Machine Learning and Statistical Shape Modelling Methodologies to Assess Vascular Morphology before and after Aortic Valve Replacement

Introduction: Statistical shape modelling (SSM) is used to analyse morphology, discover qualitatively and quantitatively unique shape features within a population, and generate mean shapes and shape modes that show morphological variability. Hierarchical agglomerative clustering is a machine learning analysis used to identify subgroups within a given population in relation to shape features. We tested the application of both methods in the clinically relevant scenario of patients undergoing aortic valve repair (AVR). Every year, around 5000 patients undergo surgical AVR in the UK. Aims: Evaluate aortic morphology and identify subgroups amongst patients who had undergone AVR, including Ozaki, Ross, and valve-sparing procedures using SSM and unsupervised hierarchical clustering analysis. This methodological framework can evaluate both pre- and post-surgical variability across subgroups undergoing different surgeries. Methods: Pre- (n = 47) and post- (n = 35) operative three-dimensional (3D) aortic models were reconstructed from computed tomography (CT) and cardiac magnetic resonance (CMR) images. Computational analyses for SSM and hierarchical clustering were run separately for the two subgroups, assessing (a) ascending aorta only and (b) the whole aorta. This allows for exploring possible variations in morphological classification related to the input shape. Results: Most patients in the Ross procedure subgroup exhibited differences in aortic morphology from other subgroups, including an elongated ascending and wide aortic arch pre-operatively, and an elongated ascending aorta with a slightly enlarged sinus post-operatively. In hierarchical clustering, the Ross aortas also appeared to cluster together compared to the other surgical procedures, both pre-operatively and post-operatively. There were significant differences between clusters in terms of clustering distance in the pre-operative analyses (p = 0.003 for ascending aortas, p = 0.016 for whole aortas). There were no significant differences between the clusters in post-operative analyses (p = 0.47 for ascending, p = 0.19 for whole aorta). Conclusions: We demonstrated the feasibility of evaluating aortic morphology before and after different aortic valve surgeries using SSM and hierarchical clustering. This framework could be used to further explore shape features associated with surgical decision-making pre-operatively and, importantly, to identify subgroups whose morphology is associated with poorer clinical outcomes post-operatively. Statistical shape modelling (SSM) and unsupervised hierarchical clustering are two statistical methods that can be used to assess morphology, show morphological variations, with the latter being able to identify subgroups within a population. These methods have been applied to the population of aortic valve replacement (AVR) patients since there are different surgical procedures (traditional AVR, Ozaki, Ross, and valve-sparing). The aim is to evaluate aortic morphology and identify subgroups within this population before and after surgery. Computed tomography and cardiac magnetic resonance images were reconstructed into 3D models of the ascending aorta and whole aorta, which were then input into SSM and hierarchical clustering. The results show that the Ross aortic morphology is quite different from the other aortas. The clustering did not classify the aortas based on the surgical procedures; however, most of the Ross group did cluster together, indicating low variability within this surgical group.

Protocol to decellularize porcine right ventricular outflow tracts using a 3D printed flow chamber

Surgical treatment of pediatric congenital heart disease with tissue grafts is a lifesaving intervention. Decellularization to reduce immunogenicity of tissue grafts is an increasingly popular alternative to glutaraldehyde fixation. Here, we present a protocol to decellularize porcine right ventricular outflow tracts using a 3D printed flow chamber. We describe steps for 3D printing the flow rig, preparing porcine tissue, and using the flow rig to utilize shear forces for decellularization. We then detail procedures for characterizing the acellular scaffold. For complete details on the use and execution of this protocol, please refer to Vafaee et al.1.

Development of a Novel Hierarchically Biofabricated Blood Vessel Mimic Decorated with Three Vascular Cell Populations for the Reconstruction of Small-Diameter Arteries

The availability of grafts to replace small-diameter arteries remains an unmet clinical need. Here, the validated methodology is reported for a novel hybrid tissue-engineered vascular graft that aims to match the natural structure of small-size arteries. The blood vessel mimic (BVM) comprises an internal conduit of co-electrospun gelatin and polycaprolactone (PCL) nanofibers (corresponding to the tunica intima of an artery), reinforced by an additional layer of PCL aligned fibers (the internal elastic membrane). Endothelial cells are deposited onto the luminal surface using a rotative bioreactor. A bioprinting system extrudes two concentric cell-laden hydrogel layers containing respectively vascular smooth muscle cells and pericytes to create the tunica media and adventitia. The semi-automated cellularization process reduces the production and maturation time to 6 days. After the evaluation of mechanical properties, cellular viability, hemocompatibility, and suturability, the BVM is successfully implanted in the left pulmonary artery of swine. Here, the BVM showed good hemostatic properties, capability to withstand blood pressure, and patency at 5 weeks post-implantation. These promising data open a new avenue to developing an artery-like product for reconstructing small-diameter blood vessels.

Surgical Patching in Congenital Heart Disease: The Role of Imaging and Modelling

In congenital heart disease, patches are not tailored to patient-specific anatomies, leading to shape mismatch with likely functional implications. The design of patches through imaging and modelling may be beneficial, as it could improve clinical outcomes and reduce the costs associated with redo procedures. Whilst attention has been paid to the material of the patches used in congenital surgery, this review outlines the current knowledge on this subject and isolated experimental work that uses modelling and imaging-derived information (including 3D printing) to inform the design of the surgical patch.

Reporting involvement activities with children and young people in paediatric research: a framework analysis

BACKGROUND

The active involvement of patients and the public in the design and delivery of health research has been increasingly encouraged, if not enforced. Knowledge of how this is realised in practice, especially where children and young people (CYP) are concerned, is limited, partly due to the low level of reporting of patient and public involvement (PPI) in general. The aim of this work was to assess how researchers funded by the National Institute for Health and Care Research (NIHR) report the involvement of CYP in the design and conduct of child health research to better understand the opportunities offered to CYP, and the realities of involvement in practice.

METHODS

A participation matrix, analysis framework and accompanying tools were adapted from existing frameworks, including a child-rights informed framework, the Guidance for Reporting Involvement of Patients and the Public Checklist Short Form (GRIPP2SF), and NIHR reporting expectations. Child-focused research reports were identified from the NIHR Journals Library, including any interventional or observational study involving CYP aged 0-< 24 years. In two co-design workshops with healthcare professionals and CYP, we tested and refined the participation matrix, analysis framework and accompanying tools.

RESULTS

Only thirty-two NIHR reports out of 169 (19%) were identified as relevant and included reporting of PPI with CYP. We identified significant variability in the way PPI with CYP was reported. Only 4/32 (12%) reports fully met NIHR (and GRIPP2SF) reporting criteria. Only 3/32 (9%) reports formally evaluated or self-reflected on PPI activities with CYP, whilst 15/32 (47%) provided minimal information about CYP involvement. The most common approach to involving CYP (23/32, 72%) was through the medium of existing groups or networks.

CONCLUSION

Despite the NIHR's commitment to increase the quality, transparency, and consistency of reporting PPI, the reporting of involvement with CYP remains sub-optimal. Neglecting to report key details of involvement methods and impacts deprives the research community of knowledge to advance the field of delivering 'meaningful' PPI with CYP. Practical guidance on how researchers can report the processes and outputs of CYP involvement more rigorously may help child health researchers to involve them more meaningfully. This research offers practical tools informed by CYP to aid the reporting process.

The Role of Immersive Virtual Reality and Augmented Reality in Medical Communication: A Scoping Review

Communication between clinicians and patients and communication within clinical teams is widely recognized as a tool through which improved patient outcomes can be achieved. As emerging technologies, there is a notable lack of commentary on the role of immersive virtual reality (VR) and augmented reality (AR) in enhancing medical communication. This scoping review aims to map the current landscape of literature on this topic and highlights gaps in the evidence to inform future endeavors. A comprehensive search strategy was conducted across 3 databases (PubMed, Web of Science, and Embase), yielding 1000 articles, of which 623 were individually screened for relevance. Ultimately, 22 articles were selected for inclusion and review. Similarities across the cohort of studies included small sample sizes, observational study design, use of questionnaires, and more VR studies than AR. The majority of studies found these technologies to improve medical communication, although user tolerability limitations were identified. More studies are required, presenting more robust findings, in order to draw more definitive conclusions and stronger recommendations for use of immersive VR/AR in clinical environments.

"Please keep on beating"-Participation in a Creative Workshop Offers Unexpected Benefits to Women With Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy (TCM) or "broken heart syndrome" is a rare condition that is more common in women than men, particularly those who are postmenopausal. It mimics a myocardial infarction and psychological factors have been implicated in its etiology as well as being consequences of its presentation. As part of a public engagement project we brought together 8 women (of 12 invited) previously diagnosed with TCM to facilitate a discussion, through participation in a creative workshop-based process, about their illness experience, how they made sense of it, and the meaning it had for them in their lives, and to identify areas of unmet need. Through a range of creative activities we identified that participants had high levels of unmet need in terms of information and psychosocial support. All participants enjoyed the creative process and meeting other people with a diagnosis of TCM. The workshop overall was perceived as empowering. Exploring patient narratives during artist-facilitated workshops is one approach for providing the first steps to addressing unmet need, although the importance of ensuring psychological safety cannot be over-stated.

Feasibility of Wave Intensity Analysis from 4D Cardiovascular Magnetic Resonance Imaging Data

Congenital heart defects (CHD) introduce haemodynamic changes; e.g., bicuspid aortic valve (BAV) presents a turbulent helical flow, which activates aortic pathological processes. Flow quantification is crucial for diagnostics and to plan corrective strategies. Multiple imaging modalities exist, with phase contrast magnetic resonance imaging (PC-MRI) being the current gold standard; however, multiple predetermined site measurements may be required, while 4D MRI allows for measurements of area (A) and velocity (U) in all spatial dimensions, acquiring a single volume and enabling a retrospective analysis at multiple locations. We assessed the feasibility of gathering hemodynamic insight into aortic hemodynamics by means of wave intensity analysis (WIA) derived from 4D MRI. Data were collected in n = 12 BAV patients and n = 7 healthy controls. Following data acquisition, WIA was successfully derived at three planes (ascending, thoracic and descending aorta) in all cases. The values of wave speed were physiological and, while the small sample limited any clinical interpretation of the results, the study shows the possibility of studying wave travel and wave reflection based on 4D MRI. Below, we demonstrate for the first time the feasibility of deriving wave intensity analysis from 4D flow data and open the door to research applications in different cardiovascular scenarios.

Perspectives on medical 3D printing at the point-of-care from the new European 3D Printing Special Interest Group

This editorial presents the vision for the newly formed (2022) European 3D Special Interest Group (EU3DSIG) in the landscape of medical 3D printing. There are four areas of work identified by the EU3DSIG in the current landscape, namely: 1) creating and fostering communication channels among researches, clinicians and industry, 2) generating awareness of hospitals point-of-care 3D technologies; 3) knowledge sharing and education; 4) regulation, registry and reimbursement models.

Assessment of post-infarct ventricular septal defects through 3D printing and statistical shape analysis

BACKGROUND

Post-infarct ventricular septal defect (PIVSD) is a serious complication of myocardial infarction. We evaluated 3D-printing models in PIVSD clinical assessment and the feasibility of statistical shape modeling for morphological analysis of the defects.

METHODS

Models (n = 15) reconstructed from computed tomography data were evaluated by clinicians (n = 8). Statistical shape modeling was performed on 3D meshes to calculate the mean morphological configuration of the defects.

RESULTS

Clinicians' evaluation highlighted the models' utility in displaying defects for interventional/surgical planning, education/training and device development. However, models lack dynamic representation. Morphological analysis was feasible and revealed oval-shaped (n = 12) and complex channel-like (n = 3) defects.

CONCLUSION

3D-PIVSD models can complement imaging data for teaching and procedural planning. Statistical shape modeling is feasible in this scenario.

Prospective multiparametric CMR characterization and MicroRNA profiling of anthracycline cardiotoxicity: A pilot translational study

Background

Anthracycline cardiotoxicity is a significant clinical challenge. Biomarkers to improve risk stratification and identify early cardiac injury are required.

Objectives

The purpose of this pilot study was to prospectively characterize anthracycline cardiotoxicity using cardiovascular magnetic resonance (CMR), echocardiography and MicroRNAs (MiRNAs), and identify baseline predictors of LVEF recovery.

Methods

Twenty-four patients (age 56 range 18-75 years; 42 % female) with haematological malignancy scheduled to receive anthracycline chemotherapy (median dose 272 mg/m2 doxorubicin equivalent) were recruited and evaluated at three timepoints (baseline, completion of chemotherapy, and 6 months after completion of chemotherapy) with multiparametric 1.5 T CMR, echocardiography and circulating miRNAs sequencing.

Results

Seventeen complete datasets were obtained. CMR left ventricular ejection fraction (LVEF) fell significantly between baseline and completion of chemotherapy (61 ± 3 vs 53 ± 3 %, p < 0.001), before recovering significantly at 6-month follow-up (55 ± 3 %, p = 0.018). Similar results were observed for 3D echocardiography-derived LVEF and CMR-derived longitudinal, circumferential and radial feature-tracking strain. Patients were divided into tertiles according to LVEF recovery (poor recovery, partial recovery, good recovery). CMR-derived mitral annular plane systolic excursion (MAPSE) was significantly different at baseline in patients exhibiting poor LVEF recovery (11.7 ± 1.5 mm) in comparison to partial recovery (13.7 ± 2.7 mm), and good recovery (15.7 ± 3.1 mm; p = 0.028). Furthermore, baseline miRNA-181-5p and miRNA-221-3p expression were significantly higher in this group. T2 mapping increased significantly on completion of chemotherapy compared to baseline (54.0 ± 4.6 to 57.8 ± 4.9 ms, p = 0.001), but was not predictive of LVEF recovery. No changes to LV mass, extracellular volume fraction, T1 mapping or late gadolinium enhancement were observed.

Conclusions

Baseline CMR-derived MAPSE, circulating miRNA-181-5p, and miRNA-221-3p were associated with poor recovery of LVEF 6 months after completion of anthracycline chemotherapy, suggesting their potential predictive role in this context. T2 mapping increased significantly on completion of chemotherapy but was not predictive of LVEF recovery.

A Segmental Approach from Molecular Profiling to Medical Imaging to Study Bicuspid Aortic Valve Aortopathy

Bicuspid aortic valve (BAV) patients develop ascending aortic (AAo) dilation. The pathogenesis of BAV aortopathy (genetic vs. haemodynamic) remains unclear. This study aims to identify regional changes around the AAo wall in BAV patients with aortopathy, integrating molecular data and clinical imaging. BAV patients with aortopathy (n = 15) were prospectively recruited to surgically collect aortic tissue and measure molecular markers across the AAo circumference. Dilated (anterior/right) vs. non-dilated (posterior/left) circumferential segments were profiled for whole-genomic microRNAs (next-generation RNA sequencing, miRCURY LNA PCR), protein content (tandem mass spectrometry), and elastin fragmentation and degeneration (histomorphometric analysis). Integrated bioinformatic analyses of RNA sequencing and proteomic datasets identified five microRNAs (miR-128-3p, miR-210-3p, miR-150-5p, miR-199b-5p, and miR-21-5p) differentially expressed across the AAo circumference. Among them, three miRNAs (miR-128-3p, miR-150-5p, and miR-199b-5p) were predicted to have an effect on eight common target genes, whose expression was dysregulated, according to proteomic analyses, and involved in the vascular-endothelial growth-factor signalling, Hippo signalling, and arachidonic acid pathways. Decreased elastic fibre levels and elastic layer thickness were observed in the dilated segments. Additionally, in a subset of patients n = 6/15, a four-dimensional cardiac magnetic resonance (CMR) scan was performed. Interestingly, an increase in wall shear stress (WSS) was observed at the anterior/right wall segments, concomitantly with the differentially expressed miRNAs and decreased elastic fibres. This study identified new miRNAs involved in the BAV aortic wall and revealed the concomitant expressional dysregulation of miRNAs, proteins, and elastic fibres on the anterior/right wall in dilated BAV patients, corresponding to regions of elevated WSS.

Interdisciplinarity and Patient Engagement: New Representations of Cardiovascular Anatomy

Background

This article presents and discusses the genesis, making and public presentation of two artworks by British artist Sofie Layton, namely Blueprints and The Bud, which explore the anatomy of the heart infusing it with experiential and narrative elements.

Methods

Artist-led workshops with a range of audiences (cardiac patients, medical staff, medical students, creative professionals, and patient relatives) led to explore narratives and imagery that, in turn, was re-presented in artworks exploring the complexity of the cardiovascular system.

Results

While positioning themselves in a long tradition of artistic representations of the heart, often purely anatomical or autobiographical, these artworks stem from a process of patient involvement and participation. Integral to the pieces is an interdisciplinary approach, which is central to arts-and-health collaborations.

Conclusions

At a time in which the role of the arts in improving health and wellbeing is increasingly recognised and supported by evidence, these artworks offer an opportunity to reflect not only on ways of representing cardiovascular anatomy, but also on its experiential value and on the important of patient engagement and involvement.

Research priorities in children and adults with congenital heart disease: a James Lind Alliance Priority Setting Partnership

OBJECTIVE

To bring together patients, parents, charities and clinicians in a Priority Setting Partnership to establish national clinical priorities for research in children and adults with congenital heart disease.

METHODS

The established James Lind Alliance methodology was used to identify and prioritise research on the management of congenital heart disease, focusing on diagnosis, treatment and outcomes. An initial open survey was used to gather potential uncertainties which were filtered, categorised, converted into summary questions and checked against current evidence. In a second survey, respondents identified the unanswered questions most important to them. At two final workshops, patients, parents, charities and healthcare professionals agreed the top 10 lists of priorities for child/antenatal and adult congenital heart disease research.

RESULTS

524 respondents submitted 1373 individual questions, from which 313 out of scope or duplicate questions were removed. The remaining 1060 questions were distilled into summary questions and checked against existing literature, with only three questions deemed entirely answered and removed. 250 respondents completed the child/antenatal survey (56 uncertainties) and 252 completed the adult survey (47 uncertainties). The questions ranked the highest by clinicians and non-clinicians were taken forward to consensus workshops, where two sets of top 10 research priorities were agreed.

CONCLUSIONS

Through an established and equitable process, we determined national clinical priorities for congenital heart disease research. These will be taken forward by specific working groups, a national patient and public involvement group, and through the establishment of a UK and Ireland network for collaborative, multicentre clinical trials in congenital heart disease.

Relationship between Pulmonary Regurgitation and Ventriculo-Arterial Interactions in Patients with Post-Early Repair of Tetralogy of Fallot: Insights from Wave-Intensity Analysis

This study aimed to investigate the effect of pulmonary regurgitation (PR) on left ventricular ventriculo-arterial (VA) coupling in patients with repaired tetralogy of Fallot (ToF). It was hypothesised that increasing PR severity results in a smaller forward compression wave (FCW) peak in the aortic wave intensity, because of right-to-left ventricular interactions. The use of cardiovascular magnetic resonance (CMR)-derived wave-intensity analysis provided a non-invasive comparison between patients with varying PR degrees. A total of n = 201 patients were studied and both hemodynamic and wave-intensity data were compared. Wave-intensity peaks and areas of the forward compression and forward expansion waves were calculated as surrogates of ventricular function. Any extent of PR resulted in a significant reduction in the FCW peak. A correlation was found between aortic distensibility and the FCW peak, suggesting unfavourable (VA) coupling in patients that also present stiffer ascending aortas. Data suggest that VA coupling is affected by increased impedance.

Molecular and haemodynamic interplay in bicuspid aortic valve aortopathy: segmental differences across the aortic circumference

Background

Bicuspid aortic valve (BAV) patients develop ascending aortic (AAo) dilation. The pathogenesis of BAV-aortopathy (genetic vs. hemodynamic) remains unclear.

Purpose

To identify regional changes around the AAo wall in BAV patients with aortopathy integrating clinical imaging and molecular data.

Methods

BAV patients with aortopathy (n=20) were recruited prospectively to surgically collect aortic tissue and perform four-dimensional cardiac magnetic resonance (CMR) scans. Molecular markers were measured analysing the tissue biopsies (n=15) and wall shear stress (WSS) across the AAo circumference was calculated from the 4D CMR data (n=11 patients, and n=7 additional healthy volunteers for comparison). Dilated (anterior/right) vs. non-dilated (posterior/left) circumferential segments were profiled for whole genomic microRNAs (Next Generation RNA-Sequencing, miRCURY LNA PCR), proteins content (Tandem Mass Spectrometry) and elastin fragmentation and degeneration (histomorphometric analysis). Picture 1 summarises the study approach (including a map of the AAo divided in the following segments: A=anterior, AR=anterior-right, PR=posterior-right, P=posterior, PL=posterior-left, AL=anterior-left).

Results

Integrated bioinformatic analyses of RNA-sequencing and proteomic datasets identified 5 microRNAs (miR-128-3p, miR-210-3p, miR-150-5p, miR-199b-5p, and miR-21-5p) differentially expressed across the AAo circumference. Among them, three miRNAs (miR-128-3p, miR-150-5p, and miR-199b-5p) were predicted to have an effect on eight common target genes, whose expression was dysregulated according to proteomic analyses and involved in vascular endothelial growth factor signalling, hippo signaling and arachidonic acid pathway. Decreased elastic fibre levels and elastic layer thickness were observed in the dilated segments in the histomorphometric analysis. Increased WSS and flow-velocity, helical streamlines and asymmetrical flow were observed at the anterior/right wall in asymmetrically and symmetrically dilated patients (the latter exhibiting higher WSS), compared to healthy volunteers.

Conclusion

This study has newly revealed concomitant expressional dysregulation of miRNAs, proteins, and elastic fibres on the anterior/right wall in dilated BAV patients, corresponding to regions of elevated WSS, contributing to advance the understanding of the interplay of genetic and hemodynamic factors underpinning BAV aortopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation and Above & Beyond

Feasibility of a longitudinal statistical atlas model to study aortic growth in congenital heart disease

Background

Studying anatomical shape progression over time is of utmost importance to refine our understanding of clinically relevant processes. These include vascular remodelling, such as aortic dilation, which is particularly important in some congenital heart defects (CHD).

Purpose

A novel methodological framework for analysing three-dimensional (3D) shape changes over time (“growth”) has been applied for the first time in a CHD scenario, i.e., bicuspid aortic valve (BAV) disease, the most common CHD.

Methods

Three-dimensional aortic shapes (n=94) reconstructed as surface meshes from cardiovascular magnetic resonance imaging (MRI) data represented the input for a longitudinal shape atlas model, using multiple scans over time (n=2–4 scans per patient). This model relies on diffeomorphic transformations in the absence of point-to-point correspondence, and on the correct combination of initialization, estimation, and registration parameters.

Results

We computed the 3D shape trajectory of an average disease progression over time in our cohort (Picture 1, grey to blue shapes), as well as time-dependent parameters, geometric variations and the average shape of the population (Picture 1, red shape). Results cover a spatiotemporal spectrum of visual and numerical information that can be further used to investigate clinical associations and stratify patients, as such capturing aortic remodelling in the presence of BAV aortopathy.

Conclusion

This proof-of-concept study demonstrates the feasibility of applying advanced statistical shape models to track disease progression and stratify patients with CHD.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation and NIHR BRC

Left ventricular morphology in patients with aortic coarctation and bicuspid aortic valve: novel insights from a statistical shape modelling framework

Background

The functional implications of left ventricular (LV) morphological characterization in congenital heart disease (CHD) are not widely explored.

Purpose

This study qualitatively and quantitatively assessed LV shape associations with a) LV function and b) thoracic aortic morphology in patients with aortic coarctation (CoA) with/without bicuspid aortic valve (BAV).

Methods

A statistical shape modelling (SSM) framework was employed to analyse three-dimensional (3D) LV shapes from cardiac magnetic resonance (CMR) imaging data in n=110 cases including: isolated CoA (n=25), CoA+BAV (n=30), isolated BAV (n=30), and age-matched healthy controls (n=25). Average 3D templates (Picture 1) and deformations were computed. Correlations between shape data and CMR-derived morphometric parameters (i.e. sphericity, conicity) as well as CMR-derived global and apical strain values were assessed to elucidate possible functional implications. The relationship between LV shape features and arch architecture (i.e. gothicity, tortuosity) was also explored by means of regression analysis.

Results

The LV template was shorter and more spherical in CoA patient (Picture 1), as also confirmed by statistical analysis of the SSM-derived shape modes. LV sphericity, which was higher in CoA, was associated (p≤0.04) with lower global longitudinal, radial and circumferential strain, irrespective of the presence of aortic stenosis and/or regurgitation. Conversely, neither LV morphology nor LV strain was not associated with arch architecture.

Conclusions

Differences in LV morphology were observed between CoA and BAV patients. Increasing LV sphericity was associated with reduced strain, independent of aortic arch architecture and functional aortic valve disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation and NIHR BRC

What Arts-and-Health Practices Teach Us About Participation, Re-presentation, and Risk

This article explores the implications of risk in arts-and-health collaborations that represent illness narratives for the purpose of engaging the public. Based on an artist's, bioengineer's, and health psychologist's reflections from pediatric and adult group workshop practice settings, this article canvasses 8 dimensions of risk that deserve ethical attention.

Three-Dimensional Printed Models of the Heart Represent an Opportunity for Inclusive Learning

Three-dimensional (3D) printed models of anatomic structures offer an alternative to studying manufactured, "idealized" models or cadaveric specimens. The utility of 3D printed models of the heart for clinical veterinary students learning echocardiographic anatomy is unreported. This study aimed to assess the feasibility and utility of 3D printed models of the canine heart as a supplementary teaching aid in final-year vet students. We hypothesized that using 3D printed cardiac models would improve test scores and feedback when compared with a control group. Students (n = 31) were randomized to use either a video guide to echocardiographic anatomy alongside 3D printed models (3DMs) or video only (VO). Prior to a self-directed learning session, students answered eight extended matching questions as a baseline knowledge assessment. They then undertook the learning session and provided feedback (Likert scores and free text). Students repeated the test within 1 to 3 days. Changes in test scores and feedback were compared between 3DM and VO groups, and between track and non-track rotation students. The 3DM group had increased test scores in the non-track subgroup. Track students' test scores in the VO group increased, but not in the 3DM group. Students in the 3DM group had a higher completion rate, and more left free-text feedback. Feedback from 3DM was almost universally positive, and students believed more strongly that these should be used for future veterinary anatomy teaching. In conclusion, these pilot data suggest that 3D printed canine cardiac models are feasible to produce and represent an inclusive learning opportunity, promoting student engagement.

The use of 3D-printed models in patient communication: a scoping review

3D models have been used as an asset in many clinical applications and a variety of disciplines, and yet the available literature studying the use of 3D models in communication is limited. This scoping review has been conducted to draw conclusions on the current evidence and learn from previous studies, using this knowledge to inform future work. Our search strategy revealed 269 papers, 19 of which were selected for final inclusion and analysis. When assessing the use of 3D models in doctor-patient communication, there is a need for larger studies and studies including a long-term follow up. Furthermore, there are forms of communication that are yet to be researched and provide a niche that may be beneficial to explore.

Feasibility of a longitudinal statistical atlas model to study aortic growth in congenital heart disease

Studying anatomical shape progression over time is of utmost importance to refine our understanding of clinically relevant processes. These include vascular remodeling, such as aortic dilation, which is particularly important in some congenital heart defects (CHD). A novel methodological framework for three-dimensional shape analysis has been applied for the first time in a CHD scenario, i.e., bicuspid aortic valve (BAV) disease, the most common CHD. Three-dimensional aortic shapes (n = 94) reconstructed from cardiovascular magnetic resonance imaging (MRI) data as surface meshes represented the input for a longitudinal atlas model, using multiple scans over time (n = 2-4 per patient). This model relies on diffeomorphism transformations in the absence of point-to-point correspondence, and on the right combination of initialization, estimation and registration parameters. We computed the shape trajectory of an average disease progression in our cohort, as well as time-dependent parameters, geometric variations and the average shape of the population. Results cover a spatiotemporal spectrum of visual and numerical information that can be further used to run clinical associations. This proof-of-concept study demonstrates the feasibility of applying advanced statistical shape models to track disease progression and stratify patients with CHD.

Isolating the Effect of Arch Architecture on Aortic Hemodynamics Late After Coarctation Repair: A Computational Study

Objectives

Effective management of aortic coarctation (CoA) affects long-term cardiovascular outcomes. Full appreciation of CoA hemodynamics is important. This study aimed to analyze the relationship between aortic shape and hemodynamic parameters by means of computational simulations, purposely isolating the morphological variable.

Methods

Computational simulations were run in three aortic models. MRI-derived aortic geometries were generated using a statistical shape modeling methodology. Starting from n = 108 patients, the mean aortic configuration was derived in patients without CoA (n = 37, "no-CoA"), with surgically repaired CoA (n = 58, "r-CoA") and with unrepaired CoA (n = 13, "CoA"). As such, the aortic models represented average configurations for each scenario. Key hemodynamic parameters (i.e., pressure drop, aortic velocity, vorticity, wall shear stress WSS, and length and number of strong flow separations in the descending aorta) were measured in the three models at three time points (peak systole, end systole, end diastole).

Results

Comparing no-CoA and CoA revealed substantial differences in all hemodynamic parameters. However, simulations revealed significant increases in vorticity at the site of CoA repair, higher WSS in the descending aorta and a 12% increase in power loss, in r-CoA compared to no-CoA, despite no clinically significant narrowing (CoA index >0.8) in the r-CoA model.

Conclusions

Small alterations in aortic morphology impact on key hemodynamic indices. This may contribute to explaining phenomena such as persistent hypertension in the absence of any clinically significant narrowing. Whilst cardiovascular events in these patients may be related to hypertension, the role of arch geometry may be a contributory factor.

Role of 3D printing technology in paediatric teaching and training: a systematic review

BACKGROUND

In the UK, undergraduate paediatric training is brief, resulting in trainees with a lower paediatric knowledge base compared with other aspects of medicine. With congenital conditions being successfully treated at childhood, adult clinicians encounter and will need to understand these complex pathologies. Patient-specific 3D printed (3DP) models have been used in clinical training, especially for rarer, complex conditions. We perform a systematic review to evaluate the evidence base in using 3DP models to train paediatricians, surgeons, medical students and nurses.

METHODS

Online databases PubMed, Web of Science and Embase were searched between January 2010 and April 2020 using search terms relevant to "paediatrics", "education", "training" and "3D printing". Participants were medical students, postgraduate trainees or clinical staff. Comparative studies (patient-specific 3DP models vs traditional teaching methods) and non-comparative studies were included. Outcomes gauged objective and subjective measures: test scores, time taken to complete tasks, self-reported confidence and personal preferences on 3DP models. If reported, the cost of and time taken to produce the models were noted.

RESULTS

From 587 results, 15 studies fit the criteria of the review protocol, with 5/15 being randomised controlled studies and 10/15 focussing on cardiovascular conditions. Participants using 3DP models demonstrated improved test scores and faster times to complete procedures and identify anatomical landmarks compared with traditional teaching methods (2D diagrams, lectures, videos and supervised clinical events). User feedback was positive, reporting greater user self-confidence in understanding concepts with users wishing for integrated use of 3DP in regular teaching. Four studies reported the costs and times of production, which varied depending on model complexity and printer. 3DP models were cheaper than 'off-the-shelf' models available on the market and had the benefit of using real-world pathologies. These mostly non-randomised and single-centred studies did not address bias or report long-term or clinically translatable outcomes.

CONCLUSIONS

3DP models were associated with greater user satisfaction and good short-term educational outcomes, with low-quality evidence. Multicentred, randomised studies with long-term follow-up and clinically assessed outcomes are needed to fully assess their benefits in this setting.

PROSPERO REGISTRATION NUMBER

CRD42020179656.