Duct Stenting in Duct-Dependent Systemic Blood Flow, Past, Present, and Future.

Arterial duct stenting, pioneered in the early 1990s for newborns with a duct-dependent pulmonary and systemic circulation, has evolved significantly over the past decades. This progressive technique has led to the development of novel therapeutic strategies, including the Hybrid approach introduced three decades ago, and more recently, a complete transcatheter approach for treating newborns with hypoplastic left heart syndrome (HLHS). Subsequently, the transcatheter method has been extended to bi-ventricular lesions and patients with pulmonary hypertension, establishing a reverse Potts-shunt pathophysiology. Considering current experiences, this review aims to assess the strengths, weaknesses, and complications associated with ductal stenting, which represents a critical component of these complex treatment strategies. Despite advancements, the mortality rate of Norwood and Hybrid stage-1 procedures has plateaued, underscoring the importance of enhancing the quality of life of affected patients as the primary therapeutic goal. The prerequisite is a gentle, almost atraumatic medicine, particularly during the newborn period. It is essential to recognize that both the Hybrid and total transcatheter approaches demand comparable experience to Norwood surgery. Successful outcomes hinge on much more than merely inserting a stent into the duct; they require meticulous attention to detail and comprehensive management strategies.

Left Ventricular Physiology and Ventricular-Vascular Interactions in Young Patients After Heart Transplantation.

Background In patients after heart transplantation, systemic arterial hypertension and enhanced central aortic stiffness contribute to increased ventricular afterload, which might lead to graft dysfunction. The aim of our study was to characterize systemic arterial elastance and its impact on left ventricular function and ventriculo-arterial coupling in a cohort of children, adolescents, and young adults after heart transplantation using invasive conductance catheter technique. Methods and Results Thirty patients who had heart transplants (age, 20.0±6.5 years, 7 female) underwent invasive cardiac catheterization including pressure-volume loop analysis. Load-independent parameters of systolic (ventricular elastance [Ees]) and diastolic (ventricular compliance) function as well as systemic arterial elastance (Ea, end-systolic pressure/stroke volume) and ventriculo-arterial coupling (Ea/Ees) were assessed at baseline level and during dobutamine infusion (10 µg/kg/min). Ees showed an appropriate increase under inotropic stimulation from 0.43 (0.11-2.52) to 1.00 (0.20-5.10) mm Hg/mL/m2 (P<0.0001), whereas ventricular compliance remained rather unchanged (0.16±0.10 mm Hg/mL/m2 to 0.12±0.07 mm Hg/mL/m2; P=0.10). Ventriculo-arterial coupling Ea/Ees was abnormal at rest and did not improve significantly under dobutamine (1.7 [0.6-6.7] to 1.3 [0.5-4.9], P=0.70) due to a simultaneous rise in Ea from 0.71 (0.37-2.82) to 1.10 (0.52-4.03) mm Hg/mL/m2 (P<0.0001). Both Ees and ventricular compliance were significantly associated with Ea at baseline and under dobutamine infusion. Conclusions Patients who underwent heart transplantation show impaired ventriculo-arterial coupling at rest and under inotropic stimulation despite preserved left ventricular contractile reserve. An abnormal response in vascular function resulting in increased afterload seems to represent an important factor that may play a role for the development of late graft failure.

Functional regeneration of dilated cardiomyopathy by transcatheter bilateral pulmonary artery banding: first-in-human case series.

Background: Dilated cardiomyopathy (DCM) is a leading cause of heart transplantation (HTx) in children. Surgical pulmonary artery banding (PAB) is used worldwide to achieve functional heart regeneration and remodelling. Case summary: We report for the first-time successful bilateral transcatheter implantation of bilateral pulmonary artery flow restrictors in a case series of three infants with severe DCM based on left-ventricular non-compaction morphology associated with Barth syndrome in one and a non-classified syndrome in another. Functional cardiac regeneration was observed in two patients after almost 6 months of endoluminal banding, and in the neonate with Barth syndrome already after 6 weeks. Accompanied by an improvement in functional class (Class IV to Class I), the left ventricular end-diastolic dimensions z-score normalized, as did the elevated serum brain natriuretic peptide levels. A listing for HTx could be avoided. Discussion: Percutaneous bilateral endoluminal PAB is a novel minimally invasive approach that enables functional cardiac regeneration in infants with severe DCM and preserved right ventricular function. Interruption of the ventriculo-ventricular interaction, the key mechanism for recovery, is avoided. Intensive care for these critically ill patients is reduced to a minimum. However, investing in 'heart regeneration to avoid transplantation' remains a challenge.

Fetal Echocardiography in Predicting Postnatal Outcome in Borderline Left Ventricle.

OBJECTIVES: Prenatal prediction of postnatal univentricular versus biventricular circulation in patients with borderline left ventricle (bLV) remains challenging. This study investigated prenatal fetal echocardiographic parameters and postnatal outcome of patients with a prenatally diagnosed bLV. METHODS: We report a retrospective study of bLV patients at four prenatal centers with a follow-up of one year. BLV was defined as z-scores of the left ventricle (LV) between -2 and -4. Single-ventricle palliation (SVP), biventricular repair (BVR), and no surgical or catheter-based intervention served as the dependent outcome. Prenatal ultrasound parameters were used as independent variables. Cut-off values from receiver operating characteristic curves (ROC) were determined for significant discrimination between outcomes. RESULTS: A total of 54 patients were diagnosed with bLV from 2010 to 2018. All were live births. Out of the entire cohort, 8 (15 %) received SVP, 34 (63 %) BVR, and 12 (22 %) no intervention. There was no significant difference with regard to genetic or extracardiac anomalies. There were significantly more patients with endocardial fibroelastosis (EFE) in the SVP group compared to the BVR group (80 % vs. 10 %), (p < 0.001). Apex-forming LV (100 % vs. 70 %) and lack of retrograde arch flow (20 % vs. 80 %) were associated with no intervention (p < 0.001). With respect to BVR vs. SVP, the LV sphericity index provided the highest specificity (91.7 %) using a cutoff value of ≤ 0.5. CONCLUSION: The majority of bLV patients maintained biventricular circulation. EFE, retrograde arch flow, and LV sphericity can be helpful parameters for counseling parents and further prospective studies can be developed.

Hypoplastic Left Heart Syndrome Palliation: Technical Aspects and Common Pitfalls of the Hybrid Approach.

The Giessen hybrid strategy is used for initial palliation of HLHS and variants when the intent is to pursue further staged palliative reconstruction toward Fontan circulation. It is also used for initial palliation of HLHC and other anomalies with potential for eventual biventricular repair. From June 1998 - October 2021, 197 patients with HLHS and related variants underwent hybrid stage 1. Follow-up is complete (median 8.3 [range 0-23.3] years). Operative mortality for hybrid stage I was 3.6% (7/197); reduced to 2.8% since 2010 (4/141). Interstage mortality was 4.1% (8/197). Operative mortality for comprehensive stage II was 5.8% (10/172), and since 2010 was 1.8% (2/113 patients). Fontan completion has been accomplished in 117 patients, and 33 are still awaiting stage III. Twelve patients underwent heart transplantation. Over 23 years, overall survival is 77.7% and transplant-free survival is 73.6%.

Hypoplastic Left Ventricle: Left Ventricular Recruitment With Hybrid Approach.

Decision-making for biventricular repair (BVR) or univentricular palliation is challenging in neonates with hypoplastic left heart complex (HLHC). Hybrid strategy can be used successfully to achieve BVR in some of these patients. Between June 1998 and January 2022, 342 patients with a diagnosis of HLHS/variants, ductal-dependent lower body circulation with two ventricles, or HLHC with borderline left ventricle (LV) underwent initial bilateral pulmonary artery banding and ductal stenting in our institution. Among these 342 patients, 224 patients were defined as HLHS/variants and underwent univentricular palliation. 118 patients were determined to have borderline LV and hypoplastic left ventricular structures (HLHC, n = 48) or ductal-dependent lower body circulation with two ventricles (n = 70) considered suitable for BVR. 48 patients had multilevel obstructions including both aortic and mitral valve hypoplasia, aortic arch hypoplasia, and borderline LV. These were considered to have HLHC. These 48 HLHC patients are the subject of this report. Neonatal hybrid palliation at a median age of seven days was performed in 48 patients and 46 patients underwent BVR at a median age of 156 days. In 46 patients who underwent BVR, hospital mortality was not observed. The median follow-up was 66 months, with no late mortality. Heart transplant-free survival at 5, 10, and 15 years was 95.7%. 12 patients (26%) required reoperation and 9 (19.5%) required catheter reinterventions. Hybrid palliation may increase the chances for biventricular circulation in patients with borderline LV and small left-sided structures. Giessen hybrid approach as a left ventricular recruitment strategy achieves excellent early and long-term results.

Can Pediatric Heart Failure Therapy Be Improved? Yes It Can, But .

Given the heterogenous etiology of pediatric heart failure (pHF), evidence-based studies improving pHF are unlikely. A paradigm shift towards updated medicine-based evidence is therefore necessary. In view of the life expectancy of children, cardiac regeneration strategies are required. Therefore, age- and disease-related differences in myocardial (receptor) physiology require individualized precision medicine. First-line diuretic therapy, adopted from the treatment of adults with HF with no chance for recovery, should be questioned in the treatment of pHF with potential for recovery. Inadequate use of diuretics is a common reason for additional stimulation of the neurohumoral axis. Consecutive intravascular volume depletion led to an inadequate treatment with ß-blocker and renin-angiotensin-aldosterone antagonists. Given the age-related catecholamine-driven cardiovascular (patho-) physiology, highly selective ß1-blockers (bisoprolol) protect against ß1-(noradrenaline)-related myocytic apoptosis and necrosis, but allow ß2-receptor-mediated myocardial regeneration. Based on its high safety-efficacy profile with rarely seen adverse effects but easily monitorable efficacy by the surrogate of heart rate (reduction), bisoprolol is our first-line drug in infancy. Reduced heart rate economizes the heart and full body oxygen consumption and extends the diastolic filling and coronary perfusion time. Based on our many years of institutional experience, physicians should be encouraged to use ß1-selected blockers in infants with dilated cardiomyopathy and hypoplastic left heart syndrome after stage-1 procedure, but also to treat ventricular septal defects with a significant left-to-right shunt. In summary, individualized pHF therapy is the prerequisite for a causal treatment to improve HF symptoms, but above all for the most functional regeneration possible.

Impact of Right Ventricular Pressure Load After Repair of Tetralogy of Fallot.

Background Right ventricular outflow tract (RVOT) stenosis after repair of tetralogy of Fallot has been linked with favorable right ventricular remodeling but adverse outcomes. The aim of our study was to assess the hemodynamic impact and prognostic relevance of right ventricular pressure load in this population. Methods and Results A total of 296 patients with repaired tetralogy of Fallot (mean age, 17.8±7.9 years) were included in a prospective cardiovascular magnetic resonance multicenter study. Myocardial strain was quantified by feature tracking technique at study entry. Follow-up, including the need for pulmonary valve replacement, was assessed. The combined end point consisted of ventricular tachycardia and cardiac death. A higher echocardiographic RVOT peak gradient was significantly associated with smaller right ventricular volumes and less pulmonary regurgitation, but lower biventricular longitudinal strain. During a follow-up of 10.1 (0.1-12.9) years, the primary end point was reached in 19 of 296 patients (cardiac death, n=6; sustained ventricular tachycardia, n=2; and nonsustained ventricular tachycardia, n=11). A higher RVOT gradient was associated with the combined outcome (hazard ratio [HR], 1.03; 95% CI, 1.00-1.06; P=0.026), and a cutoff gradient of ≥25 mm Hg was predictive for cardiovascular events (HR, 3.69; 95% CI, 1.47-9.27; P=0.005). In patients with pulmonary regurgitation ≥25%, a mild residual RVOT gradient (15-30 mm Hg) was not associated with a lower risk for pulmonary valve replacement. Conclusions Higher RVOT gradients were associated with less pulmonary regurgitation and smaller right ventricular dimensions but were related to reduced biventricular strain and emerged as univariate predictors of adverse events. Mild residual pressure gradients did not protect from pulmonary valve replacement. These results may have implications for the indication for RVOT reintervention in this population.

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.

Exercise-dependent changes in ventricular-arterial coupling and aortopulmonary collateral flow in Fontan patients: a real-time CMR study.

AIMS: Inefficient ventricular-arterial (V-A) coupling has been described in Fontan patients and may result in adverse haemodynamics. A varying amount of aortopulmonary collateral (APC) flow is also frequently present that increases volume load of the single ventricle. The aim of the study was to assess changes in V-A coupling and APC flow during exercise CMR. METHODS AND RESULTS: Eighteen Fontan patients (age 24 ± 3 years) and 14 controls (age 23 ± 4 years) underwent exercise CMR using a cycle ergometer. Ventricular volumetry and flow measurements in the ascending aorta (AAO), inferior (IVC), and superior (SVC) vena cava were assessed using real-time sequences during stepwise increases in work load. Measures of systemic arterial elastance Ea, ventricular elastance Ees, and V-A coupling (Ea/Ees) were assessed. APC flow was quantified as AAO - (SVC + IVC). Ea remained unchanged during all levels of exercise in both groups (P = 0.39 and P = 0.11). Ees increased in both groups (P = 0.001 and P < 0.001) with exercise but was lower in the Fontan group (P = 0.04). V-A coupling was impaired in Fontan patients at baseline (P = 0.04). Despite improvement during exercise (P = 0.002) V-A coupling remained impaired compared with controls (P = 0.001). Absolute APC flow in Fontan patients did not change during exercise even at maximum work load (P = 0.98). CONCLUSIONS: Inefficient V-A coupling was already present at rest in Fontan patients and aggravated during exercise due to a limited increase in ventricular contractility which demonstrates the importance of a limited functional reserve of the single ventricle. APC flow remained unchanged suggesting no further increase in volume load during exercise.

Hemodynamic and prognostic impact of the diastolic pulmonary arterial pressure in children with pulmonary arterial hypertension-a registry-based analysis.

BACKGROUND: Diastolic pulmonary arterial pressure (dPAP) is regarded to be less sensitive to flow metrics as compared to mean PAP (mPAP), and was therefore proposed for the assessment of a precapillary component in patients with postcapillary pulmonary hypertension (PH). To analyze the diagnostic and prognostic impact of dPAP in patients with pure precapillary PH, we purposed to compare the correlation between dPAP and mPAP, as well as hemodynamically-derived calculations [ratio of PAP to systemic arterial pressure (PAP/SAP), pulmonary vascular resistance index (PVRI), transpulmonary gradient (TPG)], using both dPAP and mPAP, at rest and during acute vasoreactivity testing (AVT) in children with idiopathic or heritable pulmonary arterial hypertension (IPAH/HPAH). Furthermore, we aimed to assess the association of these metrics (at baseline and changes after AVT) with transplant-free survival. METHODS: We conducted a retrospective analysis of the TOPP (Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension) registry including 246 IPAH/HPAH patients. Of these, 45 children (18.3%) died, and 13 (5.3%) received lung transplantation during the observation period. RESULTS: dPAP and mPAP-derived variables showed almost linear relationship. Higher mPAP/mSAP, and dPAP-/mPAP-derived PVRI at rest was associated with time to death/transplantation. At maximum AVT-response, the decrease of dPAP and mPAP, diastolic pulmonary gradient (DPG) and TPG, as well as dPAP/dSAP and mPAP/mSAP was associated with time to death/transplantation, showing higher significance than corresponding baseline values. Remarkably, no predictive value was found for PVRI-reduction during AVT, neither dPAP- nor mPAP-derived. CONCLUSIONS: There is a strong relationship between dPAP and mPAP-derived variables. According to our results, hemodynamics during AVT (irrespectively of dPAP- or mPAP-derived) may have more prognostic implications than resting hemodynamics in children with IPAH/HPAH, except for PVRI.