PISA Method Research Articles

Association with Outcomes of Correcting the PISA Method to Quantitate Secondary Tricuspid Regurgitation

Association with Outcomes of Correcting the PISA Method to Quantitate Secondary Tricuspid Regurgitation

'Color Doppler stripes’ make it difficult to diagnose the severity of valvular heart diseases: a report of two cases

BackgroundEchocardiography remains the reference-standard imaging technique for assessing valvular heart disease (VHD), but artifacts like the ‘color Doppler stripe’ can complicate diagnosis. This artifact is not widely recognized and can mimic severe VHD, leading to potential misdiagnoses. We present two cases where color Doppler stripes mimicked severe VHD, highlighting the need for awareness and accurate interpretation in echocardiographic assessments.Case presentationsCase 1: An 85-year-old patient was referred for mitral valve surgery due to suspected severe mitral regurgitation (MR). Upon evaluation, transthoracic echocardiography (TTE) showed mitral valve prolapse (P3) and a high-echoic, vibrating structure attached to the mitral valve, indicative of chordal rupture. Color Doppler echocardiography revealed strong systolic signals in the left atrium, mimicking severe MR. Transesophageal echocardiography (TEE) also detected the vibrating structure and color Doppler stripes in the left atrium, left ventricle, and outside the cardiac chambers. The PISA method on TEE indicated moderate MR and left ventriculography showed Sellers grade II MR. The artifact was identified as color Doppler stripes caused by the vibrating high-echoic structure from the ruptured chorda. Case 2: A 64-year-old patient with severe aortic stenosis, end-stage kidney disease requiring hemodialysis, and a history of coronary bypass grafting presented for routine follow-up. B-mode echocardiography showed a severely calcified tricuspid aortic valve with a vibrating calcified nodule and restricted opening, corresponding to severe aortic stenosis. During systole, color Doppler signals were observed around the aortic, pulmonary, and tricuspid valves, mimicking significant pulmonary stenosis and tricuspid regurgitation. However, pulmonary stenosis was ruled out as the pulmonary valve opening was normal. Mild tricuspid regurgitation was confirmed in the apical view.ConclusionsThese cases highlight the diagnostic challenges posed by color Doppler stripes. Recognizing and understanding this artifact are crucial for the accurate diagnosis and management of VHD, ensuring appropriate treatment and patient outcomes.

Application of PISA method for monopile design in layered soil

The foundation design for offshore wind turbines (OWTs) is critical to ensuring their structural integrity and long-term stability. Large-diameter monopiles are widely used for OWTs owing to their proven effectiveness. The conventional design approach, derived from the oil and gas industry’s p-y model, has limitations when applied to monopiles for OWTs. Consequently, a novel design method based on the PISA joint industry research project was developed, which extends beyond the traditional lateral soil resistance (p-y curves) and incorporates additional soil reaction components from shaft friction, pile base shear, and base moment. Unlike the simplistic rule-based conventional approaches, the proposed method necessitates site-specific 3D finite element (FE) simulations for precise calibration of soil reaction curves. Although successfully applied in European offshore wind farms, the PISA method’s performance in regions with distinct seabed compositions, such as China, remains to be verified. Therefore, this paper presents a comprehensive case study conducted at the Xiangshan wind farm, a representative site characterized by layered soil. The study employed in-situ investigations (cone penetration test, borehole) and laboratory tests (direct simple shear, bender element) to delineate the seabed soil profile and derive essential soil parameters for accurate foundation design. To facilitate the design, an Abaqus-based design tool was developed, which automated the extraction of soil reaction curves from the 3D FE simulations, calibration of PISA springs, and execution of one-dimensional beam-spring analyses employing Timoshenko beam theory. Comparative analyses were performed on the computed responses of piles, encompassing load-deflection curves, pile deflections, and bending moment profiles. The outcomes from the 3D FE simulations, uncalibrated rule-based PISA model, and calibrated PISA model were compared to validate the PISA method for monopile design in layered soil conditions.

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.

Comparison of effective regurgitant orifice area by the PISA method and tricuspid coaptation gap measurement to identify very severe tricuspid regurgitation and stratify mortality risk

Abstract Background Various definitions of very severe (VS) tricuspid regurgitation (TR) have been proposed based on the effective regurgitant orifice area (EROA) or tricuspid coaptation gap (TCG). Because of the inherent limitations associated with the EROA, we hypothesized that the TCG would be more suitable for defining VSTR and predicting outcomes. Purpose To compare EROA and TCG for outcome prediction in patients with severe TR. Methods In this French multicentre retrospective study, we included 606 patients with ≥ moderate-to-severe isolated TR (without structural valve disease or an overt cardiac cause) according to the recommendations of the European Association of Cardiovascular Imaging. Patients were further stratified into VSTR according to the EROA (≥60 mm²) and then according to the TCG (≥10 mm). The primary endpoint was all-cause mortality and the secondary endpoint was cardiovascular mortality. Results The relationship between the EROA and TCG was poor (R²=0.21), especially when the size of the defect was large. Four-year survival was comparable between patients with an EROA &amp;lt;60 mm² vs. ≥ 60 mm² (67±3% vs. 64±4%, p=0.64), even after adjustment, for all-cause (p=0.72) and cardiovascular mortality (p=0.18). A TCG ≥10 mm was associated with lower four-year survival than a TCG &amp;lt;10 mm (53±7% vs. 69±3%, p&amp;lt;0.001). After adjustment for covariates, including age, comorbidity, right heart failure, dose of diuretics, and right ventricular dysfunction, a TCG ≥10 mm remained independently associated with higher all-cause mortality (adjusted HR[95%CI]=1.46[1.15-2.18], p=0.015) and cardiovascular mortality (adjusted HR[95%CI]=1.95[1.22-3.14], p &amp;lt;0.001), whereas an EROA ≥60 mm² was not associated with all-cause or cardiovascular mortality (adjusted HR[95%CI]:1.07[0.75-1.51], p=0.720, and adjusted HR[95%CI]:1.35[0.87-2.09], p=0.176, respectively). Conclusion The correlation between the TCG and EROA is weak and decreases with increasing defect size. A TCG ≥10mm is associated with increased all-cause and cardiovascular mortality and should be used to define VSTR in isolated TR.Correlation between EROA and TCGEvent free survival curves

Consistency of echocardiographic assessment of the severity of mitral regurgitation using volumetric and PISA methods with MRI data in patients with secondary mitral regurgitation with reduced ejection fraction

Objectives: to compare the consistency of echocardiographic Vmr and FR obtained by PISA and volumetric methods with Vmr and FR obtained by MRI in patients with secondary MR with reduced LV EF.Materials and methods. The analysis included data from 433 patients with secondary mitral regurgitation with reduced LV EF (less than 35%). The patients were divided into 2 groups: Group 1 – 286 patients with an average age of 64 ± 10 years, in whom the calculation of Rvol and RF was carried out by the PISA method. Group 2 – 147 patients with an average age of 63 ± 11 years, in whom the calculation of Rvol and RF was carried out by the volumetric method.Results. A moderate correlation was found between the indicators obtained by MRI and echocardiography, regardless of the method used, volumetric method Rvol r = 0.54 p = 0.01 and RF r = 0.56, p = 0.01, PISA method Rvol, r = 0.36, p = 0.01 and RF, r = 0.3, p = 0.01. The agreement in MR severity categorical scores between PISA and MRI was 27% in the diagnosis of severe mitral regurgitation and 50% in the diagnosis of moderate MR. The consistency in categorical MR severity scores between volumetric and MRI was 46% in the diagnosis of severe mitral regurgitation and 65% in the diagnosis of moderate MR. In the Bland–Altman analysis, the average difference in Rvol between PISA and MRI was 7.6 ± 13 ml with coincidence limits (30; –25 ml), the average difference in Rvol between volumetric and MRI was –2.5 ± 7.3 ml with coincidence limits (–12; 17 ml).Conclusions. MRI and echocardiography regardless of the method used have only a moderate correlation in the assessment of Rvol and RF in patients with secondary MR with reduced EF. The volumetric method may be the method of choice when calculating quantitative indicators of MR severity, as it has better agreement with MRI data compared to the PISA method.

Monopile Foundation Stiffness Estimation of an Instrumented Offshore Wind Turbine through Model Updating

Rapid development of offshore wind foundation models has resulted in a large number of built structures with generally underestimated foundation stiffness properties and a need to update and validate both the individual structural models and the underlying foundation design frameworks. This paper outlines a structural health monitoring approach, based on the combination of output only structural health monitoring methods and model updating, to estimate foundation stiffness parameters using field monitored data. Field monitoring data from an offshore wind turbine under idling conditions, over a large monitoring period, are presented and operational modal analysis is applied to estimate the modal parameters. Those are compared to modal properties predicted by finite element models, employing either old (API/DNVGL) or new (PISA) foundation design properties, which are calibrated using geotechnical site investigation data. A new approach to interpret seabed level statically equivalent foundation stiffness, in terms of effective lateral and rotational stiffness against load eccentricity, is presented. Seabed level statically equivalent foundation properties are updated by comparison against the observed modal behaviour and the optimised foundation parameters are presented, demonstrating a close match to the predictions of the PISA method.

Proportionality concept of mitral regurgitation-truly valid?

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Medical Centre Ljubljana, Slovenia. Background The results of studies of transcatheter mitral valve repair introduced a new conceptual framework that categorized mitral regurgitation (MR) into proportionate (propMR) and disproportionate (dispropMR) according to the relationship between effective regurgitant orifice area (EROA) and left ventricular (LV) end-diastolic volume (EDV). However, pathophysiological mechanisms behind these entities have not been well defined. Purpose To identify the echocardiographic characteristics which could explain the underlying mechanism of dispropMR. Methods We retrospectively included 179 consecutive patients (age: 69±12 years, male: 132 [74%]) with HFrEF and more than mild MR referred to clinically indicated echocardiography. The disproportional cut-off value specific for our group was calculated from the theoretical line of proportionality based on the ratio EROA/EDV, considering the clinical characteristics of the study group. Correspondingly, the cut-off value for disproportionality was 0.126. Potential factors which might affect proportionality scheme were analysed: factors affecting EDV measurements (LV foreshortening) and factors affecting EROA calculation (dynamic variation of MR flow rate (MRFR) and different PISA approaches for EROA calculation: standard single-point PISA method vs. serial PISA method). Results In our cohort, 55 (32%) patients had dispropMR. Patients with dispropMR had more frequent LV foreshortened images for EDV calculation than patients with propMR (31 patients (56.4%) vs. 37 patients (32.7%); p = 0.003), resulting in smaller EDV in dispropMR group. DispropMR group had more substantial dynamic variation of regurgitant flow compared to propMR (Figure A), resulting in a more significant overestimation of MRFR in dispropMR than propMR when using instantaneous MRFR from standard single-point PISA (p = 0.001). EROA was consistently overestimated by standard single-point PISA method compared to serial PISA method (Figure B). Consequently, 73% of patients classified as dispropMR had either a foreshortened image or overestimation of EROA measurement. Conclusion Our results suggest that higher EROA/EDV ratio in dispropMR could be explained by underestimation of EDV due to LV foreshortening and overestimation of EROA by standard single-point PISA method due to more substantial dynamic variation of regurgitant flow. The data suggest that methodological limitations have an important impact on echocardiographic measurements used in the definition of proportionality. The proportionality concept is questionable and may not support the patients’ selection for treatment strategies.

Comparison of effective regurgitant orifice area by the PISA method and tricuspid coaptation gap measurement to identify very severe tricuspid regurgitation and stratify mortality risk

Abstract Funding Acknowledgements Type of funding sources: None. Background Various definitions of very severe (VS) tricuspid regurgitation (TR) have been proposed based on the effective regurgitant orifice area (EROA) or tricuspid coaptation gap (TCG). Because of the inherent limitations associated with the EROA, we hypothesized that the TCG would be more suitable for defining VSTR and predicting outcomes. Purpose To compare EROA and TCG for outcome prediction in patients with severe TR Methods In this French multicentre retrospective study, we included 606 patients with ≥ moderate-to-severe isolated TR (without structural valve disease or an overt cardiac cause) according to the recommendations of the European Association of Cardiovascular Imaging. Patients were further stratified into VSTR according to the EROA (≥60 mm²) and then according to the TCG (≥10 mm). The primary endpoint was all-cause mortality and the secondary endpoint was cardiovascular mortality. Results The relationship between the EROA and TCG was poor (R²=0.21), especially when the size of the defect was large. Four-year survival was comparable between patients with an EROA &amp;lt;60 mm² vs. ≥ 60 mm² (67±3% vs. 64±4%, p = 0.64), even after adjustment, for all-cause (p = 0.72) and cardiovascular mortality (p = 0.18). A TCG ≥10 mm was associated with lower four-year survival than a TCG &amp;lt;10 mm (53±7% vs. 69±3%, p&amp;lt;0.001). After adjustment for covariates, including age, comorbidity, right heart failure, dose of diuretics, and right ventricular dysfunction, a TCG ≥10 mm remained independently associated with higher all-cause mortality (adjusted HR[95%CI]=1.46[1.15–2.18], p = 0.015) and cardiovascular mortality (adjusted HR[95%CI]=1.95[1.22–3.14], p &amp;lt;0.001), whereas an EROA ≥60 mm² was not associated with all-cause or cardiovascular mortality (adjusted HR[95%CI]:1.07[0.75–1.51], p = 0.720, and adjusted HR[95%CI]:1.35[0.87–2.09], p = 0.176, respectively) Conclusion The correlation between the TCG and EROA is weak and decreases with increasing defect size. A TCG ≥10mm is associated with increased all-cause and cardiovascular mortality and should be used to define VSTR in isolated TR.

Comparison of effective regurgitant orifice area by the PISA method and tricuspid coaptation gap measurement to identify very severe tricuspid regurgitation and stratify mortality risk

Various definitions of very severe (VS) tricuspid regurgitation (TR) have been proposed based on the effective regurgitant orifice area (EROA) or tricuspid coaptation gap (TCG). Because of the inherent limitations associated with the EROA, we hypothesized that the TCG would be more suitable for defining VSTR and predicting outcomes. In this French multicentre retrospective study, we included 606 patients with ≥ moderate-to-severe isolated functional TR (without structural valve disease or an overt cardiac cause) according to the recommendations of the European Association of Cardiovascular Imaging. Patients were further stratified into VSTR according to the EROA (≥ 60 mm2) and then according to the TCG (≥ 10 mm). The primary endpoint was all-cause mortality and the secondary endpoint was cardiovascular mortality. The relationship between the EROA and TCG was poor (R2 = 0.22), especially when the size of the defect was large. Four-year survival was comparable between patients with an EROA < 60 mm2 vs. ≥ 60 mm2 (68 ± 3% vs. 64 ± 5%, P = 0.89). A TCG ≥ 10 mm was associated with lower four-year survival than a TCG < 10 mm (53 ± 7% vs. 69 ± 3%, P < 0.001). After adjustment for covariates, including comorbidity, symptoms, dose of diuretics, and right ventricular dilatation and dysfunction, a TCG ≥ 10 mm remained independently associated with higher all-cause mortality (adjusted HR [95%CI] = 1.47 [1.13–2.21], P = 0.019) and cardiovascular mortality (adjusted HR [95%CI] = 2.12 [1.33–3.25], P = 0.001), whereas an EROA ≥ 60 mm2 was not associated with all-cause or cardiovascular mortality (adjusted HR [95%CI]: 1.16 [0.81–1.64], P = 0.416, and adjusted HR [95%CI]: 1.07 [0.68–1.68], P = 0.784, respectively). The correlation between the TCG and EROA is weak and decreases with increasing defect size. A TCG ≥ 10 mm is associated with increased all-cause and cardiovascular mortality and should be used to define VSTR in isolated functional TR (Fig. 1).

Holding Capacity of Suction Anchor in Cohesive Soils based on Soil-Spring Model

In this paper, a soil-spring model was applied to evaluate the holding capacity according to the loading position of the suction anchor. The API(2010) method, which is mainly applied to small-diameter piles, the PISA(2015) method, which recently introduced research results in offshore wind power design, and the Jeanjean(2009) method, which was presented as a model suitable for large-diameter piles in cohesive soil, were analyzed. A comparative review of the finite element analysis(ALE) was applied was performed for the conditions. A procedure for calculating the holding capacities for each loading position of the suction anchor was established using the soil-spring model, and it was confirmed that it was a method that could be used practically. When the soil-spring model of Jeanjean(2009) was applied, the results (5~10%) most similar to the FEM(ALE) analysis results in tendency and holding capacity could be obtained.

Comparison of effective regurgitant orifice area by the PISA method and tricuspid coaptation gap measurement to identify very severe tricuspid regurgitation and stratify mortality risk.

Various definitions of very severe (VS) tricuspid regurgitation (TR) have been proposed based on the effective regurgitant orifice area (EROA) or tricuspid coaptation gap (TCG). Because of the inherent limitations associated with the EROA, we hypothesized that the TCG would be more suitable for defining VSTR and predicting outcomes. In this French multicentre retrospective study, we included 606 patients with ≥moderate-to-severe isolated functional TR (without structural valve disease or an overt cardiac cause) according to the recommendations of the European Association of Cardiovascular Imaging. Patients were further stratified into VSTR according to the EROA (≥60 mm2) and then according to the TCG (≥10 mm). The primary endpoint was all-cause mortality and the secondary endpoint was cardiovascular mortality. The relationship between the EROA and TCG was poor (R2 = 0.22), especially when the size of the defect was large. Four-year survival was comparable between patients with an EROA <60 mm2 vs. ≥60 mm2 (68 ± 3% vs. 64 ± 5%, p = 0.89). A TCG ≥10 mm was associated with lower four-year survival than a TCG <10 mm (53 ± 7% vs. 69 ± 3%, p < 0.001). After adjustment for covariates, including comorbidity, symptoms, dose of diuretics, and right ventricular dilatation and dysfunction, a TCG ≥10 mm remained independently associated with higher all-cause mortality (adjusted HR[95% CI] = 1.47[1.13-2.21], p = 0.019) and cardiovascular mortality (adjusted HR[95% CI] = 2.12[1.33-3.25], p = 0.001), whereas an EROA ≥60 mm2 was not associated with all-cause or cardiovascular mortality (adjusted HR[95% CI]: 1.16[0.81-1.64], p = 0.416, and adjusted HR[95% CI]: 1.07[0.68-1.68], p = 0.784, respectively). The correlation between the TCG and EROA is weak and decreases with increasing defect size. A TCG ≥10 mm is associated with increased all-cause and cardiovascular mortality and should be used to define VSTR in isolated significant functional TR.

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.

Assessment of Functional Mitral Regurgitation Severity by Proximal Isovelocity Surface Area via 3D Transthoracic Echocardiography

Background: Accurate quantitative evaluation of MR severity remains challenging because limited scan plane orientation of 2D echocardiography does not provide direct measurement of the regurgitant lesion. Three-dimensional echocardiography, which has become a clinically established technique, has been shown to provide useful information for flow quantification and so has the potential to address the major drawbacks of 2D-based approaches.&#x0D; Objectives: To assess the reliability of PISA measurement using real-time 3D color trans-thoracic echocardiographic imaging in clinical practice and to compare its derived EROA, regurgitant volume (Rvol) and regurgitant fraction with that obtained by 2D trans thoracic PISA.&#x0D; Patients and Methods: This cross-sectional study, included 30 patients with at least moderate functional MR came for evaluation on clinical basis indications at Al-Hussein and Bab El-Shaareya University Hospitals during the period from November 2020 to July 2021. Two- and three-dimensional echocardiography was done to asses MR and calculate vena contract width, 2D PISA and derived EORA and regurgitant volume. Also, calculation of 3D EROA using PISA method by 3D probe.&#x0D; Results: There was a significant positive correlation between 2D EPISA and 3D EROA using PISA method and EROA, p value was 0.0001. With higher values for 3D EROA using PISA method when compared with 2D PISA in different degrees of MR as summarized in “the mean value of EROA by 2D PISA in moderate MR was 0.25 ±0.042 cm2, while it was 0.32±0.059 cm2 by 3D EROA using PISA method. While the mean value of EROA by 2D PISA in severe MR was 0.58 ±0.14 cm2, and it was 0.47 ±0.049 cm2 by 3D EROA”. Also showed significant difference in different direction of MR jets especially in eccentric jet as shown by the mean value of EROA by 2D PISA in central MR was 0.41±0.19 cm2, while it was 0.41±0.87 cm2 by 3D method. While the mean value of EROA by 2D PISA in eccentric MR was 0.53 ±0.21 cm2, and it was 0.44 ±0.096 cm2 by 3D EROA using PISA method.&#x0D; Conclusion: The use of 3D EROA using PISA method and simple calculation of a mean systolic regurgitation orifice area proved to be superior to 2D measures (VC, 2D-PISA) for distinguishing moderate from severe MR, evaluation, classification and grading of MR in a routine clinical cardiology setting. 3D EROA reduces assumptions and seemingly improves diagnostic value as compared with 2D-PISA.

Impact of leaflet-tethering angle correction on the assessment of tricuspid regurgitation severity using the PISA method

Abstract Funding Acknowledgements Type of funding sources: None. Background Severe tricuspid regurgitation (TR) is associated with excess mortality and morbidity. Therefore, assessment of TR severity is pivotal. Calculation of the effective regurgitant orifice area (EROA) and the regurgitant volume (RVol) using flow convergence method (PISA) by echocardiography are still the recommended parameters to define TR severity. However, the distortion of the proximal convergence zone related to the extent of valve leaflet tethering may result in smaller PISA radius and in underestimation of TR severity. Correcting for the angle of the leaflet tethering could reduce errors due to geometric assumption of a flat valvular plane and improve the accuracy of the calculations. Purpose: The aims of our study were (1) to evaluate whether taking into account the extent of leaflet tethering by applying the angle correction (AC) in the PISA formula improves the accuracy of the quantitative assessment of TR severity; (2) to assess the potential clinical impact of AC. Methods Forty-one patients with functional TR (73.5 ± 11.8 years,51% men,36% sinus rhythm,17% severe), underwent 2D and 3D echocardiography. We compared the RVol obtained by volumetric method (as reference) with the RVol by PISA with and without AC. TR RVol by volumetric method was calculated as: total RV stroke volume (RVSV) – left ventricular forward SV (LVSV), where RVSV was obtained by subtracting the end-systolic from end-diastolic RV volume measured by 3D echocardiography and LV SV was calculated by multiplying LV outflow area by velocity time integral (VTI) (Fig. 1). TR RVol by PISA was calculated as EROA x VTITR. Uncorrected EROA was calculated using the formula: 6.28 r2 xVa/ PeakVTR (r - PISA radius, Va, aliasing velocity, PeakVTR – TR peak velocity). The corrected EROA accounting for the PISA geometric distortion by leaflet tethering angle (α) was calculated as: 6.28 r2 x Va (α/180)/ PeakV TR (PISAac), where α was measured using a protractor generated by dedicated software. Results Application of AC to PISA method resulted in larger EROA and RVol (0.34± 0.38 cm2 vs 0.24± 0.24cm2 and, 25.2± 19.3 mL vs 18.6 ± 13.1mL, respectively). The percentage change in EROAac was over 40%. When compared to the volumetric method, RVol by corrected PISA method was significantly closer and correlated (bias -3.95mL, LOA ± 6.41 mL, r= .987; p&amp;lt; .001) than the conventional PISA without AC (bias -10.5 mL, LOA ± 15 mL, r= .975). Angle correction resulted in a change of TR severity in 32% of cases (Fig. 2) and in a greater concordance of TR severity grade with the volumetric method (75%, 31/41 with AC vs 52%, 22/41 without AC). Conclusions Angle-corrected PISA method that accounts for the extent of the leaflet tethering in TR provided significantly larger TR RVol that were closely correlated with the volumetric RVol by 3D echocardiography. A simple geometric angle correction of the proximal flow with PISA method reclassified up to 1/3 of patients with functional TR. Abstract Figure. Representation of study method Abstract Figure. Reclassification of TR severity

Comparison of mitral regurgitant volume assessment between proximal flow convergence and volumetric methods in patients with significant primary mitral regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background. Discrepancies have been observed between transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (MRI) severity grading in primary mitral regurgitation (MR). Purpose. To compare mitral regurgitant volume (RV) obtained by the proximal flow convergence method (PISA) method by TTE and by volumetric methods (TTE and MRI), and study the relationship between LV size and RV obtained by either the PISA or volumetric methods. Methods and results. 188 patients from 2 heart valve clinics with at least moderate-to-severe primary MR due to prolapse in sinus rhythm who underwent evaluation with TTE and MRI were included. RV was estimated by either PISA or volumetric methods (Left ventricular [LV] stroke volume minus systolic aortic outflow volume)) by either MRI (MRI-RV) or TTE (TTE-RV)). PISA-RV and either MRI-RV or TTE-RV weakly correlated (r = 0.29 and 0.30,p &amp;lt; 0.001). On multivariable analysis, LV end-diastolic volume (LVEDV) and bileaflet prolapse independently correlated with the magnitude of the difference between PISA and volumetric methods. While PISA-RV and LVEDV were unrelated, MRI-RV and TTE-RV strongly correlated with LVEDV (r = 0.66 and 0.68,p &amp;lt; 0.001). In contrast, LVEDV and regurgitant fraction (RF = RV/LVEDV) either with TTE or MRI were poorly related (r = 0.17,p = 0.02 and r = 0.12,p = 0.10). Conclusion. RV estimated by the PISA and volumetric methods are not comparable. The expected proportional relationship between volumetric RV and LV size, which is not observed with PISA-RV suggests the inaccuracy of PISA-RV. Given that RV by volumetric methods depends on LV size, determination of a unique RV threshold for severe MR is challenging. Calculation of RF may overcome this limitation. Abstract Figure. RV assessed by PISA or volumetric method Abstract Figure. Illustrative example

Impact of endocardial leads on the effectiveness of interventional edge-to-edge repair of tricuspid regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background A considerable proportion of patients who are considered for percutaneous tricuspid valve edge-to-edge repair (pTVR) interventions have endocardial lead induced tricuspid regurgitation (TR). The aim of this study was to examine the impact of lead-leaflet interaction on the effectiveness of pTVR. Methods For each patient, the lead position within the tricuspid valve (central, commissural, or towards one of the three leaflets) and the type of lead-leaflet interaction (leaflet impingement or adhesion) were identified during thorough 2D/3D transthoracic and transesophageal echocardiography examinations. Before and after pTVR, echocardiographic data, including 3D full-volume datasets, were obtained and quantified. TR severity was graded from 1+ to 5+, based upon the effective regurgitant orifice area by the PISA method (EROAPISA) and the vena contracta area (VCA3D) as measured by multiplanar reconstruction from a 3D color Doppler loop. Maximal diastolic tricuspid annulus area from a 3D zoom image, tricuspid tenting area, and right atrial volume were quantified. Right ventricular assessments included ejection fraction (RVEF3D) and diastolic (RVVd3D) and systolic (RVVs3D) volumes. Results Out of 99 patients who underwent pTVR at our hospital, 38 patients had implanted cardiac devices of the following types: pacemakers (n = 25, 66%), cardiac defibrillators (n = 7, 18%), and biventricular pacemakers (n = 6, 16%). In 24 (63%) of these device patients, TR grade was ≤2+ after pTVR. In 14 of the device patients, TR grade remained severe after intervention (Grade 3+ in 15%, grade 4+ in 11%, and Grade 5+ in 11% of the device group). In comparison, in 78% of patients without endocardial leads, moderate TR was achieved after pTVR. Figure 1 shows the distribution of lead positions within the tricuspid valve. A relevant lead-leaflet interference (rLLI) for pTVR interventions was defined as impingement or adhesion in the target area of the coaptation device (anteroseptal or posteroseptal). Binary logistic regression analysis showed an increase risk (Odds ratio 11, R2 0.34, 95% CI 0.019-0.44, p = 0.003) for a suboptimal pTVR result (TR grade &amp;gt; 2+ after intervention) in patients with rLLI. Although patients with rLLI (n = 17) had significantly higher VCA3D values as compared to patients without rLLI (n = 21), it was not predictive for pTVR results. Echocardiographic parameters of right ventricular and tricuspid valve dimensions showed only a trend to higher values in the group with rLLI (Table 1). Conclusion Endocardial lead induced TR negatively impacts the effectiveness of pTVR irrespective of the initial degree of TR. Abstract Figure. Abstract Table 1 Echocardiographic parameters

Prognostic value of three-dimensional echocardiographic assessment of tricuspid valve geometry and parameters of severity in atrial and ventricular functional tricuspid regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial and ventricular functional tricuspid regurgitation (A-FTR and V-FTR) have recently emerged as different phenotypes of FTR. Given the difference in mechanisms that are postulated to be underlying these 2 entities, a different remodeling of tricuspid valve (TV) apparatus can occur and therefore also a specific quantitative approach could be deemed. Aim Aim of this study was to investigate the TV apparatus remodeling in the two different phenotypes of FTR: ventricular (V-FTR) and atrial (A-FTR) and the role of echocardiographic parameters of TV remodeling and TR severity to predict clinical outcomes. Material and methods The present retrospective study included consecutive patients with moderate to severe functional tricuspid regurgitation (FTR) referred for echocardiography in two Italian centers. The composite endpoint of death for any cause and heart failure (HF) hospitalization was used as primary outcome of this analysis. According to more recent guidelines, patients were considered having A-FTR if having history of long- standing atrial fibrillation, without history of pulmonary hypertension and left side heart disease. Results. A total of 180 patients were included. Despite the right atrial volume (RAV) was not different in the 2 groups, in A-FTR tethering height was significantly lower (11.7 ±4.8 mm vs 15.0 ± 5.5 in V-FTR. p &amp;lt;0.01) and the 3D-derived tricuspid annulus (TA) diameters were larger both in end-diastolic and mid-systolic phase (3D-TA-End diastolic- major axis: 45.2 ± 6.2 mm in A-FTR vs 42.8 ± 5.4 in V-FTR. p= 0.04; 3D-TA mid systolic major axis: 41,7 ± 6,4mm in A-FTR vs 37,9 ± 5,1 in V-FTR, P &amp;lt;0,01). 3D-TA-End diastolic- minor axis: 39.7 ± 6.8 vs 37.1 ± 5.2. p= 0.03). Regarding the parameters of severity of FTR. patients with V-FTR had larger vena contracta (VC). either when 2D estimated or 3D (2D-VC-average: 5.3 ± 2.8 mm in A-FTR vs 6.6 ± 3.7 in V-FTR. P= 0.02; 3D-VCA: 0.9 ± 0.4 cm2 vs 1.3 ± 1.1 cm2 p= 0.02); conversely the value of 2D-ERO and regurgitant volume estimated with 2D-PISA method did not show significant difference between the 2 groups (table 1). After a median follow-up of 24 months (IQR: 2-48) 72 patients (40%) reached the primary end-point and 64 (36%) hospitalized for HF. Different predictors of combined end point were found in the 2 groups: tenting height. 2D-VC. 3D-VCA and regurgitant fraction were prognostic correlates in V-FTR; TA dimensions as well as all the parameters of severe TR. including EROA with PISA method were related to the prognosis in A-FTR (table 2). Conclusions Prognostic role of quantitative parameters of FTR in A-FTR and V-FTR is different, thus reaffirming the difference in underlying pathogenic mechanisms and the needing for a more specific diagnostic approach and prognostic stratification in these two FTR phenotypes

Nano-assemblies of phosphonium-functionalized diblock copolymers with fabulous antibacterial properties and relationships of structure-activity.

As a novel antimicrobial material, quaternary phosphonium salts (QPSs) have been drawing close attention because of their excellent antimicrobial capacity with high activity and low bacterial survivability. Polymeric QPSs (PQPSs) also exhibit selectivity and long-term stability, however the polymerization of QPSs is severely challenged by low controllability and narrow selectivity of cation type. In this study, high-conversion RAFT polymerization is employed to prepare innovative phosphonium-functionalized diblock copolymers (PFDCs) with desired molecular weights and particle sizes. The excellent antibacterial activity of the PFDCs achieves lowest MIC values of 40 and 60 μg mL-1 (i.e., 1.4 and 2.2 μmol L-1) against E. coli and S. aureus, respectively. Mixing with an ink, dye, and latex coating does not weaken the antibacterial activity of the PFDCs, which inhibited 99.9% E. coli, showing broad applicability in different media. The effects of the cation type, synthesis medium, crosslinking content, and particle size on the morphology and antibacterial activity are studied. In summary, the RAFT polymerization of QPSs through the versatile design of ionic liquid monomers and the polymerization-induced self-assembly (PISA) method for constructing nano-assemblies with various micromorphology and particle size provides an exceedingly efficient way to build up multifunctional and multi-morphological polymeric nano-objects that open up vast possibilities in the fields of antibiotics, drug delivery, templated synthesis, and catalysis.

181 Impact of leaflet-tethering angle correction on the assessment of tricuspid regurgitation severity using the PISA method

Abstract Aims Severe tricuspid regurgitation (TR) is associated with excess mortality and morbidity. Therefore, accurate assessment of TR severity is pivotal. In clinical routine, the calculation of the effective regurgitant orifice area (EROA) and the regurgitant volume (RVol) using flow convergence method (PISA) by echocardiography are among the recommended parameters to define TR severity. However, the distortion of the proximal convergence zone related to the extent of valve leaflet tethering may result in smaller PISA radius and in underestimation of TR severity. Correcting for the angle of the leaflet tethering could reduce errors due to geometric assumption of a flat valvular plane and improve the accuracy of the calculations. The aims of our study were: (1) to evaluate whether taking into account the extent of leaflet tethering by applying the angle correction (AC) in the PISA formula improves the accuracy of the quantitative assessment of TR severity; (2) to assess the potential clinical impact of AC. Methods and results Forty-one patients with functional TR (73.5 ± 11.8 years, 51% men, 36% sinus rhythm, 17% severe), underwent 2D and 3D echocardiography. We compared the RVol obtained by volumetric method (as reference) with the RVol by PISA with and without AC. TR RVol by volumetric method was calculated as: total RV stroke volume (RV SV)–left ventricular forward SV (LV SV), where RV SV was obtained by subtracting the end-systolic from end-diastolic RV volume measured by 3D echocardiography and LV SV was calculated by multiplying LV outflow area by velocity time integral (VTI). TR RVol by PISA was calculated as EROA × VTI TR. Uncorrected EROA was calculated using the formula: 6.28 r2 × Va/PeakV TR (r—PISA radius, Va, aliasing velocity, PeakV TR—TR peak velocity). The corrected EROA accounting for the PISA geometric distortion by leaflet tethering angle (α) was calculated as: 6.28 r2 × Va (α/180)/PeakV TR (PISAAC), where α was measured using a protractor generated by dedicated software. PISA radius and angle were 5.5 ± 1.97 mm and 211.2° ± 13.6°, respectively. Application of AC to PISA method resulted in larger EROA and RVol (0.34 ± 0.38 cm2 vs. 0.24 ± 0.24 cm2 and, 25.2 ± 19.3 ml vs. 18.6 ± 13.1 ml, respectively). The percentage change in EROAAC was over 40%. When compared to the volumetric method, RVol by corrected PISA method was significantly closer and correlated (bias −3.95 ml, LOA ± 6.41 ml, r = 0.987; P &amp;lt; 0.001) than the conventional PISA without AC (bias −10.5 ml, LOA ± 15 ml, r = 0.975). Angle correction resulted in a change of TR severity in 32% of cases and in a greater concordance of TR severity grade with the volumetric method (75%, 31/41 with AC vs. 52%, 22/41 without AC). Conclusions Angle-corrected PISA method that accounts for the extent of the leaflet tethering in TR provided significantly larger TR RVol that were closely correlated with the volumetric RVol by 3D echocardiography. A simple geometric angle correction of the proximal flow with PISA method reclassified up to one-third of patients with functional TR.