Novel Uses of the SwiftNinja Steerable Microcatheter for Pediatric Cardiovascular Interventions

In the present era, the intricacy of procedures undertaken by a pediatric interventional cardiologist has increased, primarily attributed to dealing with smaller, younger patients with more complex anatomies. To adapt to these smaller and more complex patients, we must adapt our interventions and our equipment to perform these procedures. This article outlines various innovative applications of the SwiftNinja steerable microcatheter within the pediatric cardiac catheterization laboratory.

Results of the multicenter early feasibility study (EFS) of the Renata Minima stent as treatment for branch pulmonary artery stenosis and coarctation of aorta in infants

BACKGROUND

Stent implantation has become standard of care in older children and adults for treatment of branch pulmonary artery stenosis (BPAS) and coarctation aorta (CoAo). There are no stents approved or available for infants that have the potential to be dilated to adult diameters. The Minima stent was designed to fulfill this unmet need.

METHODS

Multicenter, prospective, nonrandomized early feasibility study evaluating safety and effectiveness of the Minima stent for treatment of BPAS and CoAo. Primary endpoints included: (1) successful deployment across lesion, (2) stenosis relief defined by an increase in angiographic diameter of >50% and (3) freedom from stent explant, embolization or migration at 30 days and 6 months.

RESULTS

Between 2/2022 and 5/2022, 10 pts underwent Minima stent implantation with a median age and weight of 9 months (4-43 months) and 7.6 kg (5.1-16.9 kg). Procedural success and predefined stenosis relief was achieved in all cases (CoAo [n = 4], BPAS [n = 6]). Adverse events occurred in 3 pts: transient diminished lower extremity pulse (n = 2), distal stent on-balloon displacement successfully managed in the catheterization suite (n = 1). There were no deaths or major adverse events. All patients were free from stent explant and migration at 30 days and 6 months with no evidence for significant restenosis at latest follow-up.

CONCLUSIONS

Implantation of the Renata Minima stent was safe and effective for the treatment of BPAS and CoAo in this small cohort of infants and young children during early follow-up. Based on these early results, an expanded study with longer follow-up is warranted.

Transcatheter knocking of a stuck mechanical tricuspid valve

Immobilisation of mechanical valve leaflets can be a life-threatening complication. In the acute setting, medical therapy can be attempted but is not always successful. We present the first described case of a patient with a mechanical tricuspid valve with recurrent leaflet immobilisation that was able to be mobilised using a transcatheter knocking technique.

Incidence, risk factors, and management following cardiac catheterization via carotid and axillary artery approaches: A single-center experience on pseudoaneurysms in young infants

BACKGROUND

Use of alternate access for complex neonatal interventions has gained acceptance with carotid and axillary artery access being used for ductal and aortic interventions.

METHODS

This study was a retrospective, single-center study at Cincinnati Children's Hospital Medical Center. The study included infants, aged ≤90 days, who underwent cardiac catheterization with either carotid or axillary artery access between 2013 and 2022. Data encompassing demographics, clinical information, catheterization data, and the incidence of pseudoaneurysm as a procedural complication were collected.

RESULTS

Among 29 young infants (20 males, 69%), 4 out of 15 patients (27%) who underwent the carotid approach developed pseudoaneurysms, while 1 out of 14 patients (7.1%) who underwent the axillary approach developed one. Two patients required transcatheter intervention due to enlargement of pseudoaneurysms, involving the placement of transarterial flow-diverting stent and occlusion of left common carotid artery. Longer sheath in-to-out time (135 vs. 77 min, p = 0.001), and higher closing activated clotting times (ACT) (268 vs. 197 s, p = 0.021) were observed among patients with pseudoaneurysms compared to those without.

CONCLUSIONS

Young infants with alternative access via the carotid and axillary arteries may be at risk of pseudoaneurysm formation during longer procedures and with higher ACTs for closure. Ultrasound-guided compression can be employed to prevent the progression and in resolution of these lesions.

Catheterization for Congenital Heart Disease Adjustment for Risk Method II

BACKGROUND

Current metrics used to adjust for case mix complexity in congenital cardiac catheterization are becoming outdated due to the introduction of novel procedures, innovative technologies, and expanding patient subgroups. This study aims to develop a risk adjustment methodology introducing a novel, clinically meaningful adverse event outcome and incorporating a modern understanding of risk.

METHODS

Data from diagnostic only and interventional cases with defined case types were collected for patients ≤18 years of age and ≥2.5 kg at all Congenital Cardiac Catheterization Project on Outcomes participating centers. The derivation data set consisted of cases performed from 2014 to 2017, and the validation data set consisted of cases performed from 2019 to 2020. Severity level 3 adverse events were stratified into 3 tiers by clinical impact (3a/b/c); the study outcome was clinically meaningful adverse events, severity level ≥3b (3bc/4/5).

RESULTS

The derivation data set contained 15 224 cases, and the validation data set included 9462 cases. Clinically meaningful adverse event rates were 4.5% and 4.2% in the derivation and validation cohorts, respectively. The final risk adjustment model included age <30 days, Procedural Risk in Congenital Cardiac Catheterization risk category, and hemodynamic vulnerability score (C statistic, 0.70; Hosmer-Lemeshow P value, 0.83; Brier score, 0.042).

CONCLUSIONS

CHARM II (Congenital Heart Disease Adjustment for Risk Method II) risk adjustment methodology allows for equitable comparison of clinically meaningful adverse events among institutions and operators with varying patient populations and case mix complexity performing pediatric cardiac catheterization.

The Fontan Udenafil Exercise Longitudinal Trial: Subgroup Analysis

The Pediatric Heart Network's Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT02741115) demonstrated improvements in some measures of exercise capacity and in the myocardial performance index following 6 months of treatment with udenafil (87.5 mg twice daily). In this post hoc analysis, we evaluate whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. The effect of udenafil on exercise was evaluated within subgroups defined by baseline characteristics, including peak oxygen consumption (VO2), serum brain-type natriuretic peptide level, weight, race, gender, and ventricular morphology. Differences among subgroups were evaluated using ANCOVA modeling with fixed factors for treatment arm and subgroup and the interaction between treatment arm and subgroup. Within-subgroup analyses demonstrated trends toward quantitative improvements in peak VO2, work rate at the ventilatory anaerobic threshold (VAT), VO2 at VAT, and ventilatory efficiency (VE/VCO2) for those randomized to udenafil compared to placebo in nearly all subgroups. There was no identified differential response to udenafil based on baseline peak VO2, baseline BNP level, weight, race and ethnicity, gender, or ventricular morphology, although participants in the lowest tertile of baseline peak VO2 trended toward larger improvements. The absence of a differential response across subgroups in response to treatment with udenafil suggests that the treatment benefit may not be restricted to specific sub-populations. Further work is warranted to confirm the potential benefit of udenafil and to evaluate the long-term tolerability and safety of treatment and to determine the impact of udenafil on the development of other morbidities related to the Fontan circulation.Trial Registration NCT0274115.

Use of mechanical thrombectomy in very early-onset inflammatory bowel disease patient with extensive venous thrombosis

Mechanical thrombectomy is generally used in adult patients with pulmonary embolism or extensive venous thromboembolism, but it is starting to become more prevalent in the children. We present a unique case of a 3-year-old female with very early-onset inflammatory bowel disease with extensive venous thromboembolism who underwent successful mechanical thrombectomy.

Right atrial thrombus removal with use of the ŌNŌ retrieval device

Intracardiac masses and specifically right atrial thrombi can be difficult to manage and carry a high mortality rate. Typically, surgical removal or mechanical thrombectomy can be performed though may not be suitable for all patients. We present a unique case of a sickle cell patient with a large pedunculated right atrial thrombus that was successfully extracted using the novel ŌNŌ Retrieval Device.

3-year follow-up of a prospective, multicenter study of the Amplatzer Piccolo™ Occluder for transcatheter patent ductus arteriosus closure in children ≥ 700 grams

OBJECTIVE

This study describes 3-year follow-up of 200 infants weighing ≥ 700 grams who underwent transcatheter patent ductus arteriosus (PDA) closure with the Amplatzer Piccolo™ Occluder.

STUDY DESIGN

Between June 2017 and February 2019, 200 children were enrolled in this U.S. study (NCT03055858). PDA closure, survival, and device- or procedure-related events were evaluated. A total of 156 of the available 182 patients (86%) completed the study.

RESULTS

The implant success rate was 95.5% (191/200). At 3 years, PDA closure was observed in 100% (33/33) of patients. Survival was >95% with 9 reported deaths. No deaths were adjudicated as device- or procedure-related. Notable events included aortic obstruction (2) requiring stent placement and tricuspid regurgitation (5), for which no interventions were required.

CONCLUSIONS

This follow-up study demonstrates high rates of PDA closure, low serious complication rates, and survival > 95% at 3 years. The Amplatzer Piccolo™ Occluder is a safe and effective therapy for PDA treatment in premature infants.

CLINICALTRIALS

gov identifier: NCT0305585.

Comparison of treatment strategies for neonates with tetralogy of Fallot and pulmonary atresia

OBJECTIVE

Neonates with tetralogy of Fallot and pulmonary atresia (TOF/PA) but no major aorta-pulmonary collaterals are dependent on the arterial duct for pulmonary blood flow and require early intervention, either by primary (PR) or staged repair (SR) with initial palliation (IP) followed by complete repair (CR). The optimal approach has not been established.

METHODS

Neonates with TOF/PA who underwent PR or SR were retrospectively reviewed from the Congenital Cardiac Research Collaborative. Outcomes were compared between PR and SR (IP + CR) strategies. Propensity scoring was used to adjust for baseline differences. The primary outcome was mortality. Secondary outcomes included complications, length of stay, cardiopulmonary bypass and anesthesia times, reintervention (RI), and pulmonary artery (PA) growth.

RESULTS

Of 282 neonates, 106 underwent PR and 176 underwent SR (IP: 144 surgical, 32 transcatheter). Patients who underwent SR were more likely to have DiGeorge syndrome and greater rates of mechanical ventilation before the initial intervention. Mortality was not significantly different. Duration of mechanical ventilation, inotrope use, and complication rates were similar. Cumulative length of stay, cardiopulmonary bypass, and anesthesia times favored PR (P ≤ .001). Early RI was more common in patients who underwent SR (rate ratio, 1.42; P = .003) but was similar after CR (P = .837). Conduit size at the time of CR was larger with SR. Right PA growth was greater with PR.

CONCLUSIONS

In neonates with TOF/PA, SR is more common in greater-risk patients. Accounting for this, SR and PR strategies have similar mortality. Perioperative morbidities, RI, and right PA growth generally favor PR, whereas SR allows for larger initial conduit implantation.

Pulmonary Artery Hypoplasia in Neonates With Tetralogy of Fallot

BACKGROUND

Neonates with symptomatic tetralogy of Fallot (sTOF) with hypoplastic pulmonary arteries (hPA) are considered high risk. Data are needed to inform the impact of hPA on outcomes, and the ideal management strategy.

OBJECTIVES

The objectives of this study were to quantify the impact of hPA on outcomes in neonates with sTOF and measure the impact of strategy on pulmonary artery (PA) growth in this population.

METHODS

Neonates with sTOF from 2005 to 2017 were reviewed from the Congenital Cardiac Research Collaborative. Criteria for hPA included a unilateral PA z score <-2.0 and contralateral PA z score <0. Primary outcome was mortality. Secondary outcomes included reintervention and PA growth.

RESULTS

We included 542 neonates with sTOF, including 188 (35%) with hPA and 354 (65%) with normal PA, with median follow-up of 4.1 years. Median right and left hPA z scores were -2.19 (25th-75th percentile: -2.55 to -1.94) and -2.23 (25th-75th percentile: -2.64 to -1.91), respectively. Staged repair (vs primary TOF repair) was less common in the hPA cohort (36 vs 44%; P = 0.07). Survival was similar between groups (unadjusted P = 0.16; adjusted P = 0.25). Reintervention was more common in the hPA group (HR: 1.28; 95% CI: 1.01-1.63; P = 0.044); there was no difference after definitive repair (HR: 1.21; 95% CI: 0.93-1.58; P = 0.16). PA growth at 1 year was greater in the hPA cohort, particularly for the right PA (P < 0.001).

CONCLUSIONS

Despite perception, the presence of hPA in neonates with sTOF conferred no increase in overall hazard of mortality or reintervention after definitive repair. PA growth was superior in the hPA cohort. These findings suggest that the presence of hPA does not adversely impact outcomes in sTOF.

Retrograde Pulmonary Valve Perforation and Stenting through a Major Aorto-Pulmonary Collateral Artery

Management of pulmonary atresia, ventricular septal defect with major aorto-pulmonary collateral arteries, and hypoplastic native pulmonary arteries focuses on growth of the native pulmonary arteries. One strategy to grow the native pulmonary arteries is through pulmonary valve perforation followed by right ventricular outflow tract stenting, if suitable. We present a unique case of retrograde pulmonary valve perforation and stenting of the right ventricular outflow tract through a major aorto-pulmonary collateral artery.

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.

Novel Diabolo Configuration of a Large Covered Stent to Treat Cyanosis Related to Pulmonary Arteriovenous Malformations

Microvascular pulmonary arteriovenous malformations (pAVMs) can lead to profound hypoxemia. "Hepatic factor" is postulated to play a role in their development. Certain patients with congenital heart disease are at particular risk to develop pAVMs, including those with heterotaxy syndromes and complex Fontan palliation. Ideally, an underlying cause is identified and corrected, although pAVMs may persist despite those interventions. We report a patient with heterotaxy syndrome s/p Fontan who had pAVMs that persisted despite Fontan revision with equal hepatic flow to both lungs. We employed a novel method to produce a diabolo configuration of a large covered stent to restrict lung flow while maintaining the potential for future dilation.

Transcatheter Melody Valve Placement in a Native Right Atrioventricular Valve in a Pediatric Patient

Transcatheter tricuspid valve placement in congenital heart disease is becoming increasingly used when a previously placed surgical ringed valve becomes dysfunctional. Surgically repaired and/or native tricuspid inflows are generally not amenable to transcatheter valve placement without a prior ring being placed. We present the second pediatric case to our knowledge of transcatheter tricuspid valve placement in a surgically repaired tricuspid valve in the absence of a ring.

Early Postoperative Congenital Cardiac Catheterization Outcomes: A Multicenter Study

BACKGROUND

Early postoperative catheterizations (EPOCs) within 6 weeks after a congenital heart surgical procedure can treat residual lesions and provide important clinical information. However, EPOCs are often assumed to impose additional risk on a vulnerable patient population. This study aimed to describe the EPOC population, evaluate procedural safety, compare EPOC patients with procedure-matched non-EPOC patients, and determine risk factors for poor outcomes using data from the Congenital Cardiac Catheterization Project on Outcomes registry.

METHODS

In a retrospective cohort, demographic, clinical, and procedural characteristics were analyzed for diagnostic and interventional catheterizations performed in 13 participating institutions from January 2014 to December 2017, excluding patients after heart transplant. The primary outcome was a high-severity adverse event (AE). Three distinct analyses included (1) describing the full cohort and EPOC patients, (2) comparing EPOC patients with and without a high-severity AE, and (3) comparing EPOC patients with controls matched on case type.

RESULTS

This study included 17,776 catheterizations, with 1399 EPOCs. The high-severity AE rate was 6.4% overall, 8.9% in the EPOC cohort, and 8.4% in matched controls (P = .74). The association between EPOC status and high-severity AE was not significant in a multivariable model (P = .17). In EPOCs with a high-severity AE, median procedure duration was 30 minutes longer (P < .001), and median time from surgical procedure to catheterization was 3 days longer (P = .05).

CONCLUSIONS

EPOC was not associated with additional risk. Individual patient characteristics of size and hemodynamic vulnerability may serve as informative predictors. Timely catheterization may preempt further clinical deterioration, and intraprocedure duration optimization may correlate with improved outcomes.

Impact of Management Strategy on Feeding and Somatic Growth in Neonates with Symptomatic Tetralogy of Fallot: Results from the Congenital Cardiac Research Collaborative

OBJECTIVE

To evaluate early growth following primary or staged repair of neonatal symptomatic tetralogy of Fallot (sTOF).

STUDY DESIGN

We performed a retrospective, multicenter cohort study of consecutive infants with sTOF who underwent initial intervention at age ≤30 days, from 2005 to 2017. Management strategies were either primary repair or staged repair (ie, initial palliation followed by complete repair). The primary outcome was change in weight-for-age z-score (ΔWAZ) from the initial intervention to age 6 ± 2 months. Secondary outcomes included method and mode of feeding, feeding-related medications, and feeding-related readmissions. Propensity score adjustment was used to account for baseline differences between groups. A secondary analysis was performed comparing patients stratified by the presence of adequate growth (6-month ΔWAZ > -0.5) or inadequate growth (6-month ΔWAZ ≤ -0.5), independent of treatment strategy.

RESULTS

The study cohort included 143 primary repair subjects and 240 staged repair subjects. Prematurity was more common in the staged repair group. After adjustment, median ΔWAZ did not differ between treatment groups over the first 6 months of life (primary: -0.43 [IQR, -1.17 to 0.50]; staged: -0.31 [IQR, -1.31 to 0.71]; P = .55). For the entire cohort, ΔWAZ was negative (-0.36; IQR, -1.21 to 0.63). There were no between-group differences in the secondary outcomes. Secondary analysis revealed that the subjects with adequate growth were more likely to be orally fed at initial hospital discharge (P = .04).

CONCLUSIONS

In neonates with sTOF, growth trajectory over the first 6 months of life was substandard, irrespective of treatment strategy. Those patients with adequate growth were more likely to be discharged from the index procedure on oral feeds.

Palliation Strategy to Achieve Complete Repair in Symptomatic Neonates with Tetralogy of Fallot

Neonates with symptomatic tetralogy of Fallot (sTOF) may undergo palliations with varying physiology, namely systemic to pulmonary artery connections (SPC) or right ventricular outflow tract interventions (RVOTI). A comparison of palliative strategies based on the physiology created is lacking. Consecutive sTOF neonates undergoing SPC or RVOTI from 2005-2017 were reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was survival with successful complete repair (CR) by 18 months. A variety of secondary outcomes were assessed including overall survival, hospitalization-related comorbidities, and interstage reinterventions. Propensity score adjustment was utilized to compare treatment strategies. The cohort included 252 SPC (surgical shunt = 226, ductus arteriosus stent = 26) and 68 RVOTI (balloon pulmonary valvuloplasty = 48, RVOT stent = 11, RVOT patch = 9) patients. Genetic syndrome (29 [42.6%] v 75 [29.8%], p = 0.04), weight < 2.5 kg (28 [41.2%] v 68 [27.0%], p = 0.023), bilateral pulmonary artery Z-score < - 2 (19 [28.0%] v 36 [14.3%], p = 0.008), and pre-intervention antegrade flow (48 [70.6%] v 104 [41.3%], p < 0.001) were more common in RVOTI. Significant center differences were noted (p < 0.001). Adjusted survival to CR by 18 months (HR = 0.87, 95% CI = 0.63-1.21, p = 0.41) and overall survival (HR = 2.08, 95% CI = 0.93-4.65, p = 0.074) were similar. RVOTI had increased interstage reintervention (HR = 2.15, 95% CI = 1.36-3.99, p = 0.001). Total anesthesia (243 [213, 277] v 328 [308, 351] minutes, p < 0.001) and cardiopulmonary bypass times (117 [103, 132] v 151 [143, 160] minutes, p < 0.001) favored RVOTI. In this multicenter comparison of physiologic palliation strategies for sTOF, survival to successful CR and overall survival were similar; however, reintervention burden was significantly higher in RVOTI.

Single-Centre Case Series Assessment of Early Exercise Capacity Data Among Patients Who Received an Alterra Prestent and SAPIEN 3 Valve Placement

Previous studies have used cardiopulmonary exercise test (CPET) data to objectively assess physiological changes in patients undergoing percutaneous pulmonary valve implantation. A retrospective review was performed to assess pre- and post-CPET data among patients undergoing Alterra Adaptive Prestent and SAPIEN 3 transcatheter heart valve (Alterra) placement. Of the 7 patients eligible for the study, 5 (71%) were male. The mean age was 22 years (range: 12-49 years). CPET data showed significant (P = 0.03) improvement in ventilatory efficiency (VE/VCO2) while only 2 (29%) patients had an improvement of percent predicted peak oxygen consumption (VO2). These findings suggest favourable haemodynamic changes though further investigation is needed.

An unexpected circular shunt: Novel method to treat semilunar valve insufficiency in a single ventricle patient on mechanical circulatory support

Severe semilunar valve insufficiency in single ventricle patients supported with mechanical circulatory support while awaiting transplant remains a complex clinical scenario with few favorable options for management. We present the first case, to our knowledge, of transcatheter closure of the pulmonic valve in a patient palliated with a hybrid stage 1 procedure for hypoplastic left heart syndrome.

Cardiac Magnetic Resonance to Predict Coronary Artery Compression in Transcatheter Pulmonary Valve Implantation Into Conduits

OBJECTIVES

The aim of this study was to evaluate the accuracy of cardiac magnetic resonance (CMR) in predicting coronary artery (CA) compression during transcatheter pulmonary valve implantation (TPVi).

BACKGROUND

TPVi is a widely available option to treat dysfunctional right ventricle (RV)-to-pulmonary artery (PA) conduits, but CA compression is an absolute contraindication. CMR can evaluate coronary anatomy, but its utility in predicting CA compression is not well established.

METHODS

After Institutional Review Board approval was obtained, all patients at 9 centers with attempted TPVi in RV-PA conduits and recent CMR (≤12 months) were analyzed. A core laboratory reviewed all CMR studies for the shortest orthogonal distance from a CA to the conduit, the shortest distance from a CA to the most stenotic area of the conduit, and subjective assessment of CA compression risk.

RESULTS

Among 231 patients, TPVi was successful in 198 (86%); in 24 (10%), balloon testing precluded implantation (documented CA compression or high risk). Distance to the RV-PA conduit ≤2.1 mm (area under the curve [AUC]: 0.70) and distance to most stenotic area ≤13.1 mm (AUC: 0.69) predicted CA compression. Subjective assessment had the highest AUC (0.78), with 96% negative predictive value. Both distances and qualitative assessment remained independently associated with CA compression when controlling for abnormal coronary anatomy or degree of conduit calcification.

CONCLUSIONS

CMR can help predict the risk for CA compression during TPVi in RV-PA conduits but cannot completely exclude CA compression. CMR may assist in patient selection and counseling families prior to TPVi, although balloon testing remains essential.

Comparative Costs of Management Strategies for Neonates With Symptomatic Tetralogy of Fallot

BACKGROUND

Recent data have demonstrated that overall mortality and adverse events are not significantly different for primary repair (PR) and staged repair (SR) approaches to management of neonates with symptomatic tetralogy of Fallot (sTOF). Cost data can be used to compare the relative value (cost for similar outcomes) of these approaches and are a potentially more sensitive measure of morbidity.

OBJECTIVES

This study sought to compare the economic costs associated with PR and SR in neonates with sTOF.

METHODS

Data from a multicenter retrospective cohort study of neonates with sTOF were merged with administrative data to compare total costs and cost per day alive over the first 18 months of life in a propensity score-adjusted analysis. A secondary analysis evaluated differences in department-level costs.

RESULTS

In total, 324 subjects from 6 centers from January 2011 to November 2017 were studied (40% PR). The 18-month cumulative mortality (P = 0.18), procedural complications (P = 0.10), hospital complications (P = 0.94), and reinterventions (P = 0.22) did not differ between PR and SR. Total 18-month costs for PR (median $179,494 [IQR: $121,760-$310,721]) were less than for SR (median: $222,799 [IQR: $167,581-$327,113]) (P < 0.001). Cost per day alive (P = 0.005) and department-level costs were also all lower for PR. In propensity score-adjusted analyses, PR was associated with lower total cost (cost ratio: 0.73; P < 0.001) and lower department-level costs.

CONCLUSIONS

In this multicenter study of neonates with sTOF, PR was associated with lower costs. Given similar overall mortality between treatment strategies, this finding suggests that PR provides superior value.

Stent Angioplasty for Post-Operative Coronary Artery Stenosis in Infants

INTRODUCTION

While frequently performed in the adult population, percutaneous coronary artery stent angioplasty (CSA) in infants is rare. CSA in infants is challenging because of limited options in terms of appropriately sized (length and diameter) stents, concern about stenting vessels with significant growth potential and limited data regarding durability of benefit. We report a multicenter case series of infants who underwent CSA.

METHODS

A multicenter, retrospective case series of infants who underwent percutaneous CSA to treat post-operative coronary artery stenoses was performed.

RESULTS

Six infants from 3 institutions who underwent post-operative CSA were identified. The anatomic diagnoses were d-transposition of the great arteries in 3 cases, anomalous left coronary artery from the pulmonary artery in 2 and supravalvar aortic stenosis in 1. All infants were critically ill at the time of CSA. Diameters of coronary artery stents used ranged from 2.25 to 2.75 mm. There were no procedural complications. All stents were patent immediately after placement and the clinical condition improved or stabilized in all patients. Follow-up angiography was available for 3 patients at 4 to 16 months post-CSA, at which time 67% (2/3) remained patent.

CONCLUSION

CSA is a feasible and effective therapy for critically ill infants with post-surgical coronary obstruction. Treatment appears to allow at least short-term reperfusion to facilitate recovery of ventricular function and potential development of collateral circulation when longer-term stent patency is not achieved. Longer-term stent patency and coronary artery health remain unanswered questions.

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.

Transcatheter pulmonary valve-in-valve implantation within the expandable Inspiris Resilia® bioprosthetic valve

Transcatheter pulmonary valve implantation (TPVI) is a common intervention for patients with repaired congenital heart disease. A key issue relates to the presence of an appropriately sized implantation zone for the transcatheter valve. We report the first case, to our knowledge, of TPVI within the newly engineered Inspiris Resilia® bioprosthetic valve, intentionally designed with a balloon-expandable valve ring (a.k.a. VFit zone) for prospective valve implantation.

Reintervention and Survival After Transcatheter Pulmonary Valve Replacement

BACKGROUND

Transcatheter pulmonary valve (TPV) replacement (TPVR) has become the standard therapy for postoperative pulmonary outflow tract dysfunction in patients with a prosthetic conduit/valve, but there is limited information about risk factors for death or reintervention after this procedure.

OBJECTIVES

This study sought to evaluate mid- and long-term outcomes after TPVR in a large multicenter cohort.

METHODS

International registry focused on time-related outcomes after TPVR.

RESULTS

Investigators submitted data for 2,476 patients who underwent TPVR and were followed up for 8,475 patient-years. A total of 95 patients died after TPVR, most commonly from heart failure (n = 24). The cumulative incidence of death was 8.9% (95% CI: 6.9%-11.5%) 8 years after TPVR. On multivariable analysis, age at TPVR (HR: 1.04 per year; 95% CI: 1.03-1.06 per year; P < 0.001), a prosthetic valve in other positions (HR: 2.1; 95% CI: 1.2-3.7; P = 0.014), and an existing transvenous pacemaker/implantable cardioverter-defibrillator (HR: 2.1; 95% CI: 1.3-3.4; P = 0.004) were associated with death. A total of 258 patients underwent TPV reintervention. At 8 years, the cumulative incidence of any TPV reintervention was 25.1% (95% CI: 21.8%-28.5%) and of surgical TPV reintervention was 14.4% (95% CI: 11.9%-17.2%). Risk factors for surgical reintervention included age (0.95 per year [95% CI: 0.93-0.97 per year]; P < 0.001), prior endocarditis (2.5 [95% CI: 1.4-4.3]; P = 0.001), TPVR into a stented bioprosthetic valve (1.7 [95% CI: 1.2-2.5]; P = 0.007), and postimplant gradient (1.4 per 10 mm Hg [95% CI: 1.2-1.7 per 10 mm Hg]: P < 0.001).

CONCLUSIONS

These findings support the conclusion that survival and freedom from reintervention or surgery after TPVR are generally comparable to outcomes of surgical conduit/valve replacement across a wide age range.

Anatomical Classification and Posttreatment Remodeling Characteristics to Guide Management and Follow-Up of Neonates and Infants With Coronary Artery Fistula: A Multicenter Study From the Coronary Artery Fistula Registry

BACKGROUND

Coronary artery fistulas (CAFs) presenting in infancy are rare, and data regarding postclosure sequelae and follow-up are limited.

METHODS

A retrospective review of all the neonates and infants (<1 year) was conducted from the CAF registry for CAF treatment. The CAF type (proximal or distal), size, treatment method, and follow-up angiography were reviewed to assess outcomes and coronary remodeling.

RESULTS

Forty-eight patients were included from 20 centers. Of these, 30 were proximal and 18 had distal CAF; 39 were large, 7 medium, and 2 had small CAF. The median age and weight was 0.16 years (0.01-1) and 4.2 kg (1.7-10.6). Heart failure was noted in 28 of 48 (58%) patients. Transcatheter closure was performed in 24, surgical closure in 18, and 6 were observed medically. Procedural success was 92% and 94 % for transcatheter closure and surgical closure, respectively. Follow-up data were obtained in 34 of 48 (70%) at a median of 2.9 (0.1-18) years. Angiography to assess remodeling was available in 20 of 48 (41%). I. Optimal remodeling (n=10, 7 proximal and 3 distal CAF). II. Suboptimal remodeling (n=7) included (A) symptomatic coronary thrombosis (n=2, distal CAF), (B) asymptomatic coronary thrombosis (n=3, 1 proximal and 2 distal CAF), and (C) partial thrombosis with residual cul-de-sac (n=1, proximal CAF) and vessel irregularity with stenosis (n=1, distal CAF). Finally, (III) persistent coronary artery dilation (n=4). Antiplatelets and anticoagulation were used in 31 and 7 patients post-closure, respectively. Overall, 7 of 10 (70%) with proximal CAF had optimal remodeling, but 5 of 11 (45%) with distal CAF had suboptimal remodeling. Only 1 of 7 patients with suboptimal remodeling were on anticoagulation.

CONCLUSIONS

Neonates/infants with hemodynamically significant CAF can be treated by transcatheter or surgical closure with excellent procedural success. Patients with distal CAF are at higher risk for suboptimal remodeling. Postclosure anticoagulation and follow-up coronary anatomic evaluation are warranted.

Factors Influencing Reintervention Following Ductal Artery Stent Implantation for Ductal-Dependent Pulmonary Blood Flow: Results From the Congenital Cardiac Research Collaborative

BACKGROUND

Stenting of the patent ductus arteriosus (PDA) is an established palliative option for infants with ductal-dependent pulmonary blood flow. Following initial palliation, reintervention on the PDA stent is common, but risk factors have not been characterized.

METHODS

Infants with ductal-dependent pulmonary blood flow palliated with PDA stent between 2008 and 2015 were reviewed within the Congenital Cardiac Research Collaborative. Rates and risk factors for reintervention were analyzed.

RESULTS

Among 105 infants who underwent successful PDA stenting, 41 patients (39%) underwent a total of 53 reinterventions on the PDA stent, with all but one occurring within 6 months of the initial intervention. Stent redilation constituted the majority of reintervention (n=35; 66%) followed by additional stent placement (n=11; 21%) and surgical shunt placement (n=7; 13%). The majority of reintervention was nonurgent, and there were no deaths during the reintervention procedure. All but one reintervention occurred within 6 months of the initial procedure. On univariate analysis, risk factors for reintervention included anticipated single-ventricle physiology, lack of prior balloon pulmonary valvuloplasty, use of drug-eluting stent, and increased ductal tortuosity.

CONCLUSIONS

In infants with ductal-dependent pulmonary blood flow palliated with PDA stent implantation, reintervention is common, can be performed safely, and is associated with both anatomic/procedural factors and anticipated final physiology.

Multicenter Study of Endocarditis After Transcatheter Pulmonary Valve Replacement

BACKGROUND

Endocarditis has emerged as one of the most impactful adverse events after transcatheter pulmonary valve replacement (TPVR), but there is limited information about risk factors for and outcomes of this complication.

OBJECTIVES

The purpose of this study was to evaluate risk factors for and outcomes of endocarditis in a large multicenter cohort.

METHODS

The authors established an international registry focused on characterizing endocarditis after TPVR, including the incidence, risk factors, characteristics, and outcomes.

RESULTS

Investigators submitted data for 2,476 patients who underwent TPVR between July 2005 and March 2020 and were followed for 8,475 patient-years. In total, 182 patients were diagnosed with endocarditis a median of 2.7 years after TPVR, for a cumulative incidence of 9.5% (95% CI: 7.9%-11.1%) at 5 years and 16.9% (95% CI: 14.2%-19.8%) at 8 years (accounting for competing risks: death, heart transplant, and explant) and an annualized incidence of 2.2 per 100 patient-years. Staphylococcus aureus and Viridans group Streptococcus species together accounted for 56% of cases. Multivariable analysis confirmed that younger age, a previous history of endocarditis, and a higher residual gradient were risk factors for endocarditis, but transcatheter pulmonary valve type was not. Overall, right ventricular outflow tract (RVOT) reintervention was less often to treat endocarditis than for other reasons, but valve explant was more often caused by endocarditis. Endocarditis was severe in 44% of patients, and 12 patients (6.6%) died, nearly all of whom were infected with Staphylococcus aureus.

CONCLUSIONS

The incidence of endocarditis in this multicenter registry was constant over time and consistent with prior smaller studies. The findings of this study, along with ongoing efforts to understand and mitigate risk, will be critical to improve the lifetime management of patients with heart disease involving the RVOT. Although endocarditis can be a serious adverse outcome, TPVR remains an important tool in the management of RVOT dysfunction.

Transcatheter Pulmonary Valve Replacement With the Sapien Prosthesis

BACKGROUND

There are limited published data focused on outcomes of transcatheter pulmonary valve replacement (TPVR) with either a Sapien XT or Sapien 3 (S3) valve.

OBJECTIVES

This study sought to report short-term outcomes in a large cohort of patients who underwent TPVR with either a Sapien XT or S3 valve.

METHODS

Data were entered retrospectively into a multicenter registry for patients who underwent attempted TPVR with a Sapien XT or S3 valve. Patient-related, procedural, and short-term outcomes data were characterized overall and according to type of right ventricular outflow tract (RVOT) anatomy.

RESULTS

Twenty-three centers enrolled a total of 774 patients: 397 (51%) with a native/patched RVOT; 183 (24%) with a conduit; and 194 (25%) with a bioprosthetic valve. The S3 was used in 78% of patients, and the XT was used in 22%, with most patients receiving a 29-mm (39%) or 26-mm (34%) valve. The implant was technically successful in 754 (97.4%) patients. Serious adverse events were reported in 67 patients (10%), with no difference between RVOT anatomy groups. Fourteen patients underwent urgent surgery. Nine patients had a second valve implanted. Among patients with available data, tricuspid valve injury was documented in 11 (1.7%), and 9 others (1.3%) had new moderate or severe regurgitation 2 grades higher than pre-implantation, for 20 (3.0%) total patients with tricuspid valve complications. Valve function at discharge was excellent in most patients, but 58 (8.5%) had moderate or greater pulmonary regurgitation or maximum Doppler gradients >40 mm Hg. During limited follow-up (n = 349; median: 12 months), 9 patients were diagnosed with endocarditis, and 17 additional patients underwent surgical valve replacement or valve-in-valve TPVR.

CONCLUSIONS

Acute outcomes after TPVR with balloon-expandable valves were generally excellent in all types of RVOT. Additional data and longer follow-up will be necessary to gain insight into these issues.

Comparison of management strategies for neonates with symptomatic tetralogy of Fallot and weight <2.5 kg

OBJECTIVE

To compare management strategies for neonates <2.5 kg with tetralogy of Fallot and symptomatic cyanosis who either undergo staged repair (SR) (initial palliation followed by later complete repair) or primary repair (PR).

METHODS

Consecutive neonates with tetralogy of Fallot and symptomatic cyanosis weighing <2.5 kg at initial intervention and between 2005 and 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. Primary outcome was mortality and secondary outcomes included component (eg, initial palliation, complete repair, or primary repair) and cumulative (SR: initial palliation followed by later complete repair) hospital and intensive care unit lengths of stay, durations of ventilation, inotrope use, cardiopulmonary bypass time, procedural complications, and reintervention. Outcomes were compared with propensity score adjustments with PR as the reference group.

RESULTS

The cohort included 76 SR (initial palliation: 53 surgical and 23 transcatheter) and 44 PR patients. The observed risk of overall mortality was similar between SR and PR groups (15.8% vs 18.2%: P = .735). The adjusted hazard of mortality remained similar between groups overall (hazard ratio, 0.59; 95% confidence interval, 0.26-1.36; P = .214), as well as during short-term (<4 months: hazard ratio, 0.37; 95% confidence interval, 0.13-1.09; P = .071) and midterm (>4 months: hazard ratio, 1.32; 95% confidence interval, 0.30-5.79; P = .717) follow-up. Reintervention in the first 18 months was common in both groups (53.2% vs 48.4%; hazard ratio, 1.69; 95% confidence interval, 0.96-2.28; P = .072). Adjusted procedural complications and neonatal morbidity burden were overall lower in the SR group. Cumulative secondary outcome burdens largely favored the PR group.

CONCLUSIONS

In this study comparing SR and PR treatment strategies for neonates with tetralogy of Fallot and symptomatic cyanosis and weight <2.5 kg, mortality and reintervention burden was highly independent of treatment strategy. Other potential advantages were observed with each approach.

Acute and medium term results of balloon expandable stent placement in the transverse arch-a multicenter pediatric interventional cardiology early career society study

OBJECTIVES AND BACKGROUND

Coarctation of the aorta represents 5-8% of all congenital heart disease. Although balloon expandable stents provide an established treatment option for native or recurrent coarctation, outcomes from transverse arch (TAO) stenting, including resolution of hypertension have not been well studied. This study aims to evaluate immediate and midterm results of TAO stenting in a multi-center retrospective cohort.

METHODS

TAO stenting was defined as stent placement traversing any head and neck vessel, with the primary intention of treating narrowing in the transverse aorta. Procedural details, complications and medications were assessed immediately post procedure, at 6 month follow-up and at most recent follow-up.

RESULTS

Fifty-seven subjects, 12 (21%) native, and 45 (79%) surgically repaired aortic arches, from seven centers were included. Median age was 14 years (4 days-42 years), median weight 54 kg (1.1-141 kg). After intervention, the median directly measured arch gradient decreased from 20 mmHg (0-57 mmHg) to 0 mmHg (0-23 mmHg) (p < .001). The narrowest arch diameter increased from 9 mm (1.4-16 mm) to 14 mm (2.9-25 mm) (p < .001), with a median increase of 4.9 mm (1.1-10.1 mm). One or more arch branches were covered by the stent in 55 patients (96%). There were no serious adverse events. Two patients warranted stent repositioning following migration during deployment. There were no late complications. There were 8 reinterventions, 7 planned, and 1 unplanned (6 catheterizations, 2 surgeries). Antihypertensive management was continued in 19 (40%) at a median follow-up of 3.2 years (0.4-7.3 years).

CONCLUSIONS

TAO stenting can be useful in selected patients for resolution of stenosis with minimal complications. This subset of patients are likely to continue on antihypertensive medications despite resolution of stenosis.

Amplatzer Piccolo Occluder clinical trial for percutaneous closure of the patent ductus arteriosus in patients ≥700 grams

Objectives

Characterize the safety and effectiveness of the Amplatzer Piccolo Occluder for patent ductus arteriosus (PDA) closure.

Background

The presence of a hemodynamically significant PDA has been associated with an increased risk of morbidity and mortality in children born premature.

Methods

This was a single arm, prospective, multicenter, non‐randomized study to evaluate the Amplatzer Piccolo Occluder to treat PDA in patients ≥700 g. From June 2017 to February 2019, 200 patients were enrolled at nine centers, with 100 patients weighing ≤2 kg. Primary effectiveness endpoint was the rate of PDA closure at 6‐month follow‐up. Primary safety endpoint was the rate of major complications through 6 months. Secondary endpoint was rate of significant pulmonary or aortic obstruction through 6 months' follow‐up.

Results

The implant success rate was 95.5% (191/200) overall and 99% in patients ≤2 kg (99/100). The primary effectiveness endpoint was achieved in 99.4% of implanted patients. Four patients experienced a primary safety endpoint event (2 transfusions, 1 hemolysis, and 1 aortic obstruction). There were no branch pulmonary artery obstructions. Five patients, all ≤2 kg, were noted to have worsening of tricuspid regurgitation (TR) after the procedure. None of the TR incidences manifested clinically. The Amplatzer Piccolo Occluder received FDA approval in January 2019 and became the first device approved for PDA closure in patients ≥700 g.

Conclusions

This study supports the safety and effectiveness of the Amplatzer Piccolo Occluder, particularly in patients between 700 g and 2 kg where there is currently a significant unmet need in the United States. ClinicalTrials.gov identifier: NCT03055858.

Longitudinal Improvements in Radiation Exposure in Cardiac Catheterization for Congenital Heart Disease

Background:

The C3PO-QI (Congenital Cardiac Catheterization Project on Outcomes – Quality Improvement), a multicenter registry launched in 2015, instituted quality improvement (QI) initiatives to reduce patient radiation exposure. Through regular collaboration, this initiative would allow for harmony among active participants, maximizing efforts and efficiency at achieving radiation best practices. This study sought to report these efforts with a detailed methodology for which institutions can target initiatives, reducing radiation exposure, and increasing patient safety.

Methods:

Data were collected prospectively by 8 C3PO-QI institutions between January 1, 2015 and December 31, 2017. Radiation exposure was measured in dose area product per body weight (dose area product/kg; µGy*m 2 /kg) and reported by expected radiation exposure categories (REC) and institution for 40 published unique procedure types. Targeted interventions addressing selected strategic domains for radiation reduction were implemented in the pediatric catheterization labs of the C3PO-QI institutions.

Results:

The study consisted of 15 257 unique cases. Median exposure (dose area product/kg) was decreased by 30% for all procedures. Dose area product/kg was reduced in all 3 REC, with the greatest improvement observed in REC I (REC I, −37%; REC II, −23%; REC III, −27%). Although the baseline radiation exposures and exact percent decrease varied across all C3PO-QI sites, each institution demonstrated improvements in radiation dose over time. These improvements occurred with the implementation of institution-specific QI interventions accelerated by participation in the C3PO-QI multicenter collaborative.

Conclusions:

Substantial radiation dose reductions can be achieved using targeted QI methodology and interventions. Participation in a multicenter QI collaborative may accelerate improvement across all centers due to enhanced engagement and shared learning between sites.

Results of the FUEL Trial

BACKGROUND

The Fontan operation creates a total cavopulmonary connection, a circulation in which the importance of pulmonary vascular resistance is magnified. Over time, this circulation leads to deterioration of cardiovascular efficiency associated with a decline in exercise performance. Rigorous clinical trials aimed at improving physiology and guiding pharmacotherapy are lacking.

METHODS

The FUEL trial (Fontan Udenafil Exercise Longitudinal) was a phase III clinical trial conducted at 30 centers. Participants were randomly assigned udenafil, 87.5 mg twice daily, or placebo in a 1:1 ratio. The primary outcome was the between-group difference in change in oxygen consumption at peak exercise. Secondary outcomes included between-group differences in changes in submaximal exercise at the ventilatory anaerobic threshold, the myocardial performance index, the natural log of the reactive hyperemia index, and serum brain-type natriuretic peptide.

RESULTS

Between 2017 and 2019, 30 clinical sites in North America and the Republic of Korea randomly assigned 400 participants with Fontan physiology. The mean age at randomization was 15.5±2 years; 60% of participants were male, and 81% were white. All 400 participants were included in the primary analysis with imputation of the 26-week end point for 21 participants with missing data (11 randomly assigned to udenafil and 10 to placebo). Among randomly assigned participants, peak oxygen consumption increased by 44±245 mL/min (2.8%) in the udenafil group and declined by 3.7±228 mL/min (-0.2%) in the placebo group (P=0.071). Analysis at ventilatory anaerobic threshold demonstrated improvements in the udenafil group versus the placebo group in oxygen consumption (+33±185 [3.2%] versus -9±193 [-0.9%] mL/min, P=0.012), ventilatory equivalents of carbon dioxide (-0.8 versus -0.06, P=0.014), and work rate (+3.8 versus +0.34 W, P=0.021). There was no difference in change of myocardial performance index, the natural log of the reactive hyperemia index, or serum brain-type natriuretic peptide level.

CONCLUSIONS

In the FUEL trial, treatment with udenafil (87.5 mg twice daily) was not associated with an improvement in oxygen consumption at peak exercise but was associated with improvements in multiple measures of exercise performance at the ventilatory anaerobic threshold.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02741115.

Intentional Fracture of Bioprosthetic Valve Frames in Patients Undergoing Valve-in-Valve Transcatheter Pulmonary Valve Replacement

BACKGROUND

Percutaneous transcatheter pulmonary valve replacement (TPVR) has good clinical and hemodynamic outcomes in treating dysfunctional bioprosthetic valves (BPV) in the pulmonary position. Valve-in-valve therapy can further decrease the inner diameter (ID), potentially resulting in patient-prosthesis mismatch in patients with smaller BPVs.

METHODS AND RESULTS

To evaluate feasibility and outcomes of intentional BPV fracture to enlarge the pulmonary valve orifice with TPVR, 37 patients from 13 centers who underwent TPVR with intended BPV fracture were evaluated. A control cohort (n=70) who underwent valve-in-valve TPVR without attempted fracture was evaluated. BPV was successfully fractured in 28 patients and stretched in 5 while fracture was unsuccessful in 4. A Melody valve was implanted in 25 patients with fractured/stretched frame and a Sapien (XT 3) valve in 8. Among patients whose BPV was fractured/stretched, the final ID was a median of 2 mm larger (0-6.5 mm) than the valve's true ID. The narrowest diameter after TPVR in controls was a median of 2 mm smaller ( P<0.001) than true ID. Right ventricular outflow tract gradient decreased from median 40 to 8 mm Hg in the fracture group. Cases with fracture/stretching were matched 1:1 (weight, true ID) to controls. Post-TPVR peak gradient was lower but not significant (8.3±5.2 versus 11.8±9.2 mm Hg; P=0.070). There were no fracture-related adverse events.

CONCLUSIONS

Preliminary experience shows intentional fracture of BPV frame can be useful for achieving larger ID and better hemodynamics after valve-in-valve TPVR.