Clinical Outcomes and Echocardiographic Predictors of Reintervention After Interrupted Aortic Arch Repair

Left ventricular outflow tract obstruction (LVOTO) remains a significant complication after primary repair of interrupted aortic arch with ventricular septal defect (IAA-VSD). Clinical and echocardiographic predictors for LVOTO reoperation are controversial and procedures to prophylactically prevent future LVOTO are not reliable. However, it is important to identify the patients at risk for future LVOTO intervention after repair of IAA-VSD. Patients who underwent single-stage IAA-VSD repair at our center 2006-2021 were retrospectively reviewed, excluding patients with associated cardiac lesions. Two-dimensional measurements, LVOT gradients, and 4-chamber (4C) and short-axis (SAXM) strain were obtained from preoperative and predischarge echocardiograms. Univariate risk analysis for LVOTO reoperation was performed using unpaired t-test. Thirty patients were included with 21 (70%) IAA subtype B and mean weight at surgery 3.0 kg. Repair included aortic arch patch augmentation in 20 patients and subaortic obstruction intervention in three patients. Seven (23%) required reoperations for LVOTO. Patient characteristics were similar between patients who required LVOT reoperation and those who did not. Patch augmentation was not associated with LVOTO reintervention. Patients requiring reintervention had significantly smaller LVOT AP diameter preoperatively and at discharge, and higher LVOT velocity, smaller AV annular diameter, and ascending aortic diameter at discharge. There was an association between LVOT-indexed cross-sectional area (CSAcm2/BSAm2) ≤ 0.7 and reintervention. There was no significant difference in 4C or SAXM strain in patients requiring reintervention. LVOTO reoperation was not associated with preoperative clinical or surgical variables but was associated with smaller LVOT on preoperative echo and smaller LVOT, smaller AV annular diameter, and increased LVOT velocity at discharge.

Valved Sano conduit improves immediate outcomes following Norwood operation compared with nonvalved Sano conduit

OBJECTIVE

Use of a valved Sano during the Norwood procedure has been reported previously, but its impact on clinical outcomes needs to be further elucidated. We assessed the impact of the valved Sano compared with the nonvalved Sano after the Norwood procedure in patients with hypoplastic left heart syndrome.

METHODS

We retrospectively reviewed 25 consecutive neonates with hypoplastic left heart syndrome who underwent a Norwood procedure with a valved Sano conduit using a femoral venous homograft and 25 consecutive neonates with hypoplastic left heart syndrome who underwent a Norwood procedure with a nonvalved Sano conduit between 2013 and 2022. Primary outcomes were end-organ function postoperatively and ventricular function over time. Secondary outcomes were cardiac events, all-cause mortality, and Sano and pulmonary artery reinterventions at discharge, interstage, and pre-Glenn time points.

RESULTS

Postoperatively, the valved Sano group had significantly lower peak and postoperative day 1 lactate levels (P = .033 and P = .025, respectively), shorter time to diuresis (P = .043), and shorter time to enteral feeds (P = .038). The valved Sano group had significantly fewer pulmonary artery reinterventions until the Glenn operation (n = 1 vs 8; P = .044). The valved Sano group showed significant improvement in ventricular function from the immediate postoperative period to discharge (P < .001). From preoperative to pre-Glenn time points, analysis of ventricular function showed sustained ventricular function within the valved Sano group, but a significant reduction of ventricular function in the nonvalved Sano group (P = .003). Pre-Glenn echocardiograms showed competent conduit valves in two-thirds of the valved Sano group (n = 16; 67%).

CONCLUSIONS

The valved Sano is associated with improved multi-organ recovery postoperatively, better ventricular function recovery, and fewer pulmonary artery reinterventions until the Glenn procedure.

Influence of preoperative aortic regurgitation on long-term autograft durability and dilatation in children and adolescents undergoing the Ross procedure

OBJECTIVE

Primary aortic insufficiency (AI) is a risk factor for autograft reintervention in adults undergoing the Ross procedure. We sought to examine the influence of preoperative AI on autograft durability in children and adolescents.

METHODS

From 1993 to 2020, 125 consecutive patients between ages 1 and 18 underwent a Ross procedure. The autograft was implanted using a full-root technique in 123 (98.4%) and included in a polyethelene terephthalate graft in 2 (1.6%). Patients with aortic stenosis (aortic stenosis group) (n = 85) were retrospectively compared with those with AI or mixed disease (AI group) (n = 40). Median length of follow-up was 8.2 years (interquartile range, 3.3-15.4 years). The primary end point was the incidence of severe AI or autograft reintervention. Secondary end points included changes in autograft dimensions analyzed using mixed-effect models.

RESULTS

The incidence of severe AI or autograft reintervention was 39.0% ± 13.0% in the AI group and 8.8% ± 4.4% in the aortic stenosis group at 15 years (P = .02). Annulus z scores increased in both aortic stenosis and AI groups over time (P < .001). However, the annulus dilated at a faster rate in the AI group (absolute difference, 3.8 ± 2.0 vs 2.5 ± 1.7; P = .03). Sinus of Valsalva z scores increased in both groups as well (P < .001), but at similar rates over time (P = .11).

CONCLUSIONS

Children and adolescents with AI undergoing the Ross procedure have higher rates of autograft failure. Patients with preoperative AI have more pronounced dilatation at the annulus. Akin to adults, a surgical aortic annulus stabilization technique that modulates growth is needed in children.

Outcomes and Risk Factors of Interventions for Pediatric Post-operative Pulmonary Vein Stenosis

Pulmonary vein stenosis (PVS) in children is a challenging condition with poor outcomes. Post-operative stenosis can occur after repair of anomalous pulmonary venous return (APVR) or stenosis within native veins. There is limited data on the outcomes of post-operative PVS. Our objective was to review our experience and assess surgical and transcatheter outcomes. Single-center retrospective study was performed including patients < 18 years who developed restenosis after baseline pulmonary vein surgery that required additional intervention(s) from 1/2005 to 1/2020. Non-invasive imaging, catheterization and surgical data were reviewed. We identified 46 patients with post-operative PVS with 11 (23.9%) patient deaths. Median age at index procedure was 7.2 months (range 1 month-10 years), and median follow-up was 10.8 months (range 1 day-13 years). Index procedure was surgical in 36 (78.3%) and transcatheter in 10 (21.7%). Twenty-three (50%) patients developed vein atresia. Mortality was not associated with number of affected veins, vein atresia, or procedure type. Single ventricle physiology, complex congenital heart disease (CCHD), and genetic disorders were associated with mortality. Survival rate was higher in APVR patients (p = 0.03). Patients with three or more interventions had a higher survival rate compared to patients with 1-2 interventions (p = 0.02). Male gender, necrotizing enterocolitis, and diffuse hypoplasia were associated with vein atresia. In post-operative PVS, mortality is associated with CCHD, single ventricle physiology, and genetic disorders. Vein atresia is associated with male gender, necrotizing enterocolitis, and diffuse hypoplasia. Multiple repeated interventions may offer a patient survival benefit; however, larger prospective studies are necessary to elucidate this relationship further.

An Ex Vivo Porcine Model for Hydrodynamic Testing of Experimental Aortic Valve Procedures and Novel Medical Devices

The options for testing new cardiac procedures and investigative medical devices prior to use in an animal model are limited. In this study, we present a method for mounting a porcine aortic valve in a pulse duplicator to evaluate its hydrodynamic properties. These properties can then be evaluated before and after the procedure under investigation is performed and/or the investigative medical device is applied. Securing the inflow segment presents some difficulty owing to the lack of circumferential myocardium in the left ventricular outflow tract. This method addresses that issue by securing the inflow segment using the anterior leaflet of the mitral valve and then suturing the left ventricular free wall around the inflow fixture. The outflow segment is secured simply by inserting the fixture into an incision in the superior aspect of the aortic arch. We found that specimens had significantly different hydrodynamic properties before and after tissue fixation. This finding induced us to use fresh specimens in our testing and should be considered when using this method. In our work, we used this method to test novel intracardiac patch materials for use in the valvular position by performing an aortic valve neocuspidization procedure (Ozaki procedure) on the mounted porcine aortic valves. These valves were tested before and after the procedure to assess the change in hydrodynamic properties in comparison to the native valve. Herein, we report a platform for hydrodynamic testing of experimental aortic valve procedures that enables comparison with the native valve and between different devices and techniques used for the procedure under investigation.

Operative mortality after Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1 to 3 procedures: Deficiencies and opportunities for quality improvement

OBJECTIVES

We examined cases of operative mortality at a single quaternary academic center for patients undergoing relatively lower-risk (Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1-3) procedures, as a means of identifying systemic weaknesses and opportunities for quality improvement.

METHODS

A retrospective review of all operative mortality events for patients who underwent a Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1, 2, or 3 index procedure (2009-2020) at our institution was performed. After a detailed chart review was performed by 2 independent faculty for each case, factors and system deficiencies that contributed to mortality were identified.

RESULTS

A total of 42 mortalities were identified. A total of 37 patients (88%) had at least 1 Society of Thoracic Surgeons-designated risk factor, including prior cardiac operations (48%), extracardiac malformations (43%), and preoperative ventilation (33%). Eight patients (19%) had non-Society of Thoracic Surgeons-designated preoperative patient-level variables considered as at potential risk, including severe ventricular dysfunction, pulmonary hypertension, lung hypoplasia, and undiagnosed severe coronary abnormalities. Four patients (10%) had no identified preoperative risk factors. After detailed chart review, 5 broad categories were identified: patient-related factors (n = 33; 78%), postoperative infection (n = 13; 31%), postoperative residual lesions (n = 7; 17%), Fontan physiology failure (n = 4; 10%), and unexplained left ventricular failure after tetralogy of Fallot repair (n = 3; 7%). A total of 74% of patients had at least 1 preoperative, intraoperative, or postoperative system deficiency. A total of 50% of surgeries were urgent or emergency.

CONCLUSIONS

Operative mortality after Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 1 to 3 procedures is related to the presence of multifactorial risk patterns (Society of Thoracic Surgeons and non-Society of Thoracic Surgeons-designated patient-level risk factors and variables, broad risk categories, system deficiencies, emergency surgery). A multidisciplinary approach to care, with early recognition and treatment of modifiable additional burdens, could reduce this risk.

In Vitro Proof of Concept of a First-Generation Growth-Accommodating Heart Valved Conduit for Pediatric Use

Currently available heart valve prostheses have no growth potential, requiring children with heart valve diseases to endure multiple valve replacement surgeries with compounding risks. This study demonstrates the in vitro proof of concept of a biostable polymeric trileaflet valved conduit designed for surgical implantation and subsequent expansion via transcatheter balloon dilation to accommodate the growth of pediatric patients and delay or avoid repeated open-heart surgeries. The valved conduit is formed via dip molding using a polydimethylsiloxane-based polyurethane, a biocompatible material shown here to be capable of permanent stretching under mechanical loading. The valve leaflets are designed with an increased coaptation area to preserve valve competence at expanded diameters. Four 22 mm diameter valved conduits are tested in vitro for hydrodynamics, balloon dilated to new permanent diameters of 23.26 ± 0.38 mm, and then tested again. Upon further dilation, two valved conduits sustain leaflet tears, while the two surviving devices reach final diameters of 24.38 ± 0.19 mm. After each successful dilation, the valved conduits show increased effective orifice areas and decreased transvalvular pressure differentials while maintaining low regurgitation. These results demonstrate concept feasibility and motivate further development of a polymeric balloon-expandable device to replace valves in children and avoid reoperations.

Comparative outcomes and risk analysis after cone repair or tricuspid valve replacement for Ebstein's anomaly

Objective

Ebstein's anomaly is a rare congenital heart malformation for which surgical and medical management are still controversial. The cone repair has transformed surgical outcomes in many of these patients. We aimed to present our results on the outcomes of patients with Ebstein's anomaly who underwent a cone repair or tricuspid valve replacement.

Methods

A total of 85 patients who underwent a cone repair (mean age, 16.5 years) or tricuspid valve replacement (mean age, 40.8 years) between 2006 and 2021 were included. Univariate, multivariate, and Kaplan-Meier analyses were used to evaluate operative and long-term outcomes.

Results

Residual/recurrent greater than mild-to-moderate tricuspid regurgitation at discharge was higher after cone repair compared with tricuspid valve replacement (36% vs 5%; P = .010). However, at last follow-up, the risk of greater than mild-to-moderate tricuspid regurgitation was not different between groups (35% in the cone group vs 37% in the tricuspid valve replacement group; P = .786). The tricuspid valve replacement group had a higher risk of tricuspid valve reoperation (37% vs 9%; P = .005) and tricuspid stenosis (21% vs 0%; P = .002) compared with the cone repair group. Kaplan-Meier freedom from reintervention was 97%, 91%, and 91% at 2, 4, and 6 years after cone repair, respectively, and 84%, 74%, and 68% at 2, 4, and 6 years after tricuspid valve replacement, respectively (P = .0191). At last follow-up, right ventricular function was significantly worse from baseline in the tricuspid valve replacement group (P = .0294). There were no statistical differences between age-stratified cohorts or surgeon volume in the cone repair group.

Conclusions

The cone procedure offers excellent results, with stable tricuspid valve function and low reintervention and death rates at last follow-up. The rate of greater than mild-to-moderate residual tricuspid regurgitation at discharge was higher after cone repair compared with tricuspid valve replacement, but this did not expose the patient to a higher risk of reoperation or death at last follow-up. Tricuspid valve replacement was associated with a significantly higher risk of tricuspid valve reoperation and tricuspid valve stenosis, and worse right ventricular function at last follow-up.

Age-related enhanced degeneration of bioprosthetic valves due to leaflet calcification, tissue crosslinking, and structural changes

AIMS

Bioprosthetic heart valves (BHVs), made from glutaraldehyde-fixed heterograft materials, are subject to more rapid structural valve degeneration (SVD) in paediatric and young adult patients. Differences in blood biochemistries and propensity for disease accelerate SVD in these patients, which results in multiple re-operations with compounding risks. The goal of this study is to investigate the mechanisms of BHV biomaterial degeneration and present models for studying SVD in young patients and juvenile animal models.

METHODS AND RESULTS

We studied SVD in clinical BHV explants from paediatric and young adult patients, juvenile sheep implantation model, rat subcutaneous implants, and an ex vivo serum incubation model. BHV biomaterials were analysed for calcification, collagen microstructure (alignment and crimp), and crosslinking density. Serum markers of calcification and tissue crosslinking were compared between young and adult subjects. We demonstrated that immature subjects were more susceptible to calcification, microstructural changes, and advanced glycation end products formation. In vivo and ex vivo studies comparing immature and mature subjects mirrored SVD in clinical observations. The interaction between host serum and BHV biomaterials leads to significant structural and biochemical changes which impact their functions.

CONCLUSIONS

There is an increased risk for accelerated SVD in younger subjects, both experimental animals and patients. Increased calcification, altered collagen microstructure with loss of alignment and increased crimp periods, and increased crosslinking are three main characteristics in BHV explants from young subjects leading to SVD. Together, our studies establish a basis for assessing the increased susceptibility of BHV biomaterials to accelerated SVD in young patients.

Polymeric prosthetic heart valves: A review of current technologies and future directions

Valvular heart disease is an important source of cardiovascular morbidity and mortality. Current prosthetic valve replacement options, such as bioprosthetic and mechanical heart valves are limited by structural valve degeneration requiring reoperation or the need for lifelong anticoagulation. Several new polymer technologies have been developed in recent years in the hope of creating an ideal polymeric heart valve substitute that overcomes these limitations. These compounds and valve devices are in various stages of research and development and have unique strengths and limitations inherent to their properties. This review summarizes the current literature available for the latest polymer heart valve technologies and compares important characteristics necessary for a successful valve replacement therapy, including hydrodynamic performance, thrombogenicity, hemocompatibility, long-term durability, calcification, and transcatheter application. The latter portion of this review summarizes the currently available clinical outcomes data regarding polymeric heart valves and discusses future directions of research.

Outcomes After Anatomic Versus Physiologic Repair of Congenitally Corrected Transposition of the Great Arteries: A Systematic Review and Meta-Analysis

Surgical treatment for congenitally corrected transposition of the great arteries is widely debated, with both physiologic repair and anatomic repair holding advantages and disadvantages. This meta-analysis, which includes 44 total studies consisting of 1857 patients, compares mortality at different time points (operative, in-hospital, and post-discharge), reoperation rates, and postoperative ventricular dysfunction between these two categories of procedures. Although anatomic and physiologic repair had similar operative and in-hospital mortality, anatomic repair patients had significantly less post-discharge mortality (6.1% vs 9.7%; P = .006), lower reoperation rates (17.9% vs 20.6%; P < .001), and less postoperative ventricular dysfunction (16% vs 43%; P < .001). When anatomic repair patients were subdivided into those who had atrial and arterial switch versus those who had atrial switch with Rastelli, the double switch group had significantly lower in-hospital mortality (4.3% vs 7.6%; P = .026) and reoperation rates (15.6% vs 25.9%; P < .001). The results of this meta-analysis suggest a protective benefit of favoring anatomic repair over physiologic repair.

Tricuspid Valve Endocarditis in Four Patients with Unrepaired Restrictive Perimembranous Ventricular Septal Defects

Congenital heart disease (CHD) is the most common predisposing factor for pediatric infective endocarditis (IE). Although patients with unrepaired ventricular septal defects (VSDs) are at greater risk of IE than those without CHD, the American Heart Association (AHA) considers VSDs to be relatively low risk and therefore does not recommend antibiotic prophylaxis against IE. Even among patients with VSDs who develop IE, current AHA and European Society for Cardiology (ESC) guidelines do not recommend surgical VSD closure, despite the potential for a second IE event. We present a case series of four children with small, restrictive, perimembranous VSDs who developed tricuspid valve (TV) IE. All four experienced delayed diagnosis and secondary complications, including three with septic pulmonary emboli. All four patients ultimately underwent surgical VSD closure. These cases highlight the importance of recognizing IE as a possible cause of prolonged fever in children, even among those with even 'low-risk' CHD. The cases also draw attention to the potential benefits of VSD closure in patients who develop IE.

Ross Procedure in Neonate and Infant Populations: A Meta-Analysis Review

Objective

This study aims to perform a meta-analysis of early and late outcomes of the Ross/Ross-Konno procedures in neonates/infants.

Methods

A meta-analysis was performed in accordance with PRISMA guidelines. We used Ovid versions of MEDLINE/PubMed for relevant studies and included those that reported Ross/Ross-Konno operations in neonates/infants and at least one of the predetermined clinical outcomes. I2 and double arcsine methods assessed the heterogeneity between pooled estimates. We used a random-effect model to account for heterogeneity with MetaXL. We calculated point estimates of a pooled estimates along with its 95% CI.

Results

587 neonate/infant patients were included with median age of 87.5 days old. The follow-up range was five days to 23 years. Early mortality reported in 25 studies with pooled estimates of 18.3% (95% CI: 13.6%-23.5%). Estimates ranged from 0% to 50% with relatively substantial heterogeneity ( P = .01, I2 = 48.6%). Late mortality reported in 22 studies with pooled incidence of 9.7% (95% CI: 5.9%-14.3%). Estimates ranged from 0% to 53% with relatively substantial heterogeneity ( P = .01, I2 = 46.1%). Autograft reintervention reported in 18 studies with pooled estimate of 19.2% (95% CI: 7.3%-34.5%). Estimates ranged from 0% to 81.8% with high heterogeneity ( P < .001, I2 = 90.5%). Right ventricle-to-pulmonary artery conduit reintervention reported in 16 studies with pooled estimates of 32.0% (95% CI: 20.9%-44.12%). Estimates ranged from 0% to 92.3% with high heterogeneity ( P < .001, I2 = 75.9%).

Conclusions

The data suggest that the Ross/Ross-Konno procedure in neonates/infants still carries significant risk of early/late mortality and autograft/conduit reintervention. The high variability of results among centers confirms the need for surgical expertise and good patient selection. Prospective multicenter studies are warranted to investigate the rate of autograft reintervention and the impact on long-term survival in this specific population.

A biomimetic multilayered polymeric material designed for heart valve repair and replacement

Materials currently used to repair or replace a heart valve are not durable. Their limited durability related to structural degeneration or thrombus formation is attributed to their inadequate mechanical properties and biocompatibility profiles. Our hypothesis is that a biostable material that mimics the structure, mechanical and biological properties of native tissue will improve the durability of these leaflets substitutes and in fine improve the patient outcome. Here, we report the development, optimization, and testing of a biomimetic, multilayered material (BMM), designed to replicate the native valve leaflets. Polycarbonate urethane and polycaprolactone have been processed as film, foam, and aligned fibers to replicate the leaflet's architecture and anisotropy, through solution casting, lyophilization, and electrospinning. Compared to the commercialized materials, our BMMs exhibited an anisotropic behavior and a closer mechanical performance to the aortic leaflets. The material exhibited superior biostability in an accelerated oxidization environment. It also displayed better resistance to protein adsorption and calcification in vitro and in vivo. These results will pave the way for a new class of advanced synthetic material with long-term durability for surgical valve repair or replacement.

Surgical Management of Complex Aortic Valve Disease in Young Adults: Repair, Replacement, and Future Alternatives

The ideal aortic valve substitute in young adults remains unknown. Prosthetic valves are associated with a suboptimal survival and carry a significant risk of valve-related complications in young patients, mainly reinterventions with tissue valves and, thromboembolic events and major bleeding with mechanical prostheses. The Ross procedure is the only substitute that restores a survival curve similar to that of a matched general population, and permits a normal life without functional limitations. Though the risk of reintervention is the Achilles' heel of this procedure, it is very low in patients with aortic stenosis and can be mitigated in patients with aortic regurgitation by tailored surgical techniques. Finally, the Ozaki procedure and the transcatheter aortic valve implantation are seen by many as future alternatives but lack evidence and long-term follow-up in this specific patient population.

Transcatheter Closure of Atrial and Ventricular Septal Defects: JACC Focus Seminar

The field of congenital interventional cardiology has experienced tremendous growth in recent years. Beginning with the development of early devices for transcatheter closure of septal defects in the 1970s and 1980s, such technologies have evolved to become a mainstay of treatment for many atrial septal defects (ASDs) and ventricular septal defects (VSDs). Percutaneous device closure is now the preferred approach for the majority of secundum ASDs. It is also a viable treatment option for selected VSDs, though limitations still exist. In this review, the authors describe the current state of transcatheter closure of ASDs and VSDs in children and adults, including patient selection, procedural approach, and outcomes. Potential areas for future evolution and innovation are also discussed.

Interventions for Congenital Atrioventricular Valve Dysfunction: JACC Focus Seminar

Innovation and creativity have led to tremendous advancements in the care and management of patients with congenital heart disease (CHD) that have resulted in considerably increased survival. Catheter-based interventions have contributed significantly to these advancements. However, catheter-based interventions for congenital lesions of the atrioventricular (AV) valves have been limited in scope and effectiveness mainly because of patient size and anatomical challenges. Thus, surgical repair and replacement for congenital AV valve lesions have remained the preferred therapy. However, the ongoing transcatheter heart valve revolution has led to techniques and technologies that are changing the landscape, particularly for adult CHD patients. Many devices for AV valve repair and replacement are being studied in adult patients without CHD, and translation of select practices to CHD patients has begun, with many more to come. Transcatheter AV valve interventions represent exciting opportunities for the growing numbers of adult CHD patients.

Outcomes after neonatal cardiac surgery: The impact of a dedicated neonatal cardiac program

OBJECTIVES

Prematurity is a risk factor for in-hospital mortality after cardiac surgery. The structure of intensive care unit models designed to deliver optimal care to neonates including those born preterm with critical congenital heart disease is unknown. The objective of this study was to evaluate in-hospital outcomes after cardiac surgery across gestational ages in an institution with a dedicated neonatal cardiac program.

METHODS

This study is a single-center, retrospective review of infants who underwent cardiac surgical interventions from our dedicated neonatal cardiac intensive care program between 2006 and 2017. We evaluated in-hospital mortality and morbidity rates across all gestational ages.

RESULTS

A total of 1238 subjects met inclusion criteria over a 11-year period. Overall in-hospital mortality after cardiac surgery was 6.1%. The mortality rate in very preterm infants (n = 68; <34 weeks' gestation at birth) was 17.6% (odds ratio, 3.52 [1.4-8.53]), versus 4.3% in full-term (n = 563; 39-40 weeks) referent/control infants. Very preterm infants with isolated congenital heart disease (without evidence of other affected organ systems) experienced a mortality rate of 10.5% after cardiac surgery. Neither the late preterm (34-36 ^6/7 weeks) nor the early term (37-38 ^6/7) groups had significantly increased odds of mortality compared with full-term infants. Seventy-eight percent of very preterm infants incurred a preoperative or postoperative complication (odds ratio, 4.78 [2.61-8.97]) compared with 35% of full-term infants.

CONCLUSIONS

In this study of a single center with a dedicated neonatal cardiac program, we report some of the lowest mortality and morbidity rates after cardiac surgery in preterm infants in the recent era. The potential survival advantage of this model is most striking for very preterm infants born with isolated congenital heart disease.

Peri-operative changes in diastolic function and outcomes in congenital aortic valve surgery

Background

The ratio of early diastolic mitral inflow velocity (E) to early diastolic mitral annular tissue velocity (e’), or E/e’, is an echocardiographic measure of left ventricular filling pressure. Peri‐operative changes in E/e’ and association with outcomes have been demonstrated in adults undergoing surgery for aortic stenosis (AS). We sought to explore changes in E/e’ and other diastolic indices in the setting of congenital AS surgery and to assess for association with post‐operative outcomes among children and young adults.

Methods

A retrospective, single‐center study was performed among patients 6 months to 30 years of age who underwent congenital AS surgery from 2006 to 2018. Tissue Doppler indices were collected from pre‐ and post‐operative echocardiograms. Post‐operative outcomes were reviewed.

Results

Sixty‐six subjects with subvalvar (45%), valvar (47%), and supravalvar (8%) AS underwent surgery at a median age of 9.5 years (IQR: 4.0–14.8). Pre‐operatively, the lateral E/e’ ratio was 8.6 (6.7–11.0); 33% had E/e’≥10. Post‐operatively, the lateral e’ decreased to 9.9 cm/s (8.0–11.4), the E/e’ ratio increased to 10.4 (8.3–13.1); and 53% had E/e’≥10 (p‐values < 0.0001, 0.0072, and < 0.001, respectively). Pre‐operative lateral e’ correlated modestly with duration of intubation (ρ = −0.24, p‐value 0.048) and post‐operative lateral e’ correlated modestly with duration of intubation and length of hospital stay (ρ = −0.28 and −0.26, p‐values = 0.02 and 0.04, respectively).

Conclusions

Children and young adults who underwent congenital AS surgery had echocardiographic evidence of diastolic dysfunction pre‐operatively that worsened post‐operatively. Lateral e’ may be a sensitive indicator of impaired ventricular relaxation in these patients and may impact duration of intubation and hospital stay.

Environmental Exposures and Congenital Heart Disease

Congenital heart disease (CHD) is the most common congenital abnormality worldwide, affecting 8 to 12 infants per 1000 births globally and causing >40% of prenatal deaths. However, its causes remain mainly unknown, with only up to 15% of CHD cases having a determined genetic cause. Exploring the complex relationship between genetics and environmental exposures is key in understanding the multifactorial nature of the development of CHD. Multiple population-level association studies have been conducted on maternal environmental exposures and their association with CHD, including evaluating the effect of maternal disease, medication exposure, environmental pollution, and tobacco and alcohol use on the incidence of CHD. However, these studies have been done in a siloed manner, with few examining the interplay between multiple environmental exposures. Here, we broadly and qualitatively review the current literature on maternal and paternal prenatal exposures and their association with CHD. We propose using the framework of the emerging field of the exposome, the environmental complement to the genome, to review all internal and external prenatal environmental exposures and identify potentiating or alleviating synergy between exposures. Finally, we propose mechanistic pathways through which susceptibility to development of CHD may be induced via the totality of prenatal environmental exposures, including the interplay between placental and cardiac development and the internal vasculature and placental morphology in early stages of pregnancy.

Design optimization of a cardiovascular stent with application to a balloon expandable prosthetic heart valve

A cardiovascular stent design optimization method is proposed with application to a pediatric balloon-expandable prosthetic heart valve. The prosthetic valved conduit may be expanded to a larger permanent diameter in vivo via subsequent transcatheter balloon dilation procedures. While multiple expandable prosthetic heart valves are currently at different stages of development, this work is focused on one particular design in which a stent is situated inside of an expandable polymeric valved conduit. Since the valve and conduit must be joined with a robust manufacturing technique, a polymeric glue layer is inserted between the two, which results in radial retraction of the valved region after expansion. Design of an appropriate stent is proposed to counteract this phenomenon and maintain the desired permanent diameter throughout the device after a single non-compliant balloon dilation procedure. The finite element method is used to compute performance metrics related to the permanent expansion diameter and required radial force. Additionally, failure due not only to high cycle fatigue but also due to ductile fracture is incorporated into the design study through the use of an existing ductile fracture criterion for metals. Surrogate models are constructed with the results of the high fidelity simulations and are subsequently used to numerically obtain a set of Pareto-optimal stent designs. Finally, a single design is identified by optimizing a normalized aggregate objective function with equal weighting of all design objectives.

Cardiac transplantation in adult congenital heart disease with prior sternotomy

BACKGROUND

Adult congenital heart disease (ACHD) patients who require orthotopic heart transplantation are surgically complex due to anatomical abnormalities and multiple prior surgeries. In this study, we investigated these patients' outcomes using our institutional database.

METHODS

ACHD patients who had prior intracardiac repair and subsequent heart transplant were included (2008-2018). Adult patients without ACHD were extracted as a control. A comparison of patients with functional single ventricular (SV) and biventricular (BV) hearts was performed.

RESULTS

There were 9 SV and 24 BV patients. The SV group had higher central venous pressure/pulmonary capillary wedge pressure (P = .028), hemoglobin concentration (P = .010), alkaline phosphatase (P = .022), and were more likely to have liver congestion (P = .006). Major complications included infection in 16 (48.5%), temporary dialysis in 12 (36.4%), and graft dysfunction requiring perioperative mechanical support in 7 (21.2%). Overall in-hospital mortality was 15.2%. Kaplan-Meier analysis showed a higher, but not statistically significant, survival after 10 years between the ACHD and control groups (ACHD 84.9% vs. control 67.5%, P = .429). There was no significant difference in 10-year survival between SV and BV groups (78% vs. 88%, P = .467).

CONCLUSIONS

Complex ACHD cardiac transplant recipients have a high incidence of early morbidities after transplantation. However, long-term outcomes were acceptable.

Weight impacts 1-year congenital heart surgery outcomes independent of race/ethnicity and payer

Body mass index, race/ethnicity, and payer status are associated with operative mortality in congenital heart disease (CHD). Interactions between these predictors and impacts on longer term outcomes are less well understood. We studied the effect of body mass index, race/ethnicity, and payer on 1-year outcomes following elective CHD surgery and tested the degree to which race/ethnicity and payer explained the effects of body mass index. Patients aged 2-25 years who underwent elective CHD surgery at our centre from 2010 to 2017 were included. We assessed 1-year unplanned cardiac re-admissions, re-interventions, and mortality. Step-wise, multivariable logistic regression was performed.Of the 929 patients, 10.4% were underweight, 14.9% overweight, and 8.5% obese. Non-white race/ethnicity comprised 40.4% and public insurance 29.8%. Only 0.5% died prior to hospital discharge with one additional death in the first post-operative year. Amongst patients with continuous follow-up, unplanned re-admission and re-intervention rates were 14.7% and 12.3%, respectively. In multivariable analyses adjusting for surgical complexity and surgeon, obese, overweight, and underweight patients had higher odds of re-admission than normal-weight patients (OR 1.40, p = 0.026; OR 1.77, p < 0.001; OR 1.44, p = 0.008). Underweight patients had more than twice the odds of re-intervention compared with normal weight (OR 2.12, p < 0.001). These associations persisted after adjusting for race/ethnicity, payer, and surgeon.Pre-operative obese, overweight, and underweight body mass index were associated with unplanned re-admission and/or re-intervention 1-year following elective CHD surgery, even after accounting for race/ethnicity and payer status. Body mass index may be an important modifiable risk factor prior to CHD surgery.

Characterization of Extracorporeal Membrane Oxygenation Support for Single Ventricle Patients

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) can provide crucial support for single ventricle (SV) patients at various stages of palliation. However, characterization of the utilization and outcomes of ECMO in these unique patients remains incompletely studied.

METHODS

We performed a single-center retrospective review of SV patients between 2010 and 2017 who underwent ECMO cannulation with primary end point of survival to discharge and secondary end point of survival to decannulation or orthotopic heart transplantation (OHT). Multivariate analysis was performed for factors predictive of survival to discharge and survival to decannulation.

RESULTS

Forty SV patients with a median age of one month (range: 3 days to 15 years) received ECMO support. The incidence of ECMO was 14% for stage I, 3% for stage II, and 4% for stage III. Twenty-seven (68%) patients survived to decannulation, and 21 (53%) patients survived to discharge, with seven survivors to discharge undergoing OHT. Complications included infection (40%), bleeding (40%), thrombosis (33%), and radiographic stroke (45%). Factors associated with survival to decannulation included pre-ECMO lactate (hazard ratio [HR]: 0.61, 95% confidence interval [CI]: 0.41-0.90, P = .013) and post-ECMO bicarbonate (HR: 1.24, 95% CI: 1.0-1.5, P = .018). Factors associated with survival to discharge included central cannulation (HR: 40.0, 95% CI: 3.1-500.0, P = .005) and lack of thrombotic complications (HR: 28.7, 95% CI: 2.1-382.9, P = .011).

CONCLUSIONS

Extracorporeal membrane oxygenation can be useful to rescue SV patients with approximately half surviving to discharge, although complications are frequent. Early recognition of the role of heart transplant is imperative. Further study is required to identify areas for improvement in this population.

The Risks of Being Tiny: The Added Risk of Low Weight for Neonates Undergoing Congenital Heart Surgery

The aims of this study were (1) to describe the additive risk of performing cardiac surgery in neonates born ≤ 2.0 kg, after accounting for the baseline risks of low birth weight, and (2) to describe the additive risk of being born ≤ 2.0 kg in neonates undergoing cardiac surgery. We used a risk difference analysis in a retrospective cohort, 2006-2016. Neonates born ≤ 2.0 kg undergoing congenital heart surgery during initial postnatal admission were included. Data were standardized alternatingly for birth weight and cardiac surgical risk using national population data to estimate the number of deaths expected had they not required cardiac surgery or were they of normal weight. Of 105 neonates ≤ 2 kg, median birth weight was 1.6 kg (IQR 1.3-1.8 kg). Median gestational age was 33 weeks (IQR 31-35 weeks). Observed operative mortality was 14.3%; 0% for neonates ≤ 1.0 kg (CI 0-33.6%), 20.6% for neonates > 1.0-1.5 kg (CI 8.7-37.9%), and 12.9% for neonates > 1.5-2.0 kg (CI 5.7-23.9%). Among neonates ≤ 2.0 kg not undergoing cardiac surgery, expected mortality was 4.8% (CI 1.6-10.8); cardiac surgery increased the risk of mortality 9.5% (CI 1.7-17.4%). Conversely, the expected risk for normal birth weight neonates undergoing cardiac surgery was 5.7% (CI 2.1-12.0%); low birth weight increased the risk of mortality 8.6% (CI 0.5-16.6%). To continue making advancements in cardiac surgery, we must understand that the rate of mortality observed in normal weight infants is not a realistic target and that, despite advances, the risk attributable to the surgery remains higher among low birth weight patients.

Neonates With Complex Cardiac Malformation and Congenital Diaphragmatic Hernia Born to SARS-CoV-2 Positive Women-A Single Center Experience

BACKGROUND

Our understanding of the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on pregnancies and perinatal outcomes is limited. The clinical course of neonates born to women who acquired coronavirus disease 2019 (COVID-19) during their pregnancy has been previously described. However, the course of neonates born with complex congenital malformations during the COVID-19 pandemic is not known.

METHODS

We report a case series of seven neonates with congenital heart and lung malformations born to women who tested positive for SARS-CoV-2 during their pregnancy at a single academic medical center in New York City.

RESULTS

Six infants had congenital heart disease and one was diagnosed with congenital diaphragmatic hernia. In all seven infants, the clinical course was as expected for the congenital lesion. None of the seven exhibited symptoms generally associated with COVID-19. None of the infants in our case series tested positive by nasopharyngeal test for SARS-CoV-2 at 24 hours of life and at multiple points during their hospital course.

CONCLUSIONS

In this case series, maternal infection with SARS-CoV-2 during pregnancy did not result in adverse outcomes in neonates with complex heart or lung malformations. Neither vertical nor horizontal transmission of SARS-CoV-2 was noted.

Evolution of pediatric ventricular assist devices and their neurologic and renal complications-A 24-year single-center experience

Utilization of ventricular assist devices (VADs) in adult populations with severe heart failure as a bridge to transplant has become the standard of care over the past two decades. Analogously, the use of VADs in pediatric populations has become more commonplace as pediatric heart transplantation has become more prevalent. We still have much to learn, however, about the complications after VAD placement in pediatric patients, their impact on transplantation and, in particular, how outcomes have changed over time. The objectives of this study were to (a) review the experience of a single pediatric VAD center, (b) identify risk factors that could lead to poor outcomes in patients on the transplant waitlist after VAD implantation and (c) demonstrate changes in outcomes over time. A retrospective cohort analysis was performed comparing death as a primary outcome and stroke and acute kidney injury (AKI) as secondary outcomes, across the study period divided into three timed eras. We analyzed 88 patients supported by a VAD over a 24-year timeframe. The duration, age at implant and indication for VAD support did not change significantly across the eras. We found that the incidence of stroke decreased over the study period and, while the rates of AKI did not change over the study period, those who developed AKI, while supported on VAD, had an increased risk of death.

Mechanical considerations for polymeric heart valve development: Biomechanics, materials, design and manufacturing

The native human heart valve leaflet contains a layered microstructure comprising a hierarchical arrangement of collagen, elastin, proteoglycans and various cell types. Here, we review the various experimental methods that have been employed to probe this intricate microstructure and which attempt to elucidate the mechanisms that govern the leaflet's mechanical properties. These methods include uniaxial, biaxial, and flexural tests, coupled with microstructural characterization techniques such as small angle X-ray scattering (SAXS), small angle light scattering (SALS), and polarized light microscopy. These experiments have revealed complex elastic and viscoelastic mechanisms that are highly directional and dependent upon loading conditions and biochemistry. Of all engineering materials, polymers and polymer-based composites are best able to mimic the tissue-level mechanical behavior of the native leaflet. This similarity to native tissue permits the fabrication of polymeric valves with physiological flow patterns, reducing the risk of thrombosis compared to mechanical valves and in some cases surpassing the in vivo durability of bioprosthetic valves. Earlier work on polymeric valves simply assumed the mechanical properties of the polymer material to be linear elastic, while more recent studies have considered the full hyperelastic stress-strain response. These material models have been incorporated into computational models for the optimization of valve geometry, with the goal of minimizing internal stresses and improving durability. The latter portion of this review recounts these developments in polymeric heart valves, with a focus on mechanical testing of polymers, valve geometry, and manufacturing methods.

Indications and results for hybrid interventions in patients with congenital heart disease

A hybrid therapy or procedure is a new treatment modality that develops by combining therapies from different subspecialties. In congenital heart disease, a growing number of such procedures have been described in recent decades, as a result of increasing collaboration between surgeons and interventionalists. The ideas behind these therapies include enabling the performance of procedures of different complexity in a less invasive manner, shortening procedural times, avoiding cardiopulmonary bypass, facilitating vascular access and decreasing the number of complications associated with more invasive approaches. Over the years, hybrid therapy has gained a place as a widely accepted therapeutic option for the management of several conditions in high-risk patients with congenital heart disease.

State of the Art: Tissue Engineering in Congenital Heart Surgery

Congenital heart disease is the leading cause of death secondary to congenital abnormalities in the United States and the incidence has increased significantly over the last 50 years. For those defects requiring surgical repair, bioprosthetic xenografts, allografts, and synthetic materials have traditionally been used. However, none of these modalities offer the potential for growth and accommodation within the pediatric population. Tissue engineering has been an area of great interest in a variety of cardiac applications as an innovative solution to create a product that can grow and regenerate within the body over time. Over the last 30 years, the original tissue engineering paradigm of a scaffold seeded with cells and cultured in a bioreactor has been expanded upon to include innovative methods of decellularization and production of "off-the-shelf" tissue-engineered products capable of in situ host cell repopulation. Despite progress in conceptual design and promising clinical results, widespread use of tissue-engineered products remains limited due to both regulatory and ongoing scientific challenges. Here, we describe the current state of the art with regards to in vitro, in vivo, and in situ tissue engineering as applicable within the field of congenital heart surgery and provide a brief overview of challenges and future directions.