Recent advances in cardiac catheterization for congenital heart disease

Patient Screening for Self-Expanding Percutaneous Pulmonary Valves Using Virtual Reality

BACKGROUND

In recent years, self-expanding technology to treat pulmonary regurgitation in the native right ventricular outflow tract became Food and Drug Administration approved in the United States and is now routinely used. The current practice for selection of patients who are candidates for these devices includes screening for "anatomic fit," performed by each of the manufacturing companies. Our study aims to validate the use of virtual reality (VR) as a tool for local physician-led screening of patients.

METHODS AND RESULTS

This retrospective study from Children's Hospital Colorado included patients who underwent pulmonary valve replacement and had screening for a Harmony TPV or Alterra Prestent performed between September 2020 and January 2022. The data from the commercial companies' dedicated analysis for self-expanding transcatheter pulmonary valve frames evaluation with perimeter analysis were collected. VR simulation was performed blinded by 2 congenital interventional cardiologists using Elucis VR software and an Oculus Quest 2 headset. Among the 27 evaluated cases, the use of a self-expandable valve was recommended by companies' dedicated analysis in 23 cases (85.2%), by VR assessment in 26 cases (96.3), and finally implanted in 25 cases (92.6%). Regarding the level of agreement, both modalities (manufacturer and VR) were good at screening-in patients who received a self-expanding valve (100% versus 96.1%). When it came to screening-out the patients, VR presented good capacity to accurately classify nonsuitable patients (50% versus 100%).

CONCLUSIONS

Our institutional experience with VR transcatheter pulmonary valve implantation planning accurately predicted clinical outcomes. This paves the way for routine use of VR in patient selection for self-expanding valve technologies.

Multimodality 3D image fusion with live fluoroscopy reduces radiation dose during catheterization of congenital heart defects

Introduction

Imaging fusion technology is promising as it is radiation and contrast sparing. Herein, we compare conventional biplane angiography to multimodality image fusion with live fluoroscopy using two-dimensional (2D)-three-dimensional (3D) registration (MMIF2D-3D) and assess MMIF2D-3D impact on radiation exposure and contrast volume during cardiac catheterization of patients with congenital heart disease (CHD).

Methods

We matched institutional MMIF2D-3D procedures and controls according to patient characteristics (body mass index, age, and gender) and the seven procedure-type subgroups. Then, we matched the number of tests and controls per subgroup using chronological ordering or propensity score matching. Subsequently, we combined the matched subgroups into larger subgroups of similar procedure type, keeping subgroups with at least 10 test and 10 control cases. Air kerma (AK) and dose area product (DAP) were normalized by body weight (BW), product of body weight and fluoroscopy time (BW × FT), or product of body weight and number of frames (BW × FR), and stratified by acquisition plane and irradiation event type (fluoroscopy or acquisition). Three senior interventionists evaluated the relevance of MMIF2D-3D (5-point Likert scale).

Results

The Overall group consisted of 54 MMIF2D-3D cases. The combined and matched subgroups were pulmonary artery stenting (StentPUL), aorta angioplasty (PlastyAO), pulmonary artery angioplasty (PlastyPUL), or a combination of the latter two (Plasty). The FT of the lateral plane reduced significantly by 69.6% for the Overall MMIF2D-3D population. AKBW and DAPBW decreased, respectively, by 43.9% and 39.3% (Overall group), 49.3% and 54.9% (PlastyAO), and 36.7% and 44.4% for the Plasty subgroup. All the aforementioned reductions were statistically significant except for DAPBW in the Overall and Plasty (sub)groups. The decrease of AKBW and DAPBW in the StentPUL and PlastyPUL subgroups was not statistically significant. The decrease in the median values of the weight-normalized contrast volume (CMCBW) in all five subgroups was not significant. Cardiologists considered MMIF2D-3D very useful with a median score of 4.

Conclusion

In our institution, MMIF2D-3D overall enabled significant AKBW reduction during the catheterization of CHD patients and was mainly driven by reduced FT in the lateral plane. We observed significant AKBW reduction in the Plasty and PlastyAO subgroups and DAPBW reduction in the PlastyAO subgroup. However, the decrease in CMCBW was not significant.

Efficiency and Impact of Hypnoanalgesia for Cardiac Catheterisation in Paediatric Population

Hypnoanalgesia is a promising non-pharmacologic adjunct technique in paediatric interventions. Its safety, efficiency, and impacts on paediatric cardiac catheterisation (CC) are unknown.

METHODS

In a prospective study, patients aged <16 years who underwent CC under hypnoanalgesia from January to December 2021 were included. Pain and anxiety were assessed using the analgesia nociception index (ANI) and the visual analogue scale (VAS).

RESULTS

Sixteen patients were included; the mean age was 10.5 years, and the mean weight was 37 kg. Catheterisations were interventional in 10 patients (62.5%). Hypnoanalgesia indications were general anaesthesia (GA) contraindication in four patients (25.0%), the need for accurate pressure measurements in three patients (18.7%), and interventionist/patient preferences in nine (56.3%). CC was accomplished in 15 patients (93.7%), even in complicated cases. In one case, pulmonary artery pressures were normalised compared to previous catheterisation under local anaesthesia alone. The VAS score was under 5/10 for all patients. The ANI remained above 50 (no painful zone) for all but one patient. There was no significant decrease in the ANI during the intervention compared to the baseline (p = 0.62). No complications were reported.

CONCLUSION

Paediatric CC is feasible and safe under hypnoanalgesia, even in complicated cases. Hypnoanalgesia was efficient in managing pain and stress, and it ensures more reliable pressure measurements.

Diagnostic Reference Levels in Interventional Pediatric Cardiology: Two-Year Experience in a Tertiary Referral Hospital in Latin America

The goal of the present study was to propose the first local diagnostic reference levels (DRLs) for interventional pediatric cardiology procedures in a large hospital in Colombia. The data collection period was from April 2020 to July 2022. The local DRLs were calculated as the 3rd quartile of patient-dose distributions for the kerma-area product (Pka) values. The sample of collected clinical procedures (255) was divided into diagnostic and therapeutic procedures and grouped into five weight and five age bands. The Pka differences found between diagnostic and therapeutic procedures were statistically significant in all weight and age bands, except for the 1-5-year age group. The local DRLs for weight bands were 3.82 Gy·cm2 (<5 kg), 7.39 Gy·cm2 (5-<15 kg), 19.72 Gy·cm2 (15-<30 kg), 28.99 Gy·cm2 (30-<50 kg), and 81.71 Gy·cm2 (50-<80 kg), respectively. For age bands, the DRLs were 3.97 Gy·cm2 (<1 y), 9.94 Gy·cm2 (1-<5 y), 20.82 Gy·cm2 (5-<10 y), 58.00 Gy·cm2 (10-<16 y), and 31.56 Gy·cm2 (<16 y), respectively. In conclusion, when comparing our results with other existing DRL values, we found that they are similar to other centers and thus there is scope to continue optimizing the radiation dose values. This will contribute to establishing national DRLs for Colombia in the near future.

Cardiovascular Critical Care in Children

Pediatric cardiac critical care has evolved with advances in congenital heart surgery, interventional cardiac catheterization, and diagnostic advances. Debate remains over the optimal location of care and training background despite data showing that systems established in collaboration with multidisciplinary experts in the care of children with congenital heart disease are associated with the best outcomes. Operative mortality is low, and preventing morbidity is the new focus of the future. Advances in screening and fetal diagnosis, mechanical circulatory support, and collaborative research and quality improvement initiatives are reviewed in this article.

Role of CT in the Pre- and Postoperative Assessment of Conotruncal Anomalies

Conotruncal anomalies, also referred to as outflow tract anomalies, are congenital heart defects that result from abnormal septation of the great vessels' outflow tracts. The major conotruncal anomalies include tetralogy of Fallot, double-outlet right ventricle, transposition of the great arteries, truncus arteriosus, and interrupted aortic arch. Other defects, which are often components of the major anomalies, include pulmonary atresia with ventricular septal defect, pulmonary valve agenesis, aortopulmonary window, and double-outlet left ventricle. CT has emerged as a robust diagnostic tool in preoperative and postoperative assessment of various congenital heart diseases, including conotruncal anomalies. The data provided with multidetector CT imaging are useful for treatment planning and follow-up monitoring after surgery or intervention. Unlike echocardiography and MRI, CT is not limited by a small acoustic window, metallic devices, and need for sedation or anesthesia. Major advances in CT equipment, including dual-source scanners, wide-detector scanners, high-efficiency detectors, higher x-ray tube power, automatic tube current modulation, and advanced three-dimensional postprocessing, provide a low-risk, high-quality alternative to diagnostic cardiac catheterization and MRI. This review explores the various conotruncal anomalies and elucidates the role of CT imaging in their pre- and postoperative assessment. Keywords: CT, CT Angiography, Stents, Pediatrics © RSNA, 2022.

3D-printed heart models for hands-on training in pediatric cardiology - the future of modern learning and teaching?

BACKGROUND

This project aims to develop a new concept in training pediatric cardiologists to meet the requirements of interventional cardiac catheterizations today in terms of complexity and importance. This newly developed hands-on training program is supposed to enable the acquisition of certain skills which are necessary when investigating and treating patients in a catheter laboratory.

METHODS

Based on anonymous CT-scans of pediatric patients' digital 3D heart models with or without cardiac defects were developed and printed three-dimensionally in a flexible material visible under X-ray. Hands-on training courses were offered using models of a healthy heart and the most common congenital heart defects (CHD). An evaluation was performed by quantifying fluoroscopy times (FL-time) and a questionnaire.

RESULTS

The acceptance of theoretical and practical contents within the hands-on training was very positive. It was demonstrated that it is possible to master various steps of a diagnostic procedure and an intervention as well as to practice and repeat them independently which significantly reduced FL-time. The participants stated that the hands-on training led to more confidence in interventions on real patients.

CONCLUSION

With the development of a training module using 3D-printed heart models, basic and advanced training in the field of diagnostic cardiac examinations as well as interventional therapies of CHD is possible. The learning effect for both, practical skills and theoretical understanding, was significant which underlines the importance of integrating such hands-on trainings on 3D heart models in education and practical training.

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.

Catheter strategy to ease the procedure and reduce radiation exposure when requiring neck access

Objectives

To assess the potential occupational radiation reduction and technical feasibility in patients rotated 180° (upside-down) when requiring neck access for transcervical or trans-subclavian catheterisation.

Methods

Upside-down positioning is defined as rotating patients in supine position by 180°, so that the feet come to rest where the head would otherwise be. We retrospectively evaluated all these procedures performed between March 2016 and May 2019. Furthermore, two different phantoms (paediatric and adult) were used prospectively to quantify the occupational dose between conventional or upside-down positioning. In this context, ambient dose equivalents were measured using real-time dosimeters. Three different projection angles were applied.

Results

44 patients with median age and body weight of 1.0 year (range 0–56) and 9.5 kg (range 1.3–74.3) underwent 63 procedures positioned upside-down. This position proved advantageous for practical reasons, since the length of the examination table could be optimally used. Additionally, it resulted in a significantly lower overall ambient dose equivalent for the primary operator (PO) of 94.8% (mean: 2569±807 vs 135±23 nSv; p<0.01) in the adult, and of 65.5% (mean: 351±104 vs 121±56 nSv; p<0.01) in the paediatric phantom, respectively.

Conclusion

Upside-down positioning facilitates handling in a straightforward manner when access from the neck is required. Moreover, it significantly reduces local radiation exposure for the PO in the paediatric and, most impressively, in the adult phantom.

Frequency of thyroid dysfunction in pediatric patients with congenital heart disease exposed to iodinated contrast media - a long-term observational study

Background The thyroid gland of patients with congenital heart disease may be exposed to large doses of iodine from various sources. We assessed the thyroid response after iodine exposure during conventional angiography in cardiac catheterization and angiographic computer tomography in childhood. Methods Retrospective mid- to long-term follow-up of 104 individuals (24% neonates, 51% infants, 25% children) with a median age and body weight of 104 days [0-8 years] and 5.3 kg [1.6-20]. Serum levels of thyroid-stimulating hormone, free triiodthyronine and free thyroxine were evaluated at baseline and after excess iodine. We also assessed risk factors that may affect thyroid dysfunction. Results Baseline thyroidal levels were within normal range in all patients. The mean cumulative iodinate contrast load was 6.6 ± 1.6 mL/kg. In fact, 75% had experienced more than one event involving iodine exposure, whose median frequency was three times per patient [1-12]. During the median three years follow-up period [0.5-10], the incidence of thyroid dysfunction was 15.4% (n=16). Those patients developed acquired hypothyroidism (transient n=14, long-lasting n=2 [both died]) with 10 of them requiring temporary replacement therapy for transient thyroid dysfunction, while four patients recovered spontaneously. 88 individuals (84.6%) remained euthyroid. Repeated cardiac interventions, use of drugs that interfere with the thyroid and treatment in the intensive care unit at the index date were strong predictors for acquired thyroid dysfunction. Conclusions The incidence of acquired hypothyroidism after iodine excess was 15.4%. However, most patients developed only transient hypothyroidism. Systemic iodine exposure seems to be clinically and metabolically well tolerated during long-term follow-up.

Predicting the Future: Tetralogy of Fallot Will Be Primarily Treated with Catheter Based Intervention Within Two Decades. Surgeon's Perspective

Interventional cardiology has made extraordinary advances over recent years, but most are still limited to addressing single intracardiac or valvular lesions. This debate considers whether complete interventional repair of more complex congenital defects might become achievable. Tetralogy of Fallot (ToF) is probably the first candidate where complete interventional repair might be achieved-given that various components of the defect have already been successfully addressed-albeit as either a palliative intervention (RVOT stenting) or to address the sequelae of standard surgery (percutaneous PVR). This article considers the challenges that would need to be overcome in terms of the morphology of the condition, the age limitations, and the necessary technological advancements that would be required-while setting these against the benchmark of current surgical outcomes and the parallel progress that is being developed in surgical correction. While complete interventional repair of ToF may still be beyond current techniques, a hybrid approach between surgeons and intentional cardiologists can strive to create a life-long paradigm of care that minimizes the need for surgery and focuses on the maintenance of a healthy right ventricle, such that patients born with ToF can achieve normal life expectancy.

Interventional Treatment of Cardiac Emergencies in Children with Congenital Heart Diseases

Cardiac emergencies in children represent an extremely important issue in medical practice. In general, interventional treatment could be optional in many situations, however it can be indicated in emergency conditions. There are many diseases at pediatric age that can benefit from interventional treatment, thus reducing the surgical risks and subsequent complications. Balloon atrioseptostomy, patent ductus arteriosus (PDA) closure, percutaneous or hybrid closure of a ventricular septal defect, pulmonary or aortic valvuloplasty, balloon angioplasty for aortic coarctation, implantation of a stent for coarctation of the aorta, for severe stenosis of the infundibulum of the right ventricle, or for PDA correction are among the procedures that can be performed in emergency situations. This review aims to present the current state of the art in the field of pediatric interventional cardiology.