Impact of pulmonary stenosis on right ventricular global longitudinal strain in repaired tetralogy of Fallot patients post transcatheter pulmonary valve replacement.

BACKGROUND: Mixed pulmonary disease with pulmonary regurgitation (PR) and stenosis (PS) in repaired tetralogy of Fallot (rTOF) can negatively impact ventricular health. Myocardial strain has been shown to be more sensitive at detecting occult ventricular dysfunction compared to right ventricular ejection fraction (RV EF). We hypothesize that rTOF patients with predominant PS will have lower RV global longitudinal strain (RV GLS) prior to and post-transcatheter pulmonary valve replacement (TPVR). METHODS: A retrospective cohort of rTOF patients who underwent cardiac magnetic resonance (CMR) and cardiac catheterization for right ventricular pressure (RVSP) measurement were analyzed at three time points: before valve implantation, at discharge and within 18 months post-TPVR. Patients were dichotomized into three groups based on RVSP: 0%-49%, 50%-74%, and >75%. RV GLS and left ventricular (LV) GLS by speckle tracking echocardiography (STE) were obtained from the apical 4-chamber using TomTec software (TOMTEC IS, Germany). RESULTS: Forty-eight patients were included. Every 14.3% increase in preimplantation RVSP above 28% was associated with an absolute magnitude 1% lower RV GLS (p = .001). Preimplantation RVSP when 75% or higher had 3.36% worse RV GLS than the lowest bin (p = .014). Overall, average RV strain magnitude was higher when preimplantation RVSP was less than 50% and had greater improvement over the three time points. Higher post implantation RVSP correlated with lower strain magnitude. CONCLUSION: Patients with significant PS (>50%) may benefit from earlier PVR and not depend solely on RV size and EF. Myocardial strain may be a more sensitive marker of function; however, larger, prospective studies are needed.

Assessing the State of Training in Congenital Interventional Cardiology: A Global Survey of Program Directors.

This study aimed to evaluate the current state of congenital interventional cardiology training worldwide, with a focus on case volumes, competency assessment, and the need for ongoing mentorship during early career stages. A survey was conducted among program directors (PDs) of congenital interventional training programs across the globe. The survey gathered data on training pathways, case volumes, types of procedures performed, trainee competency assessment, and the role of ongoing mentorship. Of the 79 PDs who completed the survey, it was observed that training pathways and case volumes varied significantly, particularly between the United States and other countries. Most PDs reported an annual laboratory case volume of >500 congenital cardiac cases, with most cases being interventional. While trainees demonstrated competency in simple procedures (diagnostic cases, simple ASD closure), complex interventions (such as patent ductus arteriosus closure in premature infants) require ongoing mentorship for graduates. PDs recommended a minimum case volume of 400 total cases for trainees, including 250 interventional cases. In addition to case volumes, assessing trainee competency was deemed important, with clinical reasoning, judgment, skillset, teamwork, and complication management being key areas of evaluation. The study highlights the variability in congenital interventional cardiology training and the need for ongoing mentorship during the early career years. External mentorship programs, facilitated by national and international societies, are proposed to provide critical support for early career interventionalists thus enhancing patient care for congenital heart disease. Ultimately, the findings of this survey may serve as a framework for future training standards and guidelines in this specialized field.

Optimizing 3D Rotational Angiography for Congenital Cardiac Catheterization.

The aim of the study was to determine the variables associated with high-quality (HQ) versus low-quality (LQ) three-dimensional rotational angiography (3DRA) and create guides for optimization of approach to 3DRA in congenital cardiac catheterization (CCC). CCC has adopted 3DRA as a mainstay, but there has not been systematic analysis of approach to and factors associated with HQ 3DRA. This was a single-center, retrospective study of 3DRAs using Canon Infinix-I platform. Reconstructions were graded by 3 interventionalists. Quality was dichotomized into HQ and LQ. Univariable analyses and multivariable logistic regression models were performed. From 8/2016 to 12/2018, 208 3DRAs were performed in 195 CCCs; median age 7 years (2, 16), weight 23 kg (12, 57). The majority of 3DRAs were performed in patients with biventricular physiology (N = 137, 66%) and in pulsatile sites (N = 144, 69%). HQ 3DRA (N = 182, 88%) was associated with greater total injection volume [2.20 mL/kg (1.44, 3.29) vs. 1.62 mL/kg (1.10, 1.98), p = 0.005] and more dilute contrast solution [60% (50, 100) vs. 100% (60, 100), p = 0.007], but not with contrast volume administered (p = 0.2) on univariable analysis. On multivariable logistic regression, HQ 3DRA was significantly associated with patient weight [OR 0.97 (95% CI (0.94, 0.99), p = 0.018], total injection volume [OR 1.04 (95% CI 1.01, 1.07) p = 0.011], and percent contrast solution [OR 0.97 (95% CI 0.95, 1.00), p = 0.022]. These data resulted in creation of scatter plots and a novel 3DRA Nomogram for estimating the probability of HQ 3DRA. This is the first study to create evidence-based contrast dose guides and nomogram for 3DRA in CCC. HQ 3DRA was associated with lower weight, higher total injection volumes, and more dilute contrast solution.

The Need for Surgery After Vascular or Cardiac Trauma, or Technical Adverse Events in the Congenital Cardiac Catheterization Laboratory.

Data on the frequency and outcome of surgical interventions as a result of adverse events (AE) encountered in the pediatric and congenital cardiac catheterization laboratory are limited. This study analyzes the outcomes of specific types of AE that are most likely to require immediate surgical intervention. Data from the C3PO registry were analyzed to identify specific types of significant vascular/cardiac trauma or technical adverse events (stent/device/coil embolization/migration). The relationship between these AE and an "adverse outcome" (defined as either surgery, ECMO, or death) were analyzed. Between 01/2014 and 12/2017, 25,731 cases were entered into the C3PO registry. Vascular or cardiac trauma were observed in 92 cases (0.36% cases in C3PO), and technical adverse events were observed in 176 cases (0.68% cases in C3PO). The two highest procedure type risk categories (PREDIC3T) accounted for 61% of the cases in the cardiac/vascular trauma cohort, and 34% in the technical AE cohort. For vascular/cardiac trauma, 24 (26%) had an adverse outcome, with ECMO in 8 (9%), surgery in 19 (20%), and death in 9 (10%). For technical AE 25 (14%) had an adverse outcome, with ECMO in 3 (2%), surgery in 23 (13%), and death in 3 (2%). Survival after cardiac surgery secondary to an AE was 68% for cardiac/vascular trauma, and 96% for technical adverse events. RF perforation of the pulmonary valve was the procedure most likely to result in cardiac/vascular trauma (10%), with 57% of those having an adverse outcome. Atrial septal interventions accounted for 29% of all adverse outcomes in the cardiac/vascular trauma cohort. Non-elective or emergent cases were associated with a significantly higher incidence of an adverse outcome for both, cardiac/vascular trauma (OR 7.1) and technical adverse events (OR 2.7). Surgery within the last 30 days was associated with a significantly higher incidence of an adverse outcome for cardiac/vascular trauma only (OR 4.2). Significant cardiac/vascular trauma or stent/device/coil embolization/migration are rare, but high consequence AE. With appropriate surgical and ECMO backup, a high survival can be achieved. The potential need for and impact of immediate surgical backup seems to be higher for cardiac/vascular trauma (in particular after specific case types), than for device/coil migration/embolization, and as such case specific backup arrangements are required.

Safety and Short-Term Outcomes for Infants < 2.5 kg Undergoing PDA Device Closure: A C3PO Registry Study.

To evaluate short-term procedural outcomes and safety for infants < 2.5 kg who underwent catheterization with intended patent ductus arteriosus (PDA) device closure in a multi-center registry, as performance of this procedure becomes widespread. A multi-center retrospective review was performed using data from the Congenital Cardiac Catheterization Project on Outcomes (C3PO) registry. Data were collected for all intended cases of PDA closure in infants < 2.5 kg from April 2019 to December 2020 at 13 participating sites. Successful device closure was defined as device placement at the conclusion of the catheterization. Procedural outcomes and adverse events (AE) were described, and associations between patient characteristics, procedural outcomes and AEs were analyzed. During the study period, 300 cases were performed with a median weight of 1.0 kg (range 0.7-2.4). Successful device closure was achieved in 98.7% of cases with a 1.7% incidence of level 4/5 AEs, including one periprocedural mortality. Neither failed device placement nor adverse events were significantly associated with patient age, weight or institutional volume. Higher incidence of adverse events associated with patients who had non-cardiac problems (p = 0.017) and cases with multiple devices attempted (p = 0.064). Transcatheter PDA closure in small infants can be performed with excellent short-term outcomes and safety across institutions with variable case volume.

Interpreting Quality Improvement When Introducing New Technology: A Collaborative Experience in ASD Device Closures.

The objective of this study was to evaluate the impact of the regular introduction of new technologies into interventional cardiac catheterization procedures, in this case new atrial septal defect (ASD) closure devices, while conducting a multi-center collaborative initiative to reduce radiation usage during all procedures. Data were collected prospectively by 8 C3PO institutions between January 1, 2014 and December 31, 2017 for ASD device closure procedures in the cardiac catheterization lab during a quality improvement (QI) initiative aimed at reducing patient radiation exposure. Radiation exposure was measured in dose area product per body weight (µGy*m2/kg). Use of proposed practice change strategies at the beginning and end of the QI intervention period was assessed. Radiation exposure was summarized by institution and by initial type of device used for closure. This study included 602 ASD device closures. Without changes in patient characteristics, total fluoroscopy duration, or number of digital acquisitions, median radiation exposure decreased from 37 DAP/kg to 14 DAP/kg from 2014 to 2017. While all individual centers decreased overall median DAP/kg, the use of novel devices for ASD closure correlated with a temporary period of worsening institutional radiation exposure and increased fluoroscopy time. The introduction of new ASD closure devices resulted in increased radiation exposure during a QI project designed to reduce radiation exposure. Therefore, outcome assessment must be contextualized in QI projects, hospital evaluation, and public reporting, to acknowledge the expected variation during innovation and introduction of novel therapies.

The incidence of recurrent laryngeal nerve injury resulting in vocal cord paralysis following interventional congenital catheterisation procedures.

BACKGROUND: Recurrent laryngeal nerve injury leading to vocal cord paralysis is a known complication of cardiothoracic surgery. Its occurrence during interventional catheterisation procedures has been documented in case reports, but there have been no studies to determine an incidence. OBJECTIVE: To establish the incidence of left recurrent laryngeal nerve injury leading to vocal cord paralysis after left pulmonary artery stenting, patent ductus arteriosus device closure and the combination of the procedures either consecutively or simultaneously. METHODS: Members of the Congenital Cardiovascular Interventional Study Consortium were asked to perform a retrospective analysis to identify cases of recurrent laryngeal nerve injury after the aforementioned procedures. Twelve institutions participated in the analysis. They also contributed the total number of each procedure performed at their respective institutions for statistical purposes. RESULTS: Of the 1337 patients who underwent left pulmonary artery stent placement, six patients (0.45%) had confirmed vocal cord paralysis. 4001 patients underwent patent ductus arteriosus device closure, and two patients (0.05%) developed left vocal cord paralysis. Patients who underwent both left pulmonary artery stent placement and patent ductus arteriosus device closure had the highest incidence of vocal cord paralysis which occurred in 4 of the 26 patients (15.4%). Overall, 92% of affected patients in our study population had resolution of symptoms. CONCLUSION: Recurrent laryngeal nerve injury is a rare complication of left pulmonary artery stent placement or patent ductus arteriosus device closure. However, the incidence is highest in patients undergoing both procedures either consecutively or simultaneously. Additional research is necessary to determine contributing factors that might reduce the risk of recurrent laryngeal nerve injury.

Use of rotational angiography in congenital cardiac catheterisations to generate three-dimensional-printed models.

BACKGROUND: Three-dimensional printing is increasingly utilised for congenital heart defect procedural planning. CT or MR datasets are typically used for printing, but similar datasets can be obtained from three-dimensional rotational angiography. We sought to assess the feasibility and accuracy of printing three-dimensional models of CHD from rotational angiography datasets. METHODS: Retrospective review of CHD catheterisations using rotational angiography was performed, and patient and procedural details were collected. Imaging data from rotational angiography were segmented, cleaned, and printed with polylactic acid on a Dremel® 3D Idea Builder (Dremel, Mount Prospect, IL, USA). Printing time and materials' costs were captured. CT scans of printed models were compared objectively to the original virtual models. Two independent, non-interventional paediatric cardiologists provided subjective ratings of the quality and accuracy of the printed models. RESULTS: Rotational angiography data from 15 catheterisations on vascular structures were printed. Median print time was 3.83 hours, and material costs were $2.84. The CT scans of the printed models highly matched with the original digital models (root mean square for Hausdorff distance 0.013 ± 0.003 mesh units). Independent reviewers correctly described 80 and 87% of the models (p = 0.334) and reported high quality and accuracy (5 versus 5, p = NS; κ = 0.615). CONCLUSION: Imaging data from rotational angiography can be converted into accurate three-dimensional-printed models of CHD. The cost of printing the models was negligible, but the print time was prohibitive for real-time use. As the speed of three-dimensional printing technology increases, novel future applications may allow for printing patient-specific devices based on rotational angiography datasets.

Implantable pulmonary artery pressure monitoring device in patients with palliated congenital heart disease: Technical considerations and procedural outcomes.

OBJECTIVE: We describe the technical considerations of transcatheter implantation of the CardioMEMS™ HF System (Abbott, Abbott Park, IL) in adult patients with complex palliated congenital heart disease (CHD) and advanced heart failure (HF). BACKGROUND: Ambulatory pulmonary artery (PA) pressure monitoring with implantable hemodynamic monitors (IHMs) has been shown to reduce HF-related hospital admissions in non-CHD populations. HF is a common late cardiovascular complication in adult CHD necessitating better understanding of IHM application in this population. METHODS: We analyzed adults with complex CHD and advanced HF who were referred for CardioMEMS™ device implantation (2015-2018). Feasibility of device implantation, defined by successful device implantation and calibration, and procedural outcomes were evaluated. RESULTS: CardioMEMS™ was successfully implanted in all 14 adults (35.5 ± 9.2 years old, 72 ± 12 kg) with complex CHD (single ventricle/Fontan, n = 8 [57%]; d-transposition of the great arteries/atrial switch, n = 6 [43%]). The device was delivered via femoral venous access in 13 (93%) patients and implanted in the left PA in 12 (86%). A long sheath was used in 8 (57%) patients, including 5/6 with an atrial switch operation. There was one device migration that did not require retrieval. CONCLUSIONS: Transcatheter implantation of an IHM is feasible in select complex adult CHD patients with advanced HF. Further studies evaluating integration of ambulatory hemodynamics and the impact on clinical care are needed. This technology has the potential to improve medical management of advanced HF in patients with Fontan and atrial switch physiologies and provide new insights into their ambulatory hemodynamics.

Absent pulmonary valve or pulmonary atresia with intact ventricular septum: Which is it?

A fetal echocardiogram noted valvar pulmonary atresia vs critical pulmonary valve stenosis, confluent pulmonary arteries, patent ductus arteriosus, and an apical muscular ventricular septal defect vs coronary sinusoid. Postnatal echocardiogram documented an absent pulmonary valve, coronary artery fistula to the right ventricle, confluent pulmonary arteries, and a patent ductus arteriosus. Catheterization confirmed the postnatal echocardiographic findings except there was no antegrade flow from the right ventricle to the pulmonary arteries. Close evaluation of all imaging modalities revealed the final diagnosis of absent pulmonary valve with a double-chambered right ventricle with no egress from the right ventricle to pulmonary artery.

Follow-up after Percutaneous Patent Ductus Arteriosus Occlusion in Lower Weight Infants.

OBJECTIVES: To describe longer term outcomes for infants <6 kg undergoing percutaneous occlusion of the patent ductus arteriosus (PDA). STUDY DESIGN: This was a retrospective cohort study of infants <6 kg who underwent isolated percutaneous closure of the PDA at a single, tertiary center (2003-2017). Cardiopulmonary outcomes and device-related complications (eg, left pulmonary artery obstruction) were examined for differences across weight thresholds (very low weight, <3 kg; low weight, 3-<6 kg). We assessed composite measures of respiratory status during and beyond the initial hospitalization using linear mixed effects models. RESULTS: In this cohort of lower weight infants, 92 of 106 percutaneous occlusion procedures were successful. Median age and weight at procedure were 3.0 months (range, 0.5-11.1 months) and 3.7 kg (range, 1.4-5.9 kg), respectively. Among infants with pulmonary artery obstruction on initial postprocedural echocardiograms (n = 20 [22%]), obstruction persisted through hospital discharge in 3 infants. No measured variables were associated with device-related complications. Rates of oxygenation failure (28% vs 8%; P < .01) and decreased left ventricular systolic function (29% vs 5%; P < .01) were higher among very low weight than low weight infants. Pulmonary scores decreased (indicating improved respiratory status) following percutaneous PDA closure. CONCLUSIONS: Percutaneous PDA occlusion among lower weight infants is associated with potential longer term improvements in respiratory health. Risks of device-related complications and adverse cardiopulmonary outcomes, particularly among very low weight infants, underscore the need for continued device modification. Before widespread use, clinical trials comparing percutaneous occlusion vs alternative treatments are needed.

Severely regurgitant left ventricle to ascending aorta conduit in a failing fontan patient treated with a vascular endograft and melody transcatheter pulmonary valve via hybrid approach.

A 28-year-old male with single ventricular heart disease status post Fontan palliation and subsequent placement of left ventricle to ascending aorta (LV-AAo) valved conduit developed ascites and edema. Diagnostic catheterization revealed elevated ventricular end diastolic pressures (EDP) secondary to severe LV-AAo conduit regurgitation. Given the unique anatomy, surgical access via the right axillary artery provided optimal route for transcatheter valve implantation within the conduit. The procedure resulted in significant hemodynamic improvement with no complications. © 2016 Wiley Periodicals, Inc.

Contained rupture of patched right ventricular outflow tracts during balloon sizing for percutaneous pulmonary valve implantation.

Transcatheter pulmonary valves are being used off-label to treat pulmonary insufficiency in patched right ventricular outflow tracts (RVOTs). We describe the first reported cases of patched RVOT rupture, during balloon sizing for percutaneous pulmonary valve implantation, in two patients with tetralogy of Fallot status post repair. Both RVOTs were too large for subsequent catheter-based intervention. The ruptures remained stable over time, and both patients were managed conservatively with follow-up imaging.

The Use and Outcomes of Small, Medium and Large Premounted Stents in Pediatric and Congenital Heart Disease.

We sought to describe the use and outcomes of small, medium and large premounted stents in patients with congenital heart disease, including incidence of and risk factors for re-intervention and development of in-stent stenosis. Premounted stents offer several advantages over traditional manually crimped bare-metal stents, especially in small patients. There are no data describing the medium-term effectiveness and outcomes of premounted stents in congenital heart disease. We performed a single-center retrospective review of all small, medium and large premounted stents implanted over an 8-year period. Premounted stents were implanted in 71 vessels within 59 patients with a 97 % success rate. Regardless of implantation site, premounted stent implantation resulted in significant improvements in vessel size and pressure gradient (p < 0.0001). Over a median follow-up duration of 3.1 years [interquartile range (IQR) 1.3-5.2], 25 patients (43 %) required re-intervention (18 catheter based, 3 surgical and 4 hybrid) at a median time of 1.4 years (IQR 0.9-3.0) from implant. Factors associated with re-intervention included age ≤1.9 years [hazard ratio (HR) 2.4, p = 0.03], weight ≤11.5 kg (HR 2.5, p = 0.03) and bare-metal premounted stents compared to covered premounted stents (HR 4.2, p = 0.001). In-stent stenosis was diagnosed in 42 % of premounted stents which underwent follow-up angiography. No identified characteristics were associated with in-stent stenosis, including "oversizing" the premounted stent. Small, medium and large premounted stents are effective in treating vascular stenosis in congenital heart disease. Frequent follow-up is required, especially in smaller patients with expected somatic growth, and to evaluate for in-stent stenosis which occurs in nearly half of premounted stents.

Transhepatic Central Venous Catheters in Pediatric Patients With Congenital Heart Disease.

OBJECTIVES: Patients with congenital heart disease may have limited venous access routes as a result of multiple central venous catheters, surgical interventions, and catheterization procedures. Unconventional venous access includes transhepatic central venous catheter. We evaluated transhepatic central venous catheter placed in patients with congenital heart disease and risk factors associated with complications and outcomes. DESIGN: Demographic, procedural, and complication data were retrospectively collected on all patients who underwent transhepatic central venous catheter placement at our center over the past 10 years. SETTING: This study was completed in a tertiary congenital heart center. PATIENTS: A total of 92 transhepatic central venous catheters were placed in 54 patients (63% male patients). The median age and weight of the patient population was 5.7 months and 5.5 kg, respectively. INTERVENTIONS: Placement of a transhepatic central venous catheter. MEASUREMENTS AND MAIN RESULTS: Successful catheter placement occurred in 96% of cases with median procedure time of 54 minutes with a procedural complication rate of 14%. A total of 86 complications occurred in 54 catheters placed during 2,166 catheter-days (39.7 complications per 1,000 catheter-days). Individual complication rates per 1,000 catheter-days included catheter dysfunction (14.8), dislodgement (8.8), systemic infection (5.1), thrombosis (4.2), local infection (3.7), and bleeding (3.2). Two complications contributed to patient deaths. Factors associated with developing complications included polyurethane central venous catheters (p = 0.03) and catheter duration at least 21 days (p = 0.004). The overall mortality in this population was 50% with median length of hospitalization of 49 days (interquartile range, 33-97). CONCLUSIONS: Transhepatic central venous catheters represent a viable option for patients with limited access. Polyurethane catheters and catheter duration at least 21 days are associated with increased transhepatic central venous catheter complications. Although complication rates are higher than more traditional forms of central venous catheters, the long duration of hospitalization and high mortality rates in this patient population attest to their risks for poor outcomes irrespective of venous access.

Percutaneous Balloon-Expandable Stent Implantation to Treat Transverse Aortic Arch Obstruction: Medium- to Long-Term Outcomes of a Retrospective Multicenter Study.

BACKGROUND: Transverse aortic arch obstruction is a challenging lesion for which stent implantation provides a potentially important alternate therapy. The objectives were to evaluate the technical, procedural, and medium-to-long-term clinical outcomes of percutaneous stent implantation of transverse aortic arch obstruction. METHODS: This is a retrospective, multicenter study of transverse aortic arch stent implantation. Univariable and multivariable analyses were performed. RESULTS: Index catheterization included 187 stent implants in 146 patients. The median age is 14.3 years (interquartile range, 9.3-19), weight is 53 kg (30-69), and follow-up is 53 months (12-120). The most common stent design was open cell (n=90, 48%). Stents overlapped 142 arch vessels (37 carotid arteries) in 118 (81%) cases. Technical and procedural success rates were 100% and 88%, respectively. Lower weight (P=0.018), body surface area (P=0.013), and minimum-to-descending aortic diameter ratio (P<0.001) were associated with higher baseline aortic gradient. The residual gradient was inversely associated with implant and final dilation diameters (P<0.001). The combined incidence of aortic injury and stent-related complications was 14%. There were no reports of abnormal brain scans or stroke. Blood pressure cuff gradient, echocardiographic arch velocity, and hypertension rates improved within 1-year follow-up with increased antihypertensive medication use. Reintervention was reported in 60 (41%) patients at a median of 84 (22-148) months to first reintervention. On multivariable logistic regression, residual aortic gradient >10 mm Hg was associated with increased odds of reintervention at all time points when controlling for each final dilation diameter, weight, and minimum-to-descending aortic diameter ratio. CONCLUSIONS: Transverse aortic arch stent implantation has high rates of technical, procedural, and medium-to-long-term clinical success. Aortic gradient >10 mm Hg is associated with increased odds of reintervention at 1-year and most recent follow-ups. Open cell stent design was frequently used for its advantages in conformability, perfusion of arch vessels, low fracture rate, and the ability to perform effective angioplasty of side cells.

Preemptive stenting of the left pulmonary artery during comprehensive stage 2 procedure does not influence Fontan candidacy.

Objective: Pulmonary artery reconstruction during comprehensive stage 2 (CS2) procedure can be challenging. Since 2017, we have employed preemptive left pulmonary artery (LPA) stenting. We hypothesized that LPA stenting promotes adequate growth and without compromising Fontan candidacy. Herewith, we report our midterm results. Methods: From 2002 to 2020, 159 patients underwent CS2. Patients were divided as follows: no stent (n = 122; Group 1) and perioperative LPA stent (n = 37; Group 2). Group 2 was subdivided according to unplanned stent (n = 17; Group 2a) or preemptive stent (n = 20; Group 2b). Relevant perioperative data was reviewed. Nonparametric statistics were utilized. Results: Median age and weight at surgery and hospital length of stay after CS2 did not differ between groups. Median cardiopulmonary bypass and crossclamp times were significantly greater in Group 1 (265 vs 243 minutes [P = .021] and 46 vs 26 minutes [P = .008]). In-hospital mortality was similar between Groups 1 and 2 (9.0% vs 18.9%, respectively [P = .1348]). Group 2b demonstrated a superior survival compared to Group 2a (P = .0335) but not Group 1 (P > .9999). Preemptive stenting significantly increased median hilar LPA diameter at CS2 exit angiogram compared with no stenting (P < .0001). Groups 2a and 2b significantly increased the pre-Fontan diameter of the hilar LPA when compared with Group 1 (6.1 and 6.8 vs 5.7 mm, respectively [P < .0001]). A further 120 patients underwent Fontan operation (75%). Median follow-up for Groups 1 and 2 were 7.4 and 3.0 years, respectively. Conclusions: Perioperative LPA stenting during CS2 does not adversely affect pulmonary growth. Preemptive stenting seems advantageous for LPA growth in preparation for Fontan completion.

Evaluation of tissue-engineered human acellular vessels as a Blalock-Taussig-Thomas shunt in a juvenile primate model.

Objectives: Palliative treatment of cyanotic congenital heart disease (CCHD) uses systemic-to-pulmonary conduits, often a modified Blalock-Taussig-Thomas shunt (mBTTs). Expanded polytetrafluoroethylene (ePTFE) mBTTs have associated risks for thrombosis and infection. The Human Acellular Vessel (HAV) (Humacyte, Inc) is a decellularized tissue-engineered blood vessel currently in clinical trials in adults for vascular trauma, peripheral artery disease, and end-stage renal disease requiring hemodialysis. In addition to restoring blood flow, the engineered HAV demonstrates the capacity for host cellular remodeling into native-like vasculature. Here we report preclinical evaluation of a small-diameter (3.5 mm) HAV as a mBTTs in a non-human primate model. Methods: We implanted 3.5 mm HAVs as right subclavian artery to pulmonary artery mBTTs in non-immunosuppressed juvenile rhesus macaques (n = 5). HAV patency, structure, and blood flow were assessed by postoperative imaging from 1 week to 6 months. Histology of HAVs and surrounding tissues was performed. Results: Surgical procedures were well tolerated, with satisfactory anastomoses, showing feasibility of using the 3.5 mm HAV as a mBTTs. All macaques had some immunological reactivity to the human extracellular matrix, as expected in this xenogeneic model. HAV mBTTs remained patent for up to 6 months in animals, exhibiting mild immunoreactivity. Two macaques displaying more severe immunoreactivity to the human HAV material developed midgraft dilatation without bleeding or rupture. HAV repopulation by host cells expressing smooth muscle and endothelial markers was observed in all animals. Conclusions: These findings may support use of 3.5 mm HAVs as mBTTs in CCHD and potentially other pediatric vascular indications.

1-Year Outcomes in a Pooled Cohort of Harmony Transcatheter Pulmonary Valve Clinical Trial Participants.

BACKGROUND: The Harmony transcatheter pulmonary valve (TPV) is the first U.S. Food and Drug Administration-approved device for severe pulmonary regurgitation (PR) in the native or surgically repaired right ventricular outflow tract (RVOT). OBJECTIVES: One-year safety and effectiveness of the Harmony TPV were evaluated in patients from the Harmony Native Outflow Tract Early Feasibility Study, Harmony TPV Pivotal Study, and Continued Access Study, representing the largest cohort to date of Harmony TPV recipients. METHODS: Eligible patients had severe PR by echocardiography or PR fraction ≥ 30% by cardiac magnetic resonance imaging and clinical indications for pulmonary valve replacement. The primary analysis included 87 patients who received a commercially available TPV22 (n = 42) or TPV25 (n = 45) device; 19 patients who received an early device iteration prior to its discontinuation were evaluated separately. RESULTS: In the primary analysis, median patient age at treatment was 26 years (IQR: 18-37 years) in the TPV22 group and 29 years (IQR: 19-42 years) in the TPV25 group. At 1 year, there were no deaths; 98% of TPV22 and 91% of TPV25 patients were free from the composite of PR, stenosis, and reintervention (moderate or worse PR, mean RVOT gradient >40 mmHg, device-related RVOT reoperation, and catheter reintervention). Nonsustained ventricular tachycardia occurred in 16% of patients. Most patients had none/trace or mild PR (98% of TPV22 patients, 97% of TPV25 patients). Outcomes with the discontinued device are reported separately. CONCLUSIONS: The Harmony TPV device demonstrated favorable clinical and hemodynamic outcomes across studies and valve types through 1 year. Further follow-up will continue to assess long-term valve performance and durability.

COVID-19 international experience in paediatric patients with congenital heart disease.

OBJECTIVE: As COVID-19 continues to affect the global population, it is crucial to study the impact of the disease in vulnerable populations. This study of a diverse, international cohort aims to provide timely, experiential data on the course of disease in paediatric patients with congenital heart disease (CHD). METHODS: Data were collected by capitalising on two pre-existing CHD registries, the International Quality Improvement Collaborative for Congenital Heart Disease: Improving Care in Low- and Middle-Income Countries and the Congenital Cardiac Catheterization Project on Outcomes. 35 participating sites reported data for all patients under 18 years of age with diagnosed CHD and known COVID-19 illness during 2020 identified at their institution. Patients were classified as low, moderate or high risk for moderate or severe COVID-19 illness based on patient anatomy, physiology and genetic syndrome using current published guidelines. Association of risk factors with hospitalisation and intensive care unit (ICU) level care were assessed. RESULTS: The study included 339 COVID-19 cases in paediatric patients with CHD from 35 sites worldwide. Of these cases, 84 patients (25%) required hospitalisation, and 40 (12%) required ICU care. Age <1 year, recent cardiac intervention, anatomical complexity, clinical cardiac status and overall risk were all significantly associated with need for hospitalisation and ICU admission. A multivariable model for ICU admission including clinical cardiac status and recent cardiac intervention produced a c-statistic of 0.86. CONCLUSIONS: These observational data suggest risk factors for hospitalisation related to COVID-19 in paediatric CHD include age, lower functional cardiac status and recent cardiac interventions. There is a need for further data to identify factors relevant to the care of patients with CHD who contract COVID-19 illness.