Left Valvar Morphology Is Associated With Late Regurgitation in Atrioventricular Canal Defect

FEBio FINESSE: An Open-Source Finite Element Simulation Approach to Estimate In Vivo Heart Valve Strains Using Shape Enforcement

PURPOSE

Finite element simulations are an enticing tool to evaluate heart valve function; however, patient-specific simulations derived from 3D echocardiography are hampered by several technical challenges. The objective of this work is to develop an open-source method to enforce matching between finite element simulations and in vivo image-derived heart valve geometry in the absence of patient-specific material properties, leaflet thickness, and chordae tendineae structures.

METHODS

We evaluate FEBio Finite Element Simulations with Shape Enforcement (FINESSE) using three synthetic test cases considering a range of model complexity. FINESSE is then used to estimate the in vivo valve behavior and leaflet strains for three pediatric patients.

RESULTS

Our results suggest that FINESSE can be used to enforce finite element simulations to match an image-derived surface and estimate the first principal leaflet strains within ± 0.03 strain. Key considerations include: (i) defining the user-defined penalty, (ii) omitting the leaflet commissures to improve simulation convergence, and (iii) emulating the chordae tendineae behavior via prescribed leaflet free edge motion or a chordae emulating force. In all patient-specific cases, FINESSE matched the target surface with median errors of approximately the smallest voxel dimension. Further analysis revealed valve-specific findings, such as the tricuspid valve leaflet strains of a 2-day old patient with HLHS being larger than those of two 13-year old patients.

CONCLUSIONS

FEBio FINESSE can be used to estimate patient-specific in vivo heart valve leaflet strains. The development of this open-source pipeline will enable future studies to begin linking in vivo leaflet mechanics with patient outcomes.

Left Atrioventricular Valve Regurgitation After Atrioventricular Septal Defect Repair

BACKGROUND

Whether patients with moderate left atrioventricular valve regurgitation (LAVVR) after surgical repair of complete atrioventricular septal defect (CAVSD) should be observed or undergo reoperation remains unclear.

METHODS

Moderate LAVVR was diagnosed in 87 of 220 patients who underwent CAVSD repair: 47 during the initial hospital stay and 40 after a median of 7 months (interquartile range, 2-18 months) after the initial operation.

RESULTS

Of these 87 patients who had moderate LAVVR, 15 died, for an overall mortality of 17%. The regurgitation became severe in 39 patients (45%) within a median of 2 months (interquartile range, 1-7 months) leading to 33 reoperations and 10 deaths. In 23 of 87 patients (26%), regurgitation remained at a moderate level over a median follow-up period of 8 months (interquartile range, 1-48 months). In 25 of 87 patients (29%), the regurgitation decreased to mild after a median of 9 months (interquartile range, 5-19 months). The only independent risk factor for increased severity of regurgitation and reoperation was the echocardiographic appearance of the jet centered around the cleft rather than central at the time of diagnosis of moderate regurgitation (odds ratio, 3.5; 95% CI, 1.5-9.0; P = .007).

CONCLUSIONS

Moderate LAVVR after CAVSD repair is often linked to death and reoperation, but regurgitation remains stable in one-quarter of patients and improves in one-third. The deterioration usually occurs within the first year after surgery. The initial observation of patients with residual or new moderate regurgitation for up to 1 year or until further deterioration seems reasonable, as long as the regurgitation is centrally located.

Risk factors for the recurrence of left atrioventricular valvular regurgitation after surgical repair of partial and transitional atrioventricular septal defect

Background

Left atrioventricular valvular regurgitation (LAVVR) recurrence after partial and transitional atrioventricular septal defect (AVSD) repair is the main risk factor associated with reoperation or mortality. The purpose of this study was to identify risk factors associated with the recurrence of LAVVR after surgical repair of transitional and partial AVSD at a single institution.

Methods

A hundred and fifty-seven patients who underwent anatomical repair for partial and transitional AVSD from January 2013 to December 2021 were included in our institutional database. Demographic characteristics, operative information, comorbidities, complications, and outcomes were retrieved from electronic medical records. Echocardiographic evaluations included cardiac dimensions, the degree of LAVVR, and the anatomy of the atrioventricular valve.

Results

After a median follow-up period of 5.8 years, 40 patients had recurrent moderate or even more severe LAVVR. Compared with patients without recurrent LAVVR, those experiencing LAVVR recurrence were more likely to have larger preoperative left atrial (LA) size and larger left ventricular (LV) size after standardization, larger left atrioventricular valve (LAVV) cleft width, higher proportions of preoperative moderate or even more severe LAVVR, and immediately postoperative mild to moderate or even more severe LAVVR. Univariate Cox regression analysis showed that age at first repair, height, LA size after standardization, LV size after standardization, the severity of preoperative LAVVR, immediately postoperative LAVVR, and the LAVV cleft width more than 1cm were risk factors for recurrent LAVVR (P<0.05 for all). Multivariable Cox regression analysis showed that mild to moderate or even more severe LAVVR postoperatively [hazard ratio (HR) 9.53, 95% confidence interval (CI): 3.78-24.01; P<0.001], the width of LAVV cleft more than 1 cm (HR: 3.90, 95% CI: 1.80-8.48; P<0.001) and age at first repair (HR: 0.45, 95% CI: 0.31-0.66; P<0.001) were independently associated with the recurrence of LAVVR.

Conclusions

The width of LAVV cleft, mild to moderate or even more severe LAVVR immediately after surgery, and age at initial surgery are risk factors for recurrent LAVVR. The presence of recurrent LAVVR necessitates proactive surveillance to facilitate timely reintervention.

Introduction of transcatheter edge-to-edge repair in patients with congenital heart disease at a children's hospital

BACKGROUND

Atrioventricular valve regurgitation (AVVR) is a devastating complication in children and young adults with congenital heart disease (CHD), particularly in patients with single ventricle physiology. Transcatheter edge-to-edge repair (TEER) is a rapidly expanding, minimally invasive option for the treatment of AVVR in adults that avoids the morbidity and mortality associated with open heart surgery. However, application of TEER in in CHD and in children is quite novel. We describe the development of a peri-procedural protocol including image-derived pre-intervention simulation, with successful application to four patients.

AIMS

To describe the initial experience using the MitraClip system for TEER of dysfunctional systemic atrioventricular valves in patients with congential heart disease within a pediatric hospital.

METHODS

A standardized screening and planning process was developed using cardiac magnetic resonance imaging, three dimensional echocardiography and both virtual and physical simulation. Procedures were performed using the MitraClip G4 system and patients were clinically followed post-intervention.

RESULTS

A series of four CHD patients with at least severe AVVR were screened for suitability for TEER with the MitraClip system: three patients had single ventricle physiology and Fontan palliation, and one had repair of a common atrioventricular canal defect. Each patient had at least severe systemic AVVR and was considered at prohibitively high risk for surgical repair. Each patient underwent a standardized preprocedural screening protocol and image-derived modeling followed by the TEER procedure with successful clip placement at the intended location in all cases.

CONCLUSIONS

The early results of our protocolized efforts to introduce TEER repair of severe AV valve regurgitation with MitraClip into the CHD population within our institution are encouraging. Further investigations of the use of TEER in this challenging population are warranted.

Visualization and Quantification of the Unrepaired Complete Atrioventricular Canal Valve Using Open-Source Software

BACKGROUND

Repair of complete atrioventricular canal (CAVC) is often complicated by residual left atrioventricular valve regurgitation. The structure of the mitral and tricuspid valves in biventricular hearts has previously been shown to be associated with valve dysfunction. However, the three-dimensional (3D) structure of the entire unrepaired CAVC valve has not been quantified. Understanding the 3D structure of the CAVC may inform optimized repair.

METHODS

Novel open-source work flows were created in SlicerHeart for the modeling and quantification of CAVC valves on the basis of 3D echocardiographic images. These methods were applied to model the annulus, leaflets, and papillary muscle (PM) structure of 35 patients (29 with trisomy 21) with CAVC using transthoracic 3D echocardiography. The mean leaflet and annular shapes were calculated and visualized using shape analysis. Metrics of the complete native CAVC valve structure were compared with those of normal mitral valves using the Mann-Whitney U test. Associations between CAVC structure and atrioventricular valve regurgitation were analyzed.

RESULTS

CAVC leaflet metrics varied throughout systole. Compared with normal mitral valves, the left CAVC PMs were more acutely angled in relation to the annular plane (P < .001). In addition, the anterolateral PM was laterally and inferiorly rotated in CAVC, while the posteromedial PM was more superiorly and laterally rotated, relative to normal mitral valves (P < .001). Lower native CAVC atrioventricular valve annular height and annular height-to-valve width ratio before repair were both associated with moderate or greater left atrioventricular valve regurgitation after repair (P < .01).

CONCLUSIONS

It is feasible to model and quantify 3D CAVC structure using 3D echocardiographic images. The results demonstrate significant variation in CAVC structure across the cohort and differences in annular, leaflet, and PM structure compared with the mitral valve. These tools may be used in future studies to catalyze future research intended to identify structural associations of valve dysfunction and to optimize repair in this vulnerable and complex population.

Dynamic Annular Modeling of the Unrepaired Complete Atrioventricular Canal Annulus

BACKGROUND

Repair of complete atrioventricular canal (CAVC) is often complicated by atrioventricular valve regurgitation, particularly of the left-sided valve. Understanding the 3-dimensional (3D) structure of the atrioventricular canal annulus before repair may help to inform optimized repair. However, the 3D shape and movement of the CAVC annulus has been neither quantified nor rigorously compared with a normal mitral valve annulus.

METHODS

The complete annuli of 43 patients with CAVC were modeled in 4 cardiac phases using transthoracic 3D echocardiograms and custom code. The annular structure was compared with the annuli of 20 normal pediatric mitral valves using 3D metrics and statistical shape analysis (Procrustes analysis).

RESULTS

The unrepaired CAVC annulus varied in shape significantly throughout the cardiac cycle. Procrustes analysis visually demonstrated that the average normalized CAVC annular shape is more planar than the normal mitral annulus. Quantitatively, the annular height-to-valve width ratio of the native left CAVC atrioventricular valve was significantly lower than that of a normal mitral valve in all systolic phases (P < .001).

CONCLUSIONS

The left half of the CAVC annulus is more planar than that of a normal mitral valve with an annular height-to-valve width ratio similar to dysfunctional mitral valves. Given the known importance of annular shape to mitral valve function, further exploration of the association of 3D structure to valve function in CAVC is warranted.

Atrial septal defect in adulthood: a new paradigm for congenital heart disease

Atrial septal defects (ASDs) represent the most common congenital heart defect diagnosed in adulthood. Although considered a simple defect, challenges in optimal diagnostic and treatment options still exist due to great heterogeneity in terms of anatomy and time-related complications primarily arrhythmias, thromboembolism, right heart failure and, in a subset of patients, pulmonary arterial hypertension (PAH). Atrial septal defects call for tertiary expertise where all options may be considered, namely catheter vs. surgical closure, consideration of pre-closure ablation for patients with atrial tachycardia and suitability for closure or/and targeted therapy for patients with PAH. This review serves to update the clinician on the latest evidence, the nuances of optimal diagnostics, treatment options, and long-term follow-up care for patients with an ASD.