortic valve area was estimated using the simplified continuity equation. The aortic stenosis jet was not seen in 39 patients (Group B), and the mean pressure gradient and aortic valve area in these patients were assessed by conventional Doppler echocardiography alone.The mean pressure gradient obtained by continuous wave Doppler study and cardiac catheterization in the 61 Group A patients correlated well (r = 0.90); the correlation was lower in the 39 Group B patients (r = 0.70). The overall correlation for the combined Groups A and B was good (r = 0.82). The aortic valve area estimated by continuous wave Doppler study and cardiac catheterization in 54 Croup A patients correlated well (r = 0.92); the correlation in 22 Group B patients was lower (r = 0.71). The correlation for all 76 patients (Groups A and B) was good (r = 0.80). The maximal nortic stenosis jet width also correlated well with the aortic valve area estimated at catheterization in 54 patients (r = 0.90). Group C represented an additional 14 patients in whom the left ventricle could not be entered during cardiac catheterization.All of these patients had severe aortic stenosis as detected by Doppler color flow mapping and had a calcified aortic valve with virtually immobile leaflets at subsequent surgery. These results show that Doppler color flow imaging combined with conventional Doppler study provides a reliable assessment of the severity of aortic stenosis and that the aortic stenosis jet width accurately estimates the degree of the aortic stenosis.