Search

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 an improvement in myocardial performance index (–0.02 vs 0.01, P =0.030), but no change in 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.

Introduction: Absent ductus arteriosus (ADA) is a poorly described feature associated with tetralogy of Fallot (TOF). We compare characteristics and outcomes of neonates with symptomatic TOF (sTOF) with ADA to those with a ductus arteriosus (DA). Hypothesis: We hypothesized: neonates with sTOF and ADA would have similar outcomes to those born with a DA, and a small portion of the ADA cohort would have critically-deficient pulmonary blood flow (CDPBF). Methods: Consecutive neonates with sTOF who underwent intervention during the neonatal period from 2005—2017 were identified from the Congenital Cardiac Research Collaborative. Those with DA on echocardiogram performed on the first day of life or on fetal echocardiogram were identified and compared to those with ADA. ADA neonates who required ECMO or intervention to augment PBF on the first day of life were defined as having CDPBF. Patient characteristics and outcomes were compared between DA and ADA groups. Results: Among 519 neonates, 460 (89%) had a DA and 59 (11%) had ADA. ADA neonates were more likely to carry a genetic or syndromic diagnosis, had smaller branch PA sizes, and were more likely to receive a transannular patch compared to those with a DA. Despite this, reintervention rates were similar (data not shown), and there was only a small difference in mortality that did not reach statistical significance. Of ADA neonates, 7/59 (12%) had CDPBF. Compared to ADA neonates without CDPBF, those with CDPBF had lower baseline oxygen saturation (58 vs 87%, p=0.031) and smaller pulmonary valve (PV) annular z-score (-2.9 vs -2.5, p=0.015) with similar reintervention rates and mortality. Conclusion: ADA is relatively common in sTOF. Despite higher rates of comorbidities, mid-term reintervention rates and mortality are similar to those with DA. CDPBF is a rare, high-risk feature of infants with sTOF and ADA. Smaller PV size may be a marker of CDPBF. Future work should focus on prenatal factors to identify fetuses with TOF, ADA and CDPBF.

Introduction: The Fontan operation results in hemodynamic, anatomic and functional alterations in single ventricle (SV) heart disease. Studies have shown that SV patients have reduced exercise capacity. We sought to determine hemodynamic and anatomic associations with exercise capacity in our Fontan cohort. Methods: We performed a retrospective chart review of all patients born 2002-2012 who underwent Fontan palliation and followed in our Fontan Surveillance Program. Surveillance cardiac magnetic resonance (cMR), cardiac catheterization (cath), and exercise stress test (EST) data were collected. Primary analysis was association of cMR and cath data on EST outcomes including percent-predicted maximum oxygen consumption (ppVO 2 max) and oxygen pulse (ppO 2 Pulse). Results: A total of 222 patients were included, 45.5% with a systemic left ventricle (LV). Hypoplastic left heart syndrome was the underlying cardiac diagnosis in 1/3 of patients. The vast majority of the Fontan procedures performed were fenestrated, 44% extracardiac conduits and 42% with a lateral tunnel graft. A total of 185 cMRs, 274 caths, and 136 ESTs were performed. The median respiratory exchange ratio and ppVO 2 max were 1.11 L/sec and 73% respectively, with a preserved ppO 2 Pulse of 93.5%. Results of correlational analysis are shown in the table. Over serial ESTs, patients with a single RV had a more gradual, but not significant decline in ppVO 2 max than patients with a single LV, r s -0.321 and -0.544 respectively (p = 0.28). Conclusions: While hemodynamic parameters do not correlate with EST functional endpoints, anatomic factors such as the Nakata index are associated with EST performance. Surveillance of Fontan patients should include regular cMR to assess for subtle changes in ejection fraction, pulmonary artery diameter and differential pulmonary blood flow. Multicenter longitudinal studies with protocolized timing are needed to further elucidate correlates of good exercise capacity.

Background: The Pediatric Heart Network’s Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT 02741115) demonstrated improvements in exercise capacity and ventricular performance following six months of treatment with udenafil (87.5 mg twice daily). In this analysis we evaluated whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. Methods: The effect of udenafil on exercise was evaluated within subgroups defined by gender, race, ventricular morphology, and baseline peak oxygen consumption (VO 2 ). Linear regression modeling evaluated for differential response to udenafil (interaction of subgroup with treatment arm). Individual subgroups were excluded if the number of participants was Results: Subgroup analyses demonstrated qualitative improvements in peak VO 2 , work rate at the ventilatory anaerobic threshold (VAT), VO 2 at VAT, and ventilatory efficiency (VE/VCO 2 ) for those randomized to udenafil compared to placebo in all subgroups (Table). There was not a differential response to udenafil based on gender, race, ventricular morphology, or baseline peak VO 2 , although participants in the lowest tertile of baseline peak VO 2 and those with single left ventricles trended toward larger improvements. Conclusion: The relatively uniform improvement among subgroups in response to treatment with udenafil is consistent with the findings from the primary analysis of the FUEL trial. While the absence of a statistically significant differential effect between subgroups suggests that the effect of udenafil may not be gender, race, or morphology specific, and may not vary based on baseline exercise performance, the possibility of a larger improvements in those with poor baseline peak VO 2 and those with single left ventricle warrants further investigation.

Introduction: In the Pediatric Heart Network double-blind Fontan Udenafil Exercise Longitudinal (FUEL) trial, treatment with udenafil (Mezzion Pharma Co Ltd) for 6 months was associated with modest improvements in exercise capacity and ventricular performance (NCT02741115). Measures of vascular function, which have been related to Fontan exercise capacity, were also obtained but have not been explored in detail. Methods: Endothelial function (Framingham reactive hyperemia index, FRHI; area under the curve to max occlusion, AUC Max ) and arterial stiffness (augmentation index, AI) were assessed with peripheral arterial tonometry. The primary outcome was the effect of udenafil vs. placebo on vascular function. Secondary outcomes included baseline, and 26-week change from baseline, measures of vascular function in subgroups of the udenafil arm, stratified by exercise response. Exercise response was defined by longitudinal change in peak oxygen consumption and categorized by 1) any positive change vs. other and 2) tertile of change. Results: Paired measures of vascular function were analyzed in 164 (82%) and 167 (84%) udenafil and placebo participants, respectively. There were no baseline differences between groups, including the use of vasoactive medications. Overall, there were no differences in change in measures of vascular function between treatment groups. In subgroup analysis, exercise responders demonstrated better baseline endothelial function (FRHI: 0.39 ± 0.37 vs. 0.29 ± 0.31, p=0.056; AUC Max : 6.53 ± 2.91 vs. 5.63 ± 2.21, p=0.023) and suggestion of a 26-week reduction in arterial stiffness (AI: -1.42 ± 10.3 vs. 1.69 ± 11.7, p=0.075). Analysis by tertile of exercise response showed that AI was significantly improved in the top tertile of exercise responders (-3.27 ± 8.4 vs. 2.62 ± 12.4 vs. 0.35 ± 11.1, p=0.022) compared with the lower tertiles. Conclusions: In the FUEL trial, treatment with udenafil was not associated with significant changes in measures of vascular function. Udenafil-treated participants with evidence of exercise responsiveness to therapy manifest better baseline endothelial function and a significant improvement in arterial stiffness. Vascular function may play a role in PDE-5 responsiveness in Fontan circulation.

Introduction: The Pediatric Heart Network’s Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT 02741115) demonstrated improvements in exercise capacity following 6 months of treatment with udenafil (87.5 mg po BID). The effect of udenafil on echocardiographic measures of single ventricle (SV) function in this cohort has not been studied. Methods: Protocol echocardiograms were obtained at baseline and 26 weeks after initiation of udenafil/placebo. Linear regression compared change from baseline in indices of SV systolic, diastolic and global function, atrioventricular valve (AVV) regurgitation and mean Fontan fenestration gradient in the udenafil cohort vs placebo, controlling for ventricular morphology (LV vs. RV/other). Effects of ventricular morphology on echo measures and its interaction over time was also evaluated. Difficult imaging windows limited consistent capture of all measures. Results: The 191 udenafil participants had significantly improved myocardial performance index (p=0.03), AVV inflow peak E and A velocities (p = 0.007 and 0.03), and annular DTI-derived peak e’ velocity (p = 0.008) compared to 195 placebo participants (Table). There were no significant differences in change in SV size, systolic function, AVV regurgitation severity or mean fenestration gradient. Although LV morphology participants had significantly more favorable indices of SV size and function (lower volumes and areas, E/e’ ratio, systolic:diastolic time and AVV regurgitation, and higher annular s’ and e’ velocity) at baseline, there was no differential effect of udenafil by ventricular morphology at 26 weeks. Conclusions: FUEL participants who received udenafil demonstrated a significant improvement in global and diastolic echo indices. The changes in diastolic function suggest improvement in pulmonary venous return and/or augmented ventricular relaxation, which may help explain improved exercise performance in that cohort.

Introduction: Neonates with tetralogy of Fallot and pulmonary atresia (TOF/PA) with pulmonary blood flow supplied by the ductus arteriosus require early intervention. This may be accomplished by: initial palliation (IP) followed by complete repair (CR) or initial primary repair (PR). The optimal approach for patients with TOF/PA has not been established. Methods: Neonates with TOF/PA who underwent IP or PR from 2005-17 were retrospectively reviewed from the Congenital Catheterization Research Collaborative. The primary outcome was mortality. Outcomes were compared as IP vs PR and IP+CR vs PR. Secondary outcomes included hospital and procedural complications and are listed in table 1. Propensity scoring was used to adjust for baseline differences between strategies. Results: Of 282 neonates with TOF/PA, 106 underwent PR and 176 underwent IP (144 surgical, 32 transcatheter). Prior to initial intervention, IP patients had higher rates of mechanical ventilation (83.9% vs 72.2%, p=0.023) and DiGeorge syndrome (14.77% vs 4.72%, p=0.009). Mortality was greater in the IP cohort (HR 2.7, 95% CI 1.02 - 7.1, p = 0.046), with no mortality in the PR cohort after 6 months post-repair. After adjustment, differences in survival were no longer significant (HR 1.4, 95% CI 0.7 - 3.1, p=0.39). Both cohorts had similar mechanical ventilation duration and inotrope use as well as procedural and hospital complications. Intensive care and hospital length of stay, cardiac bypass (CPB) and anesthesia time favored PR when compared to IP+CR (p= Conclusions: In neonates with TOF/PA, the IP approach is more often utilized in higher-risk patients. Accounting for this difference, IP and PR strategies have similar adjusted survival rates. Perioperative morbidities and lower risk for reintervention generally favor PR.

Introduction: Symptomatic neonates with tetralogy of Fallot (sTOF) and hypoplastic branch pulmonary arteries (hPA) are at high risk. Management strategies include staged repair (SR) - initial palliation (IP) followed by later complete repair (CR) - or primary repair (PR). A balanced comparison of these approaches is needed in the sTOF neonate with hPA. Methods: Consecutive neonates with sTOF and hPA - defined as one hPA z-score Results: The cohort comprised 188 neonates including 121 SR (IP: 29 transcatheter; 54 surgery) and 67 PR patients. Presence of pulmonary atresia, lower gestational age and birthweight were more common in the SR cohort. Median right and left hPA z-scores were -2.19 (IQR -2.65, -1.92) and -2.33 (-2.84, -1.99), respectively. There were significant differences in treatment strategy across centers (p Conclusions: In this multicenter comparison of SR or PR for management of neonates with sTOF and hPA, after PSA, no difference in mortality was found. Neonatal morbidities largely favored the SR group, but cumulative morbidities and reintervention favored the PR group. Further study is needed to determine late impact of these early advantages to SR.

Background: Infants with ductal-dependent pulmonary blood flow may undergo palliation with either a patent ductus arteriosus (PDA) stent or a modified Blalock-Taussig (BT) shunt. A balanced multicenter comparison of these 2 approaches is lacking. Methods: Infants with ductal-dependent pulmonary blood flow palliated with either a PDA stent or a BT shunt from January 2008 to November 2015 were reviewed from the 4 member centers of the Congenital Catheterization Research Collaborative. Outcomes were compared by use of propensity score adjustment to account for baseline differences between groups. Results: One hundred six patients with a PDA stent and 251 patients with a BT shunt were included. The groups differed in underlying anatomy (expected 2-ventricle circulation in 60% of PDA stents versus 45% of BT shunts; P =0.001) and presence of antegrade pulmonary blood flow (61% of PDA stents versus 38% of BT shunts; P P =0.31). Other reinterventions were more common in the PDA stent group (hazard ratio, 29.8; 95% CI, 9.8–91.1; P P P P =0.006), and larger (152 mm 2 /m 2 [95% CI, 132–176] versus 125 mm 2 /m 2 [95% CI, 113–138]; P =0.029) and more symmetrical (symmetry index, 0.84 [95% CI, 0.8–0.89] versus 0.77 [95% CI, 0.75–0.8]; P =0.008] pulmonary arteries at the time of subsequent surgical repair or last follow-up. Conclusions: In this multicenter comparison of palliative PDA stent and BT shunt for infants with ductal-dependent pulmonary blood flow adjusted for differences in patient factors, there was no difference in the primary end point, death or unplanned reintervention to treat cyanosis. However, other markers of morbidity and pulmonary artery size favored the PDA stent group, supporting PDA stent as a reasonable alternative to BT shunt in select patients.

Background— Daily home monitoring of oxygen saturation and weight has been reported to improve outcomes for patients with single-ventricle heart disease during the period between stage I palliation and stage II palliation. However, these studies have been limited to single institutions and used historical control subjects. Our objective was to determine the association of various interstage home monitoring strategies with outcomes using a multicenter cohort with contemporary control subjects. Methods and Results— We performed a retrospective cohort study using prospectively collected data from the National Pediatric Cardiology Quality Improvement Collaborative from 2008 to 2012. We compared interstage mortality, unscheduled readmissions, and change in weight-for-age Z score for various home monitoring strategies of oxygen saturation (n=494) or weight (n=472), adjusting for sex, syndrome, tricuspid regurgitation, arch obstruction, and shunt type. Overall interstage mortality was 8.1%, and 47% had ≥1 unscheduled readmission. We did not find any associations of home oxygen saturation or weight monitoring with mortality or readmission. Although there was no difference in weight-for-age Z score for daily (0.33±0.12) versus weekly (0.34±0.18, P =0.98) weight monitoring, daily home weight monitoring was superior to no home weight monitoring (−0.15±0.18; P Conclusions— Home weight monitoring is associated with improved weight gain during the interstage period, but we did not find any benefits in other clinical outcomes for either home oxygen saturation monitoring or home weight monitoring.

Introduction: The optimal treatment for congenital aortic stenosis (AS) is debated despite decades of experience with both balloon aortic valvuloplasty (BAV) and surgical aortic valve repair (SAV). While BAV has been the mainstay of therapy for AS, recent single-center reports suggest optimal results following SAV. Hypothesis: We propose that reintervention rates following SAV and BAV are equivalent. Methods: We queried Medline, EMBASE and Web of Science for eligible studies using the keywords: “congenital aortic stenosis”, “balloon valvotomy”, “aortic valve stenosis surgery” and “treatment outcome or reintervention”. Studies were excluded when cohort size was Results: A total of 20 studies were included in our meta-analysis: SAV alone (n=3), BAV alone (n=12), and both (n=5). The mean age at BAV was 3.1 years (range, 4 days - 7 years) with a mean follow-up duration of 6.8 years, while mean age at SAV was 2.8 years (range, 14.2 days - 7.1 years) with a mean follow-up duration of 9.1 years. Mortality rates following BAV and SAV were 12.3% (95% CI: 7.7 - 19.1) and 10.2% (95% CI: 7.0 - 14.5), respectively (p=0.27). Reintervention following initial procedure for treatment of AS was higher following BAV (35.7% [95% CI: 29 - 43.1]) compared to SAV (25.2% [95% CI: 19.9 - 31.3])(p=0.012). Long-term and mid-term follow-up in these studies showed moderate to severe AR was present in 24.1% and 28.1% of BAV and SAV patients, respectively. Conclusions: Notwithstanding publication bias, both survival rates and development of late AR following BAV and SAV are similar. However, reintervention rates are significantly higher following BAV compared to SAV.

Transformative advances in medical technology rarely occur in isolation, but rather may be indirectly informed, if not accelerated, by advances in related fields. Bonhoeffer et al1 introduced the first transcatheter valve in 2000, implanting it in a 12-year-old boy with tetralogy of Fallot. The report of the transcatheter aortic valve by Cribier a mere 2 years later suggests the interdependence of investigators on breakthroughs in related fields.2 The advancements in cardiac devices are shared among pediatric and adult cardiologists, with benefits ideally befalling both patient populations when a breakthrough occurs, whether that technology was initially introduced for adults or children. Article see p 1960 It is notable that the Melody valve implanted in 2015 is in large part the same device and delivery system as the first transcatheter valve implanted in 2000. The operator learning curve has been significant, whereas the device has remained for the most part unmodified. The unchanging character of the valve speaks to 2 issues specifically. When considering the performance and clinical utility of a bioprosthetic valve, one might subscribe to the British surgeon Dr Donald Ross’s approach: the primary consideration is the early safety and efficacy of the valve, with secondary value placed on valve durability.3 In consideration of early safety and efficacy, the Melody valve has shown excellent results. As has been demonstrated in multiple studies, a significant learning curve occurred to optimize patient safety during transcatheter valve implantation – such as careful coronary artery assessment, prestenting the outflow tract, and anticipation of outflow tract tearing.4,5 It is worth remembering that some of the experiences on this technical learning curve are embedded within the results of the current midterm study by Cheatham et al6 in this issue of Circulation . Early efficacy has also been previously demonstrated …

Background— Preoperative brain injury is an increasingly recognized phenomenon in neonates with complex congenital heart disease. Recently, reports have been published that associate preoperative brain injury in neonates with transposition of the great arteries with the performance of balloon atrial septostomy (BAS), a procedure that improves systemic oxygenation preoperatively. It is unclear whether BAS is the cause of brain injury or is a confounder, because neonates who require BAS are typically more hypoxemic. We sought to determine the relationship between preoperative brain injury in neonates with transposition of the great arteries and the performance of BAS. We hypothesized that brain injury results from hypoxic injury, not from the BAS itself. Methods and Results— Infants with transposition of the great arteries (n=26) were retrospectively included from a larger cohort of infants with congenital heart disease who underwent preoperative brain MRI as part of 2 separate prospective studies. Data collected included all preoperative pulse oximetry recordings, all values from preoperative arterial blood gas measurements, and BAS procedure data. MRI scans were performed on the day of surgery, before the surgical repair. Of the 26 neonates, 14 underwent BAS. No stroke was seen in the entire cohort, whereas 10 (38%) of 26 patients were found to have hypoxic brain injury in the form of periventricular leukomalacia. Periventricular leukomalacia was not associated with BAS; however, neonates with periventricular leukomalacia had lower preoperative oxygenation ( P =0.026) and a longer time to surgery ( P =0.028) than those without periventricular leukomalacia. Conclusions— Preoperative brain injury in neonates with transposition of the great arteries is associated with hypoxemia and longer time to surgery. We found no association between BAS and brain injury.

Introduction : Pulmonary insufficiency-induced right ventricular volume overload in adults with repaired tetralogy of Fallot (TOF) is associated with reduced exercise tolerance, ventricular arrhythmias and sudden cardiac death. Studies have shown that the severity of pulmonary insufficiency (PI) predicts these symptoms. There has been indirect evidence that pulmonary artery branch stenosis (PABS) exacerbates PI in adults with repaired TOF. However the impact of treatment of PABS on PI has not been evaluated. Hypothesis : Relief of unilateral PABS in the setting of PI alleviates the severity of PI. Methods : Newborn piglets (n=9) underwent pulmonary valve resection with transannular patch and left pulmonary artery (LPA) banding. Between 10 to 16 weeks later, a cardiac catheterization was performed with hemodynamic evaluation and stenting of the banded LPA. Immediately prior to catheterization, and then 1 week following intervention, a cardiac MRI was performed. MRI data obtained included main and branch pulmonary arterial forward and reverse flow, and right and left ventricular volume. Results: Six animals survived the protocol. At time of catheterization, the LPA had a discrete stenosis, with a mean gradient of 11.6 mmHg (range 9 –16.1) across the banded region. The mean diameter of the LPA at the banded region was 3.4 mm (range 3.1– 4.2) and 10.8 mm distally (range 9.6 –14) at baseline, compared with a mean right pulmonary artery diameter of 20.2 mm. The banded region was stented to a mean diameter of 10.4 mm (range 8 –12.6). The main pulmonary artery regurgitant fraction (RF) at baseline was a mean of 38.2%; after stenting of the LPA, the RF decreased to 29.6% (p=0.02). Flow into the LPA improved in all animals, from a mean of 12.2% of total at baseline to 33.6% following stenting (p Conclusions: In the setting of unilateral PABS, stenting alleviates the severity of PI in an animal model of repaired TOF. Though clinical studies are required, these findings should be considered in decisions regarding treatment of PABS after repair of TOF.