Coarctation Duration and Severity Predict Risk of Hypertension Precursors in a Preclinical Model and Hypertensive Status Among Patients

BACKGROUND

Coarctation of the aorta (CoA) often leads to hypertension posttreatment. Evidence is lacking for the current >20 mm Hg peak-to-peak blood pressure (BP) gradient (BPGpp) guideline, which can cause aortic thickening, stiffening, and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model and test if predictors translate to hypertension status in patients with CoA.

METHODS

Rabbits (n=75; 5-12/group) were exposed to mild, intermediate, or severe CoA (≤12, 13-19, ≥20 mm Hg BPGpp) for ≈1, 3, or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction, and endothelial function evaluated via multivariate regression. Relevance to patients with CoA (n=239; age, 0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) versus follow-up hypertension status.

RESULTS

CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and hypertension in patients with CoA. Interaction between patient age and BPGpp at surgery contributed significantly to hypertension, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that preoperative BPGpp and surgical age predict risk of hypertension along with residual postoperative BPGpp.

CONCLUSIONS

These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of hypertension.

Usefulness of three vessel-trachea view and parasagittal plan for prenatal diagnosis of interrupted aortic arch

BACKGROUND

Interrupted aortic arch (IAA) is a rare congenital heart disease characterized by loss of continuity between the ascending and the descending aorta. Prenatal diagnosis of IAA by echocardiography is challenging but nonetheless can be accomplished via a systematization of cardiac fetal evaluation.

CASE PRESENTATION

We report a case of fetal IAA type A prenatally diagnosed through two-dimensional echocardiography using both a three vessel-trachea view and a sagittal view.

CONCLUSION

Prenatal counseling regarding the diagnosis and prognosis about this anomaly is still challenging nowadays due to associated anomalies/chromosomal abnormalities who may impact the prognosis. Fetal autopsy in all cases of pregnancy termination after abnormal ultrasound findings is important in order to make a full diagnosis and characterize the anomaly.

Proof of Concept: A New Solution for Low-Profile Transcatheter Implantation of Optimus-L Stents in Small Children

BACKGROUND

There is no stent designed or approved for use in infants. We sought to obtain in vitro and in vivo data on a new concept conceived to implant Optimus-L stents at infant vessel diameters and offer a potential long term stent solution.

METHODS

Nineteen Optimus-L stents were mounted on 8 types of angioplasty balloons with diameters 6, 8, and 10 mm with the use of an injection-moulded hand crimper. We evaluated balloon-stent unit (BSU) stability before insertion and advancement through short Terumo introducers with incremental French size and possibility of side-arm contrast injections. Three types of long sheaths were tested. Stents were inflated to balloon nominal diameters and re-expanded to 18 and 23 mm. Stent recoil, foreshortening, and fracture were evaluated. In vivo implantations were performed afterward.

RESULTS

In vitro: Medtronic Evercross balloons and modified Terumo Destination sheaths were the best combination: BSUs were inserted in 6 F sheaths with possible injections (for 6 and 8 mm balloons), and 7 F sheaths without injections (for the 10 mm balloon). Retrieving BSUs inside the sheath required 1 additional F-size. Boston Scientific Sterling and Balton Lovix balloons, as well as APT Braidin L guiding sheaths showed unsatisfactory performance. Dilation up to 23 mm was possible, and stent shortening was < 24% at 18 mm and < 37% at 23 mm. Recoil was limited, and no stent fractured. In vivo: Optimus-L stents were used to treat 2 infants with aortic coarctation and 2 children with pulmonary artery stenosis with the use of 8 mm balloons and low-profile access.

CONCLUSIONS

Optimus-L stents can be implanted safely in small patients with a low-profile approach. These stents have the potential to achieve adult size while maintaining structural integrity.

Incidence of congenital heart disease in fetuses diagnosed with single isolated umbilical artery. Systematic review and meta-analysis

OBJECTIVE

To estimate the proportion of heart disease in fetuses with a prenatal diagnosis of a single isolated umbilical artery.

METHODS

We performed a search strategy in MEDLINE (OVID), EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to the present. We assessed the risk of bias and performed a meta-analysis. We completed the subgroup analysis according to the region.

RESULTS

We found 1384 studies by the search strategy. After carefully reviewing the full-text, 15 studies were included. A total of 2008 fetuses with a single isolated umbilical artery were included, and 177 had cardiac malformations. There was an overall incidence of 9% 95%CI (0.05-0.14) I2 90%. The incidence by country of origin was between 5% and 19%. The most common heart disease reported was a ventricular septal defect. Seven studies were found describing 25 cases. We described other malformations, such as tetralogy of Fallot, coarctation of the aorta, and hypoplastic left ventricle, among others.

CONCLUSION

The incidence of congenital heart disease in fetuses with a single isolated umbilical artery was high. In addition, half of these correspond to significant heart disease. Based on the above, we suggest that fetuses with a single isolated umbilical artery should have a complete anatomic evaluation emphasizing cardiac evaluation.

Ovarian Tumor Domain-Containing 7B Attenuates Pathological Cardiac Hypertrophy by Inhibiting Ubiquitination and Degradation of Krüppel-Like Factor 4

BACKGROUND

Cardiac hypertrophy (CH) is a well-established risk factor for many cardiovascular diseases and a primary cause of mortality and morbidity among older adults. Currently, no pharmacological interventions have been specifically tailored to treat CH. OTUD7B (ovarian tumor domain-containing 7B) is a member of the ovarian tumor-related protease (OTU) family that regulates many important cell signaling pathways. However, the role of OTUD7B in the development of CH is unclear. Therefore, we investigated the role of OTUD7B in CH.

METHODS AND RESULTS

OTUD7B knockout mice were used to assay the role of OTUD7B in CH after transverse aortic coarctation surgery. We further assayed the specific functions of OTUD7B in isolated neonatal rat cardiomyocytes. We found that OTUD7B expression decreased in hypertrophic mice hearts and phenylephrine-stimulated neonatal rat cardiomyocytes. Furthermore, OTUD7B deficiency exacerbated transverse aortic coarctation surgery-induced myocardial hypertrophy, abnormal cardiac function, and fibrosis. In cardiac myocytes, OTUD7B knockdown promoted phenylephrine stimulation-induced myocardial hypertrophy, whereas OTUD7B overexpression had the opposite effect. An immunoprecipitation-mass spectrometry analysis showed that OTUD7B directly binds to KLF4 (Krüppel-like factor 4). Additional molecular experiments showed that OTUD7B impedes KLF4 degradation by inhibiting lysine residue at 48 site-linked ubiquitination and suppressing myocardial hypertrophy by activating the serine/threonine kinase pathway.

CONCLUSIONS

These results demonstrate that the OTUD7B-KLF4 axis is a novel molecular target for CH treatment.

PHACE syndrome: not always 'tilting telephones' and Dandy-Walker malformations…

Linked article: This Editorial comments on Pomar et al. Click here to view the article.

Single-cell reconstruction and mutation enrichment analysis identifies dysregulated cardiomyocyte and endothelial cells in congenital heart disease

Congenital heart disease (CHD) is one of the most prevalent neonatal congenital anomalies. To catalog the putative candidate CHD risk genes, we collected 16,349 variants [single-nucleotide variants (SNVs) and Indels] impacting 8,308 genes in 3,166 CHD cases for a comprehensive meta-analysis. Using American College of Medical Genetics (ACMG) guidelines, we excluded the 0.1% of benign/likely benign variants and the resulting dataset consisted of 83% predicted loss of function variants and 17% missense variants. Seventeen percent were de novo variants. A stepwise analysis identified 90 variant-enriched CHD genes, of which six (GPATCH1, NYNRIN, TCLD2, CEP95, MAP3K19, and TTC36) were novel candidate CHD genes. Single-cell transcriptome cluster reconstruction analysis on six CHD tissues and four controls revealed upregulation of the top 10 frequently mutated genes primarily in cardiomyocytes. NOTCH1 (highest number of variants) and MYH6 (highest number of recurrent variants) expression was elevated in endocardial cells and cardiomyocytes, respectively, and 60% of these gene variants were associated with tetralogy of Fallot and coarctation of the aorta, respectively. Pseudobulk analysis using the single-cell transcriptome revealed significant (P < 0.05) upregulation of both NOTCH1 (endocardial cells) and MYH6 (cardiomyocytes) in the control heart data. We observed nine different subpopulations of CHD heart cardiomyocytes of which only four were observed in the control heart. This is the first comprehensive meta-analysis combining genomics and CHD single-cell transcriptomics, identifying the most frequently mutated CHD genes, and demonstrating CHD gene heterogeneity, suggesting that multiple genes contribute to the phenotypic heterogeneity of CHD. Cardiomyocytes and endocardial cells are identified as major CHD-related cell types.NEW & NOTEWORTHY Congential heart disease (CHD) is one of the most prevalent neonatal congenital anomalies. We present a comprehensive analysis combining genomics and CHD single-cell transcriptome. Our study identifies 90 potential candidate CHD risk genes of which 6 are novel. The risk genes have heterogenous expression suggestive of multiple genes contributing to the phenotypic heterogeneity of CHD. Cardiomyocytes and endocardial cells are identified as major CHD-related cell types.

Clinical utility of repeat fetal echocardiography in congenital heart disease

OBJECTIVES

To investigate the utility of repeat fetal echocardiography (FE) following a diagnosis of structural congenital heart disease (CHD) on the initial FE. We evaluated how often changes in management and counseling occurred based on subsequent FE findings and sought to determine which types of CHD were more likely to have changes in management and/or counseling based on repeat FE.

METHODS

This was a retrospective review of all patients who presented to our center between January 2012 and January 2019 and who had more than one FE performed for structural CHD. We reviewed consultation notes to determine whether management or counseling had changed based on FE findings at follow-up visits. Management variables included a change in location or mode of delivery, plan for atrial septostomy, initiation of prostaglandin infusion, umbilical line placement and planned admission location (nursery vs neonatal intensive care unit). We defined a counseling change as any of the above changes in management as well as any meaningful refinements in the cardiac diagnosis that led to a change in the overall prognosis or future management. Initial diagnoses were grouped into anatomically/hemodynamically relevant subgroups. Fisher's exact test was used to assess the relationship between the initial diagnosis and changes in management. Post-hoc pairwise comparisons were performed using Dunnett's test.

RESULTS

Between January 2012 and January 2019, 267 patients underwent 534 follow-up FE assessments performed for structural CHD. Management change based on repeat FE occurred in 41/267 (15.4%) cases. A change in management was associated with the diagnosis made at the initial visit (P < 0.001). The proportion of cases with a management change was highest among those with an initial diagnosis of pulmonary valve abnormality/non-critical pulmonary stenosis (4/11 (36.4%)), followed by balanced atrioventricular canal (AVC) defect (5/17 (29.4%)) and left ventricular outflow tract obstruction/aortic valve abnormality or coarctation/interrupted aortic arch (19/68 (27.9%)). No management change occurred in fetuses diagnosed with isolated ventricular septal defect (VSD), truncus arteriosus, pulmonary vein anomaly or isolated arch sidedness/branching abnormality. Compared to those with a VSD, management was significantly more likely to be changed in fetuses with a balanced AVC defect (P = 0.025) and left heart lesions (P = 0.002). Right heart lesions showed a trend towards an increased incidence of management change (P = 0.05). A counseling change based on repeat FE occurred in 108/267 (40.4%) cases. The proportion of cases with a counseling change was highest among those with an initial diagnosis of pulmonary valve abnormality/non-critical pulmonary stenosis (8/11 (72.7%)) and hypoplastic left heart syndrome/critical aortic stenosis (5/9 (55.6%)).

CONCLUSIONS

The clinical utility of follow-up FE is associated with the type of CHD diagnosed. Follow-up FE led to changes in management in several types of CHD, most commonly in cases with an initial diagnosis of right and left outflow obstructive lesions and balanced AVC defect. When developing programmatic protocols for the frequency of FE assessments, the type of CHD should be a major determinant, but additional studies are required to reach a consensus on how often serial FE should be performed for each type of CHD. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Resilience in children with congenital heart disease: a comparative study with health counterparts

OBJECTIVE

Resilience is a complex, yet rather unexplored topic in patients with congenital heart disease (CHD). The goal of this study was to assess and compare resilience in children with CHD with healthy controls during the COVID-19 pandemic.

DESIGN AND PATIENTS

From June 2020 to June 2021, 124 children with various CHDs (14.6±2.1 years, 49 girls) and 124 matched healthy controls (14.8±2.0 years, 49 girls) completed the Resilience Scale-11 short version.

RESULTS

Resilience was significantly reduced in children with CHD compared with healthy controls (CHD: 59.0±10.0 vs healthy controls: 64.4±6.5, p<0.001). That reduction was prominent in all CHD subgroups except those with left heart obstruction (aortic stenosis and coarctation of the aorta) and patients with transposition of the great arteries. Complex CHD had the lowest resilience of 57.6±8.4 (p<0.001) after adjusting for age and sex according to group differences. There was no difference between native CHD and CHD with open-heart surgery (native: 59.5±12.2 vs surgery: 58.8±9.3, p=0.758).

CONCLUSIONS

Resilience was reduced in children and adolescents with CHD compared with healthy peers during the COVID-19 pandemic. Children with complex severity appeared to be particularly affected. These findings emphasise continued efforts to provide a holistic and multidisciplinary approach in medical aftercare of these patients and their families.

Risk factors and frequency of acute and permanent femoral arterial occlusion in neonates with CHD who undergo ultrasound-guided femoral arterial access

OBJECTIVE

We investigated frequency and risk factors of acute loss of the arterial pulse and permanent femoral arterial occlusion in neonates with CHD who underwent ultrasound-guided femoral arterial access.

METHODS

We divided the patients into groups according to the presence of acute loss of the arterial pulse and permanent femoral arterial occlusion. We obtained data related to patient characteristics and access variables of ultrasound-guided femoral arterial access from our database of cardiac catheterisation between August, 2017 and May, 2021. We used an echocardiography-S6, 12-MHz linear probe, 21-gauge needle, 0.018"guidewire, and a 4F sheath for arterial access.

RESULTS

Ultrasound-guided femoral arterial access was obtained in 323 (98.8%) of the 327 neonates. We identified acute loss of the arterial pulse in 130 (40.2%) patients and permanent femoral arterial occlusion in 19 (5.9%) patients. Median weight was 3.05 (Interquartile range (IQR): 2.80-3.40) kg, first attempt success rate was 88.2%, and median access time was 46 sec (IQR: 23-94). Logistic regression analysis identified coarctation of the aorta (odds ratio: 2.46; 95% CI: 1.30-4.66; p = 0.006) as independent risk factor for acute loss of the arterial pulse, but did not identify any independent risk factors for permanent femoral arterial occlusion.

CONCLUSIONS

This study showed coarctation of the aorta as an independent risk factor for acute loss of the arterial pulse, but did not identify any independent factors for permanent femoral arterial occlusion in neonates with CHD. Although most cases of acute loss of the arterial pulse resolve in the early period, the frequency of permanent femoral arterial occlusion remains high despite effective treatment.

The Academic Impact of Congenital Heart Surgeons' Society (CHSS) Studies

PURPOSE

We reviewed all 64 articles ever published by The Congenital Heart Surgeons' Society (CHSS) Data Center to estimate the academic impact of these peer-reviewed articles.

MATERIALS AND METHODS

The Congenital Heart Surgeons' Society has performed research based on 12 Diagnostic Inception Cohorts. The first cohort (Transposition) began enrolling patients on January 1, 1985. We queried PubMed to determine the number of publications that referenced each of the 64 journal articles generated by the datasets of the 12 Diagnostic Inception Cohorts that comprise the CHSS Database. Descriptive summaries of the data were tabulated using mean with standard deviation and median with range.

RESULTS

Sixty-four peer-reviewed papers have been published based on the CHSS Database. Fifty-nine peer-reviewed articles have been published based on the 12 Diagnostic Inception Cohorts, and five additional articles have been published based on Data Science. Excluding the recently established Diagnostic Inception Cohort for patients with Ebstein malformation of tricuspid valve, the number of papers published per cohort ranged from 1 for coarctation to 11 for transposition of the great arteries. The 11 articles generated from the CHSS Transposition Cohort were referenced by a total of 111 articles (median number of references per journal article = 9 [range = 0-22, mean = 10.1]). Overall, individual articles were cited by an average of 11 (mean), and a maximum of 41 PubMed-listed publications. Overall, these 64 peer-reviewed articles based on the CHSS Database were cited 692 times in PubMed-listed publications. The first CHSS peer-reviewed article was published in 1987, and during the 35 years from 1987 to 2022, inclusive, the annual number of CHSS publications has ranged from 0 to 7, with a mean of 1.8 publications per year (median = 1, mode = 1).

CONCLUSION

Congenital Heart Surgeons' Society studies are widely referenced in the pediatric cardiac surgical literature, with over 10 citations per published article. These cohorts provide unique information unavailable in other sources of data. A tool to access this analysis is available at: [https://data-center.chss.org/multimedia/files/2022/CAI.pdf].

Association Between Prenatal Diagnosis and Age at Surgery for Noncritical and Critical Congenital Heart Defects

BACKGROUND

The relationship between the prenatal diagnosis of congenital heart defects (CHDs) and age at CHD surgery is poorly understood, despite the known relationships between age at surgery and long-term outcomes. The objective of this study was to determine the associations between prenatal diagnosis of CHD and age at surgery, and whether these associations differ for critical and noncritical CHDs.

METHODS

This is a cohort analysis of patients aged 0 to 9 years who received their initial cardiac surgery at Ann & Robert H. Lurie Children's Hospital of Chicago between 2015 and 2021 with prenatal diagnosis as the exposure variable. All data were obtained from the locally maintained Society of Thoracic Surgeons Congenital Heart Surgery Database at Lurie Children's Hospital. We used multivariable fixed effects regression models to estimate the strength of the association of prenatal diagnosis with age at surgery among patients with critical (surgery ≤60 days) and noncritical (surgery >60 days) CHDs.

RESULTS

Of 1131 individuals who met inclusion criteria, 532 (47%) had a prenatal diagnosis, 428 (38%) had critical CHDs, 533 (47%) were female, and the median age at surgery was 119 days (interquartile range, 11-309 days). After controlling for demographics, comorbidities, and surgical complexity, the mean age at surgery was significantly younger in those with prenatally versus postnatally diagnosed critical CHD (7.1 days sooner, P<0.001) and noncritical CHDs (atrial septal defects [12.4 months sooner, P=0.037], ventricular septal defects [6.0 months sooner, P<0.003], and noncritical coarctation of the aorta [1.8 months sooner, P=0.010]).

CONCLUSIONS

Younger age at CHD surgery, which is associated with postsurgical neurodevelopmental and physical outcomes, is significantly associated with prenatal CHD diagnosis. This relationship was identified for both critical and noncritical CHDs.

Prognosis Analysis of Children with Interrupted Aortic Arch Complicated with Ventricular Septal Defect and Other Associated Intracardiac Defects after One-Stage Radical Surgery

BACKGROUND

High rates of mortality and aortic arch stenosis have been reported for one-stage radical surgery of interruption of aortic arch (IAA) with ventricular septal defect (VSD) and other associated intracardiac defects, but the sample size of the study is relatively small, and the credibility of the study is not high. The risk factors of death and aortic arch stenosis will be analyzed in a large sample size of infants with IAA, VSD and other associated intracardiac defects after one-stage radical resection.

METHODS

A retrospective analysis was performed on 152 children with IAA, VSD and other associated intracardiac defects from January 2006 to January 2017 who had undergone one-stage radical resection, including 95 cases of type A and 57 cases of type B. January 2006-December 2011 as the early period, and January 2012-January 2017 as the late period. Cox proportional hazards regression model was used to analyze the risk factors for mortality and aortic arch stenosis after surgery, the overall survival rate was analyzed by the Kaplan-Meier method, and the survival curve was drawn by GraphPad Prism 8 software.

RESULTS

22 cases (14.47%) died, 27 cases (17.76%) developed aortic arch stenosis. The 1-month, 3-month, 6-month, 1-year, 3-year, and 5-year survival rates were 85.53%, 85.53%, 85.53%, 84.21%, 78.95% and 75.66%, respectively. Low age (Hazard Ratio (HR) = 0.551, 95% Confidence Interval (CI): 0.320-0.984, p = 0.004), low body weight (HR = 0.632, 95% CI: 0.313-0.966, p = 0.003), large ratio of VSD diameter/aortic diameter (VSD/AO) (HR = 2.547, 95% CI: 1.095-7.517, p = 0.044), long duration of cardiopulmonary bypass (HR = 1.374, 95% CI: 1.000-3.227, p = 0.038), and left ventricular outflow tract obstruction (LVOTO) (HR = 3.959, 95% CI: 1.123-9.268, p = 0.015) were independent risk factors for postoperative death. The surgical period (January 2006-December 2011) (HR = 0.439, 95% CI: 0.109-0.964, p = 0.046) and the addition of pericardial anastomosis to the anterior aortic wall (HR = 0.398, 95% CI: 0.182-0.870, p = 0.021) were independent risk factors for postoperative aortic arch stenosis.

CONCLUSIONS

Children with low age, low body weight, large ratio of VSD/AO, long duration of cardiopulmonary bypass, LVOTO, the surgical period (January 2006-December 2011) and pericardial anastomosis with anterior aortic wall have poor prognosis.

GATA4 rs61277615, rs73203482, and rs35813172 in Newborns with Transposition of the Great Arteries

Congenital heart disease is the most common malformative pathology in newborns, with a worldwide incidence at 0.4-5%. We investigated the possible relationship between variations in nucleotide sequences and specific cardiac malformations in the GATA-binding factor 4 (GATA4) exon 1 region by using Sanger sequencing. Forty-four newborns from a third-level neonatal intensive care unit who were diagnosed with nonsyndromic, ductal-dependent congenital heart disease (i.e., transposition of the great arteries or ductal-dependent coarctation of the aorta) were enrolled. Their DNA was extracted using commercial methods and tested using the multiplex ligation-dependent probe amplification (MLPA) technique. The Sanger sequencing for GATA4 exon 1 in the newborns' DNA identified rs61277615, rs73203482, and rs35813172 variants not reported in the ClinVar archive of human variations in newborns previously diagnosed with transposition of the great arteries (n=5) and coarctation of the aorta (n=1). The identification of these novel variants in newborns with transposition of the great arteries or ductal-dependent coarctation of the aorta may be the first step in determining the variants' contribution to the occurrence of congenital heart disease. However, these results may be inconclusive, since the observed variants within GATA4 gene were not previously reported.

Temporal evolution of mechanical stimuli from vascular remodeling in response to the severity and duration of aortic coarctation in a preclinical model

Coarctation of the aorta (CoA) is one of the most common congenital cardiovascular diseases. CoA patients frequently undergo surgical repair, but hypertension (HTN) is still common. The current treatment guideline has revealed irreversible changes in structure and function, yet revised severity guidelines have not been proposed. Our objective was to quantify temporal alterations in mechanical stimuli and changes in arterial geometry in response to the range of CoA severities and durations (i.e. age of treatment) seen clinically. Rabbits were exposed to CoA resulting in peak-to-peak blood pressure gradient (BPGpp) severities of ≤ 10, 10-20, and ≥ 20 mmHg for a duration of ~ 1, 3, or 20 weeks using permanent, dissolvable, and rapidly dissolvable sutures. Elastic moduli and thickness were estimated from imaging and longitudinal fluid-structure interaction (FSI) simulations were conducted at different ages using geometries and boundary conditions from experimentally measured data. Mechanical stimuli were characterized including blood flow velocity patterns, wall tension, and radial strain. Experimental results show vascular alternations including thickening and stiffening proximal to the coarctation with increasing severity and/or duration of CoA. FSI simulations indicate wall tension in the proximal region increases markedly with coarctation severity. Importantly, even mild CoA induced stimuli for remodeling that exceeds values seen in adulthood if not treated early and using a BPGpp lower than the current clinical threshold. The findings are aligned with observations from other species and provide some guidance for the values of mechanical stimuli that could be used to predict the likelihood of HTN in human patients with CoA.

Genetics and mechanisms of thoracic aortic disease

Aortic disease has many forms including aortic aneurysm and dissection, aortic coarctation or abnormalities in aortic function, such as loss of aortic distensibility. Genetic analysis in humans is one of the most important experimental approaches in uncovering disease mechanisms, but the relative infrequency of thoracic aortic disease compared with other cardiovascular conditions such as coronary artery disease has hindered large-scale identification of genetic associations. In the past decade, advances in machine learning technology coupled with large imaging datasets from biobank repositories have facilitated a rapid expansion in our capacity to measure and genotype aortic traits, resulting in the identification of dozens of genetic associations. In this Review, we describe the history of technological advances in genetic discovery and explain how newer technologies such as deep learning can rapidly define aortic traits at scale. Furthermore, we integrate novel genetic observations provided by these advances into our current biological understanding of thoracic aortic disease and describe how these new findings can contribute to strategies to prevent and treat aortic disease.

Aortic size predicts aortic dissection in Turner syndrome - A 25-year prospective cohort study

BACKGROUND

Women with Turner syndrome (TS) have an increased risk of aortic dissection. The current recommended cutoff to prevent aortic dissection in TS is an aortic size index (ASI) of ≥2.5 cm/m². This study estimated which aortic size had the best predictive value for the risk of aortic dissection, and whether adjusting for body size improved risk prediction.

METHODS

A prospective, observational study in Sweden, of women with TS, n = 400, all evaluated with echocardiography of the aorta and data on medical history for up to 25 years. Receiver operating characteristic (ROC) curves, sensitivity and specificity were calculated for the absolute ascending aortic diameter (AAD), ascending ASI and TS specific z-score.

RESULTS

There were 12 patients (3%) with aortic dissection. ROC curves demonstrated that absolute AAD and TS specific z-score were superior to ascending ASI in predicting aortic dissection. The best cutoff for absolute AAD was 3.3 cm and 2.12 for the TS specific z-score, respectively, with a sensitivity of 92% for both. The ascending ASI cutoff of 2.5 cm/m² had a sensitivity of 17% only. Subgroup analyses in women with an aortic diameter ≥ 3.3 cm could not demonstrate any association between karyotype, aortic coarctation, bicuspid aortic valve, BMI, antihypertensive medication, previous growth hormone therapy or ongoing estrogen replacement treatment and aortic dissection. All models failed to predict a dissection in a pregnant woman.

CONCLUSIONS

In Turner syndrome, absolute AAD and TS-specific z-score were more reliable predictors for aortic dissection than ASI. Care should be taken before and during pregnancy.

3D black blood cardiovascular magnetic resonance atlases of congenital aortic arch anomalies and the normal fetal heart: application to automated multi-label segmentation

BACKGROUND

Image-domain motion correction of black-blood contrast T2-weighted fetal cardiovascular magnetic resonance imaging (CMR) using slice-to-volume registration (SVR) provides high-resolution three-dimensional (3D) images of the fetal heart providing excellent 3D visualisation of vascular anomalies [1]. However, 3D segmentation of these datasets, important for both clinical reporting and the application of advanced analysis techniques is currently a time-consuming process requiring manual input with potential for inter-user variability.

METHODS

In this work, we present novel 3D fetal CMR population-averaged atlases of normal and abnormal fetal cardiovascular anatomy. The atlases are created using motion-corrected 3D reconstructed volumes of 86 third trimester fetuses (gestational age range 29-34 weeks) including: 28 healthy controls, 20 cases with postnatally confirmed neonatal coarctation of the aorta (CoA) and 38 vascular rings (21 right aortic arch (RAA), 17 double aortic arch (DAA)). We used only high image quality datasets with isolated anomalies and without any other deviations in the cardiovascular anatomy.In addition, we implemented and evaluated atlas-guided registration and deep learning (UNETR) methods for automated 3D multi-label segmentation of fetal cardiac vessels. We used images from CoA, RAA and DAA cohorts including: 42 cases for training (14 from each cohort), 3 for validation and 6 for testing. In addition, the potential limitations of the network were investigated on unseen datasets including 3 early gestational age (22 weeks) and 3 low SNR cases.

RESULTS

We created four atlases representing the average anatomy of the normal fetal heart, postnatally confirmed neonatal CoA, RAA and DAA. Visual inspection was undertaken to verify expected anatomy per subgroup. The results of the multi-label cardiac vessel UNETR segmentation showed 100[Formula: see text] per-vessel detection rate for both normal and abnormal aortic arch anatomy.

CONCLUSIONS

This work introduces the first set of 3D black-blood T2-weighted CMR atlases of normal and abnormal fetal cardiovascular anatomy including detailed segmentation of the major cardiovascular structures. Additionally, we demonstrated the general feasibility of using deep learning for multi-label vessel segmentation of 3D fetal CMR images.

High-Frequency Fluctuation Intensity as a Predictor of Post-Stenotic Dilatation in Swine

OBJECTIVE

To identify the turbulent components of blood flow facilitating aortic lumen dilatation in a post-stenotic dilatation (PSD) porcine model.

METHODS

The porcine abdominal aorta (AA) was moderately coarctated to induce overt flow turbulence in the downstream region and to lead to dilatation in time periods between four and twelve weeks. We propose a new metric, fluctuation intensity (FI), to quantify turbulent fluctuations of pulsatile aortic flow measured within twenty minutes post-coarctation. Lumen perimeter ratio (LPR) of the distal-to-suprarenal AA was used to assess the degree of PSD. Using k-means clustering analysis, we first divided FI frequency spectrum into low- and high-frequency fluctuation intensity (LFFI and HFFI), and subsequently grouped animals with coarctation. Receiver operating characteristic (ROC) analysis was performed to evaluate the ability of the proposed metric to predict PSD.

RESULTS

The frequency band of the FI spectrum in facilitating aortic lumen dilatation was identified to be 40∼200 Hz. Using sham group as the reference, pigs receiving coarctation were clustered into two groups with (group A) and without (group B) increases in HFFI values. Coarctation significantly increased LPR values in group A, but not in group B. Moreover, group A exhibited a high probability density distribution on severe elastic fiber fragmentation. ROC analysis indicated HFFI to be capable of predicting PSD with excellent sensitivity and specificity.

CONCLUSION

High-intensity, high-frequency components of blood flow fluctuations induced by moderate coarctation promote elastic lamella degradation and aortic lumen dilatation.

SIGNIFICANCE

HFFI application in flowmeter programs may provide a useful predictor of PSD.

Double intrathoracic arterial cannulation plus peripheral cannulation for whole-body perfusion in an infant

We report a technique for distal body perfusion in an infant with hypoplastic aortic arch and isthmus stenosis by ultrasound- guided cannulation of the femoral artery using an intra-arterial vascular sheath establishing whole-body perfusion by triple cannulation.

Coronary Artery Dominance and Cardiovascular Pathologies in Patients with Bicuspid Aortic Valve

BACKGROUND

Bicuspid aortic valve (BAV) is the most common congenital heart defect and is associated with a number of cardiac pathologies including coarctation of the aorta (CoA), aortic dilation, aortic stenosis, and premature coronary artery disease (CAD). Furthermore, BAV has been associated with left dominant coronary artery anatomy but there is still much debate regarding this association. To date, no study has investigated the association between coronary artery dominance and cardiac pathologies in patients with BAV.

METHODS

A total of 45 patients with BAV who underwent coronary computed tomography angiography (CTA) and/or cardiac catheterization at a single center were included. Coronary artery dominance, presence of CAD, CoA, and aortic dilation was determined from coronary CTA and/or cardiac catheterization reports. Incidence of aortic valve stenosis and aortic valve regurgitation was determined from echo reports.

RESULTS

Of the 45 patients with BAV, 80% (36) had right dominant coronary artery circulations. Patients with BAV with left dominant circulations had a significantly (p = 0.04) higher incidence of CoA compared to patients with right dominant circulations (44% vs. 14%). There was no significant difference when comparing the incidences of aortic dilation, aortic valve stenosis, aortic valve regurgitation and CAD in right and left dominant patients.

CONCLUSIONS

Our study found a predominance of right dominant coronary artery circulation in patients with BAV, similar to the general population. Interestingly, left dominance was significantly associated with CoA in patients with BAV. This observation highlights the importance of further studies regarding how coronary artery dominance can be associated with other cardiovascular pathologies in patients with BAV.

Mathematical modeling of shear-activated targeted nanoparticle drug delivery for the treatment of aortic diseases

The human aorta is a high-risk area for vascular diseases, which are commonly restored by thoracic endovascular aortic repair. In this paper, we report a promising shear-activated targeted nanoparticle drug delivery strategy to assist in the treatment of coarctation of the aorta and aortic aneurysm. Idealized three-dimensional geometric models of coarctation of the aorta and aortic aneurysm are designed, respectively. The unique hemodynamic environment of the diseased aorta is used to improve nanoparticle drug delivery. Micro-carriers with nanoparticle drugs would be targeting activated to release nanoparticle drugs by local abnormal shear stress rate (SSR). Coarctation of the aorta provides a high SSR hemodynamic environment, while the aortic aneurysm is exposed to low SSR. We propose a method to calculate the SSR thresholds for the diseased aorta. Results show that the upstream near-wall area of the diseased location is an ideal injection location for the micro-carriers, which could be activated by the abnormal SSR. Released nanoparticle drugs would be successfully targeted delivered to the aortic diseased wall. Besides, the high diffusivity of the micro-carriers and nanoparticle drugs has a significant impact on the surface drug concentrations of the diseased aortic walls, especially for aortic aneurysms. This study preliminary demonstrates the feasibility of shear-activated targeted nanoparticle drug delivery in the treatment of aortic diseases and provides a theoretical basis for developing the drug delivery system and novel therapy.

Spillover of Early Extubation Practices From the Pediatric Heart Network Collaborative Learning Study

OBJECTIVES

The Pediatric Heart Network Collaborative Learning Study used collaborative learning strategies to implement a clinical practice guideline that increased rates of early extubation after infant repair of tetralogy of Fallot and coarctation of the aorta. We assessed early extubation rates for infants undergoing cardiac surgeries not targeted by the clinical practice guideline to determine whether changes in extubation practices spilled over to care of other infants.

DESIGN

Observational analyses of site's local Society of Thoracic Surgeons Congenital Heart Surgery Database and Pediatric Cardiac Critical Care Consortium Registry.

SETTING

Four Pediatric Heart Network Collaborative Learning Study active-site hospitals.

PATIENTS

Infants undergoing ventricular septal defect repair, atrioventricular septal defect repair, or superior cavopulmonary anastomosis (lower complexity), and arterial switch operation or isolated aortopulmonary shunt (higher complexity).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Aggregate outcomes were compared between the 12 month pre-clinical practice guideline and 12 months after study completion (Follow Up). In infants undergoing lower complexity surgeries, early extubation increased during Follow Up compared with Pre-Clinical Practice Guideline (30.2% vs 18.8%, p = 0.006), and hours to initial postoperative extubation decreased. We observed variation in these outcomes by surgery type, with only ventricular septal defect repair associated with a significant increase in early extubation during Follow Up compared with Pre-Clinical Practice Guideline (47% vs 26%, p = 0.006). Variation by study site was also seen, with only one hospital showing an increase in early extubation. In patients undergoing higher complexity surgeries, there was no difference in early extubation or hours to initial extubation between the study eras.

CONCLUSIONS

We observed spillover of extubation practices promoted by the Collaborative Learning Study clinical practice guideline to lower complexity operations not included in the original study that was sustainable 1 year after study completion, though this effect differed across sites and operation subtypes. No changes in postoperative extubation outcomes following higher complexity surgeries were seen. The significant variation in outcomes by site suggests that center-specific factors may have influenced spillover of clinical practice guideline practices.

Predictors of Left Ventricular Outflow Tract Obstruction After Primary Interrupted Aortic Arch Repair

Left ventricular outflow tract obstruction is an important complication after interrupted aortic arch repair and subsequent interventions may adversely affect survival. Identification of patients at risk for obstruction is important to facilitate clinical decision-making and monitoring during follow-up. The aim of this review is to summarize reported risk factors for left ventricular outflow tract obstruction after corrective surgery for interrupted aortic arch. A systematic search of the literature was performed across the PubMed and EMBASE databases. Studies that reported echocardiographic and/or clinical predictors for left ventricular outflow tract obstruction in infants that underwent biventricular repair of interrupted aortic arch were included. From the 44 potentially relevant studies, eight studies met the inclusion criteria. Postoperative left ventricular outflow tract obstruction requiring an intervention was common, with an incidence ranging between 14 and 38%. Manifestation of postoperative left ventricular outflow tract obstruction was associated with a smaller pre-operative size of the aortic root (sinus of Valsalva), sinotubular junction, and aortic annulus. Anatomic and surgical risk factors for left ventricular outflow tract obstruction were the presence of an aberrant right subclavian artery, use of a pulmonary homograft or polytetrafluoroethylene interposition graft for aortic arch repair, and the presence of a small- or medium-sized ventricular septal defect. In patients with a borderline left ventricular outflow tract that undergo a primary repair, these (pre-) operative predictors can provide guidance for optimal surgical decision-making and for close monitoring during follow-up of patients at increased risk for developing left ventricular outflow tract obstruction after corrective surgery.

Peculiar features of aortic wall structure among children with coarctation

OBJECTIVE

The aim of the study to evaluate the peculiarities of the aortic wall structure at the place of coarctation.

PATIENTS AND METHODS

Materials and methods: Studying of the aortic sections removed during operative correction at the place of constriction. 10 children at the age between 1 to 6 months were undergone the operation. Intraoperative aortic biopsy specimens were observed in 10% neutral formalin. Histologic sections were prepared in a conventional way followed by staining them with hematoxylin-eosin.

RESULTS

Results: Histological examination in the areas of constriction revealed that the endothelium in all the preparations had poor expressiveness. The most significant changes were recorded in the middle layer of the aorta in the form of reduced development of elastic fibers, their fragmentation and chaotic arrangement. Angiomatosis with the formation of thin-layer small vessels by capillary type was found out. In all the preparations, areas of emptying of cells and fibers of the middle cover with the formation of cystic structures were revealed.

CONCLUSION

Conclusions: The histological examination has revealed changes in the structure of the aorta wall, which may indicate the systemic nature of the lesion and make it possible to consider coarctation of the aorta to be a manifestation of systemic vasculopathy. The above-mentioned facts determine the need for a more detailed examination of children with the specified pathology at different stages of observation.

[Reconstruction of the Aortic Arch with an Autologous Pericardial Patch in Aortic Coarctation and Interruption]

BACKGROUNDS

Direct anastomosis such as end-to-end anastomosis or extended aortic arch anastomosis are the most commonly used technique to repair aortic coarctation or interrupted aortic arch. Direct anastomosis of the aorta sometimes results in restenosis and/or bronchial compression. To avoid these complications, we have used the technique of the aortic reconstruction using an 0.6% glutaraldehyde-fixed autologous pericardium.

PATIENTS AND METHODS

The procedure was performed in 6 patients;4 with aortic coarctation and 2 with aortic interruption. Prognosis, aortic diameter, and the aortic shape measurement on 3-dimensional computed tomography( 3D-CT) were examined postoperatively.

RESULTS

There were no early or late deaths. There was no case of recurrent aortic arch obstruction and/or bronchial compression, The postoperative A/T ratio was 0.48±0.04 on 3D-CT.

CONCLUSIONS

Reconstruction of the aortic arch with a 0.6% glutaraldehyde-fixed autologous pericardium in an aortic coarctation and interruption showed excellent early and midterm outcomes. There were no complications such as bronchial compression or recoarctation. We believe that this technique leads to a higher success for reconstructing the arch to a near to normal morphology and avoiding the so-called Gothic arch, which has been reported to be associated with late complications of hypertension.

[Assessment of undiagnosed critical congenital heart disease before discharge from the maternity hospital]

Objective: Undiagnosed critical congenital heart disease (CCHD) was assessed before discharge from maternity hospital.Basic information was provided for screening CCHD in the early neonatal stage.Chi-squared test was used for comparison of categorical variables(detection rate of different types of CCHD). Method: A retrospective cohort study was conducted in neonates with CCHD who were admitted to Children's Hospital of Fudan University between 1 January 2012 and 31 December 2015. For comparing with the previously reported undiagnosed rate of CCHD at discharge, CCHD was defined as all duct dependent congenital heart disease (DDCHD) and any cyanotic CHD that required early surgery. Result: A total of 1 036 infants with CCHD were included. The prenatal detection rate of CCHD was 14.04%(122/869). As a whole, 52.51% (544/1 036) of CCHD cases were undiagnosed at discharge, and 14.09%(146/1 036)were still missed after 6-week examination. The diagnoses most likely to be unrecognized at discharge included critical coarctation of the aorta (COA) (75.00%), total anomalous pulmonary venous connection (61.54%), pulmonary atresia (PA) with ventricle septal defect (VSD) (61.45%), single ventricle (SV) (60.10%) and critical aortic stenosis (52.94%). Among newborns diagnosed prior to discharge, 54.88% (270/492) due to symptom or prenatal ultrasonographic diagnosis, 45.12% (222/492) due to abnormal findings in routine examination. Among asymptomatic CCHD cases without prenatal diagnosis, 71.02% (544/766) were undiagnosed and the most common delayed diagnosis was SV (82.78%), interrupted aortic arch (81.82%), transposition of the great arteries with intact ventricular septum (79.63%), PA/VSD (79.07%), and critical COA (78.57%). Newborns with DDC were more likely to develop symptoms within the first few days after birth, in comparison with non-DDC cases. However, their detection rates were close to each other. Conclusion: The rate of misdiagnosis of CCHD before discharge from maternity hospitals is high in China, indicates the importance of implementation of CCHD screening in Chinese maternity hospitals, so as to give timely diagnosis and proper treatment.

Covalent Surface Modification of Gallium Arsenide Photocathodes for Water Splitting in Highly Acidic Electrolyte

Efficient water splitting using light as the only energy input requires stable semiconductor electrodes with favorable energetics for the water-oxidation and proton-reduction reactions. Strategies to tune electrode potentials using molecular dipoles adsorbed to the semiconductor surface have been pursued for decades but are often based on weak interactions and quickly react to desorb the molecule under conditions relevant to sustained photoelectrolysis. Here, we show that covalent attachment of fluorinated, aromatic molecules to p-GaAs(1 0 0) surfaces can be employed to tune the photocurrent onset potentials of p-GaAs(1 0 0) photocathodes and reduce the external energy required for water splitting. Results indicate that initial photocurrent onset potentials can be shifted by nearly 150 mV in pH -0.5 electrolyte under 1 Sun (1000 W m^-2 ) illumination resulting from the covalently bound surface dipole. Though X-ray photoelectron spectroscopy analysis reveals that the covalent molecular dipole attachment is not robust under extended 50 h photoelectrolysis, the modified surface delays arsenic oxide formation that results in a p-GaAs(1 0 0) photoelectrode operating at a sustained photocurrent density of -20.5 mA cm^-2 within -0.5 V of the reversible hydrogen electrode.

The Concept of the Arch Window in the Spiral Switch of the Great Arteries

When the arterial switch operation includes the Lecompte maneuver, the arterial trunks are reconnected in parallel, rather than the spiral fashion observed in the normal heart. Thus, although the ventriculo-arterial connections are hemodynamically corrected, the anatomic arrangement cannot be considered normal. We hypothesized that, if feasible, it would be advantageous to restore a spiral configuration for the arterial trunks. In 58 patients, we reconstructed the arterial trunks such that, postoperatively, the pulmonary channel spirals round the aorta, passing to either the right or the left, and branches posteriorly. We compared the outcomes with those in 95 patients undergoing a standard non-spiraling operation over the same period. Average follow-up was 8.2 ± 4.5 years. The estimated 10-year survival was similar in the cohorts, at 94.7 % for those with spiraling trunks, as compared to 90.4 % for those with parallel outflow tracts. Reoperation-free survival at 10 years was not significantly different (87.6 vs. 90.5 %). Supravalvar pulmonary stenosis, aortic neo-coarctation, or left bronchial stenosis, however, was encountered in one-eighth of those undergoing a standard operation. None of these complications occurred in those patients who, postoperatively, had spiraling outflow tracts (P = 0.002). Reconstruction of spiraling trunks after the arterial switch has, thus far, avoided the complications of supravalvar pulmonary stenosis, neo-aortic kinking, or bronchial stenosis. The spiraling arrangement prevents compression of the pulmonary vessels and bronchial tree by the aorta, since it provides a wide window in the new aortic arch.

[Establishment of a rabbit model of congestive heart failure]

OBJECTIVE

To study the feasibility of establishing a rabbit model of congestive heart failure model by abdominal aortic coarctation combined with intravenous epinephrine infusion.

METHODS

Twenty rabbits were randomized into the study group (n=10) and control group (n=10). Congestive heart failure was induced in the study group by abdominal aortic coarctation combined with intravenous epinephrine infusion. The diameter of the abdominal aorta was reduced by 50%-60%, and epinephrine was infused at 2 weeks (5 mg.kg(-1).min(-1) for 60 min), 4 weeks (4 mg.kg(-1).min(-1) for 60 min) and 6 weeks (4 mg.kg(-1).min(-1) for 60 min) after the operation. The changes in the systolic and diastolic functions of the rabbits were assessed by echocardiography and catheterization during the progression of left hypertrophy.

RESULTS

The diameter of the abdominal aorta at the coarctation region was 4.87-/+0.53 mm before the operation, reduced to 2.26-/+0.47 mm after the operation. At 8 weeks after the operation, the hearts of the rabbits in the study group showed obvious abnormalities in echocardiography, while the hearts in the control group remained normal.

CONCLUSION

Abdominal aortic coarctation combined with intravenous epinephrine infusion allows rapid establishment of a reliable rabbit model of chronic congestive heart failure.