Proximal Isovelocity Surface Area Method Research Articles

Quantification of Mitral Valve Regurgitation in Cavalier King Charles Spaniels and Chihuahuas Using Radius of Proximal Isovelocity Surface Area

Mitral regurgitation (MR) resulting from myxomatous mitral valve disease (MMVD) is a prevalent condition in dogs, particularly smaller breeds like Cavalier King Charles Spaniels (CKCSs) and Chihuahuas (CHHs). An accurate assessment of MR severity is essential for effective treatment and disease monitoring, yet a standardized method has yet to be established. In this retrospective study, we evaluated 124 client-owned dogs diagnosed with MMVD, including 64 CKCSs and 60 CHHs. Dogs were categorized into three stages: asymptomatic (B1), remodeled (B2), and congestive heart failure (CHF, C). The MR severity was quantified using the proximal isovelocity surface area (PISA) method, specifically focusing on the PISA radius (PISA-r). The PISA-r measurements exhibited significant increases across disease stages and demonstrated strong correlations with echocardiographic parameters (ranging from 0.83 to 0.94), including the left atrial size and left ventricular internal diameter. The receiver operating characteristic (ROC) curve analysis revealed the high sensitivity and specificity of PISA-r in classifying disease stages, establishing optimal cut-off values. The method displayed excellent repeatability (interobserver variability: 0.95) and reproducibility (intraobserver variability: 0.97). In conclusion, the PISA method, specifically PISA-r, was reliable for assessing MR severity in dogs with MMVD. By simplifying the diagnosis and management of MR, this research can potentially improve the life and management of MMVD-affected dogs.

EasyPISA: Automatic Integrated PISA Measurements of Mitral Regurgitation From 2-D Color-Doppler Using Deep Learning

ObjectiveThe proximal isovelocity surface area (PISA) method is a well-established approach for mitral regurgitation (MR) quantification. However, it exhibits high inter-observer variability and inaccuracies in cases of non-hemispherical flow convergence and non-holosystolic MR. To address this, we present EasyPISA, a framework for automated integrated PISA measurements taken directly from 2-D color-Doppler sequences. MethodsWe trained convolutional neural networks (UNet/Attention UNet) on 1171 images from 196 recordings (54 patients) to detect and segment flow convergence zones in 2-D color-Doppler images. Different preprocessing schemes and model architectures were compared. Flow convergence surface areas were estimated, accounting for non-hemispherical convergence, and regurgitant volume (RVol) was computed by integrating the flow rate over time. EasyPISA was retrospectively applied to 26 MR patient examinations, comparing results with reference PISA RVol measurements, severity grades, and cMRI RVol measurements for 13 patients. ResultsThe UNet trained on duplex images achieved the best results (precision: 0.63, recall: 0.95, dice: 0.58, flow rate error: 10.4 ml/s). Mitigation of false-positive segmentation on the atrial side of the mitral valve was achieved through integration with a mitral valve segmentation network. The intraclass correlation coefficient was 0.83 between EasyPISA and PISA, and 0.66 between EasyPISA and cMRI. Relative standard deviations were 46% and 53%, respectively. Receiver operator characteristics demonstrated a mean area under the curve between 0.90 and 0.97 for EasyPISA RVol estimates and reference severity grades. ConclusionEasyPISA demonstrates promising results for fully automated integrated PISA measurements in MR, offering potential benefits in workload reduction and mitigating inter-observer variability in MR assessment.

Quantification of Mitral Regurgitation in Mitral Valve Prolapse by Three-Dimensional Vena Contracta Area: Derived Cutoff Values and Comparison With Two-Dimensional Multiparametric Approach

Echocardiographic grading of mitral regurgitation (MR) in mitral valve prolapse (MVP) is challenging. Three-dimensional (3D) vena contracta area (VCA) has been proposed as a valuable method. However, data defining the cutoff values of severity and validation in the subset of patients with MVP are scarce. The aim of this study was to validate the 3D VCA by 3D color-Doppler transesophageal echocardiography (TEE) in patients with MVP and to define the cutoff values of severity grading. The secondary aim was to compare 3D VCA to the effective regurgitant orifice area estimation by proximal isovelocity surface area (EROA-PISA) method. A total of 1,138 patients with at least moderate MR who underwent TEE were included. Three-dimensional VCA was measured, and the cutoff value and area under the curve (AUC) for the prediction of severe MR were estimated by receiver operating characteristic curve using a guideline-suggested multiparametric approach as the reference standard. In a subgroup of patients, 3D regurgitant volume (RV) and 3D fraction were calculated from mitral and left ventricular outflow tract stroke volumes to further validate 3D VCA against a 3D volumetric reference standard. The optimal 3D VCA cutoff value for predicting severe MR was 0.45cm2 (specificity, 0.87; sensitivity, 0.90) with an AUC of 0.95 using a multiparametric approach as reference. Three-dimensional VCA had a good linear correlation with EROA-PISA (r=0.62, P<.05) with larger values compared to EROA-PISA (0.63cm2 vs 0.44cm2, P<.05). A cutoff of 0.50cm2 (AUC of 0.84; sensitivity, 0.78; specificity, 0.78) predicts an EROA-PISA of 0.40cm2. Three-dimensional VCA had a good linear correlation with 3D RV (r=0.56, P<.01), with an AUC of 0.86 to predict a 3D fraction>50%. The present study suggests 0.45cm2 as the best cutoff value of 3D VCA to define severe MR in patients with MVP, showing an optimal agreement with the reference standard multiparametric approach and 3D RV.

Clinical Impact of the Volumetric Quantification of Ventricular Secondary Mitral Regurgitation by Three-Dimensional Echocardiography

The assessment of ventricular secondary mitral regurgitation (v-SMR) severity through effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) calculations using the proximal isovelocity surface area (PISA) method and the two-dimensional echocardiography volumetric method (2DEVM) is prone to underestimation. Accordingly, we sought to investigate the accuracy of the three-dimensional echocardiography volumetric method (3DEVM) and its association with outcomes in v-SMR patients. We included 229 patients (70±13years, 74% men) with v-SMR. We compared EROA and RegVol calculated by the 3DEVM, 2DEVM, and PISA methods. The end point was a composite of heart failure hospitalization and death for any cause. After a mean follow-up of 20±11months, 98 patients (43%) reached the end point. Regurgitant volume and EROA calculated by 3DEVM were larger than those calculated by 2DEVM and PISA. Using receiver operating characteristic curve analysis, both EROA (area under the curve, 0.75; 95% CI, 0.68-0.81; P=.008) and RegVol (AUC, 0.75; 95% CI, 0.68-0.82; P=.02) measured by 3DEVM showed the highest association with the outcome at 2years compared to PISA and 2DEVM (P<.05 for all). Kaplan-Meier analysis demonstrated a significantly higher rate of events in patients with EROA ≥ 0.3cm2 (cumulative survival at 2years: 28%±7% vs 32%±10% vs 30%±11%) and RegVol ≥ 45mL (cumulative survival at 2years: 21%±7% vs 24%±13% vs 22%±10%) by 3DEVM compared to those by PISA and 2DEVM, respectively. In Cox multivariable analysis, 3DEVM EROA remained independently associated with the end point (hazard ratio, 1.02, 95% CI, 1.00-1.05; P=.02). The model including EROA by 3DEVM provided significant incremental value to predict the combined end point compared to those using 2DEVM (net reclassification index=0.51, P=.003; integrated discrimination index=0.04, P=.014) and PISA (net reclassification index=0.80, P<.001; integrated discrimination index=0.06, P<.001). Effective regurgitant orifice area and RegVol calculated by 3DEVM were independently associated with the end point, improving the risk stratification of patients with v-SMR compared to the 2DEVM and PISA methods.

In vitro and clinical validation of different correction algorithms for the two-dimensional proximal isovelocity surface area method in a low-velocity flow field for quantifying tricuspid regurgitation.

The 2-dimensional proximal isovelocity surface area (2D PISA) method underestimates tricuspid regurgitation (TR) severity. Previously proposed correction algorithms should be further scrutinized. Two correction algorithms were tested. One approach involves dividing the 2D PISA effective regurgitant orifice area by a constant of 0.7 (EROA0.7). Another approach involves multiplying the unadjusted EROA by Vorifice/(Vorifice - Valiasing), where Vorifice denotes the TR jet velocity, and Valiasing represents the color aliasing velocity (EROAVo-Va). In vitro validation was performed on a commercially available multifunctional valve tester with different size orifices and peak pressure gradients. A true EROA was derived through the regurgitant volume (RVol) calculated from the tester. For clinical validation, RVol was calculated as the difference between the overall stroke volume and the forward stroke volume of the right ventricle. Volumetric EROA was derived by dividing the RVol by the TR velocity-time integral (VTI). The vena contracta area (VCA) was obtained through direct planimetry with 3D echocardiography. The mean of volumetric EROA and VCA served as the reference in clinical validation. Excellent correlation between the calculated EROAs and the true EROA was observed in vitro (r=0.98, r=0.97, and r=0.98 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively; all P values <0.0001). EROAVo-Va underestimated the true EROA and averaged 33% (P=0.3163), while EROA0.7 overestimated the true EROA and averaged 8% (P=0.0032). Clinically, these methods consistently exhibited a notable underestimation that varied with the reference EROA. This systematic underestimation was mitigated by both algorithms when either the VCA (biases of 19.6, 15.1, and 11.8 mm2 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively) or the volumetric EROA (biases of 10.1, 5.6, and 2.3 mm2 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively) served as the reference. Their ability to distinguish severe TR was similar, with area under the curve values of 0.905, 0.903, and 0.893 for uncorrected EROA, EROAVo-Va, and EROA0.7, respectively. No statistically significant differences were observed for diagnostic accuracy (all P values >0.05). Using a correction factor of 0.7 in quantifying TR provides similar accuracy when compared to other techniques. This represents a valuable clinical tool for quickly correcting the underestimation of the 2D PISA method in TR. This simple method may increase the frequency of applying the correction and earlier recognition of patients with severe TR.

Challenges and pitfalls in classification of disproportionate mitral regurgitation.

The concept of disproportionate mitral regurgitation (dispropMR) has been introduced to identify patients with functional mitral regurgitation (MR) who benefit from percutaneous treatment. We aimed to examine echocardiographic characteristics behind this entity. We retrospectively included 172 consecutive patients with reduced left ventricular ejection fraction (LVEF), and more than mild MR referred to clinically indicated echocardiography. According to the proportionality ratio (effective regurgitant orifice area (EROA)/left ventricular end-diastolic volume (LVEDV)) patients were divided into dispropMR and proportionate MR (propMR) group. Potential factors which might affect proportionality definition were analyzed. 55 patients (32%) had dispropMR. Discrepant grading of MR severity was observed when using regurgitant volume (RegVol) by proximal isovelocity surface area (PISA) method or volumetric method, with significant discordance only in dispropMR (p < 0.001). Patients with dispropMR had more frequently left ventricular foreshortened images for LVEDV calculation than patients with propMR (p = 0.003), resulting in smaller LVEDV in dispropMR group. DispropMR group had more substantial dynamic variation of regurgitant flow compared to propMR. Accordingly, EROA was consistently overestimated by standard single-point PISA method compared to serial PISA method. This was more pronounced in dispropMR (bias:10.5 ± 28.3 mm2) compared to propMR group (bias:6.4 ± 12.8 mm2). DispropMR may be found in roughly one third of clinically indicated echocardiographic studies in patients with reduced LVEF and more than mild MR. EROA overestimation due to dynamic variation of regurgitant flow and LVEDV underestimation due to LV foreshortening were more frequently found in dispropMR. Our results indicate that methodological limitations of echocardiographic MR grading could not be neglected in classifying the proportionality of MR.

M-mode proximal iso-velocity surface area-based dynamics of instantaneous flow rate and its implications for degenerative mitral regurgitation quantification

Abstract Background Instantaneous flow rate of degenerative mitral regurgitation (DMR) showed dynamic changes. However, inconsistencies exist across literatures about the timing of measurements for flow convergence in proximal iso-velocity surface area (PISA) calculation. While the 2017 ASE guideline suggested measurement of PISA radius and velocity should be performed at simultaneous moments of the regurgitant phase (PISApair), a few studies used max PISA radius (PISAmax) to calculate regurgitant volume and showed poor agreement with cardiac magnetic resonance (CMR) results. Purpose This study aimed to compare the above methods with M-mode PISA, thus to investigate the effect of instantaneous flow rate on the agreement of the diagnosis of severe mitral regurgitation (sMR). Methods We prospectively enrolled 75 DMR patients with a) at least mild MR, b) single and non- eccentric MR jet. Regurgitant volume (RVol) was calculated using three PISA methods, respectively. In 25 patients who received CMR, RVol was calculated using volumetric method. The correlation and agreement of RVol among three PISA methods and CMR were compared. The agreements of the diagnosis of sMR between PISA methods and ASE multi-parameter algorithm were analyzed using Cohen’s kappa analyses. Results The curve of instantaneous flow rate of DMR displayed unimodal pattern with at the mid-late systolic phase. The correlation of RVol between PISA methods and CMR were moderate for PISAmax (r = 0.77) and strong for PISApair and M-mode PISA ( r = 0.80 and 0.87, respectively). PISAmax derived RVol was larger than that of CMR (69.1 ± 37.1 mL versus. 49.0 ± 29.0 mL, P = 0.002). Compared to the ASE algorithm, only PISAmax significantly overestimated the percentages of sMR (74.7% versus 54.7%, P =0.010), but both PISAmax and PISApair showed moderate consistency (Kappa coefficient (k): 0.496 and 0.525, respectively). A strong agreement was found between M-mode PISA and the ASE algorithm with regard to the diagnosis of sMR (k = 0.867, P &amp;lt;0.05). Conclusion Based on the unimodal pattern of instantaneous flow rate in DMR patients, PISAmax significantly overestimated RVol and may expose a significant proportion of DMR patients to MR surgery.

Relative size of the effective regurgitant orifice to right ventricular cavity contributes significantly to the underestimation of 2D PISA method in tricuspid regurgitation quantitation

Abstract Background 2D proximal isovelocity surface area (PISA) method underestimates tricuspid regurgitation (TR) severity largely due to the distortion of proximal flow geometry under low jet velocity. Previous studies demonstrated that the confining wall geometry also strained the streamline distribution in the proximal flow field. This could add to the variability when applying 2D PISA in TR as TR presents with wider range of effective regurgitant orifice area (EROA). Purpose We aim to examine (1) the impact of ventricular wall constraint to proximal flow region on TR quantitation and (2) its relative contribution to the underestimation of 2D PISA compared with the distortion of proximal flow field under low jet velocity. Methods 150 pts with more than mild TR underwent comprehensive echocardiographic session. The standard 2D PISA EROA (EROASD)was derived as per guideline with angle correction applied for tethering leaflets. The underetimation caused by low jet velocity was corrected by multiplying the standard EROA (EROASD) with VOrifice/(VOrifice-VNyquist), where the VOrifice stands for the peak regurgitant velocity and the VNyquist represents the color Doppler aliasing velocity (EROAVo-VN). The volumetric EROA and vena contracta area serves as two independent reference methods. The ventricular wall constraint was quantified as the ratio of reference EROA to right ventricular end-diastolic volume (RVEDV). Results A consistent significant underestimation by standard 2D PISA methods, either corrected for low jet velocity or not, was observed as a function of the EROA (Figure 1). In Bland-Altman analysis, correction for low jet velocity lessened the systematic underestimation but still leaves minor while could-be-important error (VCA, bias = 19.6 and 15.1 mm2; volumetric EROA, bias = 10.1 and 5.6 mm2 for EROASD and EROAVo-VN respectively). The accuracy of both methods to differentiate severe TR was similar but the cut-off values were lower compared with guideline recommendation (AUC = 0.905 and 0.903, cut-off = 0.26 and 0.29 cm2 for EROASD and EROAVo-VN respectively). In multi-linear regression model (Table 1), the difference between standard 2D PISA EROA and reference EROA (mean of volumetric EROA and vena contracta area) was significantly related to etiology, the jet velocity-related correction coefficient, and the reference EROA/RVEDV ratio. The ventricular wall constraint contributes to the underestimation of 2D PISA to a greater extent than the low jet velocity (beta = -0.269 and 0.592 for VOrifice/(VOrifice-VNyquist) and reference EROA/RVEDV respectively). Conclusion Correction for low jet velocity lessens the extent of underestimation of TR severity by 2D PISA method but still leaves important measurement error. The confining wall geometry to proximal flow region contributes significantly to the understimation but is not accounted for in current recommendation. This could be especially important in massive and torrential TR.

Usefulness of Vena Contracta for Identifying Severe Secondary Mitral Regurgitation: A Three-Dimensional Transesophageal Echocardiography Study.

In secondary mitral regurgitation (SMR), effective regurgitant orifice area by the proximal isovelocity surface area method ( ) evaluation might cause an underestimation of regurgitant orifice area because of its ellipticity compared with vena contracta area (VCA). We aimed to reassess the SMR severity using VCA-related parameters and . The three-dimensional transesophageal echocardiography data of 128 patients with SMR were retrospectively analyzed; the following parameters were evaluated: , anteroposterior and mediolateral vena contracta widths (VCWs) of VCA (i.e., and ), calculated as ( + )/2, and calculated as ( /2) ( /2). Severe SMR was defined as 0.39 . The mean age of the patients was 77.0 8.9 years, and 78 (60.9%) were males. Compared with (r = 0.801), (r = 0.940) and (r = 0.980) were strongly correlated with VCA. On receiver-operating characteristic curve analysis, and had C-statistics of 0.981 (95% confidence interval [CI], 0.963-1.000) and 0.985 (95% CI, 0.970-1.000), respectively; these were significantly higher than 0.910 (95% CI, 0.859-0.961) in (p = 0.007 and p = 0.003, respectively). The best cutoff values for severe SMR of and were 0.78 cm and 0.42 , respectively. The prevalence of severe SMR significantly increased with an increase in (38 of 88 [43.2%] patients with 0.30 , 21 of 24 [87.5%] patients with = 0.30-0.40 , and 16 of 16 [100%] patients with 0.40 [Cochran-Armitage test; p 0.001]). Among patients with 0.30 , SMR severity based on VCA was accurately reclassified using (McNemar's test; p = 0.505) and (p = 0.182). Among patients who had SMR with of 0.30 , suggestive of moderate or less SMR according to current guidelines, 40% had discordantly severe SMR based on VCA. and values were useful for identifying severe SMR based on VCA in these patients.

The right ventricle systolic force ratio could predict the severity of the tricuspid regurgitation-RIVIERA ratio.

For assessing the severity of tricuspid regurgitation (TR), there is no gold standard. We developed a parameter, the right ventricular systolic force ratio-RIVIERA, using the continious wave Doppler analysis of TR and pulsed-wave analysis of the right ventricle outflow tract. We hypothesized that the RIVIERA would facilitate the ability to identify severe TR in clinical settings. We obtained data from routine transthoracic echocardiograms. All records reporting no or mild TR (n = 732), moderate TR (n = 584), and severe TR (n = 519) TR were reanalyzed to measure vena contracta (VC) width, TR jet area, effective regurgitant orifice (EROA) derived with the proximal isovelocity surface area method, the RIVIERA, and right-sided chamber volumes. Significant linear trends were demonstrated for right atrial volume index, end-diastolic volume index, RVOT velocity time integral, TR jet area, TR-Vmax, TR-VTI, TR acceleration, VC width, EROA with increasing TR severity. Independent predictors of severe RT included RIVIERA <4.8, VC width ≥0.7 cm, TR jet area > 10 cm2 , and EROA ≥0.4 cm2 . The RIVIERA is a feasible, effective, and independent predictor of severe TR that enhances established techniques for estimating TR severity. For clinical decision-making and management, accurate measurement and classification of TR severity are essential. Therefore, it should be thought about include the RIVIERA in the integrative method to assessing TR severity.

Benefit of 3D Vena Contracta Area over 2D-Based Echocardiographic Methods in Quantification of Functional Mitral Valve Regurgitation

The two-dimensional proximal isovelocity surface area (2D PISA) method in the quantification of an effective regurgitation orifice area (EROA) has limitations in functional mitral valve regurgitation (FMR), particularly in non-circular coaptation defects. We aimed to validate a three-dimensional vena contracta area (3D VCA) against a conventional EROA using a 2D PISA method and anatomic regurgitation orifice area (AROA) in patients with FMR. Both 2D and 3D full-volume color Doppler data were acquired during consecutive transoesophageal echocardiography (TEE) examinations. The EROA 2D PISA was calculated as recommended by current guidelines. Multiplanar reconstruction was used for offline analysis of the 3D VCA (with a color Doppler) and AROA (without a color Doppler). Receiver operating characteristic (ROC) analysis was used to calculate a cut-off value for the 3D VCA to discriminate between moderate and severe FMR as classified by the EROA 2D PISA. From 2015 to 2018, 105 consecutive patients with complete and adequate imaging data were included. The 3D VCA correlated strongly with the 2D PISA EROA and AROA (r = 0.93 and 0.94). In the presence of eccentric or multiple regurgitant jets, there was no significant difference in correlations with the 3D VCA. We found a 3D VCA cut-off of 0.43 cm2 to discriminate between moderate and severe FMR (area under curve = 0.98). The 3D VCA showed a higher interobserver agreement than the EROA 2D PISA (interclass correlation coefficient: 0.94 vs. 0.81). The 3D VCA has excellent validity and lower variability than the conventional 2D PISA in FMR. Compared to the 2D PISA, the 3D VCA was not affected by the presence of eccentric or multiple regurgitation jets or non-circular regurgitation orifices. With a threshold of 0.43 cm2 for the 3D VCA, we demonstrated reliable discrimination between moderate and severe FMR.

Quantification of Flow Rates and Flow Volumes in Valve Regurgitation Using 3-D High Frame-Rate Ultrasound

Valve regurgitation is a cardiac condition caused by the incomplete closure of a cardiac valve. Untreated, this condition may result in cardiac failure. Regular monitoring of this condition is essential in guiding the decision process for surgical intervention. Current guidelines recommend a multiparametric assessment of valve regurgitation using echocardiography, which is both time consuming and heavily dependent on the experience of the examiner. Several methods have been proposed to provide quantitative markers to facilitate the assessment of valve regurgitation, most notably the Proximal Isovelocity Surface Area (PISA) method and methods based on the quantification of the total Regurgitant Volume (RVol) from the power of backscattered blood signal. In this work, we propose a framework based on trans-thoracic 3-D high frame-rate acquisitions for the simultaneous estimation of the jet cross-sectional area and jet velocity directly at the jet core, which are then combined to estimate the instantaneous flow rate and RVol patients with aortic or mitral insufficiency. We compare two methods for the segmentation of the jet cross-sectional area from the power Doppler signal. Validation on simulated data indicates good segmentation accuracy for the best method (β = 0.97, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.91). Validation on recordings from a flow phantom shows good agreement (β = 1.2, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.88) with an external flow rate meter. Clinical feasibility of the method is also shown in a patient with mitral regurgitation.

843 QUANTIFICATION OF VENTRICULAR FUNCTIONAL MITRAL REGURGITATION USING THE VOLUMETRIC METHOD BY 3D-ECHOCARDIOGRAPHY

Abstract Background ventricular functional mitral regurgitation (v-FMR) is associated with an increased risk of mortality and hospitalization for heart failure. In this setting, the echocardiographic assessment of v-FMR severity using 2D proximal isovelocity surface area (PISA) yields several limitations, potentially leading to an underestimation of v-FMR severity. An alternative approach is to derive the regurgitant volume (RegVol) and the effective regurgitant orifice area (EROA) using the three-dimensional echocardiography (3DE) to estimate left ventricular volumes (volumetric method, VM). However, a direct comparison of these methods has never been tested. Accordingly, the aims of our study are: i; to compare both 2D PISA measurements of EROA and RegVol with those obtained by VM using 3DE, ii; to test their accuracy using the 3D planimetry of vena contracta area (3D-VCA) of MR jet, as reference. Methods we retrospectively analysed 82 (mean age 75±12, 48% men, 79% sinus rhythm, 85% with ischemic cardiomyopathy, 15% with dilated cardiomyopathy) consecutive patients with v-FMR and reduced left ventricular ejection fraction (LVEF &amp;lt;50%), acquired between July 2020 and October 2021. Exclusion criteria were: age &amp;lt; 18 years, primary MR, presence of intra-cardiac shunts, greater than mild aortic regurgitation, and inadequate acoustic window. PISA EROA was calculated using the formula: 6.28 r2×Va/Vp (where: r= PISA radius, Va= aliasing velocity, Vp= MR peak velocity). FMR regurgitant volume (RegVol) by PISA was calculated as EROA×VTIMR, where VTIMR represents the time–velocity integral of the CW Doppler MR jet tracing. FMR RegVol by 3DE volumetric method (VM) was calculated as: total LV stroke volume (LV SV) – forward LV SV (Ao SV). LV SV was obtained by subtracting the respective end-systolic (ESV) from the end-diastolic (EDV) volumes measured by 3DE. Ao SV was calculated by multiplying LV outflow area by LV outflow tract velocity time integral (VTI). EROA by VM was calculated as the MR RegVol divided by VTIMR. In a group of 10 patients, the quantification of 3D-VCA was performed by multiplanar reconstruction using a dedicated software package (EchoPAC 204 GE Vingmed, Horten, Norway). Results average LV end-diastolic and end-systolic volumes, total stroke volume, LVEF and global longitudinal strain were 211±25 mL, 134±17 mL, 73±9 mL, 36±8% and, 9.4±2.7% respectively. Median Ao SV was 50±12 mL. Left atrial volume and left atrial reservoir strain were respectively 99±19 mL and 10±16%. Both EROA and RegVol by VM were larger than EROA (0.17± 0.09 cm2 vs 0.11± 0.01 cm2; p&amp;lt;0.001) and RegVol (25.7±12.1 mL vs 17.2±9.9 mL; p&amp;lt;0.001) by PISA, respectively. Compared to 3D-VCA, EROA by VM resulted more accurate than EROA by PISA (bias= -0.15 cm2, LOA ±0.24 cm2 vs bias= -0.25 cm2, LOA ±0.29 cm2). Finally, VM EROA (r= 0.778) showed a better correlation than PISA EROA (r= 0.681) with the 3D-VCA (p&amp;lt;0.001). Conclusions in patients with v-FMR, the echocardiographic assessment of EROA and RegVol using the 3DE volumetric method showed larger values compared to the conventional PISA method, and a closer correlation with the 3D VCA. Accordingly, the 3DE VM could improve the accuracy of evaluation of v-FMR severity. Larger studies with longer clinical follow-up are needed to define if it translates into improved risk stratification and may address patients’ management.

Abstract 10890: A Simplified Method for Correction of Effective Regurgitant Orifice and Flow Underestimation by Pisa in Non-Circular Orifices: An in vitro Study

Introduction: The proximal isovelocity surface area (PISA) method has been validated for quantifying severity of mitral regurgitation (MR) in orifices with circular geometry. However, functional MR often has an elliptical orifice, which alters the proximal isovelocity contour from a hemisphere to a hemi-ellipsoid. Studies have previously shown that PISA underestimates regurgitant flow (RF) and effective regurgitant orifice (ERO) in functional MR. Hypothesis: The application of a simplified hemi-ellipsoid formula based on biplane color Doppler improves accuracy in calculating RF and ERO across elliptical orifices. Methods: An in vitro model for flow quantification was used for all experiments. Multiple size orifices with minor to major ratios ranging from 1:1 to 1:9 were constructed by 3D printing. Flow was adjusted at multiple intervals to generate peak flow velocities ranging from 4.1 to 5.5 m/s and aliasing velocities from 12 to 18 cm/s. Isovelocity contours were evaluated by biplane color Doppler (Figure 1A). RF and ERO were estimated using the traditional hemispheric PISA (HS-PISA) formula and a simplified hemiellipsoid formula (HE-PISA) based on two orthogonal diameter measurements (Figure 1A and 1B). The estimated RF and ERO values were compared and validated against those derived from a magnetic flowmeter (FM). Results: Isovelocity contours changed from hemisphere to hemi-ellipsoid orifices with increasing ellipticity ratios. HS-PISA significantly underestimated RF (116 ± 27 vs FM 155 ± 20 ml/s) and ERO (26 ± 4 vs FM 34 ± 1 mm 2 ). Underestimation was significantly reduced by HE-PISA (135 ± 17 ml/s and 30 ± 2.5 mm 2 , both p&lt;0.001). Conclusions: A simplified hemi-ellipsoid PISA method provides more accurate assessment of RF and ERO in regurgitant orifices with non-circular geometries.

Quantification of mitral regurgitation after transcatheter edge-to-edge repair: Comparison of echocardiography and patient-specific in silico models

BackgroundDoppler echocardiographic (echo) assessment of residual mitral regurgitation (MR) after transcatheter edge-to-edge repair (TEER) is challenging and often subjective. This study aimed to evaluate the accuracy and feasibility of standardized quantitative echo methods for assessment of MR severity after MitraClip repair by comparing measurements against a reference MR severity obtained from patient-specific in silico models. MethodsPost-procedure hemodynamics were simulated under five different MitraClip configurations in previously validated patient-specific in silico models for the treatment of functional MR. The residual regurgitant volume was calculated as in clinical practice using four quantitative virtual echo methods: pulsed Doppler, volumetric, proximal isovelocity surface area (PISA) and vena contracta area (VCA). Multiple permutations were performed for each method. Virtual echo MR results were evaluated against reference MR values directly extracted from the 5 patient-specific in silico models. ResultsThe echo methods with the greatest accuracy were the three-dimensional (3D) volumetric method (r = 0.957, bias −0.8 ± 1.2 ml, p = 0.01), the 3D VCA method wherein velocity time integrals were evaluated for each jet assessed (r = 0.919, bias −1.5 ± 1.7 ml, p = 0.03), and the 3D PISA method integrating surface areas throughout systole (r = 0.98, bias −2.0 ± 0.9 ml, p = 0.003). The pulsed Doppler and 2D volumetric methods had technical limitations that may result in a high underestimation or overestimation of the MR severity after TEER. In the case of multiple regurgitant jets, a more accurate MR assessment was obtained when all significant jets were evaluated. ConclusionsClinically, the 3D volumetric, 3D VCA and 3D PISA methods gave the most accurate MR quantification after TEER. Three-dimensional echo technologies harbor the potential of becoming the non-invasive imaging tool of choice for MR quantification after complex transcatheter mitral interventions.

Impact of correcting the 2D PISA method on the quantification of functional tricuspid regurgitation severity.

In functional tricuspid regurgitation (FTR) patients, tricuspid leaflet tethering and relatively low jet velocity could result in proximal flow geometry distortions that lead to underestimation of TR. Application of correction factors on two-dimensional (2D) proximal isovelocity surface area (PISA) equation may increase its reliability. This study sought to evaluate the impact of the corrected 2D PISA method in quantifying FTR severity. In 102 patients with FTR, we compared both conventional and corrected 2D PISA measurements of effective regurgitant orifice area [EROA vs. corrected (EROAc)] and regurgitant volume (RegVol vs. RegVolc) with those obtained by volumetric method (VM) using three-dimensional echocardiography (3DE), as reference. Both EROAc and RegVolc were larger than EROA (0.29 ± 0.26 vs. 0.22 ± 0.21 cm2; P &lt; 0.001) and RegVol (24.5 ± 20 vs. 18.5 ± 14.25 mL; P &lt; 0.001), respectively. Compared with VM, both EROAc and RegVolc resulted more accurate than EROA [bias = -0.04 cm2, limits of agreement (LOA) ± 0.02 cm2 vs. bias = -0.15 cm2, LOA ± 0.31 cm2] and RegVol (bias = -3.29 mL, LOA ± 2.19 mL vs. bias = -10.9 mL, LOA ± 13.5 mL). Using EROAc and RegVolc, 37% of patients were reclassified in higher grades of FTR severity. Corrected 2D PISA method led to a higher concordance of TR severity grade with the VM method (ĸ = 0.84 vs. ĸ = 0.33 for uncorrected PISA, P &lt; 0.001). Compared with VM by 3DE, the conventional PISA underestimated FTR severity in about 50% of patients. Correction for TV leaflets tethering angle and lower velocity of FTR jet improved 2D PISA accuracy and reclassified more than one-third of the patients.

A Novel Approach for Semiautomated Three-Dimensional Quantification of Mitral Regurgitant Volume Reflects a More Physiologic Approach to Mitral Regurgitation

Quantification of mitral regurgitation (MR) by echocardiography is integral to assessing lesion severity and entails the integration of multiple Doppler-based parameters. These methods are founded primarily upon the principle of proximal isovelocity surface area (PISA), a two-dimensional (2D) method known to involve several assumptions regarding MR jet characteristics. The authors analyzed the results of a semiautomated method of three-dimensional (3D)-based regurgitant volume (RVol) estimation that accounts for jet behavior throughout the cardiac cycle and compared it with conventional 2D PISA methods for MR quantification. A total of 50 patients referred for transesophageal echocardiography for evaluation of primary (n=25) and secondary (n=25) MR were included for analysis. Three-dimensional full-volume color data sets were acquired, along with standard 2D methods for PISA calculation. A 3D semiautomated MR flow quantification algorithm was applied offline to calculate 3D RVol, with simultaneous temporal curves generated from the 3D data set. Three-dimensional RVol was compared with 2D RVol. Three-dimensional vena contracta area was also performed in all cases. There was a modest correlation between 2D RVol and 3D RVol (r=0.60). The semiautomated 3D approach resulted in significantly lower values of RVol compared with 2D PISA. Real-time and dynamic flow curve patterns were used for integral estimates of 3D RVol over the cardiac cycle, with a distinct bimodal pattern in functional MR and a brief and solitary peak in primary MR. Using a semiautomated 3D software for the quantification of MR allows the simultaneous calculation of 3D RVol with an automated generation of dynamic flow curves characteristic of the underlying MR mechanism. The present flow curve pattern results highlight well-known differences between MR flow dynamics in degenerative MR compared with functional MR.

New ESC/EACTS guideline recommendations for the treatment of secondary mitral regurgitation: reflections on the evidence

New <scp>ESC</scp>/<scp>EACTS</scp> guideline recommendations for the treatment of secondary mitral regurgitation: reflections on the evidence

Correlation between standard and adjusted echocardiographic quantitative methods for evaluating tricuspid regurgitation severity

Abstract Funding Acknowledgements Type of funding sources: None. Background Current guidelines advocate for a multi-parametric approach to echocardiographic quantitation of tricuspid regurgitation (TR). The primary quantitative measure of TR severity uses the proximal isovelocity surface area (PISA) method to calculate effective regurgitant orifice area (EROA) and regurgitant volume (RegVol). However, EROA-PISA may underestimate TR severity due to low flow and tethering of the tricuspid leaflets. Purpose The purpose of this study was to compare standard EROA-PISA quantitation of TR to alternative quantitative measures, including quantitative Doppler (EROA-Doppler), flow- and angle-corrected PISA method (EROA-Corrected), and three-dimensional vena contracta area (3D-VCA), in addition to the comparison of calculated RegVol-PISA, RegVol-Doppler, and RegVol-3DVCA. Methods Patients undergoing both transthoracic (TTE) and transesophageal (TEE) echocardiographic evaluation of TR severity for transcatheter treatment were included in this study. Patients were excluded if they had ≥ moderate aortic regurgitation. TTE measurements of EROA-PISA and RegVol-PISA were performed as per American Society of Echocardiography guidelines. EROA-Doppler was performed by quantifying RegVol-Doppler (diastolic stroke volume using biplane annular area, minus left ventricular outflow stroke volume) and deriving EROA. EROA-Corrected was calculated by adjusting for both aliasing velocity and leaflet angle as per published methods. 3D-VCA was measured on TEE performed within 14 days of TTE. Results Of 44 consecutive patients, the median age was 80 ± 9 years, 61% were female, and 89% had atrial fibrillation. Most patients (86%) had functional TR, 71% had a EROA-PISA ≥ 0.4 cm2. Table 1 shows the EROA and RegVol results for each method. EROA-PISA and RegVol-PISA were significantly lower than EROA-Doppler and RegVol-Doppler, as well as 3D-VCA and RegVol-3DVCA (all p &amp;lt; 0.0001). There was no significant difference between EROA-Doppler and 3D-VCA (p = 0.51), and RegVol-Doppler and RegVol-3DVCA (p = 0.66). EROA-Corrected reduced the absolute difference with EROA-Doppler (51% to 33%, p &amp;lt; 0.0001) and 3D-VCA (52% to 32%, p &amp;lt; 0.0001), but remained statistically lower than EROA-Doppler and 3D-VCA. Although EROA-PISA was strongly correlated to EROA-Doppler (r = 0.75, p &amp;lt; 0.0001) and 3D-VCA (r = 0.68, p &amp;lt; 0.0001), the correlation between EROA-Doppler and 3D-VCA was greatest (r = 0.77, p &amp;lt; 0.0001). Adjusting EROA-PISA for angle and flow demonstrated improved correlation to EROA-Doppler without affecting correlation to 3D-VCA (Figure 1). Conclusion Our study demonstrated that EROA-PISA significantly underestimates the severity of TR by EROA-Doppler and 3D-VCA. Although PISA correction methods reduced the underestimation, both EROA-Corrected and RegVol-Corrected remained significantly lower. EROA-Doppler and 3D-VCA and the calculated RegVol by each method, were closely correlated and not significantly different. Abstract Table 1 Abstract Figure 1

Impact of regurgitant orifice ellipticity on quantitation of tricuspid regurgitation using the proximal isovelocity surface area method

Abstract Funding Acknowledgements Type of funding sources: None. Background The proximal isovelocity surface area (PISA) method to quantify tricuspid regurgitation (TR) severity relies on the geometric assumption of a circular, planar regurgitant orifice. However, the TR orifice is often non-circular resulting in underestimation of TR severity when calculating the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol). Purpose To evaluate the effect of ellipticity of the tricuspid annulus on EROA-PISA correlation with quantitative Doppler (EROA-Dopp), and three-dimensional vena contracta area (VCA-3D). Methods Patients undergoing both transthoracic (TTE) and transesophageal (TEE) echo evaluation of TR severity were included in this study. Regurgitant orifice ellipticity was calculated as the ratio of the vena contracta maximum and minimum widths (VC-Ratio). Quantification of EROA and RegVol were performed on TTE for EROA-PISA and EROA-Dopp. Vena contract area was measured on TEE (VCA-3D). Results Of 44 total pts, the median age was 80 ± 9, 61% were female, 89% had atrial fibrillation, (86%) had functional TR, 32% were graded as severe, and 71% had a EROA-PISA ≥ 0.4 cm2. Median VC-Ratio was 1.3 (IQR 1.1-1.8) and was used to differentiate more circular orifices (VC-Ratio &amp;lt;1.3) from more elliptical orifices (VC-Ratio ≥1.3) (Table). EROA-PISA was significantly smaller compared to EROA-Dopp and VCA-3D in the whole group as well as elliptical subgroups (p &amp;lt; 0.0001 for all). There was no significant difference between EROA-Dopp and 3D-VCA for the whole group, or in circular or elliptical orifice subgroups (p &amp;gt; 0.5 for all). EROA-PISA correlated better with both EROA-Dopp and VCA-3D in circular compared to elliptical orifices (Table). EROA-Dopp and VCA-3D demonstrated high correlation for both circular and elliptical orifices (r = 0.76, p &amp;lt; 0.0001 and r = 0.77, p &amp;lt; 0.0001 respectively). Conclusion Our study demonstrated that there is a significant difference in quantitative measurements of tricuspid regurgitant orifice area, with EROA-PISA significantly underestimating both EROA-Dopp and VCA-3D. In more circular orifices, the EROA-PISA correlation was higher, however EROA-Dopp and VCA-3D were still significantly larger. Whether EROA-Dopp and VCA-3D are more predictive of outcomes requires further study. Abstract Table 1 Abstract Figure 1