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

Transcatheter-Based Interventions for Tetralogy of Fallot Across All Age Groups

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. Palliative procedures, either surgical or transcatheter, aim to improve oxygen saturation, affording definitive procedures at a later stage. Transcatheter interventions have been used before and after surgical palliative or definitive repair in children and adults. This review aims to provide an overview of the different catheter-based interventions for TOF across all age groups, with an emphasis on palliative interventions, such as patent arterial duct stenting, right ventricular outflow tract stenting, or balloon pulmonary valvuloplasty in infants and children and transcatheter pulmonary valve replacement in adults with repaired TOF, including the available options for a large, dilated native right ventricular outflow tract.

Early and Long-Term Clinical Outcomes of Ductal Stenting Versus Surgical Aortopulmonary Shunt Among Young Infants with Duct-Dependent Pulmonary Circulation

Surgical aortopulmonary shunting (SAPS) and ductal stenting (DS) are the main palliations in infants with cyanotic congenital heart diseases (CHD). We aimed to study the safety and efficacy of DS and to compare it with SAPS as a palliative procedure in infants with CHD and duct-dependent pulmonary circulation. Retrospective institutional clinical data review of consecutive infants aged < 3 months who underwent DS or SAPS over 5 years. The primary outcome was procedural success which was defined as event-free survival (mortality, need for re-intervention, procedural failure) at 30 days post-procedure. The secondary outcome was defined by a composite of death, major adverse cardiovascular events, or need for re-intervention at 6 months and on long-term follow-up. We included 102 infants (DS, n = 53 and SAPS, n = 49). The median age at DS and SAPS was 4 days (IQR 2.0-8.5) and 8 days (IQR 4.0-39.0), respectively. The median weight at intervention was 3.0 kg (IQR 3.0-3.0) and 3.0 kg (IQR 2.5-3.0) in the two respective arms. Tetralogy of Fallot with pulmonary atresia was the most common indication for DS and SAPS. The 30-day mortality was significantly higher in SAPS group as compared with DS group (p < 0.05). However, 30-day major adverse cardiac events (MACE) rates were similar in both groups (p = 0.29). DS was associated with shorter duration of mechanical ventilation, duration of stay in the intensive care and hospital stay than with SAPS. At 6 months, there was no significant difference in terms of mortality or event-free survival. Long-term MACE-free survival was also comparable (p = 0.13). DS is an effective and safer alternative to SAPS in infants with duct-dependent pulmonary circulation, offering reduced procedure-related mortality and morbidity than SAPS. Careful study of ductal anatomy is crucial to procedural success. However, long-term outcomes are similar in both procedures.

Catheter-based Interventions in Tetralogy of Fallot Across the Lifespan

Surgical treatment of tetralogy of Fallot (TOF) involves surgical relief of right ventricular outflow tract (RVOT) obstruction and closure of ventricular septal defect. However, some patients may require staged palliation before surgical repair. This traditionally was achieved only with surgery but recently evolved to include catheter-based techniques. RVOT dysfunction occurs inevitably after the surgical repair of TOF and, depending on the surgical approach, manifests as either progressive stenosis, regurgitation, or a combination of both. This predisposes the individual to repeated RVOT interventions with the attendant risks of multiple open-heart surgeries. The advent of transcatheter pulmonary valve replacement has reduced the operative burden, and the expansion of transcatheter pulmonary valve replacement device platforms has widened the type and size of RVOT anatomies that can be treated. This review will discuss the transcatheter therapies available throughout the lifespan of the patient with TOF.

Favourable Short- to Mid-Term Outcome after PDA-Stenting in Duct-Dependent Pulmonary Circulation

BACKGROUND

Stenting of patent ductus arteriosus (PDA) is a minimally invasive catheter-based temporary palliative procedure that is an alternative to a surgical shunt in neonates with duct-dependent pulmonary perfusion.

METHODS

An observational, single-centre, cross-sectional study of patients with duct-dependent pulmonary perfusion undergoing PDA-stenting as a stage I procedure and an analysis of short- to mid-term follow-up until a subsequent surgical procedure (stage II), with a focus on the interstage course.

RESULTS

Twenty-six patients were treated with PDA-stenting at a median (IQR) age of 7 (4-10) days; 10/26 patients (38.5%) (6/10 single pulmonary perfusion) were intended for later univentricular palliation, 16/26 patients (61.5%) (13/16 single pulmonary perfusion) for biventricular repair. PDA diameter was 2.7 (1.8-3.2) mm, stent diameter 3.5 (3.5-4.0) mm. Immediate procedural success was 88.5%. The procedure was aborted, switching to immediate surgery after stent embolisation, malposition or pulmonary coarctation in three patients (each n = 1). During mid-term follow-up, one patient needed an additional surgical shunt due to severe cyanosis, while five patients underwent successful catheter re-intervention 27 (17-30) days after PDA-stenting due to pulmonary hypo- (n = 4) or hyperperfusion (n = 1). Interstage mortality was 8.6% (2/23), both in-hospital and non-procedure-related. LPA grew significantly (p = 0.06) between PDA-stenting and last follow-up prior to subsequent surgical procedure (p = 0.06). RPA Z-scores remained similar (p = 0.22). The subsequent surgical procedure was performed at a median age of 106 (76.5-125) days.

CONCLUSIONS

PDA-stenting is a feasible, safe treatment option, with the need for interdisciplinary decision-making beforehand and surgical backup afterwards. It allows adequate body and pulmonary vessel growth for subsequent surgical procedures. Factors determining the individual patient's course should be identified in larger prospective studies.

Transcatheter Approaches to Palliation for Tetralogy of Fallot

To this day, controversy still exists regarding the optimal method to treat symptomatic neonates and infants with Tetralogy of Fallot (TOF). Symptomatic (severely cyanotic or ductal dependent) infants with TOF can undergo either a staged repair approach (consisting of initial palliation followed by complete repair) or primary repair. Traditionally, initial palliative procedures have been surgical, for example placement of a Blalock-Taussig-Thomas (BTT) shunt. Recent advances in technology have facilitated the introduction of catheter-based procedures as palliative techniques, for example, patent ductus arteriosus (PDA) stenting and right ventricular outflow tract (RVOT) stenting as more durable solutions than balloon pulmonary valvuloplasty (BPV). In this article, we discuss the rationale for these procedures, technical aspects of these procedures and outcomes data compared to traditional surgical procedures. Recent data have suggested that RVOT and PDA stenting procedures offer many advantages over traditional surgical palliative procedures as palliative methods in this patient population. This comes at a cost of increased reintervention burden, which may be considered part of the overall treatment strategy in smaller neonates and can be minimized with a focus on technical aspects and overall treatment strategies. Advanced surgical techniques are required at the eventual complete repair to negotiate removal of stent material and pulmonary artery reconstruction in some instances. Further adoption of catheter based palliative procedures for infants with symptomatic TOF has the potential to tip the outcomes towards favoring a staged approach, particularly in high-risk infants.

Microvascular and proteomic signatures overlap in COVID-19 and bacterial sepsis: the MICROCODE study

AIMS

Although coronavirus disease 2019 (COVID-19) and bacterial sepsis are distinct conditions, both are known to trigger endothelial dysfunction with corresponding microcirculatory impairment. The purpose of this study was to compare microvascular injury patterns and proteomic signatures in COVID-19 and bacterial sepsis patients.

METHODS AND RESULTS

This multi-center, observational study included 22 hospitalized adult COVID-19 patients, 43 hospitalized bacterial sepsis patients, and 10 healthy controls from 4 hospitals. Microcirculation and glycocalyx dimensions were quantified via intravital sublingual microscopy. Plasma proteins were measured using targeted proteomics (Olink). Coregulation and cluster analysis of plasma proteins was performed using a training-set and confirmed in a test-set. An independent external cohort of 219 COVID-19 patients was used for validation and outcome analysis. Microcirculation and plasma proteome analysis found substantial overlap between COVID-19 and bacterial sepsis. Severity, but not disease entity explained most data variation. Unsupervised correlation analysis identified two main coregulated plasma protein signatures in both diseases that strictly counteract each other. They were associated with microvascular dysfunction and several established markers of clinical severity. The signatures were used to derive new composite biomarkers of microvascular injury that allow to predict 28-day mortality or/and intubation (area under the curve 0.90, p < 0.0001) in COVID-19.

CONCLUSION

Our data imply a common biological host response of microvascular injury in both bacterial sepsis and COVID-19. A distinct plasma signature correlates with endothelial health and improved outcomes, while a counteracting response is associated with glycocalyx breakdown and high mortality. Microvascular health biomarkers are powerful predictors of clinical outcomes.