Innovative interventional catheterization techniques for congenital heart disease

Use of Hybrid Stage I to Stratify Between Single Ventricle Palliation and Biventricular Repair

Background: Hybrid stage I palliation (HS1P) has been utilized for patients with single ventricle (SV) congenital heart disease (CHD). To date, reports on the use of HS1P for other indications including biventricular (BiV) CHD have been limited. Methods: We performed a single-center retrospective cohort study of patients who underwent HS1P with an anticipated physiologic outcome of BiV repair, or with an undetermined SV versus BiV outcome. Patient characteristics and outcomes from birth through definitive repair or palliation were collected and reported with descriptive statistics. Results: Nineteen patients underwent HS1P with anticipated BiV repair. Extracardiac and intracardiac risk factors (ICRF) were common. Ultimately, 13 (68%) patients underwent BiV repair, 1 (5%) underwent SV palliation, and 5 (26%) died prior to further palliation or repair. Resolution of ICRF tracked with BiV outcome (6/6, 100%), persistence of ICRF tracked with SV outcome or death (3/3, 100%). Twenty patients underwent HS1P with an undetermined outcome. Ultimately, 13 (65%) underwent BiV repair, 6 (30%) underwent SV palliation, and 1 (5%) underwent transplant. There were no deaths. Intracardiac risk factors were present in 15 of 20 patients (75%); BiV repair only occurred when all ICRF resolved (67%). Post-HS1P complications and reinterventions occurred frequently in both groups, through all phases of care. Conclusions: Hybrid stage 1 palliation can be used to defer BiV repair and to delay decision between SV palliation and BiV repair. Resolution of ICRF was associated with ultimate outcome. In this high-risk group, complications are common, and mortality especially in the marginal BiV patient is high.

Early diagnosis and targeted approaches to pulmonary vascular disease in bronchopulmonary dysplasia

Pulmonary hypertension has emerged as a life-threatening disease in preterm infants suffering from bronchopulmonary dysplasia (BPD). Its development is closely linked to respiratory disease, as vasculogenesis and alveologenesis are closely interconnected. Once clinically significant, BPD-associated pulmonary hypertension (BPD-PH) can be challenging to manage, due to poor reversibility and multiple comorbidities frequently associated. The pulmonary vascular disease process underlying BPD-PH is the result of multiple innate and acquired factors, and emerging evidence suggests that it progressively develops since birth and, in certain instances, may begin as early as fetal life. Therefore, early recognition and intervention are of great importance in order to improve long-term outcomes. Based on the most recent knowledge of BPD-PH pathophysiology, we review state-of-the-art screening and diagnostic imaging techniques currently available, their utility for clinicians, and their applicability and limitations in this specific population. We also discuss some biochemical markers studied in humans as a possible complement to imaging for the detection of pulmonary vascular disease at its early stages and the monitoring of its progression. In the second part, we review pharmacological agents currently available for BPD-PH treatment or under preclinical investigation, and discuss their applicability, as well as possible approaches for early-stage interventions in fetuses and neonates. IMPACT: BPD-associated PH is a complex disease involving genetic and epigenetic factors, as well as environmental exposures starting from fetal life. The value of combining multiple imaging and biochemical biomarkers is emerging, but requires larger, multicenter studies for validation and diffusion. Since "single-bullet" approaches have proven elusive so far, combined pharmacological regimen and cell-based therapies may represent important avenues for research leading to future cure and prevention.

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.

Transpulmonary Stent Implantation for Dysplastic Pulmonary Valve Stenosis with a Single Left Coronary Ostium and Anomalous Prepulmonary Right Coronary Artery in an English Bulldog

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Coronary artery anomalies may exist with congenital PS.

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PS occurs in both animals and humans.

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Transpulmonary stenting may be considered in dogs with PS and coronary anomalies.

Real-time 3T MRI-guided cardiovascular catheterization in a porcine model using a glass-fiber epoxy-based guidewire

PURPOSE

Real-time magnetic resonance imaging (MRI) is a promising alternative to X-ray fluoroscopy for guiding cardiovascular catheterization procedures. Major challenges, however, include the lack of guidewires that are compatible with the MRI environment, not susceptible to radiofrequency-induced heating, and reliably visualized. Preclinical evaluation of new guidewire designs has been conducted at 1.5T. Here we further evaluate the safety (device heating), device visualization, and procedural feasibility of 3T MRI-guided cardiovascular catheterization using a novel MRI-visible glass-fiber epoxy-based guidewire in phantoms and porcine models.

METHODS

To evaluate device safety, guidewire tip heating (GTH) was measured in phantom experiments with different combinations of catheters and guidewires. In vivo cardiovascular catheterization procedures were performed in both healthy (N = 5) and infarcted (N = 5) porcine models under real-time 3T MRI guidance using a glass-fiber epoxy-based guidewire. The times for each procedural step were recorded separately. Guidewire visualization was assessed by measuring the dimensions of the guidewire-induced signal void and contrast-to-noise ratio (CNR) between the guidewire tip signal void and the blood signal in real-time gradient-echo MRI (specific absorption rate [SAR] = 0.04 W/kg).

RESULTS

In the phantom experiments, GTH did not exceed 0.35°C when using the real-time gradient-echo sequence (SAR = 0.04 W/kg), demonstrating the safety of the glass-fiber epoxy-based guidewire at 3T. The catheter was successfully placed in the left ventricle (LV) under real-time MRI for all five healthy subjects and three out of five infarcted subjects. Signal void dimensions and CNR values showed consistent visualization of the glass-fiber epoxy-based guidewire in real-time MRI. The average time (minutes:seconds) for the catheterization procedure in all subjects was 4:32, although the procedure time varied depending on the subject's specific anatomy (standard deviation = 4:41).

CONCLUSIONS

Real-time 3T MRI-guided cardiovascular catheterization using a new MRI-visible glass-fiber epoxy-based guidewire is feasible in terms of visualization and guidewire navigation, and safe in terms of radiofrequency-induced guidewire tip heating.

Anesthesia for high-risk procedures in the catheterization laboratory

Recent advances in catheterization and imaging technology allow for more complex procedures to be performed in the catheterization laboratory. A number of lesions are now amenable to a percutaneous procedure, eliminating or at least postponing the need for a surgical intervention. Due to the increase in the complexity of the procedures performed, the involvement of anesthesiologists and their close collaboration with the interventional cardiologists have increased. It is important to understand the physiology and pathophysiology of the patients and to anticipate the plans and the potential complications in order to manage them. We are witnessing a rise in the number of complex interventions in newborns and infants, such as balloon valvotomy (critical aortic stenosis, pulmonary stenosis), radio frequency perforation (of pulmonary atresia and intact ventricular septum), right ventricular outflow tract stenting (in Tetralogy of Fallot), ductal stenting (in some ductus-dependent pulmonary circulation), and combined with a surgical procedure (hybrid procedure for hypoplastic left heart syndrome). Multiple registries have been created in order to understand and improve outcomes of patients with congenital heart disease undergoing catheterization procedures and to develop performance and quality metrics, from which data regarding anesthetic-related risks can be extrapolated. Experienced personnel and a multidisciplinary team approach with direct communication among the team members is a must to ensure anticipation and management of critical events when they occur.