Regurgitant Orifice Research Articles

Disproportionate mitral regurgitation: new entity or reflection of measurment errors?

Abstract Funding Acknowledgements Type of funding sources: None. Background The results of recent studies of transcatheter mitral valve repair proposed a new conceptual framework that categorized mitral regurgitation (MR) into proportionate (propMR) or disproportionate (dispropMR) according to the relationship between effective regurgitant orifice area (EROA) and left ventricular (LV) end-diastolic volume (EDV). Purpose To determine the prevalence of dispropMR in consecutive heart failure patients with reduced ejection fraction (HFrEF) undergoing clinically indicated echocardiography over one year period and to examine characteristics of this new entity. Methods We retrospectively identified 179 patients(age:69 ± 12 years, male:132[74%]) with HFrEF who were classified more than mild MR by performing echocardiographer. Following parameters of MR severity were analysed: regurgitant volume(PISA-based regurgitant volume[RVol-PISA] and RVol calculated by the difference of total LV stroke volume by LV planimetry and Doppler-estimated effective LV stroke volume[RVol-SV]), PISA-based EROA and regurgitant fraction (RF). Grading of MR severity based on RVol was performed (mild:<30 ml, mild-moderate:30-44ml, moderate-severe:45-59 ml, severe:≥60 ml). The distinction between propMR and dispropMR was determined by using a proportionality scheme by Grayburn, considering ratio EROA/LVEDV. DispropMR was identified by the ratio greater than 0.14, while the others were classified as propMR. Results In our cohort, 49(27.4%)patients had dispropMR. Both MR groups were comparable in age and gender. DispropMR group had significantly smaller LV dimensions(LV end-diastolic diameter:59 ± 9mm vs. 65 ± 8mm,p < 0.001; LVEDV:164 ± 54ml vs. 222 ± 60ml,p < 0.001) and higher EF(41 ± 11% vs. 34 ± 9%, p < 0.001). Higher proportion of primary MR was noted in dispropMR group(15[31%] vs. 4[3.3%] patients, p < 0.001). Significant differences were observed in PISA-based quantification of MR between both groups (p < 0.001, for all), whereas RVol-SV was comparable(p = 0.667;Figure A). Discrepant grading in MR severity between RVol-PISA and RVol-SV methods was observed(p < 0.001), with significant high discordance in dispropMR(p < 0.001) and no significant differences in propMR(p = 0.187;Figure B). Additionally, difference in RVol assessed by PISA method and SV method were more prominent in dispropMR (RVol difference: dispropMR:27 ml[17-46] vs. propMR:13 ml[-4 to 24],p < 0.001). MR severity would be reclassified in a substantial proportion of dispropMR when considering RVol-SV. Conclusion Our results suggest that dispropMR may be found in roughly one fourth of echocardiographic studies in patients with HFrEF. DispropMR patients have less extensive LV remodelling and more severe MR based on PISA parameters compared to propMR. However, inconsistencies between parameters of MR severity in dispropMR might suggest echocardiographic limitations of quantitative grading of the MR severity or/and LV volume assessment rather than a new pathophysiological concept of disproportionate MR. Abstract Figure A, B

External validation of the unifying concept for the quantitative assessment of secondary mitral regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background A Unifying Concept for the Quantitative Assessment of Secondary Mitral Regurgitation (SMR) was recently proposed in order to provide a solution for the ongoing guideline controversy. However, these data were derived from a single center cohort and lacks external validation. We aimed to validate the proposed algorithm in a different patient population. Methods Patients with at least mild SMR and reduced left ventricular ejection fraction (< 50%) under optimal guideline-directed medical therapy were retrospectively identified at a single-center. The cohort was stratified in low-risk (effective regurgitant orifice area [EROA] < 20 mm2 and regurgitant volume [RegVol] < 30 ml), intermediate-risk (EROA 20 to 29 mm2 and RegVol 30 to 44 ml) and high-risk (EROA ≥ 30 mm2 and RegVol ≥ 45ml) according to the defined risk-based thresholds tailored to the pathophysiological concept of SMR. In the intermediate-risk group, patients were further stratified on the basis of the hemodynamic severity of SMR, into intermediate low-risk and intermediate high-risk (regurgitant fraction < 50% or ≥ 50%, respectively). The primary endpoint was all-cause mortality. Results A total of 572 patients (median age 70 years; 76% male) were included. Median LVEF was 35% (IQR 28-40) and LVEDV was 169 ml (IQR 132-215). Median measures of SMR severity were EROA of 14 mm2 (IQR 8-22) and RegVol of 23 ml (12-34). During a median follow-up of 3.8 years (interquartile range: 1.8 to 6.2 years) there were 254 deaths (44%). The mortality at 6-years was 38.9% for the low-risk group, 30.7% for the intermediate low-risk, 64.9% in the intermediate high-risk and 63.2% in the high-risk group. On multivariable analysis, the defined thresholds of risk for SMR severity remained independently associated with all-cause mortality (adjusted hazard ratio: 1.164; 95% confidence interval [CI]: 1.020 to 1.327; P = 0.024). The unifying concept showed similar discriminative power (C-statistic 0.588; 95% CI: 0.540 to 0.635) to the American (C-statistic 0.588; 95% CI: 0.541 to 0.635; P for comparison = 1) and European guidelines (C-statistic 0.563; 95% CI: 0.515 to 0.610; P for comparison = 0.458), but it was able to increase the net reclassification index (0.143 [P < .001] and 0.026 [P = .025], respectively). Conclusions In this cohort of patients with SMR and LVEF <50%, the proposed unifying concept based on combined assessment of the EROA, the RegVol, and the RegFrac proved to be associated with an increased risk of all-cause mortality and could improve risk prediction of current guidelines. Abstract Figure.

Vena contracta area size predicts effectiveness of interventional edge-to-edge repair in tricuspid valve regurgitation

Abstract Funding Acknowledgements Type of funding sources: None. Background Percutaneous tricuspid valve edge-to-edge repair (pTVR) is a promising interventional technique for patients with tricuspid regurgitation (TR), but guidance regarding patient selection and echocardiographic screening is lacking. The aim of this study was to identify echocardiographic measurements which may predict pTVR success. Methods Before and after pTVR, echocardiographic data, including 3D full-volume datasets, were obtained and quantified. Right ventricular assessments included ejection fraction (RVEF3D) and diastolic (RVVd3D) and systolic (RVVs3D) volumes. Also evaluated were: right atrial (RA) volume, effective regurgitant orifice area by PISA method (EROAPISA), vena contracta area (VCA3D) by multiplanar reconstruction from a 3D colour Doppler loop (Figure 1a), maximal diastolic tricuspid annulus area from a 3D zoom image (Figure 1b), and tricuspid tenting area. TR severity was graded according to EROAPISA and VCA3D as grade 1+ to 5+. Results Patients (n= 44, age 72 ± 9 years, 20 male) with at least moderate to severe TR undergoing pTVR were consecutively included. The patients were divided into groups according to their post-pTVR TR grade. Group 1 had TR grade ≤2+, and group 2 had TR grade ≥3+.Echocardiographic parameters before pTVR for both groups are presented in Table 1. As expected, patients with TVR ≥3+ after pTVR had significantly worse pre-intervention echocardiographic measurements of TR severity, valve dimensions, and chamber volumes. ROC curves for the prediction of TR ≤2+ (mild to moderate) after pTVR (defined as VCA3D <0.75 cm² and EROAPISA <0.4 cm²) were drawn for different echocardiographic features (Figure 2). VCA3D by 3D colour Doppler yielded the highest area under the ROC curve followed by TV anatomy measurements (Annulus area3D, Tenting area) and right atrial volume. Conclusion A thorough evaluation of TR and valve dimensions by 3D echocardiography, particulary the evaluation of VCA3D by 3D colour Doppler, aids in the prediction of the probability of pTVR success. Abstract Figure.

Functional DSCT assessment of tricuspid regurgitation: AROA reproducibility and comparison with 3D TEE

Abstract Funding Acknowledgements Type of funding sources: None. onbehalf Minneapolis Heart Institute Foundation Background Tricuspid regurgitation (TR) assessment by echocardiography is often challenging. Functional dual-source CT (DSCT) with third-generation scanners allows accurate evaluation of leaflet anatomy and mobility. Purpose Investigate the reproducibility of tricuspid anatomical regurgitant orifice area (AROA) by DSCT, and its correlation with TR quantification by 3D TEE. Methods We evaluated patients with symptomatic TR referred for transcatheter tricuspid repair. DSCT (SOMATOM Force [Siemens, Erlangen, Germany]) and 3D TEE was performed on the same day as part of our institutional registry. DSCT scans were retrospective and ECG-gated, with a contrast protocol to enhance the right heart. The reproducibility of tricuspid AROA was assessed in 20 patients. The tricuspid AROA was compared with the TR severity (5-grade classification) and the 3D VCA by TEE (Panel 1). Results We included 60 patients (Table). The AROA had excellent intra and interobserver reliability (ICC 0.99 [0.97, 0.99] and 0.99 [0.96, 0.99]). We found a stepwise increase in tricuspid AROA from moderate to torrential TR (Panel 2A). Of 60 patients, 3D VCA was feasible in 39; in those, we found an excellent linear correlation of AROA and 3D VCA (Panel 2B). Conclusions Tricuspid AROA by DSCT was reproducible, showed a stepwise increase from moderate to massive TR and correlated with 3D VCA by TEE. Baseline Patient Characteristics All (n = 60) Age, years 82 ± 7 BSA, m2 1.8 ± 0.2 NYHA III-IV, n(%) 42 (70) Atrial Fibrilation 55 (91) Hypertension 44 (73) Pulmonary Hypertension 34 (56) Chronic Kidney Disease 25 (44) Coronary Artery Disease 17 (28) Chronic Lung Disease 14 (23) Permanent Pacemaker 13 (21) Diabetes Mellitus 10 (17) Mitral Valve Repair (MitraClip) 9 (15) Mitral Valve Replacement 7 (12) Mitral Valve Repair 3 (5) Aortic Valve Replacement 5 (8) Values are mean ± SD and n (%). BSA = body surface area. Abstract Figure. Panels

Adapting the concepts of proportionate and disproportionate functional mitral regurgitation to clinical practice

Abstract Funding Acknowledgements Type of funding sources: None. Background Despite its theoretical appeal, the concept of Proportionate and Disproportionate FMR has been limited by the lack of a simple way to assess it and by the paucity of data showing its prognostic superiority over currently established ways of grading FMR. Objectives This study sought to evaluate the prognostic value of a new and individualized method of assessing Functional Mitral Regurgitation (FMR) Proportionality. Methods Patients with at least mild FMR and reduced left ventricular ejection fraction (< 50%) under optimal guideline-directed medical therapy were retrospectively identified at a single-center. To determine FMR proportionality status, we used a novel approach where two simple equations establish an individual cut-off of regurgitant volume/effective regurgitant orifice area, categorizing the study population into non-severe, proportionate and disproportionate FMR (Figure 1). The primary endpoint was all-cause mortality. Results A total of 572 patients (median age 70 years; 76% male) were included. Median LVEF was 35% (IQR 28-40) and LVEDV was 169 ml (IQR 132-215). Disproportionate FMR was present in 109 patients (19%) with a median EROA of 26 mm2 (IQR 22-31) and a median RegVol of 40 ml (IQR 34-48), proportionate FMR in 148 patients (26%) with a median EROA of 16mm2 (IQR 12-21) and a median RegVol of 26 ml (IQR 19-32). During a median follow-up of 3.8 years (interquartile range: 1.8 to 6.2 years) there were 254 deaths (44%). The unadjusted mortality incidence per 100 persons-year rose as the degree of FMR disproportionality worsened. On multivariable analysis, disproportionate FMR remained independently associated with all-cause mortality (adjusted hazard ratio: 1.785; 95% confidence interval [CI]: 1.249 to 2.550; P = 0.001). The FMR proportionality concept showed greater discriminative power (C-statistic 0.639; 95% CI: 0.597 to 0.680) than the American (C-statistic 0.588; 95% CI: 0.550 to 0.626; P for comparison = .001) and European guidelines (C-statistic 0.563; 95% CI: 0.534 to 0.591; P for comparison < .001). It was also able to increase the net reclassification index (0.167 [P < 0.001] and 0.084 [P = 0.001], respectively). Conclusions A new, simplified and individualized method of assessing FMR Proportionality showed that disproportionate FMR is independently associated with all-cause mortality. This approach seems to outperform the risk stratification of current guidelines. Abstract Figure 1

Association of Effective Regurgitation Orifice Area to Left Ventricular End-Diastolic Volume Ratio With Transcatheter Mitral Valve Repair Outcomes

Transcatheter mitral valve repair (TMVr) plus maximally tolerated guideline-directed medical therapy (GDMT) reduced heart failure (HF) hospitalizations (HFHs) and all-cause mortality (ACM) in symptomatic patients with HF and secondary mitral regurgitation (SMR) compared with GDMT alone in the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (COAPT) trial but not in a similar trial, Multicenter Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation (MITRA-FR), possibly because the degree of SMR relative to the left ventricular end-diastolic volume index (LVEDVi) was substantially lower. To explore contributions of the degree of SMR using the effective regurgitation orifice area (EROA), regurgitant volume (RV), and LVEDVi to the benefit of TMVr in the COAPT trial. This post hoc secondary analysis of the COAPT randomized clinical trial performed December 27, 2012, to June 23, 2017, evaluated a subgroup of COAPT patients (group 1) with characteristics consistent with patients enrolled in MITRA-FR (n = 56) (HF with grade 3+ to 4+ SMR, left ventricular ejection fraction of 20%-50%, and New York Heart Association function class II-IV) compared with remaining (group 2) COAPT patients (n = 492) using the end point of ACM or HFH at 24 months, components of the primary end point, and quality of life (QOL) (per the Kansas City Cardiomyopathy Questionnaire overall summary score) and 6-minute walk distance (6MWD). The same end points were evaluated in 6 subgroups of COAPT by combinations of EROA and LVEDVi and of RV relative to LVEDVi. Interventions were TMVr plus GDMT vs GDMT alone. A total of 548 participants (mean [SD] age, 71.9 [11.2] years; 351 [64%] male) were included. In group 1, no significant difference was found in the composite rate of ACM or HFH between TMVr plus GDMT vs GDMT alone at 24 months (27.8% vs 33.1%, P = .83) compared with a significant difference at 24 months (31.5% vs 50.2%, P < .001) in group 2. However, patients randomized to receive TMVr vs those treated with GDMT alone had significantly greater improvement in QOL at 12 months (mean [SD] Kansas City Cardiomyopathy Questionnaire summary scores: group 1: 18.36 [5.38] vs 0.43 [4.00] points; P = .01; group 2: 16.54 [1.57] vs 5.78 [1.82] points; P < .001). Group 1 TMVr-randomized patients vs those treated with GDMT alone also had significantly greater improvement in 6MWD at 12 months (mean [SD] paired improvement: 39.0 [28.6] vs -48.0 [18.6] m; P = .02). Group 2 TMVr-randomized patients vs those treated with GDMT alone tended to have greater improvement in 6MWD at 12 months, but the difference did not reach statistical significance (mean [SD] paired improvement: 35.0 [7.7] vs 16.0 [9.1] m; P = .11). A small subgroup of COAPT-resembling patients enrolled in MITRA-FR did not achieve improvement in ACM or HFH at 24 months but had a significant benefit on patient-centered outcomes (eg, QOL and 6MWD). Further subgroup analyses with 24-month follow-up suggest that the benefit of TMVr is not fully supported by the proportionate-disproportionate hypothesis. ClinicalTrials.gov Identifier: NCT01626079.

Echocardiographic predictors of exercise induced pulmonary hypertension in patients with asymptomatic moderate to severe mitral regurgitation and preserved left ventricular ejection fraction.

The significant role of mitral regurgitation (MR) in development of pulmonary hypertension (PH) has been proved in previous studies. Experts suggest systolic pulmonary arterial pressure (SPAP) ⩾60 mmHg during exercise as a significant threshold of negative prognostic value in patients with MR. The aim of this study was to evaluate the changes of SPAP and to ascertain the determinants of exercise induced pulmonary hypertension (EIPH) in patients with asymptomatic primary MR. We performed a prospective study that included 50 patients with asymptomatic primary moderate to severe MR with preserved left ventricular ejection fraction (LV EF ⩾60%) at rest. They were divided into two groups according to the presence (PH group; n = 13) or absence (non-PH group; n = 37) of EIPH. Rest and stress (bicycle ergometry) echocardiography and speckle-tracking offline analysis were performed. An increment of SPAP from rest to peak stress was higher in PH group (p < 0.001). Multivariate regression analysis showed that MR effective regurgitation orifice area (EROA; p = 0.008) and regurgitant volume (RVol; p = 0.006) contributed significantly to SPAP at rest. Higher increment of MR EROA during stress and worse parameters of LV diastolic function at rest (E, A, E/e') correlated significantly with higher SPAP during peak stress and they had a major role in predicting EIPH according to univariate logistic regression analysis. In ROC analysis SPAP >33.1 mmHg at rest could predict EIPH with 84.6% sensitivity and 87.1% specificity (95%CI 0.849-1.000; p < 0.001). Parameters of MR severity (EROA and RVol) were significant determinants of SPAP at rest, while the increment of MR EROA during stress and parameters of resting LV diastolic function were the best predictors of significant EIPH.

Cardiac remodelling in secondary tricuspid regurgitation: Should we look beyond the tricuspid annulus diameter?

A better understanding of the mechanism of tricuspid regurgitation severity would help to improve the management of this disease. We sought to characterize the determinants of isolated secondary tricuspid regurgitation severity in patients with preserved left ventricular ejection fraction. This was a prospective observational multicentre study. Patients with severe tricuspid regurgitation were asked to participate in a registry that required a control echocardiogram after optimization of medical treatment and a follow-up. Patients had to have at least mild secondary tricuspid regurgitation when clinically stable, and were classified according to five grades of tricuspid regurgitation severity, based on effective regurgitant orifice area. One hundred patients with tricuspid regurgitation (12 mild, 31 moderate, 18 severe, 17 massive and 22 torrential) were enrolled. Right atrial indexed volume and tethering area were statistically associated with the degree of tricuspid regurgitation (P<0.001 and P=0.005, respectively). When the tricuspid annular diameter was≥50mm, the probability of having severe tricuspid regurgitation or a higher grade was>70%. For an increase of 10mL/m2 in right atrial volume, the effective regurgitant orifice area increased by 4.2mm2, and for an increase of 0.1cm2 in the tethering area, the effective regurgitant orifice area increased by 2.35mm2. The degree of right ventricular dilation and changes in tricuspid morphology were significantly related to tricuspid regurgitation severity class (P<0.001). No significant difference in right ventricular function variables was observed between the tricuspid regurgitation classes. For tricuspid regurgitation to be severe or torrential, both right atrial dilatation and leaflet tethering are needed. Interestingly, right cavities dilated progressively with tricuspid regurgitation severity, without joint degradation of right ventricular systolic function variables.

An orifice shape-based reduced order model of patient-specific mitral valve regurgitation

Mitral valve regurgitation (MR) is one of the most prevalent valvular heart diseases. Its quantitative assessment is challenging but crucial for treatment decisions. Using computational fluid dynamics (CFD), we developed a reduced order model (ROM) describing the relationship between MR flow rates, transvalvular pressure differences, and the size and shape of the regurgitant valve orifice. Due to its low computational cost, this ROM could easily be implemented into clinical workflows to support the assessment of MR. We reconstructed mitral valves of 43 patients from 3D transesophageal echocardiographic images and estimated the 3D anatomic regurgitant orifice areas using a shrink-wrap algorithm. The orifice shapes were quantified with three dimensionless shape parameters. Steady-state CFD simulations in the reconstructed mitral valves were performed to analyse the relationship between the regurgitant orifice geometry and the regurgitant hemodynamics. Based on the results, three ROMs with increasing complexity were defined, all of which revealed very good agreement with CFD results with a mean bias below 3% for the MR flow rate. Classifying orifices into two shape groups and assigning group-specific flow coefficients in the ROM reduced the limit of agreement predicting regurgitant volumes from 9.0 ml to 5.7 ml at a mean regurgitant volume of 57 ml.

Reproducibility of transthoracic echo-doppler parameters to assess mitral regurgitation severity. Insights from a French multicentric study

The dynamic nature of MR throughout systole and the complexity of MR mechanisms may cause uncertainty among TTE readers and lead to interobserver variability. To evaluate the interobserver agreement of parameters used in daily practice to quantify mitral regurgitation (MR) severity according to the experience of the physician. Complete MR evaluation of 25 consecutive patients were assessed by transthoracic echocardiography in 8 French tertiary public and private hospitals by 16 physicians (1 junior and 1 senior in each centre). In total, 400 analyses per parameter have been obtained. The overall interobserver agreement for effective regurgitant orifice area (EROA) and regurgitant volume (RV) was only moderate, lower in secondary MR. Interobserver agreement was better in the senior group than in the junior group regarding parameters used to quantify MR severity, i.e. EROA, respectively substantial (0.61, 95% CI: 0.45–0.75) and fair (0.33, 95% CI: 0.19–0.51) and RV with the PISA method, respectively moderate (0.50, 95% CI: 0.33–0.56) and fair (0.36, 95% CI: 0.36–0.43). Finally, using a multiparametric approach, the overall interobserver agreement for grading MR severity was fair (0.30), slightly better in the senior group than the junior group (respectively 0.31 vs. 0.28) with a substantial or almost perfect agreement more frequently observed in the senior group than in the junior group (respectively 52% vs. 36%). The use of quantitative parameters to assess MR severity was moderately reliable in daily practice, even in case of multiparametric approach. The experience of the physician and the mechanism of the MR impact interobserver agreement, paving the way for a better learning of this valvular disease and for the use of multimodality imaging in case of complex or secondary MR.

Comprehensive assessment of the aortic valve in critically ill patients for the non-cardiologist. Part II: Chronic aortic regurgitation of the native valve.

Inadequate diastolic closure of the aortic valve causes aortic regurgitation (AR). Diastolic regurgitation towards the left ventricle (LV) causes LV volume overload, resulting in eccentric LV remodelling. Transthoracic echocardiography (TTE) is the first line examination in the work-up of AR. TTE allows quantification of left ventricular end-diastolic diameter and volume and left ventricular ejection fraction, which are key elements in the clinical decision making regarding the timing of valve surgery. The qualitative echocardiographic features contributing to the AR severity grading are discussed: fluttering of the anterior mitral valve leaflet, density and shape of the continuous wave Doppler signal of the AR jet, colour flow imaging of the AR jet width, and holodiastolic flow reversal in the descending thoracic aorta and abdominal aorta. Volumetric assessment of the AR is performed by measuring the velocity time integral of the left ventricular outflow tract (LVOT) and transmitral valve (MV) plane, and diameters of LVOT and MV. We explain how the regurgitant fraction and effective regurgitant orifice area (EROA) can be calculated. Alternatively, the proximal isovelocity surface area can be used to determine the EROA. We overview the utility of pressure half time and vena contracta width to assess AR severity. Further, we discuss the role of transoesophageal echocardiography, echocardiography speckle tracking strain imaging, cardiac magnetic resonance imaging and computed tomography of the thoracic aorta in the work-up of AR. Finally, we overview the criteria for valve surgery in AR.

Prognostic validation of partition values for quantitative parameters to grade functional tricuspid regurgitation severity by conventional echocardiography.

Quantitative echocardiography parameters are seldom used to grade tricuspid regurgitation (TR) severity due to relative paucity of validation studies and lack of prognostic data. To assess the relationship between TR severity and the composite endpoint of death and hospitalization for congestive heart failure (CHF); and to identify the threshold values of vena contracta width (VCavg), effective regurgitant orifice area (EROA), regurgitant volume (RegVol), and regurgitant fraction (RegFr) to define low, intermediate, and high-risk TR based on patients' outcome data. A cohort of 296 patients with at least mild TR underwent 2D, 3D, and Doppler echocardiography. We built statistical models (adjusted for age, NYHA class, left ventricular ejection fraction, and pulmonary artery systolic pressure) for VCavg, EROA, RegVol, and RegFr to study their relationships with the hazard of outcome. The tertiles of the derived hazard values defined the threshold values of the quantitative parameters for TR severity grading. During 47-month follow-up, 32 deaths and 72 CHF occurred. Event-free rate was 14%, 48%, and 93% in patients with severe, moderate, and mild TR, respectively. Severe TR was graded as VCavg > 6 mm, EROA > 0.30 cm2, RegVol > 30 mL, and RegF > 45%. This outcome study demonstrates the prognostic value of quantitative parameters of TR severity and provides prognostically meaningful threshold values to grade TR severity in low, intermediate, and high risk.

Abstract 14534: In vitro Assessment of Transvalvular Peak Velocity Measurement for Various Orifice Shapes: Comparison Between 4D Flow MRI vs. Doppler Echocardiography

Introduction: 4D flow MRI can assess transvalvular velocity, but validation against continuous wave (CW) Doppler echo is limited in high-velocity regurgitation and stenosis situations. We sought to compare 4D flow MRI and echo peak velocity using a pulsatile echo-MRI flow phantom. Materials and Methods: An MRI-compatible flow phantom with restrictive orifice situated was driven by a left ventricular assist device at 50 bpm (figure 1A). Three orifice shapes were tested: circular, elliptical and 3D-printed patient-specific mitral regurgitant orifice model of prolapse with areas of 0.5, 0.41 and 0.35 cm 2 , respectively. CW Doppler was acquired with peak velocity extracted from the profile. Retrospectively-gated 4D flow MRI was performed (spatial resolution = 2 mm isotropic, temporal resolution = 36 ms, encoding velocity = 400 cm/s). Maximal velocity magnitude was extracted volumetrically (figure 1B). An echo-mimicking profile was also obtained with a “virtual” ultrasound beam in the 4D flow data to simulate CW Doppler (figure 1C). Bland-Altman analysis was used to assess the agreement of temporal peak velocities. Results: 4D flow MRI demonstrated a centrally directed jet for the circular and elliptical orifices and an oblique jet for the prolapse orifice (figure 1B). Peak velocities were in excellent agreement between 4D flow MRI vs. echo for the circular (peak: 5.13 vs. 5.08 m/s, bias = 0.06 ± 0.66 m/s, figure 1D) and the elliptical orifice (peak: 4.95 vs. 4.79 m/s, bias = 0.07 ± 0.87 m/s, figure 1E). The prolapse orifice velocity was underestimated somewhat by MRI by ~10% (peak: 4.41 vs. 4.90 m/s, bias=0.26±1.18, figure 1F). Conclusion: 4D flow MRI can quantify high velocities like echo for simple geometries while underestimating for more complex geometry, likely due to partial volume effects. Further investigation is warranted to systematically investigate the effects of 4D flow MRI spatial and temporal resolution as well as the jet angle on velocity quantification accuracy.

Surgical repair for canine tricuspid valve dysplasia: Technique and case report

Tricuspid valve dysplasia (TVD) is a congenital malformation of the right atrioventricular valve characterized by restricted leaflet motion, annular dilation, and tricuspid regurgitation (TR). Severe cases typically exhibit progressive right-sided congestive heart failure, affecting the quality of life and survival. This article describes a technique for surgical repair of TVD and a case report with long-term follow-up. A 1.5-year-old intact male Labrador retriever with severe TR underwent surgical repair for TVD. Valve repair was performed under cardiopulmonary bypass and consisted of neochord mobilization of the valve leaflets and partial band annuloplasty. Transthoracic echocardiogram performed 5 days after surgery showed mild TR, a 93% decrease in anatomic regurgitant orifice area, and decreased right chamber dimensions. Forty-eight months after repair, the patient was free of clinical signs, did not have a heart murmur, and was receiving no cardiac medications. Based on this case, surgical repair of TVD is feasible with long-term durability, and the outcome suggests that the described technique may be a viable treatment option for patients with severe TVD.

Impact of transcatheter aortic valve implantation on coexistent mitral regurgitation parameters.

Data on the impact of transcatheter aortic valve implantation (TAVI) on coexisting mitral regurgitation (MR) are still inconsistent. The study aimed to evaluate the impact of TAVI on coexistent MR depending on its etiology. Out of 311 patients treated with TAVI, we selected 48 with coexistent MR: functional (FMR; n = 26) or nonfunctional (nFMR; n = 22). The impact of the procedure on MR was quantitatively assessed during a 1‑year follow‑up using MR effective regurgitant orifice area (MR‑EROA) and volume (MRV). Compared with baseline, no change of MR‑EROA was observed at 1‑year follow‑up in all patients with MR (median [interquartile range (IQR)], 0.2 [0.17-0.23]cm2 vs 0.17 [0.14-0.2]cm2 ; P = 0.054). No change in MR‑EROA was also noted either in FMR (median [IQR], 0.21 [0.17-0.27]cm2 vs 0.19 [0.14-0.25]cm2 ; P = 0.142) or nFMR (median [IQR], 0.17 [0.12-0.23] cm2 vs 0.17 [0.1-0.2] cm2 ; P = 0.238) cohorts. Decreased MRV was seen in theoverall MR population after TAVI (median [IQR], 32 [28-36]ml/beat vs 26 [22-28]ml/beat; P = 0.002). Similarly, decreased MRV was noted in both FMR (median [IQR], 33 [26-42] ml/beat vs 26 [20-40] ml/beat; P = 0.042) and nFMR (median [IQR], 30 [20-46] ml/beat vs 24 [15-33] ml/beat; P = 0.015) cohorts. Transcatheter aortic valve implantation had no impact on MR‑EROA regardless of the etiology of regurgitation. However, the procedure reduced MRV in both FMR and nFMR.

Beyond effective regurgitant orifice in quantitative assessment of tricuspid regurgitation: impact on clinical outcomes

Abstract Background Quantification in tricuspid regurgitation has been poorly investigated. Recommended methods and thresholds are directly translated from mitral regurgitation; however, the anatomy, hemodynamics, and regurgitant orifice geometry are different in TR. Effective regurgitant orifice (ERO) calculation may be incorrect in very severe TR when right atrial and ventricular pressures could get equalized resulting in typically very low TR velocities. Purpose Our aim was to compare the prognostic value of different parameters for the evaluation of the tricuspid regurgitation (TR). Methods Consecutive patients with significant TR (≥ moderate echocardiographic grade) evaluated in the Heart Valve Clinic were included. TR severity was evaluated by TR radius, TR flow rate, ERO and TR regurgitant volume by PISA method and biplane vena contracta (VC) width using EPIQ system. End-point included cardiovascular mortality, tricuspid valve surgery or heart failure. Results A total of 100 patients were included (mean age: 76±10 years, 65% females, 86% functional TR, 84% in NYHA I/II). During a mean follow up of 24±10 months 36% of the patients reached the combined end-point. Patients with events showed more severe TR independently of the parameter applied (table). In univariate analysis, TR radius, TR flow rate, ERO and TR regurgitant volume were predictors of the combined endpoint (p&amp;lt;0.05 for all). Among all parameters, TR flow rate was the strongest and independent predictor of outcomes in multivariate and ROC analysis (HR per 1 ml/seg 1.02 [1.003–1.026], p=0.01). A value of TR flow rate of 109 ml/sec reached the best accuracy to predicted poor outcomes (p&amp;lt;0.01). Conclusion Among different parameters to graduate TR severity, TR flow rate was the strongest predictor of outcomes. Since it does not include the TR velocity in the calculation, its incremental benefit may be related to very severe cases of TR. In this scenario, right atrial and ventricular pressures are equalized and TR velocity calculation is not longer possible. New grading schemes for TR may include this parameter in the classification. Funding Acknowledgement Type of funding source: None

Prognostic differences between atrial functional mitral regurgitation and ventricular functional mitral regurgitation

Abstract Introduction Atrial functional mitral regurgitation (A-FMR) has been under-recognized until recently as a cause of FMR, and the prognostic difference between A-FMR and ventricular FMR (V-FMR) has not been fully elucidated. As there has been different mechanisms of FMR suggested in A-FMR and V-FMR, we hypothesized that prognosis and prognostic predictors of A-FMR may differ from those of V-FMR. Purpose To investigate the prognosis and prognostic predictors of A-FMR in comparison with V-FMR. Methods Among 1312 consecutive patients with grade 3+ (moderate to severe) or 4+ (severe) MR, 378 consecutive FMR patients were identified by excluding patients with degenerative MR, previous cardiac surgery, or concomitant aortic valve disease and/or mitral stenosis. FMR with ejection fraction (EF) &amp;lt;40% or FMR due to regional wall motion abnormalities with leaflet tethering were classified as V-FMR (N=288), and FMR due to left atrial (LA) and/or annular dilatation with preserved or mid-range EF (≥40%) were classified as A-FMR (N=90). All-cause death and heart failure hospitalization were analyzed as cardiovascular (CV) events in this study. Surgical or percutaneous mitral valve intervention without CV events was handled as not reaching an endpoint and these cases were censored. Results A-FMR were significantly older (76 [69–82] vs. 70 [58–77] years), higher rates of female (64 vs. 35%) and atrial fibrillation (88 vs. 42%), and lower B-type natriuretic peptide (BNP) values (169 [101–318] vs. 447 [213–952] pg/ml) compared to V-FMR (all P&amp;lt;0.05). On echocardiography, LV end-diastolic and end-systolic dimensions (52 [48–57] vs. 64 [58–72] mm, 34 [31–37] vs. 55 [48–64] mm), respectively) were smaller, and EF (55 [50–60] vs. 28 [19–35] %) and LA volume (99 [73–137] vs. 73 [57–91] ml/m2) were larger in A-FMR (all P&amp;lt;0.05). Effective regurgitant orifice area (32 [26–40] vs. 31 [24–45] mm2) and regurgitant volume (50±15 vs. 52±16 ml) were similar (both n.s.). During a median follow up of 1407 days, 206 (54%) patients developed CV events. Kaplan-Meier analysis revealed that V-FMR had a significantly higher rates of CV events compared to A-FMR (Figure) with adjusted hazard ratio (HR) of 1.762 [1.168–2.660], P=0.007 after adjusted for variables including age, sex, New York Heart Association functional class, previous heart failure hospitalization, estimated glomerular filtration rate (eGFR) and BNP. Further, stepwise multivariate analysis showed that independent prognostic predictors of A-FMR were LA volume and eGFR, while those for V-FMR were LA volume, age, and LV end-systolic dimension. Conclusions A-FMR had relatively better prognosis compared to V-FMR, and there were different prognostic predictors between A-FMR and V-FMR. Our results suggest that different treatment strategies need to be considered between A-FMR and V-FMR. The Kaplan-Meier life table Funding Acknowledgement Type of funding source: None

Risk stratification on echocardiography and outcome in ischaemic mitral regurgitation

Abstract Background Ischaemic mitral regurgitation (IMR) confers a poor prognosis. Transcatheter intervention may improve survival but benefit is likely to depend on severity of IMR relative to LV remodelling following myocardial infarction (MI). In theory, those with “discordant” IMR (significant regurgitant volume without severe LV dilatation or impairment), are expected to benefit most from mitral intervention. While subcategorization may help to inform treatment, there are no data on post-MI patients in this respect. Purpose To determine the incidence of discordant &amp; concordant IMR categorised on echocardiography post-MI and impact on outcomes. Methods 1000 consecutive patients admitted to our hospital with myocardial infarction who underwent coronary angioplasty were included. Early inpatient TTE was performed by accredited echocardiographers using standard multiparametric quantification. Using TTE parameters, 4 subgroups were identified (figure) according to the degree of MR relative to LV remodelling. Thresholds were based on European guidelines (± 2SD from normal) and median value among survivors for vena contracta (VC): – LVEF: 52% (♂), 54% (♀) – Indexed LV end diastolic volume (LVEDVi): 74ml/m2 (♂), 61ml/m2 (♀) – Effective regurgitant orifice area (EROA) ≥0.2cm2 – Regurgitant volume (RVol) ≥30ml – VC ≥0.5cm Results MR was seen in 294/1000 patients (29.4%) with a severity of mild (76%), moderate (21%) and severe (3%). Concordant and discordant IMR were each seen in 16/294 (5%) of IMR patients post-MI. After a mean follow up of 3.2 years, IMR patients had a 3% rate of heart failure (HF) within 1 year and 19% mortality. Non-survivors had significantly worse IMR (PISA 0.65±0.25cm vs 0.54±0.19cm; p=0.033; VC 0.63±0.25cm vs 0.49±0.18cm; p=0.014), worse LV function (LVEF 44±17% vs 51±13%; p&amp;lt;0.001), larger LV (LVEDVi 67±23ml/m2 vs 60±22ml/m2; p=0.032) and larger indexed LA volume (LAVi) (44±22ml vs 35±15ml; p&amp;lt;0.001). Those with concordant IMR had the worst survival (50%) although almost 1 in 5 of those with discordant MR died within the follow up period (19%). Using multivariable Cox regression, significant predictors of mortality included LVEF (p&amp;lt;0.001; HR 0.96, 0.94–0.98) and LAVi (p&amp;lt;0.001; HR 1.02, 1.01–1.03) but not LVEDVi. Conclusion 1) Significant predictors of mortality in IMR include LA dilatation and decline in LVEF, but not LV dilatation. 2) Although discordant severe IMR is uncommon following MI, mortality if left untreated remains high. Attention should be paid to early selection of this cohort for intervention. Funding Acknowledgement Type of funding source: None

Disproportionate functional mitral regurgitation: clinical validation of a new conceptual framework

Abstract Background Disproportionate functional mitral regurgitation (FMR) is a novel concept that tries to identify hemodynamically significant FMR by readjusting the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) cut-offs according to left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF). However, this theoretical concept lacks clinical validation. The aim of this study was to assess the clinical significance of disproportionate FMR. Methods Patients with at least mild FMR and reduced LVEF (&amp;lt;50%) who underwent transthoracic echocardiography between 2010 and 2014 were retrospectively identified in our laboratory database. Optimal medical therapy (including cardiac resynchronization when indicated) for ≥3 months was a prerequisite for inclusion. Hemodynamically significant FMR was defined as regurgitant fraction &amp;gt;50% and the patient-specific theoretical RegVol cut-off was calculated according to the formula presented in Fig. 1a. The difference between the estimated RegVol by the PISA method and the theoretical RegVol cut-off was considered to represent the haemodynamic burden of MR. The primary endpoint was all-cause death. Patients were censured if mitral intervention or heart transplant was undertaken. Survival analysis was used to assess the effect of disproportionate FMR on mortality in 2 subgroups (LVEF &amp;lt;30% and 30–49%). Results A total of 289 patients (median age 69 years [IQR 60–77], 75% male, 53% of ischemic aetiology) were included. More than 90% were on beta-blockers and renin-angiotensin inhibitors, 44% on aldosterone receptor antagonists, and 73% had implanted devices. The median LVEF and LVEDV were 34% (IQR 27–41) and 170mL (IQR 128–220), respectively. Median EROA was 10mm2 (IQR 3–21) and RegVol was 15 mL (IQR 4–30). RegVol distribution across the cohort was: &amp;lt;10mL: 41%; 10–20mL: 18%; 20–30mL: 15% and &amp;gt;30mL: 26%. Disproportionate FMR was present in 83 patients (29%). These patients had significantly higher SPAP values (41mmHg [IQR 33–50] vs. 33mmHg [IQR 29–40]; p&amp;lt;0.001). During a median follow-up of 44 months (IQR 19–73), 106 patients died. In the LVEF &amp;lt;30% subgroup, age (HR 1.05 per year [1.02–1.08]; p&amp;lt;0.001), LVEF (HR 0.94 per 1% [0.89–0.99]; p=0.042) and TAPSE (HR 0.92 per mm [0.86–0.99]; p=0.030) were independent predictors of mortality. In the LVEF 30–49% subgroup, age (HR 1.05 per year [1.02–1.08]; p=0.003), LVEF (HR 0.94 per 1% [0.89–0.99]; p=0.020) and disproportionate FMR (HR 1.02 per mL [1.01–1.03]; p=0.01) were independently associated with increased mortality. Conclusions Disproportionate FMR proved to be an important independent predictor of mortality in patients with LVEF between 30–49%. These findings were not replicated in those with LVEF&amp;lt;30%, where the degree of biventricular dysfunction seems to outweigh all other echocardiographic parameters, leaving FMR as a bystander. Figure 1 Funding Acknowledgement Type of funding source: None

Outcomes in severe tricuspid regurgitation by CMR: when severe is too severe

Abstract Introduction Tricuspid regurgitation (TR) is related to poor prognosis independently of the etiology. Recently a new scale classification has been proposed to better characterize the grading of more than severe TR. Massive and torrential TR seem to have worse prognosis based on recent echocardiographic studies. There is no information on how that classification would apply when TR is quantified by cardiac magnetic resonance (CMR). Purpose To define the cut-off value of massive and torrential TR by CMR and to investigate its potential prognostic implications. Methods Consecutive patients in stable clinical status with significant TR evaluated in the Heart Valve Clinic with a contemporaneous echo and CMR were included. TR severity was evaluated by biplane vena contracta and effective regurgitant orifice method, using EPIQ system and by TR regurgitant fraction using a 1.5 Tesla CMR Philips scanner. End-point included cardiovascular mortality, tricuspid valve surgery or heart failure. Results A total of 56 patients were included (mean age was 72±9 years, 74% females). According to echocardiography n=43 (76%) were severe TR, n=8 (14%) were massive IT and n=5 (9%) were torrential TR. Patients with massive and torrential TR showed higher RV end-diastolic volume and lower RVEF. A TR regurgitant fraction (TRF) &amp;gt;50% held the best accuracy to define massive / torrential TR. During a median follow up of 2.4 years (IQR: 1.1–3.3 years) 31% of the patients reached the combined endpoint. TR regugitant fraction was predictive of worse prognosis (hazard ratio per 1%TRF=1.085 [1.024–1.150] p=0.003). Patients with a massive and torrential TR showed a significantly higher rate of events (figure). Figure shows on the left (A) spline curves displaying survival free of events for each value of TR regurgitant fraction. y-axis represents the hazard ratio regurgitation fraction (green line) and 95% confidence interval (shadow). On the right (B) Kaplan Meier curves show a significantly higher rate of events in patients with RF&amp;gt;50%. Conclusions Our results confirm that patients with massive/torrential TR are populations at higher risk of cardiovascular events. New classification scheme may be included in CMR grading scales. Further research will establish who may benefit the most of intensive therapeutic treatments and intervention on the tricuspid valve. Funding Acknowledgement Type of funding source: None