Pulmonary Regurgitation Fraction Research Articles

Machine Learning Quantification of Pulmonary Regurgitation Fraction from Echocardiography.

Assessment of pulmonary regurgitation (PR) guides treatment for patients with congenital heart disease. Quantitative assessment of PR fraction (PRF) by echocardiography is limited. Cardiac MRI (cMRI) is the reference-standard for PRF quantification. We created an algorithm to predict cMRI-quantified PRF from echocardiography using machine learning (ML). We retrospectively performed echocardiographic measurements paired to cMRI within 3months in patients with ≥ mild PR from 2009 to 2022. Model inputs were vena contracta ratio, PR index, PR pressure half-time, main and branch pulmonary artery diastolic flow reversal (BPAFR), and transannular patch repair. A gradient boosted trees ML algorithm was trained using k-fold cross-validation to predict cMRI PRF by phase contrast imaging as a continuous number and at > mild (PRF ≥ 20%) and severe (PRF ≥ 40%) thresholds. Regression performance was evaluated with mean absolute error (MAE), and at clinical thresholds with area-under-the-receiver-operating-characteristic curve (AUROC). Prediction accuracy was compared to historical clinician accuracy. We externally validated prior reported studies for comparison. We included 243 subjects (median age 21years, 58% repaired tetralogy of Fallot). The regression MAE = 7.0%. For prediction of > mild PR, AUROC = 0.96, but BPAFR alone outperformed the ML model (sensitivity 94%, specificity 97%). The ML model detection of severe PR had AUROC = 0.86, but in the subgroup with BPAFR, performance dropped (AUROC = 0.73). Accuracy between clinicians and the ML model was similar (70% vs. 69%). There was decrement in performance of prior reported algorithms on external validation in our dataset. A novel ML model for echocardiographic quantification of PRF outperforms prior studies and has comparable overall accuracy to clinicians. BPAFR is an excellent marker for > mild PRF, and has moderate capacity to detect severe PR, but more work is required to distinguish moderate from severe PR. Poor external validation of prior works highlights reproducibility challenges.

Flow pattern analysis of right ventricular outflow tract in repaired tetralogy of Fallot through 4D flow MRI.

Cardiac magnetic resonance imaging (CMR) often shows discrepancies between right ventricular outflow tract (RVOT) flow and left ventricular outflow tract flow in patients with late-stage repaired tetralogy of Fallot (rTOF), leading to potential errors in pulmonary regurgitation fraction (PRF) assessment. This study aimed to identify the conditions under which RVOT flow can be acutely evaluated using four-dimensional (4D) flow CMR. Twenty-seven consecutive patients with rTOF underwent both two-dimensional phase-contrast (2D PC) and 4D flow CMR between 2016 and 2018, excluding those with peripheral pulmonary artery stenosis, RVOT conduit replacement, unknown surgical method, and an aortic valve regurgitation greater than 20%. Seven healthy controls also underwent only 4D Flow CMR. All healthy controls and fifteen patients with rTOF showed laminar RVOT flow, while seven patients exhibited helical, and four patients exhibited vortical RVOT flow in 4D flow CMR visualization. Flow-volume concordance between the pulmonary artery and aortic flow was significantly lower in patients with rTOF and PRF > 40% in 2D PC CMR. This concordance rate in the suprapulmonary valve was high in both the TOF and control groups, comparing at five RVOT locations in 4D flow CMR. Regarding RVOT flow regurgitation in 4D flow, the whole bulk evaluation exhibited greater variation depending on the flow type compared to the whole pixel-wise evaluation. The study confirmed the flow volume at the upper section of the pulmonary valve as the most accurate correlate of aortic flow volume. Furthermore, the 4D flow CMR using the pixel-wise method demonstrated superior accuracy compared to the traditional bulk flow method.

3D trans-thoracic echocardiography in assessment and follow up of corrected tetralogy of Fallot patients : whether it is comparable to MRI or not ?

Abstract Background Nowadays with the increasing number of repaired Fallot patients , and the chronicity of pulmonary regurgitation leading to severe right ventricle dilatation and impairment of ventricular functions , we need a method for regular follow up for the appropriate timing for intervention for pulmonary valve replacement either surgical or per-cutaneous. Cardiac MRI is the gold standard however time consuming and more expensive. 3D trans-thoracic echocardiography has recently been developed and applied for assessment of RV volumes and functions. Aim To evaluate right ventricle (RV) volume , ejection fraction (EF) and pulmonary valve (PV) regurgitant fraction in patients post tetralogy of Fallot (TOF) repair by 3D trans-thoracic echocardiography (3DE) in comparison with the gold standard cardiac MRI regarding its accuracy and variability and whether it can be used for annual follow up. Methods The study group composed of 100 patients post TOF repair with mean age group (11.66 ± 4.65) , mean BSA (1.18 ± 0.36) underwent both 3D echo. and CMR within 2 to 3 days . 3D echo assessment of Right ventricle end diastolic volume (RV EDV) , end systolic volume (RV ESV) , ejection fraction (EF) , severity of pulmonary regurgitant and regurgitant fraction were carried out by two different operators using 3D echo compared with the cardiac MRI results for the same parameters done by the standard protocol according to ESC working group of cardiovascular imaging guidelines. Results On comparing the two groups , 3DE was comparable to the CMR in assessment of EF (52.69 ± 6.44 % by 3DE vs 51.38 ± 6.86 % by CMR) with p value (0.165) by the paired test, while the RV EDVI and RV EDVI was slightly elevated by CMR vs 3 DE (RVEDVI: 147.85 ± 40.77 ml/m2, RVESVI: 72.69 ± 27.70 ml/m2) by CMR vs (RVEDVI: 136.51 ± 34.40 ml/m2 , RVESVI 65.12 ± 22.44 ml/m2) by 3 DE with p value (0.035). however there was statistical difference when comparing regurgitant fraction(RF) by CMR vs 3DE which was technically difficult and time consuming when calculating by 3DE as the RF was significantly higher by CMR (46.44 ± 11.27 %) vs 3DE (40.57 ± 10.50 %) with P value (0.000). our study also noted positive linear correlation between regurgitant fraction and RV EDVI (p value 0.000), and RV ESVI (p value = 0.010), and pulmonary valve annulus (p value = 0.000) respectively. Conclusion Three dimensional echo when compared to cardiac MRI as a method for assessment of patients with repaired TOF showed quite agreement in assessment of ejection fraction with slight difference in assessment of ventricular volumes as the accuracy of the 3DE decreases in larger volumes, however the significant difference in assessment of regurgitant fraction by 3DE makes it used as a method for serial follow up however CMR should be done as baseline.comparing RV volumes and RFcorrelation of RF and CMR paramters

Abstract 15275: Cardiac Magnetic Resonance Ventricular Function and Hemodynamic Multivariable Model Predictors of Exercise Performance in Tetralogy of Fallot Using Machine Learning and Multivariable Modelling: A Substudy of the Single Center Cardiac Magnetic Resonance Outcomes Registry-Tetralogy of Fallot

Background: There are no robust predictors of exercise performance in repaired tetralogy of Fallot (rTOF) using both ventricular function and hemodynamics. Aim: To utilize machine learning and multivariable modeling to determine cardiac magnetic resonance (CMR) and other metrics predictive of exercise performance. Methods: We retrospectively reviewed data of all rTOF pts undergoing CMR from 2005-2020. Those who had cardiopulmonary exercising testing (CPET) within 6 months of CMR were analyzed using the machine learning technique LASSO to choose candidate variables for subsequent testing with multivariable modeling. CMR parameters included right (RV) and left ventricular (LV) function and hemodynamics. Significance P<0.05. Results: 266 of 761 pts with rTOF met the inclusion criteria (age at CMR 16.1 + 9.7 years old, age at repair 0.36 years old, 56% male). Higher RV mass, RV global function index and lower pulmonary regurgitant fraction (PR) were independently associated with higher % predicted (%P) maximum oxygen consumption (VO 2 max). In addition, females and non-syndromic pts were also associated with higher %P VO 2 max (table). Those with a higher LV end-diastolic volume (EDV), females and pts without pulmonary atresia performed better at %P work. Those with a higher RV mass/volume demonstrated a worse ventilatory equivalent of carbon dioxide (VE/VCO 2 ). See table. Conclusion: RV ventricular functional parameters, PR (hemodynamics), gender and syndromic status are all independently associated with %P VO 2 max. Those with larger LV volumes were able to perform more work and those with a higher RV mass/volume had a worse VE/VCO 2 . Our findings shed some light into the etiology of poor rTOF exercise performance.

Abstract 19104: Hemodynamic Analysis of Pulmonary Artery for Congenital Right-Side Heart Disease in Adulthood by 4d-Flow MRI

Introduction: Using 4D-flow MRI, we evaluated hemodynamics in the pulmonary artery of congenital right-side heart disease in adulthood. Hypothesis: We hypothesize that 4D flow MRI may be used to assess pulmonary artery flow hemodynamics in adults with congenital right heart disease. Methods: In 20 adults, we measured energy loss (EL) and helicity of the main pulmonary artery (MPA) by cardiovascular MRI. The maximum value (peak EL) in one heartbeat and the total value were obtained for EL. Helicity was defined as a vector quantity, with clockwise rotation being positive and counterclockwise rotation being negative, and the total value was calculated. Results: The mean age was 27.9 years. The cases included 15 cases of postoperative tetralogy of Fallot without pulmonary arterial hypertension (TOF) and 5 cases of congenital heart diseases with pulmonary arterial hypertension (CHD-PAH). Peak EL, time to peak EL, and total helicity were higher in the CHD-PAH group than TOF group. Peak EL values were significantly higher during systole but were observed during diastole in 8 patients (40%). The combined mean value of helicity was positive, with clockwise predominance in 12 cases (60%). A strong correlation was found between peak EL and clockwise helicity (r=0.68) and counterclockwise helicity (r=-0.73). In addition, a correlation was observed between diastolic EL/BSA and diastolic clockwise helicity (r=0.51) and diastolic counterclockwise helicity (r=-0.52). A correlation was also observed with the pulmonary regurgitant fraction (r=0.49). Conclusions: In this study, helicity in the MPA was dominant clockwise in congenital right-side heart disease in adulthood. It was suggested that EL was involved in helicity throughout the entire cardiac cycle and that peak EL had a particularly large effect.

Rightward imbalanced pulmonary perfusion predicts better exercise stroke volume in children after Fallot repair

BackgroundResidual lesions following Fallot repair are primarily pulmonary regurgitation and right ventricular outflow tract obstruction. These lesions may impact exercise tolerance, particularly because of a poor increase in left ventricular stroke volume. Pulmonary perfusion imbalance is also common, but its effect on cardiac adaptation to exercise is not known. AimTo assess the association between pulmonary perfusion asymmetry and peak indexed exercise stroke volume (pSVi) in young patients. MethodsWe retrospectively studied 82 consecutive patients with Fallot repair (mean age 15.2±3.8 years) who underwent echocardiography, four-dimensional flow magnetic resonance imaging and cardiopulmonary testing with pSVi measurement by thoracic bioimpedance. Normal pulmonary flow distribution was defined as right pulmonary artery perfusion between 43 and 61%. ResultsNormal, rightward and leftward flow distributions were found in 52 (63%), 26 (32%) and four (5%) patients, respectively. Independent predictors of pSVi were right pulmonary artery perfusion (β=0.368, 95% confidence interval [CI] 0.188 to 0.548; P=0.0003), right ventricular ejection fraction (β=0.205, 95% CI 0.026 to 0.383; P=0.049), pulmonary regurgitation fraction (β=–0.283, 95% CI –0.495 to –0.072; P=0.006) and Fallot variant with pulmonary atresia (β=–0.213, 95% CI –0.416 to –0.009; P=0.041). The pSVi prediction was similar when the categorical variable right pulmonary artery perfusion>61% was used (β=0.210, 95% CI 0.006 to 0.415; P=0.044). ConclusionIn addition to right ventricular ejection fraction, pulmonary regurgitation fraction and Fallot variant with pulmonary atresia, right pulmonary artery perfusion is a predictor of pSVi, in that rightward imbalanced pulmonary perfusion favours greater pSVi.

Electromechanical Dyssynchrony Is Associated With Right Ventricular Remodeling and Dysfunction Independently of Pulmonary Regurgitation Late After Tetralogy of Fallot Repair

The aim of this study was to investigate the relationship among right ventricular (RV) dilatation, dysfunction, and electromechanical dyssynchrony (EMD) in patients with repaired tetralogy of Fallot (rTOF). Data from a prospective rTOF registry of subjects with moderate or greater pulmonary regurgitation (PR) and contemporary imaging were analyzed. Electrocardiograms and echocardiograms were analyzed for EMD (prolonged QRS duration [QRSd], echocardiographic septal flash, and mechanical delay) and mechanical dispersion. The relationship among these, RV measurements on cardiac magnetic resonance, exercise capacity, and incident arrhythmia or death was analyzed with adjustment for PR. In total, 271 patients with rTOF (42% women; median age, 32years; interquartile range [IQR], 23-34 years) were included. Patients had moderate to severe PR (median PR fraction, 38%; IQR, 30%-47%), moderate to severe RV enlargement (median RV end-diastolic volume index, 161 mL/m2; IQR, 138-186 mL/m2) and mild RV systolic dysfunction (median RV ejection fraction [RVEF], 44%; IQR, 38%-48%). Eleven patients (4%) experienced ventricular arrhythmia or death. Presence of EMD was associated with larger RV size (RV end-diastolic volume index and RV end-systolic volume index, P=.006 and P<.001, respectively) and lower RVEF (P<.001). A sharp inflection in the relation among QRSd, RV size, and RVEF was observed when QRSd exceeded 150msec (3.1% decrease in RVEF for every 20-msec increase in QRSd between 160 and 200msec). Similar inflection points were observed for the mechanical delay between the RV basal-lateral and midseptal segments. The mechanical delay was higher in patients with vs without incident atrial arrhythmia (371 vs 276msec, P=.014). In adults with rTOF, EMD is independently associated with larger RV size, lower RVEF, and incident atrial arrhythmias.

Machine Learning for Prediction of Adverse Cardiovascular Events in Adults With Repaired Tetralogy of Fallot Using Clinical and Cardiovascular Magnetic Resonance Imaging Variables

Background: Existing models for prediction of major adverse cardiovascular events (MACE) after repair of tetralogy of Fallot have been limited by modest predictive capacity and limited applicability to routine clinical practice. We hypothesized that an artificial intelligence model using an array of parameters would enhance 5-year MACE prediction in adults with repaired tetralogy of Fallot. Methods: A machine learning algorithm was applied to 2 nonoverlapping, institutional databases of adults with repaired tetralogy of Fallot: (1) for model development, a prospectively constructed clinical and cardiovascular magnetic resonance registry; (2) for model validation, a retrospective database comprised of variables extracted from the electronic health record. The MACE composite outcome included mortality, resuscitated sudden death, sustained ventricular tachycardia and heart failure. Analysis was restricted to individuals with MACE or followed ≥5 years. A random forest model was trained using machine learning (n=57 variables). Repeated random sub-sampling validation was sequentially applied to the development dataset followed by application to the validation dataset. Results: We identified 804 individuals (n=312 for development and n=492 for validation). Model prediction (area under the curve [95% CI]) for MACE in the validation dataset was strong (0.82 [0.74–0.89]) with superior performance to a conventional Cox multivariable model (0.63 [0.51–0.75]; P =0.003). Model performance did not change significantly with input restricted to the 10 strongest features (decreasing order of strength: right ventricular end-systolic volume indexed, right ventricular ejection fraction, age at cardiovascular magnetic resonance imaging, age at repair, absolute ventilatory anaerobic threshold, right ventricular end-diastolic volume indexed, ventilatory anaerobic threshold % predicted, peak aerobic capacity, left ventricular ejection fraction, and pulmonary regurgitation fraction; 0.81 [0.72–0.89]; P =0.232). Removing exercise parameters resulted in inferior model performance (0.75 [0.65–0.84]; P =0.002). Conclusions: In this single-center study, a machine learning-based prediction model comprised of readily available clinical and cardiovascular magnetic resonance imaging variables performed well in an independent validation cohort. Further study will determine the value of this model for risk stratification in adults with repared tetralogy of Fallot.

1-Year Outcomes in a Pooled Cohort of Harmony Transcatheter Pulmonary Valve Clinical Trial Participants

BackgroundThe Harmony transcatheter pulmonary valve (TPV) is the first U.S. Food and Drug Administration–approved device for severe pulmonary regurgitation (PR) in the native or surgically repaired right ventricular outflow tract (RVOT). ObjectivesOne-year safety and effectiveness of the Harmony TPV were evaluated in patients from the Harmony Native Outflow Tract Early Feasibility Study, Harmony TPV Pivotal Study, and Continued Access Study, representing the largest cohort to date of Harmony TPV recipients. MethodsEligible patients had severe PR by echocardiography or PR fraction ≥ 30% by cardiac magnetic resonance imaging and clinical indications for pulmonary valve replacement. The primary analysis included 87 patients who received a commercially available TPV22 (n = 42) or TPV25 (n = 45) device; 19 patients who received an early device iteration prior to its discontinuation were evaluated separately. ResultsIn the primary analysis, median patient age at treatment was 26 years (IQR: 18-37 years) in the TPV22 group and 29 years (IQR: 19-42 years) in the TPV25 group. At 1 year, there were no deaths; 98% of TPV22 and 91% of TPV25 patients were free from the composite of PR, stenosis, and reintervention (moderate or worse PR, mean RVOT gradient >40 mmHg, device-related RVOT reoperation, and catheter reintervention). Nonsustained ventricular tachycardia occurred in 16% of patients. Most patients had none/trace or mild PR (98% of TPV22 patients, 97% of TPV25 patients). Outcomes with the discontinued device are reported separately. ConclusionsThe Harmony TPV device demonstrated favorable clinical and hemodynamic outcomes across studies and valve types through 1 year. Further follow-up will continue to assess long-term valve performance and durability.

Predictors of right atrial dilatation and long-term function after right ventricular outflow tract surgical repair: Quantification of restrictive physiology matters

Right ventricular (RV) diastolic dysfunction in patients with a surgically-repaired RV outflow tract (RVOT) obstruction merits further studies. Right atrial (RA) dilation and function may be related to (RV) diastolic dysfunction in this setting. The end-diastolic forward flow (EDFF) in the pulmonary artery (PA) has been suggested as a non-invasive marker of poor RV compliance, however, there is controversy regarding its true significance; EDFF quantification may help elucidate this controversy. Objectiveto study predictors of RA enlargement and dysfunction in patients with a surgically-repaired RVOT obstruction and its relationship with quantitative EDFF. MethodsIn 81 consecutive patients (mean age: 37.5 (±7) years), transthoracic echocardiography (Echo) and cardiac magnetic resonance (CMR) were performed. Echo parameters: RA size (indexed RA area (iRAA)), RA function (RA global strain (RAGS)) and maximum EDFF velocity-time integral (VTI-EDFF) obtained during a whole respiratory cycle. CMR-indexed RA area (imRAA) was also obtained. Patients were divided into three groups according to iRAA, imRAA and RAGS; bivariate analysis was performed. A multivariate model was then applied using variables that were found to be statistically significant in the bivariate analysis. ResultsUpon multivariate analysis, higher VTI-EDFF values and the presence of significant tricuspid regurgitation proved to be independent factors associated with increased iRAA and imRAA and lower RAGS, whereas RV volumes, function and pulmonary regurgitant fraction were not. ConclusionVTI-EDFF linearly correlated with the degree of RA dilation and deformation; EDFF quantification as against qualitative assessment may be considered a non-invasive tool for diastolic RV dysfunction.

Tétralogie de Fallot réparée au long terme : paramètres échographiques en corrélation avec l'IRM cardiaque

IntroductionTetralogy of Fallot (ToF) is the most common cyanotic congenital heart disease. After surgical repair, the excellent survival rate has led to long-term complications dominated by pulmonary regurgitation (PR). Our study aimed to identify echocardiographic criteria for assessment of right ventricular (RV) function and quantification of PR correlated with cardiac MRI indices. MethodsWe conducted a descriptive study between June 2021 and March 2022 including patients followed for repaired ToF since 2016 or earlier. All patients were seen for clinical, electrocardiographic, and ultrasound evaluation. Cardiac MRI was performed with a maximum delay of 1 month from Doppler echocardiography. Results38 patients were included, with a mean age at imaging of 18 ± 9 years. Our study showed that the echocardiographic parameters of PR quantification correlated with a pulmonary regurgitation fraction on MRI greater than 40% were: the PHT value (p = 0.005) and the ratio of PR jet width to pulmonary valve annulus diameter (p = 0.032). The only ultrasound parameter estimating RV systolic function correlated with RVEF on cardiac MRI was FAC, with p = 0.007. ConclusionQuantitative assessment of RV parameters in patients followed for repaired ToF, as well as the assessment of the severity of PR, is feasible with a standardized ultrasound examination, with good correlation with cardiac MRI.

Abstract 14967: Rate of Growth of the Right Ventricular Outflow Tract in Repaired Tetralogy of Fallot: A Cardiovascular Magnetic Resonance Imaging Study

Introduction: Patients with repaired tetralogy of Fallot (rTOF) often require pulmonary valve replacement (PVR). Transcatheter PVR is a less invasive alternative to surgery but many right ventricular outflow tracts (RVOTs) are too large. Understanding the rate of RVOT growth may help optimize timing of referral. This study examined the growth of the RVOT over time in rTOF. Methods: We retrospectively analyzed serial cardiac MRI (CMR) data from 121 patients with TOF (median 3 MRIs per patient; range 2 to 10) to calculate the rate of increase in perimeter-derived diameters of the proximal infundibulum, middle RVOT, and distal RVOT at the point of PA bifurcation (Figure 1). The median age at first CMR was 14.7 years (range 3.3, 43.6 years) with a mean interval between first and last CMR of 8 years ± 3 years. Results: All parameters increased over time. The proximal RVOT increased at a rate of 4.1 mm per 10 years (p &lt; 0.001); the mid and distal RVOT both increased at a rate of 3.1 mm per 10 years (p &lt; 0.001) (Figure 2). The RVOT was larger on average in patients with a higher RV end diastolic volume (RVEDV) at first MRI and in patients with a higher pulmonary regurgitation (PR) fraction at first MRI. Patients with greater increases in RV EDV (Spearman correlation 0.48, p &lt; 0.001) or PR fraction (Spearman correlation 0.27, p = 0.003) over time had greater RVOT growth. Conclusions: This largest-to-date serial CMR study of patients with rTOF detailed the rate of growth of the RVOT over time. More rapid growth was associated with higher PR fraction and larger RVEDV. This data may be useful in the design and clinical use of transcatheter pulmonary valves.

Abstract 12962: Circulating Biomarkers Are Associated With Left and Right Ventricular Strain Measured by Cardiac Magnetic Resonance Imaging in Repaired Tetralogy of Fallot Patients

Introduction: Circulating biomarkers thought to represent myocardial fibrosis and stretch are understudied in repaired tetralogy of Fallot (TOF) patients. We aim to identify associations between biomarkers and right ventricular (RV) and left ventricular (LV) function measured as strain by cardiac magnetic resonance (CMR) in repaired TOF patients. Methods: N-terminal-pro hormone BNP (NTproBNP), galectin-3 (Gal-3) and matrix metalloproteinase 1 (MMP1) were measured in serum obtained from TOF patients at the time of standard of care CMR. High and low biomarker groups were created using the median value. CMR strain analysis was performed using cvi42 (Circle Cardiovascular Imaging). CMR parameters were compared by biomarker group using two sample Student’s t tests (given normal distribution), and Pearson correlation coefficients were obtained. Results: Twenty patients were analyzed (45% male). Median age at TOF repair and CMR was 4.1 months (interquartile range [IQR] 1.6, 6.8) and 11.5 years (IQR 10, 15.5), respectively. Patients with higher Gal-3 had worse LV global longitudinal strain (Table) . Those with higher NTproBNP had worse RV global longitudinal and circumferential strain, and those with greater MMP1 values had worse LV global circumferential strain. Gal-3 was moderately inversely correlated with pulmonary regurgitant fraction and RV end-systolic volume (Table) . NTproBNP values were moderately directly correlated with RV mass. MMP1 values were moderately directly correlated with RV end-systolic volume and inversely correlated with RV ejection fraction. Conclusions: The three biomarkers investigated have associations with right and left ventricular strain. Gal-3 and MMP1 are potential biomarkers of LV function, while NTproBNP is a potential biomarker of RV function. Further, Gal-3 may inform more favorable RV remodeling. Future studies will determine if circulating biomarkers will identify early ventricular dysfunction after TOF repair.

Abstract 14737: Right Heart Remodeling After Pulmonary Valve Replacement in Patients With Pulmonary Atresia With Intact Ventricular Septum and Critical Pulmonary Stenosis

Background: Patients with pulmonary atresia with intact ventricular septum (PA/IVS) and critical pulmonary stenosis (CPS) managed to a biventricular circulation may eventually require pulmonary valve replacement (PVR) for pulmonary regurgitation (PR). Right ventricular (RV) remodeling after PVR has been well described in tetralogy of Fallot (TOF); we sought to investigate RV volumetric and functional changes in PA/IVS using CMR. Methods: A retrospective cohort of PA/IVS and CPS patients who underwent PVR at Boston Children’s Hospital from 1995-2021 with CMR before and after PVR was matched 1:3 with TOF patients by age at PVR. Patients with initial intervention &gt;2 weeks of age or 1.5 ventricle circulation were excluded. Median regression modeling accounting for matching was performed with reduction in indexed right ventricular end diastolic volume (RVEDVi) post PVR as the primary outcome, adjusting for covariates including tricuspid regurgitation (TR) and PVR valve size. Results: Twenty PA/IVS or CPS patients (cases) were matched with 60 TOF (controls), with median age at PVR 14 years; at median follow-up 8 years post PVR, 95% were NYHA Class I. Pre-PVR RVEDVi was similar between groups (165 vs 167 ml/m 2 , p=0.7), although cases had higher RV EF (51.4 vs 48.6%, p=0.03), TR fraction (23 vs 9%, p=0.008), and a trend toward lower RV mass; PR fraction, LV volumes and EF were similar. Pre-PVR RV free wall and LV longitudinal strain were similar, although LV circumferential strain was worse in cases (-15.6 vs -17.1, p=0.01). At median 2 years after PVR, RVEDVi was similarly reduced from 166 to 118 ml/m 2 (p=0.73), although cases had higher RV EF (52.3% vs 46.9%, p=0.007) with less reduction in indexed RV mass (Δ4.5 vs 9.6 g/m 2 , p=0.02); LV volumes and EF were similar. Post PVR, RV and LV longitudinal strain remained unchanged both within and between groups; LV circumferential strain was similar post PVR and remained lower in cases vs controls. Conclusion: Patients with PA/IVS after PVR demonstrate similar RV remodeling to TOF patients, with lesser reduction in RV mass and comparatively better post RV EF. CMR strain imaging found no significant pre-post differences in RV or LV systolic parameters. Further investigation is needed to evaluate for changes in diastolic parameters.

Differential Adaptation of Biventricular Myocardial Kinetic Energy in Patients With Repaired Tetralogy of Fallot Assessed by MR Tissue Phase Mapping.

The myocardial kinetic energy (KE) and its association with pulmonary regurgitation (PR) have yet to be investigated in repaired tetralogy of Fallot (rTOF) patients. To evaluate the adaptation of myocardial KE in rTOF patients by tissue phase mapping (TPM). Prospective. A total of 49 rTOF patients (23 ± 5 years old; male=32), 47 normal controls (22 ± 1 year old; male=29). 3-T/2D dark-blood three-directional velocity-encoded gradient-echo sequence. Left and right ventricle (LV, RV) myocardial KE in radial (KEr ), circumferential (KEø ), longitudinal (KEz ) directions. The proportions of KE in each direction to the sum of all KE (KErøz ): %KEr , %KEø , %KEz . PR fraction. Student's t test, multivariable regression. Statistical significance: P< 0.05. In rTOF group, LV KEz remained normal in systole (P=0.565) and diastole (P=0.210), whereas diastolic LV %KEz (62% ± 14% vs. 72% ± 7%) and systolic LV %KEø (9% ± 6% vs. 20% ± 7%) were significantly decreased. The KEr and %KEr of both ventricles significantly increased in the rTOF group (RV in diastole: 6 ± 3 vs. 3 ± 1 μJ and 54% ± 13% vs. 27% ± 7%). The rTOF group exhibited significantly higher RV/LV ratios of %KEr (systole: 1.3 ± 0.3 vs. 1.0 ± 0.3) and %KEø (systole: 1.6 ± 0.8 vs. 1.0 ± 0.3) and significantly lower ratios of %KEz in systole (0.7 ± 0.2 vs. 1.0 ± 0.1) and diastole (0.5 ± 0.2 vs. 0.9 ± 0.1). In multivariable regression analysis, the RV peak systolic KErøz , RV systolic KEz , and LV diastolic %KEø were independently associated with PR fraction in the rTOF group (adjusted R2 =0.479). In rTOF patients, the adaptation of the KE proportion occurred earlier than that of the KE amplitude, and the biventricular balance of %KE was disrupted. PR may cause differential KE adaptation in RV and LV. TPM-derived KE may be useful in investigation of myocardial adaptation in rTOF patients. 2 TECHNICAL EFFICACY: Stage 3.

Right ventricular structure and function after novel repair of common arterial trunk

ObjectivesIn an attempt to enhance applicability and outcomes of corrections of common arterial trunk, we have recently described a novel method of correction based on the concept of morphodynamism, and preserving the structure of the right ventricle. The intermediate influence of this operation on right ventricular (RV) structure and function have not been described. Methods and resultsThirty eight Patients (age: 1–12 months) underwent the novel repair. There were 2 early and 4 late deaths. All patients underwent early CT scans, 12 had repeat CT and 8 had MRI after 1 year or more from the operation. Detailed computerized analysis of the RV size, shape, pattern of contraction and function was performed. The shape and size were preserved, at the second investigation, with no evidence of dilatation of the neo-RV outflow, which appeared to contribute to overall function of the RV. The directional pattern of contraction showed enhanced longitudinal and radial contributions with minimal twisting. The movement of the RV free wall and septum were almost equal, with normal shape of the septum. The instantaneous pattern of contraction followed a consistent peristalsis sequence with significant contraction of both the body and the neo-outflow. The pulmonary regurgitant fraction, at follow up, varied from 22% to 42% (30 ± 6%) with preserved RV to pulmonary artery ventriculo-arterial coupling. ConclusionThe size, shape and pattern of contraction of the RV following the novel common arterial trunk repair appears to be well preserved in the intermediate term.

Magnetic resonance imaging of the heart as a method of long-term monitoring of right heart function after tetralogy of Fallot surgery

&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Introduction.&amp;lt;/strong&amp;gt; Cardiac magnetic resonance imaging (CMR) is considered the reference diagnostic method for quantifying right ventricular size and function, and pulmonary regurgitation in patients with tetralogy of Fallot surgery. The aim of this paper is to confirm the importance of magnetic resonance continuous postoperative monitoring of right and left heart function parameters as a diagnostic method that provides the most precise and accurate assessment.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Methods.&amp;lt;/strong&amp;gt; The prospective observational study included subjects with TOF surgery who were diagnosed with residual morphological and/or functional disorders on control postoperative echocardiographic examinations. All subjects underwent magnetic resonance imaging of the heart on a 1.5 T scanner with dedicated coils for the heart surface according to the standard protocol for a period of one year from the beginning of the study. Criteria for exclusion from the study were: significant residual pulmonary stenosis, condition after pulmonary valve replacement, existence of residual shunt lesions, contraindications for cardiac magnetic resonance imaging (pacemaker, ICD, claustrophobia). Depending on the time elapsed since the tetralogy of Fallot surgery, the subjects were divided into groups: more than 15 years, 11&amp;minus;15 years, 6&amp;minus;10 years, less than 5 years.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Results.&amp;lt;/strong&amp;gt; The study included 131 subjects with an average age of 24.18 &amp;plusmn; 11.57 years with complete correction of TOF. Intergroup differences in values of right ventricular enddiastolic volume, right ventricular ejection fraction, and left ventricular ejection fraction were demonstrated, but there was no statistically significant intergroup difference in values of pulmonary regurgitation fraction. The negative interaction of the right and left ventricles intensifies during the years of follow-up of patients after TOF surgery, which is especially true fifteen years after surgery.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Conclusion.&amp;lt;/strong&amp;gt; CMR has the most significant role in research efforts aimed at improving the outcomes of operated patients with tetralogy of Fallot.&amp;lt;/p&amp;gt;

End-Diastolic Forward Flow and Restrictive Physiology in Repaired Tetralogy of Fallot: A Systematic Review and Meta-Analysis.

BackgroundPulmonary arterial end‐diastolic forward flow (EDFF) following repaired tetralogy of Fallot has been thought to represent right ventricular (RV) restrictive physiology, but is not fully understood. This systematic review and meta‐analysis sought to clarify its physiological and clinical correlates, and to define a framework for understanding EDFF and RV restrictive physiology.Methods and ResultsPubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for observational studies published before March 2021. Random‐effects meta‐analysis was performed to identify factors associated with EDFF. Forty‐two individual studies published between 1995 and 2021, including a total of 2651 participants (1132 with EDFF; 1519 with no EDFF), met eligibility criteria. The pooled estimated prevalence of EDFF among patients with repaired tetralogy of Fallot was 46.5% (95% CI, 41.6%–51.3%). Among patients with EDFF, the use of a transannular patch was significantly more common, and their stay in the intensive care unit was longer. EDFF was associated with greater RV indexed volumes and mass, as well as smaller E‐wave velocity at the tricuspid valve. Finally, pulmonary regurgitation fraction was greater in patients with EDFF, and moderate to severe pulmonary regurgitation was more common in this population.ConclusionsEDFF is associated with dilated, hypertrophied RVs and longstanding pulmonary regurgitation. Although several studies have defined RV restrictive physiology as the presence of EDFF, our study found no clear indicators of poor RV compliance in patients with EDFF, suggesting that EDFF may have multiple causes and might not be the precise equivalent of RV restrictive physiology.

Role of prenatal cardiovascular magnetic resonance imaging in determining pregnancy risk in repaired Tetralogy of Fallot patients

Abstract Funding Acknowledgements Type of funding sources: None. Addressing pregnancy risks poses as a new challenge among women with repaired tetralogy of Fallot (TOF). The high-output state of pregnancy may predispose women to late complications of repaired TOF. However, guidelines regarding antenatal and or perinatal cardiovascular assessment has not been outlined. Noninvasive modalities such as cardiac magnetic resonance imaging (CMR) that do not require the utilization of ionizing radiation are feasible methods of assessment. Risk stratification of baseline CMR parameters has been sparsely investigated among repaired TOF cohorts. This study aims to identify baseline CMR parameters that may predict adverse outcomes of pregnancy among women with repaired TOF. Sixty-five successful pregnancies were recorded from a cohort of 105 pregnant episodes. Patients with CMR studies performed within 5 years prior to delivery events were included. Adverse clinical outcomes of interest included arrhythmia, heart failure admissions, gestational hypertension, pre-eclampsia toxemia and all-cause mortality. Baseline CMR parameters regarding ventricular mechanics such as left and right ventricular end-diastolic and end-systolic volumes, left and right ventricular ejection fractions and pulmonary regurgitant fraction were measured, and their association with adverse clinical outcomes were evaluated using an independent-samples t-test. Within all 65 successful pregnancies, 26 baseline CMR images were obtained and included in this study. The mean maternal age was 29.7 ± 6.7 years old with a mean birth weight of 2.91 ± 0.49 kg at a mean gestational age of 38.4 ± 2.0 weeks. There was a total of 12 patients with adverse clinical outcome: 5 patients with heart failure hospitalizations, 4 patients with gestational hypertension, 4 patients with arrhythmia and 2 patients with pre-eclampsia toxemia. Assessment of baseline CMR parameters of ventricular mechanics revealed that increased left ventricular end-diastolic volumes (LVEDV) (144.7mL/m2 ± 4.9; P = 0.011), left ventricular end-systolic volumes (LVESV) (65.1mL/m2 ± 9.4; P = 0.004), right ventricular end-diastolic volumes (RVEDV) (235.2 ± 29.0; P = 0.021) and right ventricular end-systolic volumes (RVESV) (122.2mL/m2 ± 38.1; P = 0.033) were associated with an increased incidence of arrhythmia during pregnancy. Nonetheless, there was no significant association between baseline ventricular mechanics with heart failure, gestational hypertension, and pre-eclampsia toxemia. Baseline assessment of cardiac magnetic resonance imaging among pregnant TOF women revealed that larger left and right ventricular volumes were associated with arrythmia development during pregnancy. Further studies with larger cohort sizes evaluating the role of antenatal and perinatal cardiovascular imaging assessment using CMR in predicting the risks of cardiovascular complications during pregnancy are warranted.

Usefulness of Right Ventricular Free Wall Strain Obtained with Two-Dimensional Speckle-Tracking Echocardiography in Patients with Repaired Tetralogy of Fallot and Pulmonary Regurgitation.

Right ventricular (RV) dysfunction caused by chronic pulmonary regurgitation (PR) is a major determinant of clinical outcome in adults with repaired tetralogy of Fallot (rTOF). However, the accurate assessment of RV function by conventional echocardiography remains challenging. This study tested the feasibility and usefulness of RV free-wall (RVFW) strain obtained by two-dimensional (2D) speckle-tracking echocardiography (STE) in evaluation of RV function in adults with rTOF by comparing cardiac magnetic resonance (CMR) imaging. We enrolled 22 consecutive patients (male/female, 8/14; mean age, 25.0 years) with rTOF who underwent transthoracic echocardiography at Tohoku University Hospital from July 2016 to June 2019. We measured RVFW strain by STE and compared them with 22 hemodynamically normal subjects (NOR) (male/female, 9/13; mean age, 32.0 years). The correlation between RV strain and CMR-derived RV ejection fraction (RVEF) or PR fraction (PRF) were also evaluated. All rTOF patients had more than moderate PR but were near asymptomatic. RVFW longitudinal strain (RVFW-LS) was significantly decreased in the rTOF group compared with that in the NOR group (-19.6 vs. -24.7, P < 0.01). In the rTOF group, RVFW-LS correlated with PRF (r = 0.44, P < 0.05), whereas RVFW circumferential strain at the mid-ventricular level correlated with RVEF (r = 0.57, P < 0.01). Intra-observer variability of RVFW strain was acceptable. These results indicate that RV systolic function and PR severity in rTOF could be assessed by RVFW strain measured by 2D STE. This method is feasible and can be used as a complement to CMR imaging.