Valve Orifice Area Research Articles

Insights from the assessment of anatomic valve orifice area after transcatheter aortic valve implantation using transesophageal echocardiography

Abstract Background Although transthoracic echocardiography (TTE) is the gold standard for evaluating effective valve orifice area (EOA) after transcatheter aortic valve implantation (TAVI), the continuous formula is inherently different from anatomic valve orifice area because it implies a minimum jet width through the aortic valve. It has also been reported that the doppler method with TTE overestimates the mean gradient due to pressure recovery and is even less accurate after TAVI. On the other hand, recent technological developments have improved image resolution, making valve morphology possible using transesophageal echocardiography (TEE). Purpose The purpose of this study was to compare transcatheter aortic valve (TAV) area using TEE and TTE to evaluate whether there is a significant difference in each area and to explore factors that influence the difference in area. Methods Patients who underwent TEE-guided TAVI and SAPIEN3 implantation between February 2019 and March 2023 and had aortic valve evaluation with TTE before discharge were included. We retrospectively evaluated the TAV after TAVI using TTE and TEE. Aortic valve orifice area was calculated by two methods: EOA index (doppler-area: DA) calculated by the continuous doppler formula using TTE and t-AVA index (trace-area: TA) derived by the trace method using TEE. TAV tracing was performed in early systole on the short-axis image of the aortic valve. The TAV tracing was performed by physicians specializing in echocardiography, and multiple physicians were blinded to the same case to eliminate inter-rater error. The percentage change between the two groups was calculated from the difference in area by TTE and TEE, and the 75th percentile of the percentage change was defined as the cutoff value for the group with the large difference in TAV area. Results Patients whose TAV was difficult to observe by TEE were excluded, and 464 patients were finally analyzed. TA was significantly larger than DA (1.56±0.28 cm2/m2 vs 1.18±0.26 cm2, p<0.001) and similar for all TAV sizes. However, even though TA expanded as valve size increased, the largest area of DA was observed in the 26mm TAV, and the 29mm TAV was comparable to the 26mm TAV. Only a weak correlation was shown between DA and TA (correlation coefficient: 0.356). There were 43 cases of moderate prosthetic valve-patient mismatch (PPM: EOA-i<0.85cm) in DA, but only 1 case in TA. In multivariate logistic regression analysis, women (OR 2.25, 95% CI 1.17-4.34, p < 0.015) and LV mass index (OR 1.01, 95% CI 1.00-1.02, p < 0.041) were independent factors for the large difference in TAV area. Conclusion After TAVI, the TAV area with TEE was larger than the EOA-i with TTE, and PPM was rarely seen. Depending on valve size, patient background, and cardiac morphology, there are cases of overestimation of postoperative AS in TTE, which may need to be carefully evaluated in women and patients with larger LV mass index.

Prevalence of amyloidosis among patients with mild to severe aortic stenosis. Validation of screening parameters

Abstract Background Cardiac amyloidosis (CA) is an increasingly recognized cause of human heart failure. Up to 16% of patients with severe aortic stenosis (AS) undergoing transcatheter valve replacement have been reported to suffer concomitant transthyretin CA (ATTR). Since the diagnosis of CA implies distinct therapies with prognostic relevance, early diagnosis of CA is crucial. Different parameters have been described to improve screening accuracy for detection of CA, but it is unknown whether these parameters are valid, and the prevalence of CA is stable throughout the spectrum of AS. Purpose To validate screening parameters for the detection of CA in mild, moderate and severe AS. Methods Patient 65 years and above undergoing echocardiography with mild to severe AS, defined as calculated valve orifice area <2 cm2 by velocity-time-integral, and an intraventricular septum thickness > 11mm, fulfilling at least one of two additional criteria (Sokolow-Lyon-Index to left ventricular mass index ratio < 1.5 or stroke volume index < 35 ml/m2) were prospectively included and screened for CA using bone scintigraphy and immunofixation in blood and urine. Results 57 patients were included and completed the diagnostic work-up. Mean age was 83 ± 0.7 years and 71% were male. Overall, 15 (26%) of patients were diagnosed with CA (12 with ATTR and 3 with light-chain CA, Figure1A). 17 patients had mild, 21 had moderate and 19 patients were diagnosed with severe AS. Among patients with mild AS 41% were diagnosed with CA, whereas only 24% of patients with moderate and 16% of patients with severe AS suffered CA (Figure 1B), these results did not show statistically significant differences (p= 0.2, by Chi-Square Quadrat test). Patients with CA were less likely to have NYHA classes I or II (20 vs. 57%, p= 0.03), had higher values of NT-proBNP (4572 [2323; 6044] vs. 817 [589; 2571], p< 0.001) and high-sensitive troponin (66 [47; 103.5] vs. 22.5 [17; 33.6], p< 0.001) and were more likely to have an atrioventricular block of any degree (60 vs. 26%, p=0.04). Conclusion Prevalence of CA among patients fulfilling the criteria of this screening algorithm seems to be high independent of AS severity. Clinicians should not only focus on patients with severe AS to detect CA early. Further research is needed to estimate the prevalence of CA among all patients with AS. Figure 1 A: Among patients with an age >65 years, IVS >11mm, AS and SLI/LVMMI >1.5 or SVI <35 ml/m2 26% (red area) of patients were diagnosed with CA (n= 57). B: In patients with mild AS 41% were diagnosed with CA, whereas in patients with moderate AS only 24% and in patients with severe AS 16% had CA. These differences did not show statistical significance (p= 0.2). IVS: intraventricular septum, AS: aortic stenosis, SLI: Skolow-Lyon-Index, LVMM= left ventricular myocardial mass index, SVI: stroke volume index, CA: cardiac-amyloidosis. (Statistics performed by chi-square test using GraphPad Prism 9.0).

A new wearable cardiac acoustic monitoring technology for the evaluation of subclinical leaflet thrombosis after transcatheter aortic valve replacement: a pilot study

Abstract Background Subclinical leaflet thrombosis characterized by hypoattenuated leaflet thickening (HALT) and reduced leaflet motion (RLM) is a common complication after transcatheter aortic valve replacement (TAVR), whether it affects hemodynamic change is still debated. Purpose We attempted to use a novel wearable heart acoustic monitoring device, and combined multi-dimensional computed tomography (MDCT) and echocardiography to diagnose SLT and analyze the changes of transvalvular hemodynamics after TAVR. Methods Patients with severe symptomatic aortic stenosis and underwent successful TAVR were consecutively enrolled. Clinical data, acoustic cardiographic parameters including the frequency, amplitude, and energy of heart sounds , and imaging results were collected and analyzed by Core laboratory at pre- and post TAVR, and follow-up at one month and six month. According to severity of SLT at one month follow-up, we divided the patients into three groups: Group1: no SLT, Group2: mild SLT, defined as existed HALT did not qualify for Group 3, and Group 3: moderate to severe SLT, defined as at least 1 leaflet with HALT of grade 3 or 4 or RLM of ≥50%, or 2 leaflets with HALT of grade 2 or RLM of ≥50%. A consistency analysis of SLT presence between MDCT findings and acoustic cardiographic variables was performed using Kappa statistics. Results The study included 116 TAVR patients. The prevalence of SLT as detected by MDCT at one-month follow-up was 25%, with moderate to severe SLT representing 11.2% of cases. A significant decrease in aortic valve orifice area (AVA) (-0.2±0.48cm2 vs. -0.1±0.33cm2, p=0.009) and an increase in mean gradient (MG) (3.5±5.85 mmHg vs. 0.1±11.34mmHg, p=0.028) were observed in moderate to severe SLT group at one-month follow-up versus post-TAVR via echocardiography. However, no significant differences were found in the mild SLT or no SLT group. Acoustic cardiographic characteristics exhibited a distinct pattern with early systolic, baseless, and high-energy murmurs in patients with moderate to severe SLT, but not in the mild SLT or no SLT group. The sensitivity, specificity, and Kappa values for acoustic cardiography in diagnosing moderate to severe SLT were 81.82%, 83.33%, and 0.41, respectively. At the 6-month follow-up, MDCT showed that 11 (85%) patients with moderate to severe SLT who received anticoagulant therapy reached complete dissolution of SLT. Conclusion Moderate to severe SLT presented notably transvalvular hemodynamic influences following TAVR. Acoustic cardiography demonstrated specific characteristics of moderate to severe SLT, providing a valuable tool for SLT diagnosis and evaluation in clinical follow-up.Figure 1.Baseline characteristicsFigure 2.SLT and acoustic cardiography

Establishment and validation of a prediction model for the outcome of rheumatic mitral valve repair surgery based on transthoracic echocardiography

Abstract Background The outcome of mitral valve repair over replacement in degenerative diseases has been recognized, but the patient selection of mitral valve repair in rheumatic diseases are still controversial. At present, there is a lack of comprehensive evaluation methods for rheumatic mitral valve disease, which cannot guide the selection of patients before surgery. Purpose The aim of this study was to establish a comprehensive evaluation method and innovative indicators for rheumatic mitral valve disease using transthoracic echocardiography, and to establish a model for predicting the outcome of rheumatic mitral valve repair. Methods This prospective, multicenter, observational cohort study included 167 patients who underwent rheumatic mitral valve surgery in 4 centers from 2022 to 2023. Each enrolled patient underwent a comprehensive transthoracic echocardiography evaluation and measured 94 ultrasound indicators, mainly covering leaflets, annulus, subvalvular apparatus, and atrial and ventricular function. The main endpoint event was the failure of mitral valve repair (including switching to replacement after repair, and moderate to severe stenosis or regurgitation during follow-up after repair). Patients were randomly assigned to the modeling and validation groups at a ratio of 7:3. In the modeling group, LASSO regression was used for variable selection, and logistic regression was used for modeling. A nomogram was drawn and a webpage rating calculator was created. In the validation group, model comparisons were conducted using the C-statistic and Net Reclassification Index (NRI). Results 112 patients (67.1%) underwent mitral valve repair with satisfactory results, 47 patients (28.1%) ultimately underwent mitral valve replacement, and 8 patients (4.8%) found moderate to severe mitral stenosis or regurgitation during follow-up after repair. Three indicators, including mitral valve orifice area, leaflet calcification score, and anterior leaflet-annulus angle, were selected through LASSO regression. No collinearity was found between the three indicators, and they were ultimately included in the logistic regression model. The C statistics in the modeling group and validation group were 0.846 and 0.958, respectively, indicating that the constructed model has satisfactory predictive ability. Compared to the Wilkins score, the proportion of correctly classified items increased by 19.8%, significantly better than the Wilkins score. Finally, a nomogram was drawn based on the model, and a web rating calculator was created to guide clinical decision-making. Conclusion This study explored a comprehensive evaluation method and innovative indicators for rheumatic mitral valve disease by transthoracic echocardiography, established and validated a model for predicting the outcome of repair surgery, and had certain guiding significance for doctors to choose suitable patients for rheumatic mitral valve repair.Validation of the predictive modelNomogram

Mid- and long-term outcomes of percutaneous balloon mitral valvuloplasty guided solely by echocardiography

Objective: To evaluate the mid-and long-term clinical outcomes of percutaneous balloon mitral valvuloplasty (PBMV) guided solely by echocardiography. Methods: A total of 71 patients with moderate to severe mitral stenosis who underwent PBMV guided solely by echocardiography at Fuwai Hospital, Chinese Academy of Medical Sciences, from January 2016 to December 2022 were retrospectively included. The clinical data and follow-up information were collected and analyzed. Results: Finally, 71 patients (11 males and 60 females) aged (48.6±12.4) years, including 3 pregnant women were included. One patient required surgical intervention due to moderate to severe mitral regurgitation, resulting in a procedure success rate of 98.6% (70/71). The procedural duration was (84.1±40.2) minutes, with the balloon diameter of (26.5±1.1) mm and number of dilatations of 2.9±0.7. The mean mitral transvalvular pressure gradient decreased from (12.6±6.1) mmHg (1 mmHg=0.133 kPa) preoperatively to (5.4±2.4) mmHg postoperatively, while the mitral valve orifice area increased from (0.9±0.2) cm² to (1.7±0.3) cm² (both P<0.001). Before discharge, 16 patients developed new mild mitral regurgitation, five developed new moderate mitral regurgitation, and one patient had a small amount of pericardial effusion absorbed by herself. No severe complications such as death, pericardial tamponade, or thromboembolism occurred during the perioperative period. The average follow-up duration was 12-84 (49.7±21.4) months. At two years postoperatively, the mean mitral transvalvular pressure gradient was (6.2±2.5) mmHg, and the mitral valve orifice area was (1.6±0.3) cm². Eight patients underwent surgical mitral valve replacement at an median of [M(Q1, Q3)] 18 (5, 53) months postoperatively, and one patient died during the follow-up period due to non-cardiac reasons. Conclusion: The mid-and long-term outcomes of PBMV guided solely by echocardiography are favorable.

Orifice erosion effect and variable gain control method for hydraulic servo spool valve

The hydraulic servo valve orifice becomes blunted due to erosion caused by solid particle contaminants in the oil, leading to a decline in the valve's static and dynamic performance. This study analyzes the working edge scanning model and proposes using a quarter-ellipse curve to fit the working edge contour for the precise calculation of the valve orifice area. Through AMESim simulation, this study investigates the relationship between valve orifice erosion and the static and dynamic characteristics of hydraulic servo slide valves and proposes a variable gain control method for addressing valve orifice erosion. Results show that the orifice area model based on the quarter elliptic curve is accurate. As erosion increases, the nonlinear area of the valve orifice curve expands, and the valve orifice degrades into a positive opening. The ratio of the long diameter to the short diameter of the ellipse is approximately linearly related to the pressure gain and leakage in the static characteristics of the hydraulic servo valve. After variable gain control, the static and dynamic characteristics of the servo valve closely resemble those of an ideal servo valve, with the maximum deviation between the flow characteristics and the ideal valve orifice approximately 1 %. Regarding pressure characteristics, the pressure drop before the zero position is below 0.2 MPa. This study establishes the internal relationship between orifice erosion and performance degradation and provides a novel approach to enhancing the erosion resistance of hydraulic servo valves.

Echocardiographic Quantitation of Left Ventricular Size and Function in Indian Mongrel Dogs

Background: No published data on two-dimensional echocardiographic quantitation of left ventricular size and function in Indian mongrel dogs is reported till date. Methods: Reference intervals for linear and area measurements of left ventricle size and function was generated in fifty healthy mongrel dogs (25 males, 25 females; mean age=1.59±0.13 yr; mean body weight=16.66±0.73 kg) using two-dimensional echocardiography. Dogs deemed healthy after thorough clinico-physiological, hematological, radiographic, electrocardiographic and echocardiographic evaluation were included in study.Relationship between two-dimensional linear and area measurements of left ventricle and body weight and, between same measurements obtained from different tomographic planes was studied using linear regression analysis. Result: Linear left ventricular measurements, left ventricular internal and external area, mitral valve orifice area showed significant (P less than 0.001) positive correlation with body weight while fractional shortening and ejection fraction showed significant (P less than 0.001) weak negative correlation with body weight. Left ventricular internal length in diastole, interventricular septum thickness and left ventricular internal dimension in systole and left ventricular free wall thickness in diastole were significantly (P less than 0.01) higher in male dogs while mitral valve orifice area was significantly (P less than 0.01) higher in female dogs. All linear measurements of left ventricular size obtained from different tomographic planes displayed significant (P less than 0.001) correlation with each other.

Early Outcomes of Two Large Mitral Valve Transcatheter Edge-to-Edge Repair Devices-A Propensity Score Matched Multicenter Comparison.

Background/Objectives: Previous trials reported comparable results with PASCAL and earlier MitraClip generations. Limited comparative data exist for more contemporary MitraClip generations, particularly the large MitraClip XT(R/W). We aimed to evaluate acute and 30-day outcomes in patients undergoing mitral valve transcatheter edge-to-edge repair (M-TEER) with one of the large devices, either PASCAL P10 or MitraClip XT(R/W) (3rd/4th generation). Methods: A total of 309 PASCAL-treated patients were matched by propensity score to 253 MitraClip-treated patients, resulting in 200 adequately balanced pairs. Procedural, clinical, and echocardiographic outcomes were collected for up to 30 days, including subgroup analysis for mitral regurgitation (MR) etiologies. Results: PASCAL and MitraClip patients were comparable regarding age (80 vs. 79 years), sex (female: 45.5% vs. 50.5%), and MR etiology (degenerative MR: n = 94, functional MR [FMR]: n = 96, mixed MR: n = 10 in each group). Technical success rates were comparable (96.5% vs. 96.0%; p > 0.999). At discharge, the mean gradient was higher (3.3 mmHg vs. 3.0 mmHg; p = 0.038), and the residual mitral valve orifice area was smaller in MitraClip patients (3.0 cm2 vs. 2.3 cm2; p < 0.001). At discharge, the reduction to MR ≤ 2+ was comparable (92.4% vs. 87.8%; p = 0.132). However, reduction to MR ≤ 1+ was more frequently observed in PASCAL patients (67.7% vs. 56.6%; p = 0.029), driven by the FMR subgroup (74.0% vs. 60.0%; p = 0.046). No difference was observed in 30-day mortality (p = 0.204) or reduction in NYHA-FC to ≤II (p > 0.999). Conclusions: Both M-TEER devices exhibited high and comparable rates of technical success and MR reduction to ≤2+. PASCAL may be advantageous in achieving MR reduction to ≤1+ in patients with FMR.

Aortic Valve Stenosis Causes Accumulation of Extracellular Hemoglobin and Systemic Endothelial Dysfunction.

Whether aortic valve stenosis (AS) can adversely affect systemic endothelial function independently of standard modifiable cardiovascular risk factors is unknown. We therefore investigated endothelial and cardiac function in an experimental model of AS mice devoid of standard modifiable cardiovascular risk factors and human cohorts with AS scheduled for transcatheter aortic valve replacement. Endothelial function was determined by flow-mediated dilation using ultrasound. Extracellular hemoglobin (eHb) concentrations and nitric oxide (NO) consumption were determined in blood plasma of mice and humans by ELISA and chemiluminescence. This was complemented by measurements of aortic blood flow using 4-dimensional flow acquisition by magnetic resonance imaging and computational fluid dynamics simulations. The effects of plasma and red blood cell (RBC) suspensions on vascular function were determined in transfer experiments in a murine vasorelaxation bioassay system. In mice, the induction of AS caused systemic endothelial dysfunction. In the presence of normal systolic left ventricular function and mild hypertrophy, the increase in the transvalvular gradient was associated with elevated eryptosis, increased eHb, and increased plasma NO consumption; eHb sequestration by haptoglobin restored endothelial function. Because the aortic valve orifice area in patients with AS decreased, postvalvular mechanical stress in the central ascending aorta increased. This was associated with elevated eHb, circulating RBC-derived microvesicles, eryptotic cells, lower haptoglobin levels without clinically relevant anemia, and consecutive endothelial dysfunction. Transfer experiments demonstrated that reduction of eHb by treatment with haptoglobin or elimination of fluid dynamic stress by transcatheter aortic valve replacement restored endothelial function. In patients with AS and subclinical RBC fragmentation, the remaining circulating RBCs before and after transcatheter aortic valve replacement exhibited intact membrane function, deformability, and resistance to osmotic and hypoxic stress. AS increases postvalvular swirling blood flow in the central ascending aorta, triggering RBC fragmentation with the accumulation of hemoglobin in the plasma. This increases NO consumption in blood, thereby limiting vascular NO bioavailability. Thus, AS itself promotes systemic endothelial dysfunction independent of other established risk factors. Transcatheter aortic valve replacement is capable of limiting NO scavenging and rescuing endothelial function by realigning postvalvular blood flow to near physiological patterns. URL: https://www.clinicaltrials.gov; Unique identifiers: NCT05603520 and NCT01805739.

The hybrid (physical-computational) cardiovascular simulator to study valvular diseases

To better understand the impact of valvular heart disease (VHD) on the hemodynamics of the circulatory system, investigations can be carried out using a model of the cardiovascular system. In this study, a previously developed hybrid (hydro-numerical) simulator of the cardiovascular system (HCS) was adapted and used. In our HCS Björk-Shiley mechanical heart valves were used, playing the role of mitral and aortic ones. In order to simulate aortic stenosis (AS) and mitral regurgitation (MR), special mechanical devices have been developed and integrated with the HCS. The simulation results proved that the system works correctly. Namely, in the case of AS − the mean pulmonary arterial pressure was increased due to increased preload of the left ventricle and the decrease in right ventricular preload was caused by a decrease in systemic arterial pressure. The severity of AS was performed based on the transaortic pressure gradient as well as using the Gorlin and Aaslid equations. In the case of severe AS, when the mean gradient was above 40 mmHg, the aortic valve orifice area was 0.5 cm2, which is in line with ACC/AHA guidelines. For the case of MR − with increasing severity of MR, there was a decrease in the left ventricular pressure and an increase in left atrial pressure. Using mechanical heart valves to simulate VHD by the HCS can be a valuable tool for biomedical research, providing a safe and controlled environment to study and understand the pathophysiology of VHD.

Early Feasibility Study of a Hybrid Tissue-Engineered Mitral Valve in an Ovine Model.

Tissue engineering aims to overcome the current limitations of heart valves by providing a viable alternative using living tissue. Nevertheless, the valves constructed from either decellularized xenogeneic or purely biologic scaffolds are unable to withstand the hemodynamic loads, particularly in the left ventricle. To address this, we have been developing a hybrid tissue-engineered heart valve (H-TEHV) concept consisting of a nondegradable elastomeric scaffold enclosed in a valve-like living tissue constructed from autologous cells. We developed a 21 mm mitral valve scaffold for implantation in an ovine model. Smooth muscle cells/fibroblasts and endothelial cells were extracted, isolated, and expanded from the animal's jugular vein. Next, the scaffold underwent a sequential coating with the sorted cells mixed with collagen type I. The resulting H-TEHV was then implanted into the mitral position of the same sheep through open-heart surgery. Echocardiography scans following the procedure revealed an acceptable valve performance, with no signs of regurgitation. The valve orifice area, measured by planimetry, was 2.9 cm2, the ejection fraction reached 67%, and the mean transmitral pressure gradient was measured at 8.39 mmHg. The animal successfully recovered from anesthesia and was transferred to the vivarium. Upon autopsy, the examination confirmed the integrity of the H-TEHV, with no evidence of tissue dehiscence. The preliminary results from the animal implantation suggest the feasibility of the H-TEHV.

The effect of a smaller spacer in the PASCAL Ace on residual mitral valve orifice area.

Mitral transcatheter edge-to-edge repair (M-TEER) is an established treatment for functional mitral regurgitation (FMR) associated with a risk of creating iatrogenic stenosis. To investigate the impact of the P10 and its larger spacer compared to the narrower Ace and its smaller spacer on reduction of mitral valve orifice area (MVOA) during M-TEER. Consecutive patients undergoing M-TEER for treatment of severe FMR were screened retrospectively. Patients with a single PASCAL device implantation within the central segments of the MV leaflets, non-complex anatomy, and baseline MVOA ≥ 3.5cm2 were selected. Intraprocedural transesophageal echocardiography was used to compare MVOA reduction with 3D multiplanar reconstruction and direct planimetry. Device selection did not follow a prespecified MVOA threshold. Seventy-two patients (81.0 years, IQR {74.3-85.0}) were included. In 32 patients, the P10 was implanted (44.4%). MR severity (p = 0.66), MR reduction (p = 0.73), and body surface area (p = 0.56) were comparable. Baseline MVOA tended to be smaller in P10 patients with the larger spacer (5.0 ± 1.1 vs. 5.4 ± 1.3cm2, p = 0.18), however, residual MVOA was larger in these patients (2.7 ± 0.7 vs. 2.3 ± 0.6cm2, p = 0.03). Accordingly, relative MVOA reduction was significantly less in P10 patients (- 45.9 ± 7.6 vs. - 56.3 ± 7.0%, p < 0.01). Indirect annuloplasty was more pronounced in Ace patients whereas mean transmitral gradients were similar. In FMR patients with non-complex anatomy, the larger spacer of the P10 maintains greater MVOA with similar MR reduction. Hence, the use of the PASCAL Ace device in patients with small MVOAs might correlate with a risk of both clinically relevant orifice reduction and even iatrogenic stenosis.

Mitral valve repair using a semi-rigid posterior band: a 10-year Japanese single-center experience of 244 patients.

Mitral valve repair (MVr) is an established procedure for patients who require surgery for primary mitral regurgitation (PMR). The Colvin-Galloway Future Band (CGFB) is a semi-rigid posterior band expected to improve the clinical outcomes of MVr. However, information on the hemodynamic and functional performance and long-term outcomes of CGFB is limited. We evaluated the quality, durability, and clinical performance after MVr using CGFB for PMR as the cohort study. A total of 244 patients who underwent MVr with CGFB were enrolled. Clinical and echocardiographic assessments were performed (mean follow-up period, 4.0±2.4 years). Posterior mitral leaflet resection was the most common MVr procedure. CGFBs measuring 28 mm (35.2%) and 30 mm (36.5%) were used. The incidence of systolic anterior motion (SAM) was 1.6%. A total of 93.4% of the patients had no or trace MR at discharge. Over 90% of patients had no or mild MR at the last follow-up. The mean pressure gradient and mitral valve orifice area one year after MVr ranged between 2.6 and 3.6 mmHg and 2.3 and 3.4 cm2, respectively. At follow-up, 85.4% of the patients were New York Heart Association class I. Three patients underwent repeat mitral valve surgery. The CGFB demonstrates satisfactory quality and durability in MVr for PMR. Other advantages include a low occurrence of SAM and acceptable hemodynamic outcomes, particularly in patients requiring a smaller annuloplasty device.

Mitral valve orifice area predicts outcome after biventricular repair in patients with hypoplastic left ventricles

BackgroundIdentification of risk factors for biventricular (BiV) repair in children with hypoplastic left ventricles (HLV) has been challenging. We sought to identify preoperative cardiovascular magnetic resonance (CMR) predictors of outcome in patients with HLVs who underwent BiV repair, with a focus on the mitral valve (MV). MethodsSingle center retrospective analysis of preoperative CMRs on patients with HLV (≤50ml/m2) and no endocardial fibroelastosis who underwent BiV repair from 2005-2022. CMR measurements included MV orifice area in diastole. The primary composite outcome included time to death, transplant, BiV takedown, heart failure admission, left atrial decompression, or unexpected reoperation; and the secondary outcome included ≥ moderate mitral stenosis and/or regurgitation. ResultsMedian follow-up was 0.7 (IQR 0.1, 2.2) years. Of 122 patients [48% atrioventricular canal (AVC) and 52% non-AVC] age 3 ± 2.8 years at the time of BiV repair, freedom from the primary outcome at 2 years was 53% for AVC and 69% for non-AVC (log rank p=0.12), and freedom from the secondary outcome at 2 years was 49% for AVC and 79% for non-AVC (log rank p<0.01). Independent predictors of primary outcome for AVC patients included MV orifice area z-score < -2 and transitional AVC; for non-AVC patients, predictors included MV orifice area z-score < -2, abnormal MV anatomy, and conal-septal ventricular septal defect. Independent predictors of secondary outcome for AVC patients included older age at surgery, transitional AVC, and transposition of the great arteries. ConclusionsIn children with HLV, low MV orifice area and pre-existing MV pathology are risk factors for adverse outcome after BiV repair.

An In Silico Model for Predicting the Efficacy of Edge-to-Edge Repair for Mitral Regurgitation.

In recent years, transcatheter edge-to-edge repair (TEER) has been widely adopted as an effective treatment for mitral regurgitation (MR). The aim of this study is to develop a personalized in silico model to predict the effect of edge-to-edge repair in advance to the procedure for each individual patient. For this purpose, we propose a combination of a valve deformation model for computing the mitral valve (MV) orifice area (MVOA) and a lumped parameter model for the hemodynamics, specifically mitral regurgitation volume (RVol). Although we cannot obtain detailed information on the three-dimensional flow field near the mitral valve, we can rapidly simulate the important medical parameters for the clinical decision support. In the present method, we construct the patient-specific pre-operative models by using the parameter optimization and then simulate the postoperative state by applying the additional clipping condition. The computed preclip MVOAs show good agreement with the clinical measurements, and the correlation coefficient takes 0.998. In addition, the MR grade in terms of RVol also has good correlation with the grade by ground truth MVOA. Finally, we try to investigate the applicability for the predicting the postclip state. The simulated valve shapes clearly show the well-known double orifice and the improvement of the MVOA, compared with the preclip state. Similarly, we confirmed the improved reverse flow and MR grade in terms of RVol. A total computational time is approximately 8 h by using general-purpose PC. These results obviously indicate that the present in silico model has good capability for the assessment of edge-to-edge repair.

On the Material Constitutive Behavior of the Aortic Root in Patients with Transcatheter Aortic Valve Implantation

BackgroundTranscatheter aortic valve implantation (TAVI) is a minimally invasive procedure used to treat patients with severe aortic valve stenosis. However, there is limited knowledge on the material properties of the aortic root in TAVI patients, and this can impact the credibility of computer simulations. This study aimed to develop a non-invasive inverse approach for estimating reliable material constituents for the aortic root and calcified valve leaflets in patients undergoing TAVI. MethodsThe identification of material parameters is based on the simultaneous minimization of two cost functions, which define the difference between model predictions and cardiac-gated CT measurements of the aortic wall and valve orifice area. Validation of the inverse analysis output was performed comparing the numerical predictions with actual CT shapes and post-TAVI measures of implanted device diameter.ResultsA good agreement of the peak systolic shape of the aortic wall was found between simulations and imaging, with similarity index in the range in the range of 83.7% to 91.5% for n.20 patients. Not any statistical difference was observed between predictions and CT measures of orifice area for the stenotic aortic valve. After TAVI simulations, the measurements of SAPIEN 3 Ultra (S3) device diameter were in agreement with those from post-TAVI angio-CT imaging. A sensitivity analysis demonstrated a modest impact on the S3 diameters when altering the elastic material property of the aortic wall in the range of inverse analysis solution.ConclusionsOverall, this study demonstrates the feasibility and potential benefits of using non-invasive imaging techniques and computational modeling to estimate material properties in patients undergoing TAVI.

Long-Term Impact of Small Mitral Valve Orifice Area after Transcatheter Edge-to-Edge Mitral Valve Repair on Clinical Outcome: A Three-Dimensional Echocardiography Study

Iatrogenic mitral stenosis is a complication associated with transcatheter edge-to-edge mitral valve repair. Some reports revealed the impact of mean transmitral pressure gradient after procedure on long-term clinical outcomes. However, the association between prognosis and mitral valve orifice area (MVA) after the procedure has been poorly studied. This study aimed to investigate the association between postprocedural small MVA, derived from three-dimensional (3D) transesophageal echocardiography (TEE), and long-term clinical outcomes in 2 cohorts: the degenerative mitral regurgitation (MR) cohort and the functional MR cohort. This retrospective study assessed 279 consecutive patients with 3D TEE data during transcatheter edge-to-edge mitral valve repair between January 2010 and December 2016. Mitral valve orifice area after device implantation was measured by 3D planimetry. The patients with degenerative and functional MR were stratified separately into 2 groups according to postprocedural MVA: normal MVA (MVA > 1.5cm2) group and small MVA (MVA ≤ 1.5cm2) group. Of the 279 patients, 142 (51%) had degenerative MR and 137 (49%) had functional MR. The number of degenerative MR patients with small MVA was 38, whereas 42 patients were in the functional MR cohort. Patients with small MVA had higher rate of all-cause mortality in the degenerative MR group (log-rank test: P=.01) but not in the functional MR group (log-rank test: P=.52). In multivariate analysis small MVA was independently associated with all-cause mortality but not postprocedural transmitral pressure gradient. Neither small MVA nor transmitral pressure gradient was associated with all-cause mortality in patients with functional MR. Small MVA measured by 3D TEE after transcatheter mitral edge-to-edge repair was associated with poor prognosis in patients with degenerative MR.

Impact of hypertension on mean transvalvular gradients in aortic stenosis Lessons learned from in silico modelling

Abstract Introduction The influence of hypertension on the diagnostic assessment of aortic stenosis (AS) severity is unclear, yet clinically relevant. To clarify the effect of hypertension on transvalvular gradients, requires a better understanding of the impact that blood pressure change has on mean flow rate. Also, the effect of various degrees of AS severity, the valve geometry and intrinsic left ventricular contractile function (elastance) on this interaction, needs to be clarified. Existing clinical research on this topic is limited by not incorporating the full complement of factors that influences the directionality and magnitude of mean transvalvular gradient change for any given change in blood pressure. Purpose To use validated flow dynamics modelling grounded in fundamental physics principles to create a digital platform where various parameters can be manipulated to quantify the effects of bloodpressure change on mean transvalvular gradients in various pathological states. Methods A validated, zero-dimensional electro-hydraulic analogue computer model of the human cardiovascular circulatory system was generated. It was used to assess the impact of blood pressure changes on left ventricular pressure and transvalvular gradients at various flow rates, left ventricular elastances, a range of aortic valve areas and for different aortic valve morphologies. Results Mean transvalvular gradients are flow dependent. The impact of hypertension on mean flow rate (MFR), and hence on mean gradient (MG), is influenced by the aortic valve area as well as the underlying left ventricular elastance (Figure 1). Subsequently, the relationship between MFR and MG could be modelled (Figure 2). Generally, for a given change in systemic arterial pressure, the impact on MG will be the most marked for lower flow rate states such as is expected in more severe degrees of AS and for worse intrinsic left ventricular (LV) contractility. Furthermore, for a constant hemodynamic valve area, the hydraulic valve orifice area was found to be smaller in rheumatic AS compared to degenerative AS. This results in less susceptibility to blood pressure induced changes in mean transvalvular gradient. Similarly, the size of the aortic root was found to be inversely related to the susceptibility to induce a change in mean gradient for a change in blood pressure. Conclusion The interaction between hypertension and mean gradients in AS is complex. The current work places previous recommendations in perspective by quantifying the magnitude of the effect that a change in blood pressure has on mean gradient in various pathophysiological states. By doing so it provides more granularity into this multifaceted interaction compared to previously oversimplified deductions from clinical studies. The findings of this study creates a basic science framework based on first principles that dictates the scope of parameters that should be considered in future clinical research on the topic.Modelling 1Modelling 2

Cardiac magnetic resonance hemodynamic force patterns in patients with ST-segment elevation myocardial infarction and dilated cardiomyopathy as compared to healthy controls: an observational study

Abstract Background Intraventricular Pressure Gradients (IVPG) reflect the driving force behind blood motion in and out of the left ventricle (LV). IVPG can be computed non-invasively using Cardiac Magnetic Resonance (CMR) cine imaging. It is unknown how IVPG components change as a consequence of ST-segment Elevation Myocardial Infarction (STEMI) and in non-ischemic Dilated Cardiomyopathy (DCM). Aims We aimed to assess if LV dysfunction of an ischemic and non-ischemic origin translates into reduced IVPG. The IVPG values were compared to conventional CMR markers of LV systolic function, to evaluate potential future applications. Methods This analysis of prospectively included cohorts included patients with DCM (n=40), anterior (n=20) or inferior STEMI (n=19) with an LV ejection fraction (EF) ≤ 52%, and healthy control subjects (n=13). LV ejection fraction was measured on the short-axis cine images. LV global longitudinal strain (GLS) and IVPG were measured in the long-axis cine images, using feature tracking software. Contours were drawn manually and the mitral and aortic valve orifice areas were measured. The dimensionless IVPG were measured in the longitudinal direction, using feature tracking combined with valve orifice measurements. IVPG consisted of the A, B, C, and D-wave, see Figure 1. IVPG values were compared between controls and diseased cohorts by the Mann Whitney U test. Results LVEF and LV-GLS were significantly impaired in all diseased groups. DCM and anterior STEMI patients had lower overall IVPG (15.1 [IQR 12.6-17.9] vs 9.4 [IQR 7.8-13.4], p=0.001 for DCM and 11.1 [IQR 8.7-13.0], p=0.002 for anterior STEMI). DCM and anterior STEMI patients had a significantly reduced systolic ejection A-wave (21.8 [IQR 19.1-27.2] in controls vs. 13.5 [IQR 10.3-19.1] in DCM, p&amp;lt;0.001, and 16.9 [IQR 10.8-20.6] in anterior STEMI, p=0.004). Secondly, patients with DCM and inferior STEMI have significantly dampened E-wave decelerative C-waves (8.1 [IQR 6.5-12.3] in controls, vs. 3.7 [IQR 2.4-5.5], p&amp;lt;0.001 in DCM, and 6.4 [IQR 4.3-7.8], p=0.04 in inferior STEMI), due to impaired passive ventricular filling. Conclusions IVPG values are altered in patients with myocardial dysfunction due to anterior and inferior STEMI to a lesser extent than in DCM patients. Conventional measures for systolic function (i.e. LV-GLS and LV ejection fraction) were lower in all diseased groups as well. On the other hand, IVPG is a promising measure to quantify diastolic LV function on the ventricular level.

Abstract 14286: Rapid Involution of a Bioprosthetic Transcatheter Aortic Valve Replacement Presenting as Late Bioprosthetic Stenosis

A 65 year old male with a bioprosthetic 29 mm Edwards Sapien Ultra S3 TAVR implant for symptomatic severe aortic stenosis presented for evaluation after a 30-day transthoracic echocardiogram demonstrated bioprosthetic valve stenosis. Following TAVR deployment, TEE showed normal bioprosthetic valve function without evidence of significant paravalvular regurgitation. There were no procedural complications. Echocardiogram performed 1-day post-implantation demonstrated expected transvalvular gradients and valve area. The patient reported immediate symptomatic improvement following TAVR. At 30 days post-implant, TTE demonstrated a peak velocity of 3.37 m/s, mean gradient of 29 mmHg, dimensionless index of 0.29, and effective valve orifice area of 0.9 cm2. This was associated with a progressive decline in exercise capacity. At 57 days post-implant, TEE showed tissue growth of the aortic root anterior to the valve stent, causing deformation and under-expansion of the valve architecture from a circular to an ovoid shape. Notably, the bioprosthetic leaflets did not appear thickened or calcified, but exhibited restricted motion as a result of the abnormal valve architecture. Peak velocity had further increased to 4.6 m/s, with a mean gradient of 57 mmHg, dimensionless index of 0.21, and calculated effective orifice area of 0.52 cm2. Bioprosthetic aortic valve valve stenosis is an expected complication of valve replacement, though typically characterized by progressive leaflet calcification and pannus formation over several years or by valve thrombosis. Here, we present a rare case of rapidly progressive bioprosthetic TAVR stenosis identified at 30 days post-implantation after normal morphology and gradients on immediate and 1-day imaging. Stenosis was characterized by a process of tissue growth anterior to the stent with involution and underexpansion of the stent architecture and morphologically normal leaflet tissue.