Pulmonary Annulus Research Articles

Fate of the Right Ventricular Outflow Tract Following Valve-Sparing Repair of Tetralogy of Fallot

Valve-sparing repair (VSR) of tetralogy of Fallot (TOF) tends to result in higher residual right ventricular outflow tract (RVOT) gradients. We evaluated the progression and clinical implications of RVOT gradients following VSR of TOF. Demographic, clinical, and operative data were retrospectively collected from consecutive TOF patients who underwent VSR at our institution between 01/2010 and 06/2021. RVOT gradient, pulmonary valve annulus (PVA) diameter and Boston Z-scores were recorded from serial echocardiograms. Data are presented as median and interquartile range or number and percentage. A total of 156 children (boys 92, 59%) underwent VSR at 6.5 (4.9-8.4) months of age and 6.6 kg (5.6- 7.7) weight. There was 1 (0.6%) operative mortality. The remaining 155 patients were followed for 69.4 months (4-106.2). RVOT gradient was 2.4m/s (1.7-2.9) at discharge. It transiently increased, then declined and stabilized during follow-up. PVA Z-score was -1.7 (-3.1 to 0.5) at discharge and 'grew' to -0.8 (-1.7 to 0.4) at last follow-up. Freedom from RVOT re-intervention was 97%, 94% and 91% at 1, 5 and 10-year follow-up. Among 67 (43%) patients with PVA Z-score < -2, a similar RVOT gradient pattern was observed and freedom from RVOT re-intervention was 97%, 95% and 95% at 1, 5 and 8-year follow-up. Following VSR of TOF, RVOT gradients transiently increase and then fall as PVA growth catches up, resulting in durable intermediate outcomes. Patients with PVA Z-score < -2 demonstrated a similar pattern of hemodynamics in the RVOT and excellent freedom from reintervention.

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.

Rescue right ventricular outflow tract stenting for refractory hypoxic spells.

While right ventricular outflow tract stenting (RVOTS) has become an acceptable alternative to palliative surgery in Tetralogy of Fallot (TOF) and similar physiologies, its utility for relief of refractory hypoxic spells is unclear. Patients who underwent RVOTS for emergency relief of refractory hypoxic spells were identified. Specific modifications to enable expeditious RVOTS included use of stent delivery systems (guiding catheter or long sheath) upfront to minimize catheter exchanges; using coronary wires to cross RVOT initially; stabilizing the catheter with a wire in the aorta while crossing RVOT with a second wire. From 2015 to 2022, 11 patients underwent RVOTS for hypoxic spells refractory to medical management. Their median age was 27 days (IQR 8.5-442.5); weight 3.27 kg (2.7-8.96); 9 males. Median pulmonary annulus Z score was -4.13 (IQR-4.85 to-0.86). Thirteenstents with median diameter 5 (4-6.5) mm and length 19 (16-19.75) mm were implanted, fluoroscopy time:13.6 (11-26.3) min; procedure time (60, 30-70 min). All were ventilated. Oxygen saturations improved from 45% (40-60) to 90% (84-92); (p < 0.0001) with no major complications. Postprocedure ventilation was needed for 21 (20-49) hours and 4 required diuretic infusion for pulmonary over-circulation. Four needed re-stenting 13 days to 5 months later. At median follow-up of 7 (4-17) months; 2 died from unrelated causes, 3 underwent surgery (two correction and one aorto-pulmonary shunt) and 6 await surgery. RVOTS enables safe, expeditious and effective short-term palliation for refractory hypoxic spells. Specific technical modifications facilitate safety, ease and swiftness.

When do patients with Tetralogy of Fallotneed a transannular patch.

The objective of this study was to evaluate the predictive value of main pulmonary artery(MPA) Zscore, pulmonary valve annulus(PVA) prop, great aortic valve annulus(GA) ratio, PVA index(PAI), and PVA area index(PAAI) indicators in patients with Tetralogy of Fallot (TOF) and whether or not to undergo transannular patch (TAP). A retrospective analysis was performed on the clinical data of 263 patients with TOF who underwent radical operations from 2010 to 2021 at Beijing Children's Hospital. Sixteen cases were excluded, and 247 cases (male/female = 155/92) were included in this study. Based on whether TAP was selected intraoperatively, the patients were divided into the TAP group (82/247) and the non-TAP group (165/247). The diameter of the PVA, the aortic valve annulus, and the MPA were measured by echocardiography, and the PVA Zscore, MPA Zscore, PVA prop, GA ratio, PAI, and PAAI indexes were calculated, and statistical analysis was carried out. The PVA Zscore, MPA Zscore, PVA prop, GA ratio, PAI, and PAAI of the TAP group were lower than those of the non-TAP group (p < .0001, p < .0001, p < .0001, p < .0001, p < .0001, andp < .0001). Receiver-operating curveanalysis showed that the cut-off value of PVA Zscore was -1.96 (area under the curve [AUC]: 0.822; 95% confidence interval [CI]: 0.769-0.874); the cut-off value of MPA Zscore was -1.04 (AUC: 0.778;95%CI: 0.711-0.845); the cut-off value of PVA prop was 0.37 (AUC: 0.812;95%CI: 0.751-0.874); the cut-off value of GA ratio was 0.64 (AUC: 0.812;95%CI: 0.750-0.874); the cut-off value of PAI is 0.78 (AUC: 0.812;95%CI: 0.750-0.874); and the cut-off value of PAAI is 0.4 (AUC: 0.812; 95%CI: 0.750-0.874). Pulmonary valve bicuspid malformation is one reason why predictive models fail to predict the possible avoidance of TAP. Pearson's correlation and linear regression analysis showed that PAI had the strongest correlation with PVA Zscore, followed by that betweenPVA prop and PVA Zscore, and the weakest correlation between PAAI and PVA Zscore. PVA prop, GA ratio, PAI, and PAAI can well predict TAP selection, and the measurement is simple and convenient. Compared with PVA Zscore, they are not hindered by other confounding factors, and can well replace the application value of PVA Zscore in TAP prediction. The predictive efficacy of PAI and PVA prop is numerically better than theGA ratio, and PAAI, PAI, and PVA prop combined with MPA Zscore can improve the predictive value of PAI and PVA prop, respectively. Although various echocardiographic parameters can be used as indicators to predict surgical approach in patients with TOF, PV morphologyand tissue characteristics should also be considered.

Feasibility and Surgical Effect of Annulus Sparing in Consecutive Patients with Tetralogy of Fallot: A Retrospective Cohort Study

Objective: Annulus-sparing (AS) repair for tetralogy of Fallot (TOF) with a dysplastic pulmonary valve annulus (PVA) is a challenging procedure and is controversial. This study aimed to assess the feasibility and surgical effect of AS repair versus transannular patch enlargement (TAPE) repair, especially in individuals with dysplastic pulmonary valves. Methods: This retrospective cohort study included 375 pediatric patients with a primary diagnosis of TOF in the Center for Pediatric Cardiac Surgery of Fuwai hospital from January 2014 to June 2017. Among them, 60 consecutive and nonselective patients underwent 1-stage repair of TOF with aggressive PVA-preserving strategies performed by a single surgeon were enrolled in AS cohort. In AS cohort, patients were divided into AS, PVA z-score ≥−2 group (33 patients) and AS, PVA z-score &lt;−2 group (27 patients). During the same period, 315 patients underwent TAPE repair by other surgeons were enrolled as TAPE cohort, of these, 87 patients with PVA z-score ≥−2 were excluded. From the 228 patients in the TAPE group, 27 cases were selected as TAPE, PVA z-score &lt;−2 group according to the propensity score and 1:1 ratio with AS, PVA z-score &lt;−2 group. The primary outcome was a composite of reintervention, significant pulmonary regurgitation, and significant annular peak gradient (APG). Kaplan-Meier curve was plotted to show the survival rate of severe pulmonary regurgitation. Results: One death occurred after the TAPE operation in TAPE group, and 1 patient in the AS z ≥−2 group needed reintervention with a balloon. After a median follow-up of (30.3 ± 11.6) months, compared with AS z ≥−2 group, there was no difference in the technical performance score for severe pulmonary stenosis (APGs &gt; 20 mmHg) in the AS z &lt;−2 group. Compared with TAPE, AS repair was often accompanied by a postoperative APGs over 20 mmHg (P = 0.001). More patients underwent TAPE suffered from moderate or severe pulmonary regurgitation than those who received AS repair (20 (74.1%) vs. 7 (26.0%), P &lt; 0.001). AS repair was associated with a shorter duration of mechanical ventilation (20 vs. 29 hours, P = 0.039), faster discharge from the intensive care unit (2.0 vs. 4.0 days, P = 0.022) and shorter postoperative hospitalization (8.0 vs. 11.0 days, P = 0.008) compared with TAPE. Conclusions: APG demonstrated an upward trend in the TAPE group and a downtrend in the AS group after discharge from hospital. AS repair had an acceptable surgical effect in TOF patients, even in those with a dysplastic PVA. A higher APG remained upon hospital discharge in dysplastic patients with AS, but a downward trend was observed over time.

Situación Fallot reparada en la edad adulta: resultados de 3 décadas de experiencia

IntroductionWe define “Fallot situation” as the existence of significant ventricular septal defect and right ventricular outflow obstruction. Survival into adulthood is extremely rare without complete surgical repair. We present our experience operating these adults. MethodsWe consider complete surgical repair in Fallot adult patients if they have pulmonary arteries with adequate size. Retrospective study: 45 Fallot patients operated from 1993 to 2022 in our adult congenital heart unit. Statistical analysis: SPSS® 20.0. ResultsMean age: 37±13 years, 53% male, 18% prior palliation. Principal diagnosis: double chamber right ventricle+ventricular septal defect (60%), tetralogy of Fallot (27%). NYHA functional class: i 31%, ii 38%, iii 31%. Arrhythmia 20%. Mean hematocrit: 48±10%. Associated left pulmonary artery agenesis 7%, severe aortic regurgitation 7%. Main surgical indication was pulmonary stenosis 98%. Additional tests showed high gradients between the right ventricle and pulmonary artery, and good biventricular function. Surgeries were performed by median sternotomy with cardiopulmonary bypass, moderate hypothermia and aortic clamp. Ventricular septal defect was closed through the right atrium (71%). Reconstruction of the right ventricle outflow tract was done by preserving the pulmonary valve (80%), interposing bioprosthesis (16%), and using transannular patch (4%). Associated surgery (18%): tricuspid (one), aortic (6), anomalous pulmonary venous drainage (one). Inhospital mortality: one patient (2,2%). Mean follow-up: 8.9±7.6 years. Late mortality: 2 patients (4.5%). Reintervention: 7 patients (15%) because of residual lesions (3 percutaneous, 5 surgical). Nowadays, functional class: i 68%, ii 28%, iii 4%; sinus rhythm 83%. ConclusionsComplete surgical repair in adulthood of Fallot patients achieves clinical improvement by eliminating the cyanosis, closing intracardiac shunts, and decreasing right ventricular pressure overload. Our results are excellent with good rates of pulmonary annulus preservation, low mortality and acceptable reintervention rate in the follow up.

Role of great artery annulus ratio to predict transannular patch enlargement in repair of tetralogy of Fallot

BackgroundTraditionally, the pulmonary valve annulus (PVA) z-score is used to predict the requirement of transannular patch enlargement (TAPE) of right ventricular outflow tract (RVOT) and main pulmonary artery (MPA) in repair of tetralogy of Fallot (TOF). PVA z-score is highly variable and many other parameters are being reported to be accurate in predicting need of TAPE. In this study, we analyze the role of great artery annulus ratio (pulmonary valve annulus to aortic valve annulus ratio, PVA/AVA) to be used as a predictor for TAPE.MethodsWe analyzed 90 patients of TOF retrospectively who underwent repair between January 2021 and December 2021. The patients were divided as TAPE group who required TAPE of RVOT and MPA and non-TAPE group who did not have TAPE. Their baseline parameters, PVA Z-score, and cut-off great artery annulus ratio were compared.ResultsTotal 44 (48.9%) patients had transannular patch (TAPE) repair and 46 (51.1%) patients had non-transannular patch repair. The great artery annulus ratio and PVA z-score was lower in case of TAPE group with statistical significance. Receiver operating characteristic curve analysis showed great artery annulus ratio as more accurate predictor of TAPE.ConclusionGreat artery annulus ratio can be used as a simple and accurate predictor for transannular patch enlargement along with PVA z-score during repair of TOF.

The angiographic study of right ventricular outflow tract and pulmonary artery anatomy in tetralogy of Fallot

Objective: The objective of the study is to determine various anatomic variations in the pulmonary vasculature and associated cardiac defects in patients with tetralogy of Fallot (TOF). Methods: This was a cross-sectional descriptive study conducted at Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore from January 2009 to December 2017. A total of 100 patients irrespective of age and gender, who were subjected to cardiac catheterization were enrolled in the study which included all age groups. Measurement of pulmonary valve annulus, main pulmonary artery, right pulmonary artery (RPA), left pulmonary artery (LPA), and descending aorta was taken and corresponding z scores were calculated. McGoon ratio and Nakata index were also calculated. Results: The age group in our study varied from 9 months to 49 years of age. Male-to-female gender ratio was 3:2. All patients had subvalvar (infundibular) stenosis and 82% of patients had stenosis at the valvar level. Seven patients had discrete stenosis, another seven patients had disconnection of RPA or LPA and six patients had supravalvar stenosis in the form of diffuse hypoplasia of one of the pulmonary arteries (PA). Significant communicating major aortopulmonary collaterals arteries (MAPCAs) were seen in 5% of patients and 16% of the patients had a persistent patent ductus arteriosus (PDA). Persistent left superior vena cava was present in 9 patients and 13% of the patients had coronary anomalies. Conclusion: Subvalvular stenosis, confluence of PA, discrete, disconnected, and diffuse stenosis of LPA and RPA were the most common PA abnormalities found in patients with TOF. Significant-associated cardiac lesions including communicating MAPCA, PDA, and coronary anomaly were more commonly observed in these patients.

Characterization of main pulmonary artery and valve annulus region of piglets using echocardiography, uniaxial tensile testing, and a novel non-destructive technique.

Characterization of cardiovascular tissue geometry and mechanical properties of large animal models is essential when developing cardiovascular devices such as heart valve replacements. These datasets are especially critical when designing devices for pediatric patient populations, as there is often limited data for guidance. Here, we present a previously unavailable dataset capturing anatomical measurements and mechanical properties of juvenile Yorkshire (YO) and Yucatan (YU) porcine main pulmonary artery (PA) and pulmonary valve (PV) tissue regions that will inform pediatric heart valve design requirements for preclinical animal studies. In addition, we developed a novel radial balloon catheter-based method to measure tissue stiffness and validated it against a traditional uniaxial tensile testing method. YU piglets, which were significantly lower weight than YO counterparts despite similar age, had smaller PA and PV diameters (7.6–9.9 mm vs. 10.1–12.8 mm). Young’s modulus (stiffness) was measured for the PA and the PV region using both the radial and uniaxial testing methods. There was no significant difference between the two breeds for Young’s modulus measured in the elastic (YU PA 84.7 ± 37.3 kPa, YO PA 79.3 ± 15.7 kPa) and fibrous regimes (YU PA 308.6 ± 59.4 kPa, YO PA 355.7 ± 68.9 kPa) of the stress-strain curves. The two testing techniques also produced similar stiffness measurements for the PA and PV region, although PV data showed greater variation between techniques. Overall, YU and YO piglets had similar PA and PV diameters and tissue stiffness to previously reported infant pediatric patients. These results provide a previously unavailable age-specific juvenile porcine tissue geometry and stiffness dataset critical to the development of pediatric cardiovascular prostheses. Additionally, the data demonstrates the efficacy of a novel balloon catheter-based technique that could be adapted to non-destructively measure tissue stiffness in situ.

Outcome of humanitarian patients with late complete repair of tetralogy of Fallot: A 13-year long single-center experience

BackgroundSurgical repair of tetralogy of Fallot is usually performed between 3 and 6 months of age with pulmonary valve-sparing repair promoted for the best long-term result. Through a humanitarian program from developing countries, late complete surgical repair of tetralogy of Fallot has been performed at our institution for many years. MethodsRetrospective analysis of pre- and perioperative data, as well as 30-days outcome of patients older than one year with a confirmed diagnosis of tetralogy of Fallot who had a complete surgical repair between 2005 and 2018 at our institution. ResultsOne hundred sixty-five patients were included with a median age of 4.5 years [3.0–6.3], median weight of 13.5 kg [10.9 to 16.5], median transcutaneous oximetry of 78% [70 to 85] and median pulmonary valve annulus Z-score of −1.8 [-3.4 to −0.8]. There was no early surgical mortality. By multivariate analysis, only severe right ventricular hypertrophy, severe right ventricle outflow tract obstruction, and hypoplasia of the main pulmonary artery were independent predictors of failure to preserve the pulmonary annulus at surgical repair. ConclusionsLate complete surgical repair of tetralogy of Fallot has low mortality and morbidity even when pulmonary valve-sparing repair cannot be successfully performed. The preservation of the pulmonary valve function is significantly associated with shorter ventilation time, ICU and hospital lengths of stay. In the analyzed group of patients, a pulmonary valve-sparing repair cannot be predicted exclusively based on the dimension of the pulmonary valve annulus.

Incremental Value of Myocardial Deformation in Predicting Postnatal Coarctation of the Aorta: Establishment of a Novel Diagnostic Model

Prenatal detection of coarctation of the aorta (CoA) still suffers from high false-positive and false-negative rates. The objective of this study was to develop a novel model to improve the diagnostic accuracy of fetal CoA. A retrospective study was conducted in 122 fetuses with suspected CoA who also had postnatal follow-up. Fetuses with confirmed diagnoses of CoA after birth were defined as the CoA group, and the non-CoA group comprised those with false positives. Conventional fetal echocardiographic measurements, including great arterial dimensions and flow characteristics, were obtained. Left ventricular (LV) functional parameters were determined using two-dimensional speckle-tracking echocardiography. A novel multiparametric diagnostic model, including gestational age at diagnosis, aortic isthmus (AOI) Z score, and LV longitudinal strain (LVLS), was developed in univariate and multivariate logistic regression analyses. The model was validated prospectively by a validation cohort of 48 fetuses. CoA was confirmed in 62 of 122 patients (50.8%) after birth. Fetuses with postnatal CoA were diagnosed significantly earlier than those with false-positives (median, 24.5weeks [interquartile range, 23.3-26.4weeks] vs 27.8weeks [interquartile range, 24.5-30.4weeks]; P<.001). The Z scores of aortic dimensions (aortic valve annulus, ascending aorta, transverse aortic arch, and AOI) were significantly smaller (P<.001 for all), whereas the Z scores of pulmonary dimensions (pulmonary valve annulus and main pulmonary artery) were significantly greater (P<.05 for all), in cases of confirmed CoA than false positives. Compared with the non-CoA group, the CoA group displayed lower LV ejection fraction (P=.005), LV fractional area change (P<.001), and LVLS (P<.001). A multivariate logistic regression model incorporating gestational age (odds ratio, 0.74; 95% CI, 0.60-0.88; P=.001), AOI Z score (odds ratio, 0.20; 95% CI, 0.08-0.41; P<.001), and LVLS (odds ratio, 1.79; 95% CI, 1.41-2.42; P<.001) was shown to diagnose CoA more accurately (Akaike information criterion=81.77, C statistic=0.945). The performance of this model was confirmed prospectively in the validation cohort. In fetuses with suspected CoA, speckle-tracking analysis of LVLS may have incremental value in predicting postnatal CoA. The diagnostic model presented here, including gestational age, AOI Z score and LVLS, may provide a good tool for stratification of risk in fetal CoA and contribute to patient-specific perinatal management.

Outcome Predictors in Catheter Interventions for Severe Right Ventricular Outflow Tract Obstructions.

Introduction & aim of workTranscatheter treatment for critical pulmonary stenosis and membranous pulmonary atresia has become the gold standard of care in many centers. We aimed at evaluating the predictors of outcome in interventions for treatment of duct-dependent right ventricular outflow tract obstruction with intact interventricular septum.Subjects & methods68 cases with pulmonary atresia with intact interventricular septum (PA/IVS) and 50 cases with critical pulmonary stenosis (CPS), all younger than 3 months of age, were operated during the period of 10 years; excluding patients with tricuspid valve annulus Z-score smaller than −4, evidence of right ventricular-dependent coronary circulation or additional malformations.ResultsAge, weight, body surface area as well as tricuspid & pulmonary valve Z-scores were significantly less in PA/IVS; right ventricular pressure was similar in both groups however procedural success and survival to hospital discharge was higher in the CPS group. Lower age, weight and body surface area were associated with procedural failure. Weight was the only predictor of procedural success; while weight and lower post-procedural right ventricular pressure were independent predictors for survival to hospital discharge. Post-procedural right ventricular pressure and length of stay were less in the CPS group. tricuspid and pulmonary valve annulus Z-scores were the only independent predictors of the post-procedural milrinone duration in PA/IVS.ConclusionWe advocate for the use of larger balloon/pulmonary annulus ratio, to achieve a lower right ventricular pressure not fearing excessive pulmonary regurgitation that might be beneficial for right ventricular growth; and for the combination with ductal stenting in borderline or bipartite right ventricles.

The Clinical Trial Outcomes of Med-Zenith PT-Valve in the Treatment of Patients With Severe Pulmonary Regurgitation.

ObjectiveNearly 2/3 of patients with dilated right ventricular outflow tract (RVOT) were excluded from pulmonary valves transplantation due to the lack of size-matched valves. Here, we explored the safety and efficacy of the Med-Zenith PT-Valve for the treatment of patients with severe pulmonary regurgitation.Methods22 Patients with severe PR (grade 3+,4+) were enrolled based on the anatomical features of native RVOT and the valve design. The immediate, 3-months and 1-year post-procedural follow-up data were analyzed.ResultsThe baseline mean systolic diameters in the distal main pulmonary artery (MPA), MPA sinus junction, MPA sinus, pulmonary annulus, RVOT aneurysm and muscular outlet measured with computed tomography were 33.6 ± 6.1, 34.0 ± 5.8, 37.9 ± 6.0, 32.4 ± 7.3, 41.9 ± 9.3, and 34.4 ± 8.0 mm, respectively. The PT-Valve landing zone was set within these levels. Successful valve implantations were achieved in all patients without noticeable device malposition, coronary artery compression, pulmonary branch obstruction or paravalvular leak during follow-ups. Post-procedural pulmonary artery diastolic pressure increased from 5.8 ± 3.1 to 11.3 ± 2.5 mmHg. In the 3-month and 1-year follow-up, the right ventricular end diastolic volume index reduced from the baseline 181.6 ± 29.0 to 143.7 ± 29.7 ml/m2 and 123.4 ± 31.2 ml/m2, and the trans-pulmonary valve gradient decreased from 25.6 ± 22.2 to 10.64 ± 3.54 mmHg and 11.16 ± 3.0 mmHg, respectively. The 6-min walk distance increased from 416.6 ± 97.9 to 455.9 ± 64.6 m and 467.8 ± 61.2 m, respectively.ConclusionThis clinical trial revealed favorable outcomes for the safety, efficacy and feasibility of the Med-Zenith PT-Valve in the treatment of severe PR with significantly enlarged RVOT.

Effect of percutaneous pulmonary valve replacement on ventricular electrophysiological remodeling in a porcine model of repaired tetralogy of Fallot

Tetralogy of Fallot is the most common cyanotic congenital heart disease. Late after corrective surgery, patients are at risk of developing right ventricular (RV) failure due to pulmonary valve regurgitation and arrhythmias related to surgical scars and ventricular electrophysiological remodeling. Pulmonary valve replacement has been identified as an interesting strategy to reduce RV dilatation but its impact on the arrhythmic risk remains uncertain. We sought to determine whether percutaneous pulmonary valve implantation (PPVI) at an early pathological stage leads to benefical effects on right and left ventricular electrophysiological remodeling in a porcine model of repaired tetralogy of Fallot (rTOF). Piglets (<10 kg) underwent pulmonary artery banding, pulmonary valve disruption to induce RV hypertrophy and dilatation and a PTFE patch was sewn across the pulmonary annulus. Two-months later, PPVI was performed in a sub-group of rTOF pigs. At 3 months post-surgery, cardiac function was assessed by MRI in rTOF, rTOF-PPVI and Sham-operated pigs. Animals were euthanized and optical mapping of isolated left and right ventricles electrical activity was performed using the voltage-sensitive dye Di-4-ANEPPS. Expression of selected genes was assessed by quantitative RT-PCR. At 3 months post-surgery, pulmonary artery regurgitation, RV end-diastolic and end-systolic volumes normalized to body surface area were significantly increased in rTOF pigs compared to Sham animals. In rTOF-PPVI animals these parameters were partially reversed and not statistically different from Sham pigs. An action potential prolongation was observed in both the left ventricle and the RV epicardium but not in the endocardium of rTOF pigs. Within the RV epicardium, this prolongation was mainly confined to the anterior side. Interestingly, rTOF-PPVI pigs action potential durations were similar to Sham animals. In line with functional investigations, a large increase in BNP expression was found in rTOF RV compared to Sham pigs (fold change = 34) which was not as pronounced in rTOF-PPVi pigs (fold change = 3) while a lower expression of KCND3 and KCNJ2 was found in rTOF pigs. In our rTOF porcine model, PPVI at an early pathological stage reversed RV dilatation. It also successfully reversed action potential prolongation in the left ventricle and the anterior RV epicardium, and may thus have beneficial effects on the arrhythmic risk.

Non-invasive identification of slow conducting anatomical isthmuses in patients with tetralogy of Fallot by 3D late gadolinium enhancement cardiovascular magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: None. Background Patients with repaired tetralogy of Fallot (rTOF) remain at risk of sudden cardiac death due to reentrant sustained monomorphic ventricular tachycardia (SMVT). Slow conducting anatomical isthmuses (SCAI), in particular SCAI3 at the outlet septum, bordered by the pulmonary annulus and the ventricular septal defect patch, are the dominant substrate for SMVT. Electroanatomical mapping (EAM) is the invasive gold standard to identify SCAIs, and transection of SCAI by catheter ablation has been correlated with favorable long-term outcome. Non-invasive identification of SCAI for risk stratification and treatment planning is needed but has not been established yet. Three-dimensional (3D) late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) facilitates accurate visualization of morphologically complex hearts with high-spatial resolution. Objective The study thought to determine whether 3D LGE-CMR can identify SCAIs. Methods Consecutive patients with rTOF who underwent right ventricular (RV) EAM and 3D LGE-CMR were included. LGE-CMR-derived 3D RV reconstructions were created (ADAS-3D) and merged with 3D RV EAM data. Mapping points were superimposed on the CMR-derived 3D reconstruction allowing for direct comparison of EAM data and local signal intensity (SI). The optimal SI cut-off to identify low bipolar voltage (LBV, BV&amp;lt;1.76mV) was determined by receiver operating characteristic carve. An abnormal AI on LGE-CMR was defined as AI with continuous SI above the obtained cut-off connecting AI borders. Results Forty-eight rTOF patients (34±16 years, 58% male) were included. At EAM, 21 patients had normal AI, and 20 and 7 had a SCAI (&amp;lt;0.5m/s) or blocked AI, which was AI3 in all. Patients with SCAI showed low BV of AI3 (median 0.7 [range 0.25-2.59] mV). In 11 patients, 14 SMVTs could be induced, all related to SCAI3. A total of 9240 points were analyzed, showing a significant correlation between BV and SI (R=0.4, P&amp;lt;0.001). The optimal SI cut-off to identify LBV was 42% of the maximal SI (MSI) (AUC 0.80; sensitivity, 74%; specificity, 78%). Using this cut-off of MSI, a SCAI or blocked AI3 could be correctly identified by LGE-CMR in all 27 patients, and a normal AI3 could be correctly confirmed by LGE-CMR in 14/21 patients with normal EAM findings (Figure). The sensitivity and specificity of 3D LGE-CMR for identifying SCAI or blocked AI3 were 100% and 67%, respectively. Of note, among patients with normal EAM findings, those with abnormal AI3 on LGE-CMR had significantly lower BV of AI3 than those with normal AI3 on LGE-CMR (2.06 [Range, 1.62-2.60] vs. 3.53 [2.22-5.67] mV, P&amp;lt;0.01). Conclusion 3D LGE-CMR can identify SCAI with 100% sensitivity and may identify diseased AI3 even before critical conduction delay occurs. This technique may allow for non-invasive risk stratification of VT and can refine patient selection for invasive EAM.

Technique of Coronary Button Transfer Has no Impact on Neoaortic Root Size in Simple Transposition

We studied the effect of various coronary transfer techniques (CTT) on neo-aortic root size after an arterial switch operation (ASO) in simple transposition by excluding the impact of recognized predisposing factors. One hundred and seventy-eight patients with simple transposition were reviewed retrospectively (January 2004-December 2018) and grouped as Punch Hole (n=83/178), Nonpunch Hole (n=65/178; Trapdoor or Standard) and Mixed (n=30/178). Factors predicting the neo-aortic root z-scores- annulus, mid-sinus, and sinotubular junction (STJ) were analyzed by uni/multivariable linear regression. Follow-up was 6 years, Interquartile range (IQR) 3.4,10.6. Preoperative aortic (7.4 mm, IQR 6.9,8) and pulmonary annulus (7.5 mm, IQR 6.8,8.1) sizes were identical (P=0.831). The changes in preoperative, postoperative, and latest median z-scores for neo-aortic annulus (-0.2, IQR -1.2,0.9; 0.0, IQR -0.9,0.9; 0.9, IQR -0.4,2.6; P < 0.001), mid-sinus (1.1, IQR-0.1,2; 2.6, IQR 1.6,3.7; 2.9, IQR 1.8,4.3; P < 0.001) and STJ (-0.1, IQR -0.8,1.1; 2.1, IQR 0.7,3; 2.4, IQR 1,3.5; P < 0.001) were significant. On multivariate analysis, preoperative pulmonary annulus z-score predicted the latest neo-aortic annulus z-score [Beta estimate (BE)=0.32, 95% confidence interval (CI)=0.03,0.62; P=0.03] and STJ z-score (BE= 0.45, 95% CI= 0.20,0.70; P < 0.0001). CTT did not predict any of the latest neo-aortic z-scores (all P > 0.05). Mild plus neo-aortic regurgitation (neoAR) was not significantly different across CTT groups [punch hole 20% (n=15/74), mixed 37% (n=11/30), nonpunch hole 21% (n=13/62); Fisher-exact P=0.186], one patient required valve replacement for severe neoAR. The neo-aortic root enlarges significantly over time at all 3 levels following an ASO in simple transposition, however, this is not significantly influenced by the CTT utilized.

Comparison of non-invasive assessment for pulmonary vascular indices by two-dimensional echocardiography and cardiac computed tomography angiography with conventional catheter angiocardiography in unrepaired Tetralogy of Fallot physiology patients weighing more than 10 kg: a retrospective analysis.

Assessment of pulmonary vascular dimensions (PVDs) in Tetralogy of Fallot (TOF) is an integral part of planning transcatheter and surgical interventions. We sought to examine the reliability and correlation of echocardiography (ECHO) and computed tomography angiography (CTA) measurements with those obtained by cardiac catheterization and angiography (CCA). Tetralogy of Fallot physiology patients undergoing ECHO, CTA, and CCA within a month prior to surgical correction during 2018-2020 were retrospectively enrolled. Indexed diameter of pulmonary annulus (iPAnn), indexed right pulmonary artery (iRPA), indexed left pulmonary artery (iLPA) and indexed descending aorta (iDA) were measured using ECHO and CTA followed by derivation of Nakata index (NI), McGoon's ratio (MGR), ratio of predicted peak right ventricular (RV) and left ventricular (LV) pressures (pRV/pLV) and Z-scores. Comparison with CCA-derived measurements was made and correlational equations were subsequently deduced. Pulmonary vascular dimensions for 54 patients with mean age of 15.5 ± 9.3 years (range: 3-34 years) were analysed. Computed tomography angiography and CCA measurements for iPAnn, iRPA, NI, MGR, pRV/pLV, and Z-score were comparable with each other while ECHO parameters were significantly lower than CCA. However, iLPA diameter was significantly underestimated by ECHO and overestimated by CTA. Correlational analysis showed stronger correlation between CTA- and CCA-derived PVD as against ECHO measurements except for iDA, pRV/pLV, and Z-score. For unrepaired TOF physiology patients weighing more than 10 kg, CTA-acquired PVD are reliable and comparable with CCA except for DA for which ECHO is non-inferior. Non-invasive modalities though are inferior to CCA for LPA sizing. Utilizing derived equations, precise estimation of PVD can be carried out using non-invasive tools.

PE-565-03 NON-INVASIVE IDENTIFICATION OF SLOW CONDUCTING ANATOMICAL ISTHMUSES IN PATIENTS WITH TETRALOGY OF FALLOT BY 3-DIMENSIONAL LATE GADOLINIUM ENHANCEMENT CARDIOVASCULAR MAGNETIC RESONANCE IMAGING

Patients with repaired tetralogy of Fallot (rTOF) remain at risk of sudden cardiac death due to sustained monomorphic ventricular tachycardia (SMVT). The majority of SMVTs are related to slow conducting anatomical isthmuses (SCAI) in particular to SCAI3 at the outlet septum, bordered by the pulmonary annulus and the ventricular septal defect patch. Electroanatomical mapping (EAM) is the invasive gold standard to identify SCAIs; non-invasive characterization of AIs has not been established.

Long-Term Performance of Untreated Fresh Autologous Pericardium as a Valve Substitute in Pulmonary Position

Background:Pulmonary regurgitation is imminent after transannular patch (TAP). We analyze the long-term performance of untreated autologous pericardium (UAP) as valve substitute at pulmonary position in patients requiring TAP.Material and Methods:This cross-sectional study include patients operated between 2007 and 2012 (n = 92). A sample of 19 patients was selected for this study which had a follow-up of more than 3 years. This includes patients with no TAP (n = 4) and with TAP and valve substitute, a monocusp (n = 11) or a tricuspid valve (n = 4) at neopulmonary annulus. Patients underwent echocardiography for assessment of right ventricle function and 18 fluoro-deoxyglucose PET CT scan for measurements of valve substitute at neopulmonary annulus. The target to blood ratio (TBR) of uptake of glucose by monocusp was measured at the cooptation edge of the neopulmonary valve.Results:The median age of the patients is 14 (9 – 37). RV function is preserved (TAPSE 18.9 (10.6 – 22.8)) at a mean follow-up of 4 years (3-9). The measurements of monocusp shows a shrinkage in height of the cusp by 35.5% (70% – 1.0%) and length by 7% (-44% - +104%). There was less shrinkage observed in patients below 15 years of age. The TBR of monocusp was 0.945 (0.17 – 3.35) with a strong correlation between the TBR values of aortic valve leaflet and monocusp leaflet of same patient.Conclusion:The UAP is functional and successful as a valve substitute at neo pulmonary annulus at long-term follow-up. It has resisted calcification and has shown uptake of glucose in physiological limits.

The combined S velocity achieved from tricuspid annulus and pulmonary annulus with tissue Doppler imaging could predict the proximal right coronary artery occlusion in patients with inferior myocardial infarction

The combined S velocity achieved from tricuspid annulus and pulmonary annulus with tissue Doppler imaging could predict the proximal right coronary artery occlusion in patients with inferior myocardial infarction