Three-dimensional transthoracic echocardiographic evaluation of tricuspid regurgitation severity using proximal isovelocity surface area: comparison with volumetric method.

BACKGROUND: The quantification of tricuspid regurgitation(TR) using three-dimensional(3D) proximal isovelocity surface area (PISA) derived effective regurgitant orifice area (EROA) is feasible in functional TR. The aim of our study was to explore the diagnostic accuracy and utility of 3D PISA EROA in a larger population of different etiologies. METHODS: One hundred and seven patients with confirmed TR underwent 2D and 3D transthoracic echocardiography (TTE). 3D PISA EROA was calculated and EROA derived from 3D regurgitant volume (Rvol) was used as the reference. RESULTS: 3D PISA EROA showed better correlation in primary TR than in functional TR(r = 0.897, P < 0.01). 3D PISA EROA differentiated severe TR with comparable accuracy in patients with primary and functional etiology (Z-value 16.506 vs 21.202), but with different cut-offs (0.49cm2 vs. 0.41 cm2). The chi-square value for incorporated clinical symptoms, positive echocardiographic results and 3D PISA EROA to grade severe TR was higher than only included clinical symptoms or incorporated clinical symptoms and positive echocardiographic results (chi-square value 137.233, P < 0.01). CONCLUSION: TR quantification using 3D PISA EROA is feasible and accurate under different etiologies. It has incremental diagnostic value for evaluating severe TR.

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.

Background: The 2-dimensional proximal isovelocity surface area (2D PISA) method underestimates tricuspid regurgitation (TR) severity. Previously proposed correction algorithms should be further scrutinized. Methods: 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. Results: 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). Conclusions: 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.

Echocardiographic parameters recommended for assessing the severity of tricuspid regurgitation: concordance and discordance.

Background: Current guidelines recommend integrating several echocardiographic indices to evaluate the severity of tricuspid regurgitation (TR). Discordance of indices, including qualitative and quantitative methods, commonly exists in practice. The discordance among these parameters has not yet been fully elucidated. Methods: A total of 127 patients with recognizable TR jets without pulmonary regurgitation or intracardiac shunt were prospectively enrolled. We evaluated 8 parameters by 2-dimensional (2D) echocardiography: proximal iso-velocity surface area (PISA)-derived regurgitant volume (RVol), PISA-derived effective regurgitant orifice area (EROA), PISA radius, vena contracta width (VCW), color Doppler jet area, tricuspid valve annular diameter, inferior vena cava (IVC) diameter, and peak E wave. According to current guidelines, each echocardiographic parameter was determined to represent either severe or non-severe TR. A concordance score was calculated as the number of concordant parameters divided by 8, with a higher score reflecting better concordance. Data were further categorized into 3 subgroups: complete concordance (0 discordant parameters), high concordance (1-2 discordant parameters), and low concordance (3-4 discordant parameters). Results: The mean concordance score was 81%±17% for the entire cohort. There were 48 (38%) patients with complete concordance, including 6 patients with severe TR. In contrast, the low concordance group (n=43, 34%) mostly comprised severe TR patients (36 patients). When considering only EROA, RVol, and VCW, concordance improved, with 98 patients (77%) in complete agreement. Conclusions: Concordance seems limited when using echocardiographic parameters to assess TR severity. Applying only EROA, RVol, and VCW results in better concordance, as recommended by the current guidelines.

Sources of Variability in Vena Contracta Area Measurement for Tricuspid Regurgitation Severity Grading: Comparison of Technical Settings and Vendors.

BACKGROUND: Previous studies found different cutoffs of vena contracta area (VCA) to define severe tricuspid regurgitation (TR). The aim of this study was to investigate the factors associated with such variability by comparing technical variables and vendors. METHODS: Sixty-nine patients with scheduled tricuspid surgery were included in this prospective study. For each patient, TR data sets were obtained on three-dimensional color Doppler transthoracic echocardiography on at least two of three systems: GE Vivid E95 (n = 39), Siemens SC2000 Prime (n = 64), and Philips EPIQ 7C (n = 60). VCA was measured using default settings or with color baseline shifted on all three platforms and with minimal color gain (10%-20%) on the GE platform. RESULTS: Color gain reduction and baseline shift caused significant change sin VCA measurement (-46% and 10%, respectively). Intervendor comparison exhibited wide limits of agreement (narrowest range, -74% to 167%), with either default or optimized settings. Different technical settings, platforms, and reference methods all produced different VCA cutoffs for severe TR. CONCLUSIONS: VCA measurement in TR is sensitive to technical factors and demonstrates intervendor variability. Technical variables in VCA measurement should be reported in detail to allow comparison among research studies. The same vendor and settings should be used for longitudinal analysis of TR VCA in the same patient in multivendor echocardiography laboratories.