Aortic Valve Area In Patients Research Articles

Abstract 11582: Prognostic Implications of Anatomical Aortic Valve Area in Patients with Bicuspid Aortic Stenosis by Three-Dimensional Transesophageal Echocardiography

Background: Three-dimensional (3D) transesophageal echocardiography (TEE) provides high-resolution images of aortic valve area (AVA) in patients with bicuspid aortic stenosis (AS). However, the correlation with pressure gradient compared with conventional echocardiographic indices and prognostic implications of 3D TEE derived valve area (AVA 3DTEE ) has not been evaluated. Therefore, we assessed the disease severity and the prognostic value of AVA 3DTEE in patients with bicuspid AS. Methods: We retrospectively analyzed 105 patients with at least mild bicuspid AS (peak aortic velocity >2.5m/sec) and LVEF ≥50% (mean transaortic pressure gradient 46±17 mm Hg) underwent transthoracic echocardiography, two-dimensional (2D) and 3D TEE between 2012 and 2019. AVA was measured using (i) the continuity equation (CE) obtained with transthoracic echocardiography, (ii) planimetric 2D TEE, and (iii) volumetric 3D TEE. Cardiac events were defined as surgical or transcatheter aortic valve replacement and/or aortic replacement, heart failure admission, or cardiac death. Results: AVA 3DTEE was larger than AVA CE (mean difference 0.21±0.03, P <0.001), and smaller than AVA 2DTEE (mean difference 0.11±0.02, P <0.001). AVA 3DTEE had an excellent correlation with mean transaortic pressure gradient (r=0.91, P <0.001), whereas AVA 2DTEE and AVA CE showed lower correlations (r=0.81 and r=0.59, both P <0.001). AVA 3DTEE significantly reduced the proportion of inconsistent AS grading, compared with AVA CE (6% versus 17%, P <0.001). During a follow-up period (median, 853 days; range 513 to 1287 days), 101 surgical or transcatheter aortic valve replacement and/or aortic replacement, 6 heart failure admission, or 1 cardiac death occurred. AVA 3DTEE ≤1cm 2 was an independent predictor of cardiac events (adjusted hazard ratio (HR) 2.40, (1.41 to 4.09), P =0.001) and AVA 3DTEE of 1 cm 2 was the optimal cutoff value for predicting cardiovascular events with sensitivity of 71% and specificity of 100%. Conclusions: AVA measured by 3D TEE has a good correlation with mean transaortic pressure gradient and improved the hitherto inconsistent AS grading. AVA 3DTEE ≤1cm 2 is an important predictor for cardiac events of patients with bicuspid AS.

Aortic stenosis reexpanded – a novel approach to determine aortic valve area with phase contrast cardiovascular magnetic resonance imaging

Abstract Background Transthoracic echocardiography (TTE) has become the diagnostic standard for evaluating aortic stenosis (AS) severity, mainly because of its advantages in comparison to the gold standard of cardiac catheterization. However, its inaccuracies in determining stroke volume (SV) and consequentially computing aortic valve area (AVA) call for a more precise and dependable method. Phase contrast cardiovascular magnetic resonance imaging (PC-CMR) is an aspiring tool to push these boundaries. Purpose The aim of this study was to validate a novel and simple approach based on PC-CMR against the invasive and echocardiographic determination of SV and AVA in patients with moderate and severe AS. Methods A total of 50 patients with moderate or severe AS underwent TTE, cardiac catheterization and CMR; AVA by PC-CMR was determined via plotting momentary flow across the valve against momentary flow velocity. SV via 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 the continuity equation. Finally, gradients were calculated via the modified Bernoulli equation. Results SV by PC-CMR showed a strong correlation with cine-CMR with no significant bias (r: 0.730, p<0.001; SV by PC-CMR: 85±31ml; SV by cine-CMR: 85±19ml, p=0.829). Peak gradients determined by PC-CMR were 65±29mmHg and correlated inversely with AVA by PC-CMR (r: −0.371; p=0.008). Mean AVA during the whole systolic phase showed a moderate correlation (r: 0.544, p<0.001) to invasive AVA with a small bias (AVA by CMR: 0.78±0.25cm2 versus invasive AVA: 0.70±0.23cm2, bias: 0.08cm2, p=0.017). Inter-methodical correlation and bias of AVA as measured by TTE and invasive AVA (AVA by TTE: 0.81±0.23cm2, r: 0.580, p<0.001, bias 0.11cm2, p<0.001) were similar to AVA by PC-CMR and invasive AVA. Conclusion PC-CMR provides a great option to yield reliable and solid SV values in patients with moderate and severe AS. Furthermore, continuous determination of flow volumes and flow velocities is able to determine AVA in these patients in an easy and reproducible manner. Our novel approach shines a light on the diagnostic potential of PC-CMR for non-invasive AS grading, especially in cases where echocardiography reaches its limits and where clinical findings appear inconclusive. Funding Acknowledgement Type of funding sources: None. Central IllustrationCine (l,r) and PC-CMR (m) images in AS

Invasive validation of a novel approach to determine aortic valve area with phase-contrast cardiac magnetic resonance imaging

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Society of Cardiology Background. Echocardiography is considered the standard method for screening and diagnosing aortic valve stenosis. However, inaccuracies in the determination of stroke-volumes by the continuity equation might particularly make the evaluation of patients with low-flow states difficult. Phase-contrast cardiac magnetic resonance (PC-CMR) is a promising tool in overcoming these limitations by the simultaneous determination of flow volumes and velocities across the stenotic valve. Purpose The aim of this study is to validate a novel approach based on PC-CMR against the invasive determination of the aortic valve area (AVA). Methods. PC-CMR was performed in 50 patients with moderate or severe AS (n = 52; age 72 years [interquartile range (IQR) 66 - 78], 38% of patients with low-flow states). All of them were referred to invasive evaluation of aortic stenosis by cardiac catheterization. Additionally, transthoracic echocardiography (TTE) was performed. Aortic valve area (AVA) was determined by PC-CMR (AVAPC-CMR) via plotting momentary flow across the valve against momentary flow velocity. AVAPC-CMR at different time points over the entire cardiac cycle was compared to invasively determined AVA, calculated according to the Gorlin-formula. Stroke volumes (SV) were determined by the Fick-principle, pressure gradients according to the modified Bernoulli-equation. Results. Mean AVA during the whole systolic phase showed a good correlation (r: 0.544, p < 0.001) with invasive AVA with a small bias (AVACMR: 0.78 cm², IQR: [0.60-0.96] versus AVAINVASIVE: 0.70 cm², IQR: [0.52-0.87], bias: 0.08 cm², p = 0.017). Intermethodical correlation and bias of AVA as measured by TTE (AVATTE) and AVAINVASIVE were similar to AVAPC-CMR (AVATTE: 0.81 cm²; IQR: [0.64-0.96] versus AVAINVASIVE: 0.70 cm², IQR: [0.52-0.87] r: 0.580, p < 0.001, bias 0.11 cm², p < 0.001). SV by PC-CMR showed a good correlation with Cine-CMR with no significant bias (r: 0.730, p < 0.001; SVPC-CMR: 86 ± 31 ml; SVCine: 85 ± 19 ml). Maximum gradients determined by PC‑CMR were 65 ± 2 9mmHg and showed a good inverse correlation with AVAPC-CMR (r: ‑0.371; p = 0.008). Conclusion. PC-CMR with continuous determination of flow volumes and flow velocities is able to determine AVA in patients with severe aortic stenosis with a tendency to overestimate AVA compared to invasively determined AVA.

Elements of Immunoglobulin E Network Associate with Aortic valve Area in Patients with Acquired Aortic Stenosis.

Allergic mechanisms are likely involved in atherosclerosis and its clinical presentations, such as coronary artery disease (CAD). It has been previously reported that CAD severity associates with serum levels of immunoglobulin E (IgE), the molecule that, along with its high-affinity receptor (FcԑRI), plays a central role in allergic reactions. Considering multiple pathophysiological similarities between atherosclerosis and acquired aortic (valve) stenosis (AS), we speculated that allergic pathways could also contribute to the AS mechanisms and grading. To validate this hypothesis, we first checked whether total serum IgE levels associate with echocardiographic markers of AS severity. Having found a positive correlation between serum IgE and aortic valve area (AVA), we further speculated that also total IgE-determining genetic polymorphisms in FCER1A, a locus encoding an allergen-biding FcԑRI subunit, are related to acquired AS severity. Indeed, the major allele of rs2251746 polymorphism, known to associate with higher IgE levels, turned out to correlate with larger AVA, a marker of less severe AS. Our findings surprisingly suggest a protective role of IgE pathways against AS progression. IgE-mediated protective mechanisms in AS require further investigations.

Use and success evaluation of percutaneous aortic balloon valvuloplasty in different hemodynamic entities of severe aortic stenosis in the TAVR era

Abstract Background In the era of transcatheter aortic valve replacement (TAVR), there is renewed interest in percutaneous balloon aortic valvuloplasty (BAV), which may qualify as the primary treatment option of choice in special clinical situations. Success of BAV is commonly defined as a significant mean pressure gradient reduction after the procedure. Purpose To evaluate the correlation of the mean pressure gradient reduction and increase in the aortic valve area (AVA) in different flow and gradient patterns of severe aortic stenosis (AS). Methods Consecutive patients from 01/2010 to 03/2018 undergoing BAV were divided into normal-flow high-gradient (NFHG), low-flow low-gradient (LFLG) and paradoxical low-flow low-gradient (pLFLG) AS. Baseline characteristics, hemodynamic and clinical information were collected and compared. Additionally, the clinical pathway of patients (BAV as a stand-alone procedure or BAV as a bridge to aortic valve replacement) was followed-up. Results One-hundred-fifty-six patients were grouped into NFHG (n=68, 43.5%), LFLG (n=68, 43.5%) and pLFLG (n=20, 12.8%) AS. Underlying reasons for BAV and not TAVR/SAVR as the primary treatment option are displayed in Figure 1. Spearman correlation revealed that the mean pressure gradient reduction had a moderate correlation with the increase in the AVA in patients with NFHG AS (r: 0.529, p<0.001) but showed no association in patients with LFLG (r: 0.145, p=0.239) and pLFLG (r: 0.030, p=0.889) AS. Underlying reasons for patients to undergo BAV and not TAVR/SAVR varied between groups, however cardiogenic shock or refractory heart failure (overall 46.8%) were the most common ones. After the procedure, independent of the hemodynamic AS entity, patients showed a functional improvement, represented by substantially lower NYHA class levels (p<0.001), lower NT-pro BNP levels (p=0.003) and a numerical but non-significant improvement in other echocardiographic parameters like the left ventricular ejection fraction (p=0.163) and tricuspid annular plane systolic excursion (TAPSE, p=0.066). An unplanned cardiac re-admission due to heart failure was necessary in 23.7% patients. Less than half of the patients (44.2%) received BAV as a bridge to TAVR/SAVR (median time to bridge 64 days). Survival was significantly increased in patients having BAV as a staged procedure (log-rank p<0.001). Conclusion In daily clinical practice, the mean pressure gradient reduction might be an adequate surrogate of BAV success in patients with NFHG AS but is not suitable for patients with other hemodynamic entities of AS. In those patients, TTE should be directly performed in the catheter laboratory to correctly assess the increase of the AVA. BAV as a staged procedure in selected clinical scenarios increases survival and is a considerable option in all flow states of severe AS. (NCT04053192) Figure 1 Funding Acknowledgement Type of funding source: None

Estimation of Stroke Volume and Aortic Valve Area in Patients with Aortic Stenosis: A Comparison of Echocardiography versus Cardiovascular Magnetic Resonance

In aortic stenosis, accurate measurement of left ventricular stroke volume (SV) is essential for the calculation of aortic valve area (AVA) and the assessment of flow status. Current American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines suggest that measurements of left ventricular outflow tract diameter (LVOTd) at different levels (at the annulus vs 5 or 10mm below) yield similar measures of SV and AVA. The aim of this study was to assess the effect of the location of LVOTd measurement on the accuracy of SV and AVA measured on transthoracic echocardiography (TTE) compared with cardiovascular magnetic resonance (CMR). One hundred six patients with aortic stenosis underwent both TTE and CMR. SV was estimated on TTE using the continuity equation with LVOTd measurements at four locations: at the annulus and 2, 5, and 10mm below annulus. SV was also determined on CMR using phase contrast acquired in the aorta (SVCMR-PC), and a hybrid AVACMR-PC was calculated by dividing SVCMR-PC by the transthoracic echocardiographic Doppler aortic velocity-time integral. Comparison between methods was made using Bland-Altman analysis. Compared with the referent method of phase-contrast CMR for the estimation of SVCMR-PC and AVACMR-PC (SVCMR-PC 83±16mL, AVACMR-PC 1.27±0.35cm2), the best agreement was obtained by measuring LVOTd at the annulus or 2mm below (P= NS), whereas measuring 5 and 10mm below the annulus resulted in significant underestimation of SV and AVA by up to 15.9±17.3mL and 0.24±0.28cm2, respectively (P<.01 for all). Accuracy for classification of low flow was best at the annulus (86%) and 2mm below (82%), whereas measuring 5 and 10mm below the annulus significantly underperformed (69% and 61%, respectively, P<.001). Measuring LVOTd at the annulus or very close to it provides the most accurate measures of SV and AVA, whereas measuring LVOTd 5 or 10mm below significantly underestimates these parameters and leads to significant overestimation of the severity of aortic stenosis and prevalence of low-flow status.

A Pilot Study Comparing Aortic Valve Area Estimates Derived from Fick Cardiac Output with Estimates Based on Cheetah-NICOM Cardiac Output

Cardiac output during cardiac catheterization is often estimated using the modified Fick method (COFick). In this proof-of-concept, prospective non-randomized study carried out in a single academic healthcare centre, we examined whether replacing COFick in the Gorlin formula with Cheetah-NICOM monitor cardiac output (COCheetah) could produce an accurate and precise estimate of aortic valve area in patients with severe aortic stenosis. In twenty-six subjects, COFick and COCheetah were obtained concurrently. A spot and 3-minute running average of COCheetah was used. Bland and Altman analysis was used to derive bias, 95% limits of agreement (LOA) and confidence intervals (CI). The mean difference (bias) between AVACheetah (average) and AVAFick was 0.11 cm2 and the 95% LOA were ±0.42 cm2. The 95% CI of the bias was 0.02–0.2 cm2. The bias and 95% LOA of AVACheetah (spot value) were 0.14 ± 0.42cm2, with a 95% CI of 0.06–0.23 cm2. No proportional bias was present. AVACheetah thus appears to be a reasonably accurate measure of AVA in patients with severe aortic stenosis compared to AVAFick measured using a modified Fick CO. However, the limits of agreement were not narrow enough to consider AVACheetah and AVAFick interchangeable.

Abstract 13492: Usefulness of Aortic Valve Area Measurement Obtained by Single-Beat Recording of Double-Envelope Technique in Patients With Aortic Stenosis and Atrial Fibrillation

Introduction: In patients with aortic stenosis (AS) and atrial fibrillation (AF), the conventional continuity equation to evaluate aortic valve area (AVA) is cumbersome, because 5 to 10 cycles are required to ensure accuracy of results. Double-envelope (DE) is obtained by a single continuous-wave Doppler envelope with double density velocity profiles; the inner envelope represents flow across the left ventricular outflow tract and outer envelope represents flow across the aortic valve orifice. Hypothesis: The aim of this study to evaluate the usefulness of the AVA calculated from single-beat recorded inner and outer envelopes in patients with AS and AF. Methods: Eighteen AS patients (74.6±7.2 years old) with AF were examined by transthoracic echocardiography. The conventional AVA (PW/CW technique) was calculated from nonsimultaneously measured LVOT flow and AVO flow in randomly picked up 8 cardiac cycles, respectively. The AVA (DE technique) was calculated from the inner and outer envelopes simultaneously recorded. A single-beat AVA was calculated from simultaneously recorded inner and outer envelopes (by DE technique) when the preceding RR interval/pre-preceding RR interval = 1. Bland-Altman analysis was used to compare the results of two techniques and estimate the reproducibility. Results: DE profiles were successfully obtained in all patients, and mean AVA (PW/CW technique) was 1.09±0.19 cm2. AVA by Single-beat DE technique showed good correlation with that by PW/CW technique (r=0.90), and the mean bias in the AVA measurements between by PW/CW technique and by DE technique was 0.048 cm2. (Figure) Conclusions: AVA in patients with AS and AF obtained by Single-beat DE technique was feasible and in good agreement with that by PW/CW technique. We suggest that DE technique should be considered to estimate the subtle temporal change of AVA in patient with AS and AF more simply and accurately.

Echocardiographic evaluation of severe aortic stenosis: impact of three-dimensional imaging and correction for pressure recovery

Purpose: In patients with Aortic Stenosis (AS), echocardiographic grading of stenosis severity is important, in particular when valve surgery or Transcatheter Aortic Valve Implantation (TAVI) are considered. Energy Loss Index (ELI) has been proposed to improve the determination of aortic valve area (AVA) by correcting for the effects of pressure recovery. However, the impact of ELI on calculation of AVA in patients with severe AS has not been studied, and the effect of 3D echocardiography in this context is not known. Methods: Transthoracic (TTE) and Transesophageal (TEE) echocardiography studies of 40 patients (54% males) with severe AS evaluated for TAVI were analyzed. AVA was calculated by the continuity equation based on Left Ventricular Outflow Tract (LVOT) diameter measured in 2D-TTE and 2D-TEE as well as based on LVOT area measured in 3D-TEE. In addition, AVA determined by 3D-TEE measurements was corrected for ELI (ELI = [(AVA × Aortic area)/Aortic area – AVA)]/body surface area). AVA and indexed AVA (AVAI) obtained from these four methods were compared. Results: LVOT area was 2.45±0.91 cm2 calculated using 2D-TTE diameter measurements, 2.82±0.78 cm2 calculated using 2D-TEE diameter measurements, and 4.27±0.89 cm2 measured in 3D-TEE (p 0.85 cm2/m2. Conclusions: Since the true LVOT is not circular, the geometric assumptions used for calculation of AVAI from 2D measurements lead to underestimation of AVA in patients with severe AS. The effects of pressure recovery accentuate this problem. When both the true LVOT area and the effects of pressure recovery are considered, AS needs to be reclassified from severe to moderate in over a third of patients. The implementation of these parameters in echocardiographic practice might improve the accuracy of AS severity assessment.

Comparison of Left Ventricular Outflow Geometry and Aortic Valve Area in Patients With Aortic Stenosis by 2-Dimensional Versus 3-Dimensional Echocardiography

The present study sought to elucidate the geometry of the left ventricular outflow tract (LVOT) in patients with aortic stenosis and its effect on the accuracy of the continuity equation-based aortic valve area (AVA) estimation. Real-time 3-dimensional transesophageal echocardiography (RT3D-TEE) provides high-resolution images of LVOT in patients with aortic stenosis. Thus, AVA is derived reliably with the continuity equation. Forty patients with aortic stenosis who underwent 2-dimensional transthoracic echocardiography (2D-TTE), 2-dimensional transesophageal echocardiography (2D-TEE), and RT3D-TEE were studied. In 2D-TTE and 2D-TEE, the LVOT areas were calculated as π × (LVOT dimension/2)(2). In RT3D-TEE, the LVOT areas and ellipticity ([diameter of the anteroposterior axis]/[diameter of the medial-lateral axis]) were evaluated by planimetry. The AVA is then determined using planimetry and the continuity equation method. LVOT shape was found to be elliptical (ellipticity of 0.80 ± 0.08). Accordingly, the LVOT areas measured by 2D-TTE (median 3.7 cm(2), interquartile range 3.1 to 4.1) and 2D-TEE (median 3.7 cm(2), interquartile range 3.1 to 4.0) were smaller than those by 3D-TEE (median 4.6 cm(2), interquartile range 3.9 to 5.3; p <0.05 vs both 2D-TTE and 2D-TEE). RT3D-TEE yielded a larger continuity equation-based AVA (median 1.0 cm(2), interquartile range 0.79 to 1.3, p <0.05 vs both 2D-TTE and 2D-TEE) than 2D-TTE (median 0.77 cm(2), interquartile range 0.64 to 0.94) and 2D-TEE (median 0.76 cm(2), interquartile range 0.62 to 0.95). Additionally, the continuity equation-based AVA by RT3D-TEE was consistent with the planimetry method. In conclusion, RT3D-TEE might allow more accurate evaluation of the elliptical LVOT geometry and continuity equation-based AVA in patients with aortic stenosis than 2D-TTE and 2D-TEE.

Underestimation of aortic valve area in calcified aortic valve disease: Effects of left ventricular outflow tract ellipticity

BackgroundThe aortic valve area (AVA) is usually calculated using the continuity equation (CE) in which the left ventricular outflow tract (LVOT) area is estimated assuming circular geometry. We sought to evaluate the LVOT ellipticity with 64-multidetector computed tomography (MDCT) and to assess the impact of LVOT ellipticity on the evaluation of CE-based AVA in patients with calcified aortic valves. MethodsWe prospectively studied 110 patients with calcified aortic valves including 54 aortic stenosis (AS) with both 64-MDCT and transthoracic echocardiography. Double oblique transversal images for planimetry of the aortic valve and LVOT were obtained during the midsystolic phase. The short and long-axis diameters of the planimetered LVOT were measured. ResultsThe MDCT planimetered LVOT area was underestimated by the diameter-derived (π×r2) LVOT area using echocardiography (444±70mm2 versus 369±63mm2; p<0.001). The mean difference in AVA values calculated using the CE and planimetry was 0.43±0.23cm2 and mean measurement error of CE-based AVA was 18%. When the CE-based AVA was corrected using the MDCT planimetered LVOT area, the measurement error decreased from 28±5 to 5±2% in patients with severe aortic stenosis (AVA<1.0cm2), whereas from 16±5 to 3±6% in others. ConclusionEllipticity of LVOT is associated with underestimation of AVA measurements using the CE. CE-based AVA corrected with MDCT planimetered LVOT area is useful especially in severe AS.

Significance of transesophageal echocardiography in the evaluation of aortic valve stenosis

Transesophageal echocardiography (TEE) is a relatively new diagnostic method offering better resolution of cardiac anatomy than the conventional transthoracal two-dimensional echocardiography (TTE). Clinical indications for TEE have been expanding, thus the technique as a diagnostic procedure is used in numerous cardiac diseases such as endocarditis, congenital heart defect, aortic dissection, prosthetic valves dysfunction, as well as in calculation of aortic valve surface in aortic stenosis. The aim of the study was to prove TEE as a more precise method in determination of the level of seriousness of aortic valve stenosis. All the patients went through TTE and TEE. Evaluating of the aortic valve surface was performed by the use of Gorlin's formula in TTE while it was planimetric in TEE examination. Comparative analysis of all parameters obtained by TTE and TEE showed a difference between them. All the parameters values except that for surface area of the aortic valve orifice confluence were higher in TEE than in TTE examination, but no difference was statistically significant (p > 0.05; t-test for a dependant specimens). By the use of the TTE method, the size of aortic orifice stenosis was 1.22 +/- 0.54 cm2, and by the TEE method it was 1.08 +/- 0.54 cm2. CONCLUSION. Multiplain TEE is reliable in quantification of an aortic valve area in patients with aortic stenosis. It offers useful clinical information, particularly in patients with non-adequate evaluation with TE, as well as in seriously ill patients or those with a confirmed valvular defect.

Comparison of Dual-Source Computed Tomography for the Quantification of the Aortic Valve Area in Patients With Aortic Stenosis Versus Transthoracic Echocardiography and Invasive Hemodynamic Assessment

We compared the measurements of the aortic valve area (AVA) using dual-source computed tomography (DSCT) in patients with mid to severe aortic stenosis to measurements using transthoracic echocardiography (TTE) and invasive hemodynamic assessment. A total of 50 patients (mean age 73 +/- 10 years) with suspected aortic stenosis were included. The computed tomographic data were acquired using DSCT with standardized scan parameters (2 x 64 x 0.6 mm collimation, 330-ms rotation, 120-kV tube voltage, 560 mA/rot tube current). After injection of 35 ml contrast agent (flow rate 5 ml/s), a targeted volume data set, ranging from the top of the leaflets to the infundibulum, was acquired. Ten cross-sectional data sets (slice thickness 1 mm, no overlap, increment 0.6 mm) were reconstructed during systole in 5% increments of the R-R interval. The AVA determined in systole by planimetry was compared to the calculated AVA values using the continuity equation on TTE and the Gorlin formula on catheterization. DSCT allowed the planimetry of the AVA in all patients. The mean AVA using DSCT was 1.16 +/- 0.47 cm(2) compared to a mean AVA of 1.04 +/- 0.45 cm(2) using TTE and 1.06 +/- 0.45 cm(2) using catheterization, with a significant correlation between DSCT/TTE (r = 0.93, p <0.001) and DSCT/cardiac catheterization (r = 0.97, p <0.001). However, DSCT demonstrated a slight, but significant, overestimation of the AVA compared to TTE (+0.12 +/- 0.17 cm) and catheterization (+0.10 +/- 0.12 cm(2)). In conclusion, DSCT permits one to assess the AVA with a high-image quality and diagnostic accuracy compared to TTE and invasive determination.

Ejection fraction-velocity ratio for the assessment of aortic bioprosthetic valves in patients with systolic dysfunction

The continuity equation (CE) represents the 'gold standard' for the evaluation of aortic valve area in patients with aortic stenosis, but it is time-consuming and subject to error, and can be technically demanding. Recently, a new echocardiographic nonflow corrected index was introduced and demonstrated excellent accuracy in quantifying the effective orifice area (EOA) in native aortic valves and bioprostheses. This new index, the ejection fraction (EF)-velocity ratio (EFVR), is obtained by dividing the percentage left ventricular EF by the maximum aortic gradient. To assess the usefulness of this echocardiographic index for quantifying the EOA in patients with aortic bioprosthesis and left ventricular dysfunction. A total of 70 patients (25 women and 45 men) with aortic bioprosthesis and left ventricular dysfunction (EF of 49% or less) were studied. The mean (+/- SD) age of the study population was 71.4+/-9 years. The EOA was evaluated, both by the CE and by the EFVR. A significant linear correlation between the CE and the EFVR was found (r=0.80; P<0.0001). The receiver operating characteristic curve analysis showed good agreement between the CE and the EFVR. An EFVR value of 1.15 or less was found to have a good sensitivity (89%) and good specificity (91%) in identifying patients with an EOA of 1.0 cm2 or smaller, with positive and negative predictive values of 79% and 95%, respectively. The EFVR, a simple index that is less time-consuming than the CE, allows the identification of patients with aortic bioprosthesis stenosis with excellent sensitivity and specificity. It may be taken into consideration in clinical practice for the evaluation of patients with aortic bioprosthesis stenosis and left ventricular dysfunction.

Sixty-Four Slice CT Evaluation of Aortic Stenosis Using Planimetry of the Aortic Valve Area

The purpose of our study was to evaluate planimetry of the aortic valve area with 64-slice CT in comparison with transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in patients with aortic stenosis. Thirty-six patients with aortic valve disease referred for coronary 64-slice CT angiography were examined. Planimetry of the aortic valve area with 64-slice CT was compared with TTE using the Doppler continuity equation for calculation of the aortic valve area and with planimetric measurement of the aortic valve area using TEE. Planimetry of the aortic valve area with CT (1.11 +/- 0.42 cm2) showed a good correlation with TTE (1.05 +/- 0.42 cm2) (r = 0.88, p < 0.001) in 32 patients and a good correlation with TEE (1.41 +/- 1.61 cm2) (r = 0.99, p < 0.0001) in 10 patients. The mean and maximum transvalvular pressure gradients were correlated with the aortic valve area as measured with CT (r = -0.68, p = 0.0001; and r = -0.67, p = 0.0001, respectively). Beta-blockers were not given (mean heart rate, 62.5 +/- 10.7 beats per minute). MDCT allows accurate planimetry of the aortic valve area in patients with aortic stenosis. In patients referred for 64-slice CT coronary angiography, concomitant aortic stenosis can be identified and evaluated.

A comparison of echocardiographic and electron beam computed tomographic assessment of aortic valve area in patients with valvular aortic stenosis

The purpose of this study was to compare electron beam computed tomography (EBT) with transthoracic echocardiography (TTE) in determining aortic valve area (AVA). Thirty patients (9 females, 21 males) underwent a contrast-enhanced EBT scan (e-Speed, GE, San Francisco, CA, USA) and TTE within 17 ± 12 days. In end-inspiratory breath hold, a prospectively ecg-triggered scan was acquired with a beam speed of 50–100 ms, a collimation of 2 × 1.5 mm and an increment of 3.0 mm. The AVA was measured with planimetry. A complete TTE study was performed in all patients, and the AVA was computed using the continuity equation. There was close correlation between AVA measured with EBT and AVA assessed with TTE (r = 0.60, P < 0.01). The AVA measured with EBT was 0.51 ± 0.46 cm2 larger than the AVA calculated with TTE measurements. EBT appeared to be a valuable non-invasive method to measure the AVA. EBT measures the anatomical AVA, while with TTE the functional AVA is calculated, which explains the difference in results between the methods.

The Simultaneous Assessment of Aortic Valve Area and Coronary Artery Stenosis Using 16-Slice Multidetector-Row Computed Tomography in Patients With Aortic StenosisComparison With Echocardiography

Recent advancements in 16-slice multidetector-row computed tomography (16-slice MDCT) provide for non-invasive assessment of not only coronary artery disease (CAD), but also myocardial properties and the anatomy of the whole heart. The purpose of the present study was to investigate whether the aortic valve area (AVA) in patients with aortic stenosis (AS) assessed by 16-slice MDCT corresponds to echocardiographic assessment and to evaluate simultaneously the clinical accuracy in detecting CAD with 16-slice MDCT. The AVA of 29 consecutive AS patients with transthoracic echocardiography (TTE) and 16-slice MDCT were analyzed. The AVA was estimated by means of the continuity equation method in 2-dimensional echocardiography (DE) and the quantitative planimetric method after multi-planar reformation in 16-slice MDCT. Concomitantly, the severity of the coronary artery stenosis was assessed by 16-slice MDCT. In the present study, the AVA assessed by TTE and 16-slice MDCT was 1.34+/-0.32 cm(2) and 1.38+/-0.32 cm(2), respectively. Regression analysis showed that the AVA in patients with AS determined by 16-slice MDCT correlated well with those determined by 2-DE (r=0.96, p<0.001). Significant coronary artery stenosis of more than 50% diameter reduction was present in 48% of the study population. In patients with AS, the analysis of the severity of the AVA by 16-slice MDCT provides a feasible and accurate estimation with the concomitant evaluation of CAD.

Intraoperative in situ measurement of aortic valve area in patients with aortic stenosis: A comparison with echocardiographically derived variables Roland R. Brandt, Manfred Jung, Erwin P. Bauer, Hassan Bahavar, Christian W. Hamm. Kerckhoff Heart Center, Bad Nauheim, Germany

Intraoperative in situ measurement of aortic valve area in patients with aortic stenosis: A comparison with echocardiographically derived variables Roland R. Brandt, Manfred Jung, Erwin P. Bauer, Hassan Bahavar, Christian W. Hamm. Kerckhoff Heart Center, Bad Nauheim, Germany

Validation of the ejection fraction-velocity ratio: a new simplified “function-corrected” index for assessing aortic stenosis severity

A new echocardiographic method for the evaluation of aortic stenosis (AS) severity has recently been introduced: the fractional shortening-velocity ratio (FSVR = fractional shortening/4 Vmax2). An important advantage of the method is the possibility of avoiding the difficulties related to the measurement of left ventricular outflow tract in calcific AS for assessing the continuity equation. FSVR, however, also shows some significant limitations especially in patients with regional wall motion abnormalities and conduction defects. To overcome this problem, we developed a new index: the ejection fraction-velocity ratio (EFVR = ejection fraction/4 Vmax2), where percent ejection fraction and Vmax have been obtained with an apical echocardiographic approach. In 343 consecutive patients with AS, aortic valve area was measured by cardiac catheterization (Gorlin), whereas FSVR and EFVR were calculated by echo-Doppler examination performed within 24 hours. Mean valve area was 0.70 ± 0.30 cm2, mean EFVR was 0.78 ± 0.41, and mean FSVR was 0.45 ± 0.26. The linear correlation area-EFVR was highly significant (r = 0.88). Correlation valve area-FSVR was also significant (r = 0.82). EFVR allowed identification of patients with severe AS (area ≤0.8 cm2) with good sensitivity (88%) and specificity (85%), whereas FSVR demonstrated sensitivity of 88% and specificity of 73%. Thus, the EFVR, a very simple and not time-consuming index, is strongly related to aortic valve area in patients with AS. It allows identification of patients with severe AS with good sensitivity and specificity (better than FSVR). The EFVR, taking into consideration both ejection fraction and transvalvular pressure gradient, may be very useful in the evaluation of patients with AS and left ventricular dysfunction.

Comparison of Multiplane and Biplane Transesophageal Echocardiography in the Assessment of Aortic Stenosis

The aim of the study was to compare the accuracy of multiplane transesophageal echocardiography (TEE) with the more conventional biplane technique in the direct assessment of aortic valve area in patients with aortic stenosis. Short-axis images of the aortic valve adequate for measuring aortic valve area were obtained in all 81 patients studied by multiplane TEE but in only 56 of 64 patients (88%) using the biplane approach. The correlation coefficient for aortic valve area determined by multiplane TEE (r = 0.89; SEE = 0.04 cm2) was higher (p <0.01) than biplane TEE (r = 0.74; SEE = 0.06 cm2). Correlations were higher for bicuspid valves (multiplane, r = 0.93; biplane, r = 0.75) than tricuspid valves (multiplane, r = 0.87; biplane, r = 0.75). Our study has demonstrated the superiority of multiplane TEE to both biplane TEE and transthoracic echocardiography (TTE) in the direct evaluation of aortic valve area in patients with aortic stenosis.Our study has demonstrated the superiority of multiplane transesophageal echocardiography over both biplane transesophageal echocardiography and transthoracic echocardiography in the direct evaluation of aortic valve area in patients with aortic stenosis.