Congenital Heart Interventions

Extended Rhythm Monitoring to Assess for Ventricular Arrhythmias After Transcatheter Pulmonary Valve Replacement with the Harmony Valve. Yang JK, Wattenbarger L, Taylor AC, Chubb H, Romfh AW, Peng LF, Ceresnak SR, Dubin AM, McElhinney DB.  Circ Cardiovasc Interv. 2025 Jan;18(1):e014381. doi: 10.1161/CIRCINTERVENTIONS.124.014381. Epub 2024 Dec 27. PMID: 39727055 Commentary by: Dr. Konstantin Averin (Cohen Children’s Heart Center), catheterization section editor of Pediatric Cardiology Journal Watch: Take-home Points: Non-sustained ventricular tachycardia (NSVT) and ventricular ectopy are common immediately after Harmony TPVR, occurring in 50% of patients. However, these arrhythmias are typically infrequent, diminish rapidly after the procedure, and in most cases do not persist beyond the first few days post-discharge. At mid-term follow-up around 22 months, the incidence of NSVT on ambulatory monitoring returned to pre-procedural baseline levels (14%) and no patients experienced major arrhythmic events or sudden death after hospital discharge. Factors associated with early post-TPVR ventricular arrhythmias included substantial device-myocardial contact, pre-existing rhythm abnormalities, and a diagnosis of pulmonary stenosis or pulmonary atresia with intact ventricular septum.  Most patients started on new antiarrhythmic medications post-procedure were able to discontinue them by 2.5 months. In this study, Yang et al. examine ventricular arrhythmias in patients undergoing transcatheter pulmonary valve replacement (TPVR) with the Harmony valve.  This study builds upon their prior work evaluating immediate post-procedural arrhythmias and extends follow-up beyond hospital discharge using extended rhythm monitoring (ERM).   Between September 2017 and February 2024, 54 patients underwent TPVR with the Harmony valve (50% male) with 72% having Tetralogy of Fallot and the rest either pulmonary valve stenosis (PS) or pulmonary atresia with intact ventricular septum (PA-IVS).  Non-sustained ventricular tachycardia (NSVT) and ventricular ectopy were common immediately post-TPVR, occurring in 50% of patients, but were typically infrequent and diminished rapidly.  On discharge ERM, NSVT was detected in 37% but nearly all episodes occurred within the first 5 days.  Only 15% had NSVT beyond 5 days post-discharge.  On follow-up ERM at a median of 22 months, infrequent NSVT was noted in only 14% of patients, like the pre-procedural incidence.  No patients experienced major arrhythmic events after discharge.  Factors associated with early post-procedural NSVT included substantial myocardial contact of the device, pre-existing rhythm abnormalities, and underlying diagnosis of PS/PA-IVS rather than TOF. This study provides important insights into the natural history of peri-procedural ventricular arrhythmias following Harmony TPVR. Although quite frequent immediately post-implant, these arrhythmias appear to be self-limited in most patients without major clinical sequelae.  The incidence returns to baseline by mid-term follow-up without an apparent increased risk of malignant arrhythmias.  The clinical implications are reassuring for this emerging therapy.  Peri-procedural NSVT, while common, should not necessarily be viewed as a harbinger of poor outcomes and conservative management appears appropriate in most cases.  Antiarrhythmic medications, while frequently initiated, were discontinued in the majority by 2.5 months. However, important questions remain.  The exact mechanism of these arrhythmias, likely related to contact irritation, requires further study.  Moreover, the lack of apparent clinical impact in the first 1-2 years does not preclude the possibility of device-related pro-arrhythmia emerging over longer-term follow-up. Certain high-risk subsets, such as those with pre-existing VT, may benefit from a more aggressive approach.   Larger, prospective studies with systematic monitoring protocols and longer-term follow-up are needed to fully delineate the prognostic implications of post-TPVR ventricular arrhythmias.  Nonetheless, the authors should be commended for this detailed arrhythmia assessment which enhances our understanding of this increasingly utilized therapy.  Their data provide a measure of reassurance regarding the early and mid-term risk of malignant arrhythmias following Harmony TPVR.

Response of health-related quality of life following pediatric/congenital cardiac catheterization procedures O'Byrne ML, Sharma P, Huang J, Smith CL, Tang J, Callahan R, Edelson JB, Dori Y, Gillespie MJ, Rome JJ, Glatz AC. Am Heart J. 2024 Dec 4;281:71-83. doi: 10.1016/j.ahj.2024.11.017. Online ahead of print. PMID: 39643098 Commentary by: Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch: Take-home Points: Investigation of the outcomes of transcatheter interventions has thus far focused on technical success and procedural safety.  This study suggests that cardiac catheterizations (especially interventional procedures for simple congenital heart disease) have the potential to improve patient and family quality of life. Further multi center studies to better understand psychosocial outcomes in the extremely vulnerable congenital and acquired heart disease population are needed to better understand how to support these patients and families. Studies on the outcomes of pediatric and congenital cardiac catheterization lab (PCCL) procedures have historically focused on technical success and safety. However, these studies do not capture the impact of PCCL procedures on patient symptoms, exertional capacity, or psychological stress that play a large role in overall quality of life. Health related quality of life (HRQOL) is a patient-reported metric (PRM) that measures an individual’s ability to participate in age-appropriate activities and derive satisfaction from them. It is known the children with heart disease have lower HRQOL compared with healthy controls. However, the impact of procedures on HRQOL in symptomatic children has not been studied. A single center prospective cohort study over a 5-year period (2017-2022) screened 530 patients (age 8-18) and parents of which 70 consented and met inclusion criteria. Review of the patients’ medical record was used to obtain clinical data. HRQOL and other PRM (collected to provide insight into potential covariates for HRQOL) were obtained at baseline, with HRQOL also obtained within 24 hours of the procedure, 30 ± 7 days, and 90 ± 14 days using the Pediatric Cardiac Quality of Life Index (PCQLI) and Pediatric Quality of Life Index (PEDSQL) total scores score. The HRQOL surveys were answered by both patients and parents. Other clinical factors the others suspected would influence HRQOL independently outside of the catheterization were also collected (including cardiac diagnosis, which was described as simple unrepaired shunt lesion, simple biventricular repair, complex biventricular repair, single ventricle palliation, s/p heart transplant, pulmonary hypertension, and other diagnoses). Of the 70 patients in the study, 54% underwent diagnostic catheterizations, 29% were asymptomatic and underwent interventions, and 17% were symptomatic and underwent interventions. Those who underwent diagnostic catheterizations were more likely to be s/p heart transplant, have pulmonary hypertension, or to have undergone single ventricle palliation while those undergoing interventional procedures were more likely to have unrepaired simple shunts (such as an ASD or PDA) and complex biventricular CHD. In the interventional group, those with more complicated forms of CHD were more likely to be symptomatic. There were not any significant differences in baseline PCQLI and immediate post catheterization. In those undergoing diagnostic catheterizations, there was a modest trend towards higher PCQLI, though this was not statistically significant. In those who underwent an intervention, patient PCQLI increased significantly from baseline to 3 months post procedure, though this was not seen in the parent/guardian surveys. Interestingly, the increase was more prevalent in those who were asymptomatic at baseline, both in patient and parent/guardian surveys. The PEDSQL scores generally increased from baseline to follow up in both the patient and parent surveys.  This study is the first to investigate the impact of cardiac catheterizations on quality of life in children with heart disease. While not all surveys showed statistical significance and there was some discrepancy in patient and parent surveys, this study suggests improvement in quality-of-life metrics in those undergoing interventional procedures. While this is encouraging, the number of patients in this study is inadequate to draw broad sweeping conclusions, especially given that we care for such a homogenous patient population. While this study was not able to achieve recruitment levels sufficient to provide robust statistical data, it should serve as a beginning for the interventional pediatric cardiology community to recognize that while evaluating outcomes (how well we are doing) is important it does not tell the whole picture. We should also strive to understand how our procedures impact our patients’ quality of life (how well they are doing). Until we understand this we will not be able to provide the best psychosocial support possible for this vulnerable patient population and their families.

Revisiting the Role of Balloon Atrial Septostomy Prior to the Arterial Switch Operation Subramanian S, Jani S, Well A, Mikulski MF, Agrawal H, Byron Holt D, Venardos N, Mery CM, Fraser CD Jr.World J Pediatr Congenit Heart Surg. 2024 Nov;15(6):746-752. doi: 10.1177/21501351241252428. Epub 2024 Aug 9.PMID: 39119670 Commentary by: Dr. Milan Prsa (Switzerland, Europe), section editor of Congenital Heart Disease Interventions Journal Watch : Take-home Points: Balloon atrial septostomy does not ensure successful weaning off prostaglandin and may delay the arterial switch operation in neonates with dextro-transposition of the great arteries. Early arterial switch operation with prostaglandin support should be reconsidered as a more efficient strategy. This retrospective, single-center study investigated the common practice of performing balloon atrial septostomy (BAS) in neonates with dextro-transposition of the great arteries (d-TGA) prior to the arterial switch operation (ASO). The analysis included 30 patients who underwent ASO between July 2018 and March 2023, comparing outcomes between those who received BAS (n=22) and those who did not (n=8).  Key variables such as pre-operative oxygen saturation (SpO2), near-infrared spectroscopy (NIRS) readings, prostaglandin (PGE) status, and post-operative outcomes were evaluated. BAS significantly improved SpO2 levels (median increase from 83% to 87%, p=0.007). However, there was no corresponding improvement in cerebral or renal NIRS readings, suggesting the increased SpO2 did not enhance oxygen delivery to vital organs. A notable proportion of patients in the BAS group (27%, 6 out of 22) could not be weaned off PGE, and 62% (10 out of 16) required PGE re-initiation, often within 24 hours of BAS. The median age at ASO was significantly higher in the BAS group (8 days) compared to the no-BAS group (4 days, p=0.016). Additionally, the BAS group showed a trend toward longer hospital stay (median 13 days vs. 10 days in the no-BAS group). Two patients (9%) in the BAS group developed low cardiac output syndrome post-ASO, while no such complication was observed in the no-BAS group. The study’s retrospective, single-center design, small sample size, and potential selection bias may limit the generalizability of the findings. However, the results provide important insights that challenge the routine use of BAS in the preoperative management of d-TGA. This study suggests that early ASO with prostaglandin support may be a safer and more efficient alternative to BAS. While a prospective, multi-center study would be needed to establish a definitive best practice, these findings encourage a re-evaluation of BAS as a standard preoperative intervention for newborns with d-TGA.

Pre-Fontan Assessment Utilizing Combined Cardiac Catheterization and Cardiac MRI: Comparison to the Pre-Fontan Catheterization. Eilers LF, Britt JJ, Weigand J, Penny DJ, Gowda ST, Qureshi AM, Stapleton GE, Khan A, Webb MK, Bansal M.Pediatr Cardiol. 2024 Oct;45(7):1448-1454. doi: 10.1007/s00246-023-03178-x. Epub 2023 May 21.PMID: 37210685 Commentary by: Dr. Subhrajit Lahiri (Oklahoma City, OK), section editor of Congenital Heart Disease Interventions Journal Watch Take-home Points: Combined Cardiac MRI and Catheterization Streamlines Pre-Fontan Assessment. Combined Protocol Reduces Procedure and Fluoroscopy Time. Lower Rate of Additional Interventions with Combined Approach. Authors begin stating the established practice and variation of routine cardiac catheterization or cardiac MRI or both prior to Fontan surgery to risk stratify patients. At Texas Children’s Hospital the standard practice was to obtain only cardiac catheterization followed by new practice of cardiac MRI followed by cardiac catheterization on the same day under same anesthesia. The authors enlist their MRI protocol. For cardiac catheterization, standard angiograms for patients who did not have cardiac MRI prior to cardiac catheterization included superior vena cava, inferior vena cava, ascending aorta, descending aorta, and pulmonary vein(s). In patients in the combined group, an angiogram was routinely performed in the superior vena cava. An aortic root angiogram was performed at the discretion of the interventional cardiologist. The cath lab at TCH is connected to the MRI suite through a “barn-door” through which the patient can be slid in from MRI suite to cath lab. There were 37 patients in the combined MRI and cath group and 40 in the cath only group. As expected, patients who underwent combined procedure had prolonged anesthesia time and intubation time. The combined group had significantly less in-lab time, cath procedure time, contrast dose, and fluoroscopy time. As shown in the table, a significantly higher number of interventions were performed during catheterization in the catheterization-only group. In the combined group, 7 out of 37 procedures (19%) involved at least one intervention, whereas in the catheterization-only group, 19 out of 40 procedures (48%) included an intervention (p = 0.008). The interventional procedures in the combined group consisted of two aortopulmonary collateral occlusions, four veno-venous collateral occlusions, one pulmonary artery angioplasty, and one internal jugular vein angioplasty. The interventional procedures in the catheterization-only group included 11 aortopulmonary collateral occlusions, four venovenous collateral occlusions, one pulmonary artery angioplasty, one main pulmonary artery test occlusion, three coarctation stent angioplasties, and one pulmonary vein stent angioplasty. In this group, aortopulmonary collateral occlusions were performed based on a subjective assessment of high collateral burden observed on angiography. Without objective data from MRI, the decision to occlude aortopulmonary collaterals was dependent on the operator's judgment. Of note, the Fontan outcomes did not differ between two groups.  Combined(n = 37)Catheterization only(n = 40)P valueAge (months)48 [42–63]48 [42–60.2].984Weight (kg)15.6[14.3–19.7]15.3 [13.7–17.6].335Anesthesia time (min)320 [290–352]200 [165–255] < 0.001Intubation time (min)293 [51]193 [73] < 0.001In-lab time (min)156 [125–187]194 [160–248]0.002Catheterization procedure time (min)70 [51–97]114 [79–155] < 0.001Contrast dose (mL/kg)1.7 [0.8–2.5]3.8 [2.7–4.9] < 0.001Radiation exposure (cGy x cm2)86 [47.5–159]114 [80–159]0.090Fluoroscopy time (min)20.4 [10–27]26 [17–44]0.013Associated intervention (%)7 [19]19 [48]0.008 Comments: Worldwide, there has been a shift toward obtaining cardiac MRI before Fontan surgery in patients with single ventricle physiology. In fact, some studies have recommended MRI alone, without catheterization, before Fontan. However, most centers, including ours, are yet to be convinced that MRI can fully replace catheterization for risk stratifying single ventricle patients. This study highlights the benefits of MRI prior to catheterization—reducing the number of interventions and shortening catheterization time. A major contributing factor was the assessment of aortopulmonary (AP) collateral burden, which significantly impacts time and resource utilization in pre-Fontan catheterization. However, the downside of this approach is prolonged anesthesia time. An ideal solution would be an MRI-guided catheterization, utilizing MRI for cine angiograms and AP collateral burden assessment. The challenge lies in safely occluding AP collaterals in an MRI suite with MRI-compatible coils while accurately defining their anatomy to ensure safe closure. Until this becomes feasible, a shorter MRI protocol and rapid transport from the MRI suite to the cath lab could help minimize anesthesia exposure and total procedure duration. As more centers adopt pre-Fontan cardiac MRI, this process will likely be refined further. Additionally, MRI can sometimes aid in deciding between a biventricular and single ventricle approach in borderline cases.

Multicenter Pivotal Study of the Alterra Adaptive Prestent for the Treatment of Pulmonary Regurgitation. Dimas VV, Babaliaros V, Kim D, Lim DS, Morgan G, Jones TK, Armstrong AK, Berman D, Aboulhosn J, Mahadevan VS, Gillespie MJ, Balzer D, Zellers T, Yu X, Shirali G, Parthiban A, Leipsic J, Blanke P, Zahn E, Shahanavaz S. JACC Cardiovasc Interv. 2024 Oct 14;17(19):2287-2297. doi: 10.1016/j.jcin.2024.07.036.PMID: 39415386 Commentary by: Dr. Jonathon Hagel (C.S. Mott Children’s Hospital, University of Michigan) Take-home Points: The Alterra Adaptive Prestent in conjunction with the 29mm Sapien 3 THV has shown excellent valve function with 92.5% of patients demonstrating mild or less pulmonary regurgitation at 2 years  The present and valve were successfully implanted in 98.3% of patients during a single procedure with no deaths, coronary compression or device embolization reported through 2 years The Alterra/Sapien 3 system led to improved RV volumes and function, a sustained reduction in PR and high rates of NYHA Class I functional status at follow-up Pulmonary regurgitation (PR) is a common problem in patients with dilated right ventricular outflow tracts (RVOT) after previous surgical or transcatheter intervention for congenital heart disease.  Particularly after repair of tetralogy of Fallot, transcatheter pulmonary valve replacement (TPVR) has historically been challenging because native RVOTs are highly variable in size and shape without a well-defined landing zone making it difficult to anchor a balloon expandable valve. The Alterra Adaptive Prestent was specifically designed to reshape the RVOT to create a stable landing zone for a 29 mm Sapien 3 transcatheter heart valve (THV), extending TPVR eligibility to a broader patient population. The Alterra pivotal trial was a prospective, single-arm, multicenter trial conducted at 11 U.S. centers between August 2017 and September 2019. Sixty patients with moderate or greater PR underwent implantation of the Alterra prestent followed by Sapien 3 THV. The primary endpoint was THV dysfunction at 6 months, defined as need for RVOT/PV reintervention, moderate or greater total PR and moderate or greater RVOT/PV stenosis (gradient ≥35 mmHg on echocardiography). Secondary endpoints included improvement in PR at 30 days and safety measures (mortality, major complications, and device integrity). Patients were followed for 2 years with imaging (echocardiography, CT, MRI) and clinical evaluation. Of 97 patients screened, 61 were enrolled and 60 underwent the procedure with 59/60 undergoing Alterra prestent and Sapien 3 implantation in a single-stage procedure. One patient required a staged procedure to allow prestent endothelialization due to proximal migration of the prestent within the RVOT. Two patients required valve-in-valve placement during the index procedure for severe PR. No explantations or deaths occurred within 24 hours of implantation. At 2 years, 92.5% of patients had mild or less PR, there were no deaths, coronary compression or endocarditis reported. There was one case of reintervention due to RVOT obstruction successfully managed with a stent and Sapien 3 THV. Twenty-two patients experienced arrhythmia with 21 occurring within 24 hours of the procedure, 12 of which were non-sustained ventricular tachycardia that was medically managed and only 3 patients remained on antiarrhythmic medications beyond 6 months. All patients remained NYHA class I or II throughout follow-up with 93% remaining functional class I.  The Alterra Adaptive Prestent, paired with the 29mm Sapien 3 THV, successfully addresses the anatomical variability of the native RVOT, offering a safe and effective transcatheter solution for patients with severe pulmonary regurgitation. Long-term surveillance will be critical to evaluate durability, arrhythmias, and monitor for potential coronary compression with repeat interventions, but the 2-year results are highly encouraging, confirming the system’s role in expanding transcatheter therapy options for patients with dysfunctional RVOTs.

Thromboelastography-guided Intraoperative Platelet Transfusion in Pediatric Heart Surgery. Emani S, Donahue R, Callender A, Ghebremichael M, Nathan M, Ibla JC, Emani S.Ann Thorac Surg. 2024 Dec;118(6):1271-1278. doi: 10.1016/j.athoracsur.2024.09.003. Epub 2024 Sep 12.PMID: 39277157 Commentary By: David Preston, DO Children’s Medical Center, Dallas TX Take Home Points What is already knownIntraoperative viscoelastic testing in pediatric cardiac surgery can assist in targeted blood product transfusion to reduce post-operative bleeding complications. What this study adds A TEG-MA-driven calculator of appropriate platelet transfusion volume enables a patient-specific approach to platelet transfusion after cardiopulmonary bypass. A target TEG-MA of at least 45mm in conjunction with a fibrinogen level >190mg/dL was determined to be ideal to minimize risk of post-operative bleeding. Incorporating a calculator utilizing viscoelastic testing into an overall transfusion algorithm has the potential for more effective and responsible transfusion practices. Navigating the balance of hemostasis with appropriate blood product utilization is a critical task for the pediatric cardiac anesthesiologist.  The use of viscoelastic testing has allowed a more targeted approach to product transfusion after cardiopulmonary bypass (CPB).1 This study from Boston Children’s Hospital presents the validation of a TEG-MA-guided platelet transfusion calculator to decrease post-operative bleeding complications after CPB.2 Summary of the Study The authors conducted a single center retrospective analysis of patients 18 years or younger who underwent procedures involving CPB at Boston Children’s Hospital.  Notably, patients who received any cryoprecipitate, fresh frozen plasma (FFP), or factor VIIa during the perioperative period were excluded.  Thromboelastography maximum amplitude (TEG-MA) data during both the rewarming phase of CPB and on arrival to the ICU were evaluated in conjunction with the volume of platelets administered after CPB.  Post-operative bleeding was defined as the administration of any blood products or surgical re-exploration for bleeding within 24 hours.  The incidence of any thrombotic events was followed for the duration of the hospitalization.  The calculated volume of platelets required to achieve a TEG-MA of at least 45mm and less than 60mm was compared with the actual administrated volume of platelets during the case in order to classify each patient as under-transfused or over-transfused. A total of 1000 cases over a 22-month period were evaluated.  Comparison of calculator-predicted TEG-MA values (based on warming TEG-MA values and platelet transfusion volume) with actual post-operative TEG-MA values revealed a moderate correlation of the TEG-MA calculator with actual post-operative values (Pearson r = 0.7). Plotting post-operative bleeding percentages against post-operative TEG-MA values revealed an optimal TEG-MA of at least 45mm to prevent post-operative bleeding complications. The factors independently associated with post-operative bleeding complications were a TEG-MA < 45mm, an administered platelet volume determined as an undertransfusion (calculated resultant TEG-MA <45mm based on volume of platelets administered), and a fibrinogen level of <190mg/dL.  In multivariate analysis, there was no association of a TEG-MA value with post-operative thrombotic complications.  The authors acknowledge both the modesty of the association achieved with the platelet calculator as well as the multifactorial nature of post-operative bleeding and thrombotic events complicating this analysis. What Does This Mean for Our Practice? Algorithms utilizing viscoelastic testing during CPB to guide post-CPB transfusion practices are common.3,4 However, the development of a calculator to dictate a platelet volume based on a goal viscoelastic parameter adds a new layer of elegance and precision to transfusion practice.  The ability to calculate an exact platelet volume necessary to correct coagulopathy and minimize the risk of post-operative bleeding presents an opportunity to spare the neonate or small infant from unnecessary hemodilution from over-transfusion of platelets and minimize their untoward effects.5 Conversely, this approach may also prevent excess blood loss from inadequate correction of coagulopathy secondary to an initial under-transfusion of platelets.  However, the precision here does depend heavily on the validity of the TEG-MA value of 45mm determined to be the minimum goal for prevention of post-operative bleeding complications.  And even with external validation, this value would only be applicable to those centers utilizing TEG 6s® for viscoelastic testing. An interesting facet of this study is the exclusion of patients receiving cryoprecipitate and FFP to isolate the effect of platelets on TEG-MA values.  While it is necessary to capture the validity of the calculator, it would be helpful to determine if this optimal TEG-MA of 45mm is independent of the relative contribution of platelets or fibrinogen to the maximum amplitude.  This question is partially answered in the determination that a fibrinogen level of <190mg/dL was independently associated with bleeding complications. But what about settings in which fibrinogen supplementation contributes to a TEG-MA >45mm, yet platelet dysfunction may still exist?  Would this shift the optimal TEG-MA?  Hopefully, this study opens the door to continued refining and expansion of such calculators to each component of a viscoelastic test. It is important to remember that, as our ability to normalize coagulation parameters becomes more elegant and precise, the post-CPB phase remains anything but elegant, requiring balanced resuscitation of ongoing surgical bleeding while correcting coagulopathy.  There will always be some degree of mud in the water with regard to achieving perioperative hemostasis in pediatric cardiac surgery, yet this study demonstrates a useful and targeted approach to minimizing exposure to blood products. References Emani S, Sleeper LA, Faraoni D, Mulone M, Diallo F, DiNardo JA, Ibla J, Emani SM. Thromboelastography Is Associated With Surrogates for Bleeding After Pediatric Cardiac Operations. Ann Thorac Surg. 2018 Sep;106(3):799-806. doi: 10.1016/j.athoracsur.2018.04.023. Epub 2018 May 16. PMID: 29753821. Emani S, Donahue R, Callender A, Ghebremichael M, Nathan M, Ibla JC, Emani S. Thromboelastography-guided Intraoperative Platelet Transfusion in Pediatric Heart Surgery. Ann Thorac Surg. 2024 Dec;118(6):1271-1278. doi: 10.1016/j.athoracsur.2024.09.003. Epub 2024 Sep 12. PMID: 39277157. Faraoni D, Willems A, Romlin BS, Belisle S, Van der Linden P. Development of a specific algorithm to guide haemostatic therapy in children undergoing cardiac surgery: a single-centre retrospective study. Eur J Anaesthesiol. 2015 May;32(5):320-9. doi: 10.1097/EJA.0000000000000179. PMID: 25387300. Romlin BS, Wåhlander H, Berggren H, Synnergren M, Baghaei F, Nilsson K, Jeppsson A. Intraoperative thromboelastometry is associated with reduced transfusion prevalence in pediatric cardiac surgery. Anesth Analg. 2011 Jan;112(1):30-6. doi: 10.1213/ANE.0b013e3181fe4674. Epub 2010 Nov 3. PMID: 21048096. Van Hout FM, Hogervorst EK, Rosseel PM, van der Bom JG, Bentala M, van Dorp EL, van Geloven N, Brand A, van der Meer NJ, van de Watering LM. Does a Platelet Transfusion Independently Affect Bleeding and Adverse Outcomes in Cardiac Surgery? Anesthesiology. 2017 Mar;126(3):441-449. doi: 10.1097/ALN.0000000000001518. PMID: 28092320.

Extravascular protrusion of the Alterra adaptive prestent identified on surveillance computed tomography imaging. Gillespie MJ, Maschietto N, Aboulhosn JA, Balzer DT, Qureshi AM, McElhinney DB. Catheter Cardiovasc Interv. 2024 Aug;104(2):256-263. doi: 10.1002/ccd.31147. Epub 2024 Jul 5.PMID: 38967206 Take Home Points Cardiovascular perforation by the Alterra pre-stent is an observed phenomenon that can be detected incidentally on post-procedure CT imaging In the patients presented, no clinical complications occurred from the Alterra perforation, though the potential to become clinically significant remains The pre-stent perforated the main PA in all 6 patients and in 1 patient there was also perforation of the subvalvar RVOT Commentary from Dr. Jonathon Hagel (C.S. Mott Children’s Hospital, University of Michigan) Patients with patched or native right ventricular outflow tracts (RVOTs) that are too large for traditional balloon expandable pulmonary valves are now often treated with a self-expanding platform. The Alterra adaptive pre-stent is a transcatheter self-expanding device that provides a landing zone for a balloon expandable 29 mm Sapien 3 valve implant. The authors of this study reported selected cases of the Alterra-Sapien implant form 6 institutions to document the phenomenon and provide considerations for potential procedural and patient characteristics in such cases. Each institution provided one patient with a perforation of the Alterra pre-stent that was incidentally discovered on a CT scan performed one day to 21 months after implant. The age range of patients included in this descriptive case series was 16-50 years. Three patients had a history of Tetralogy of Fallot, two had valvar pulmonary stenosis (PS) and one had pulmonary atresia with an intact ventricular septum. One of the valvar PS patients underwent balloon valvuloplasty only and had no history of surgical RVOT intervention. All procedures were acutely successful without significant compilations. In all patients there was perforation of the main pulmonary artery by the distal row of the pre-stent and in one case there was also perforation of the subvalvar RVOT. The perforations did not cause clinical complications in any of the presented cases, though the authors do note, however, in 4 patients the perforating stent cell was in proximity or even extending into the adjacent vascular structure including the ascending aorta, left pulmonary vein, and left atrial appendage. Procedural considerations noted by the authors include asymmetrical delivery of the pre-stent due to inability to achieve coaxial alignment of the delivery system and difficulty advancing the 29 mm Sapien valve through the newly implanted pre-stent. The authors propose that perforation did not cause clinical compromise with extravasation of blood due to direct occlusion of the perforation with the device itself or scar tissue filling the potential space that could allow for fluid to accumulate. As such, the authors note that those who have only had a balloon valvuloplasty and no surgical history may be at increased risk of extravasation of blood due to the absence of scar tissue. The authors note that this study was designed to explain the phenomenon and ensure implanters are aware of the potential clinical significance. A larger study designed to determine risk factors, incidence, and implications of this phenomenon is needed.

Percutaneous Balloon-Expandable Stent Implantation to Treat Transverse Aortic Arch Obstruction: Medium- to Long-Term Outcomes of a Retrospective Multicenter Study. Salavitabar A, Eisner M, Armstrong AK, Boe BA, Chisolm JL, Cheatham JP, Cheatham SL, Forbes T, Jones TK, Krings GJ, Morray BH, Steinberg ZL, Akam-Venkata J, Voskuil M, Berman DP. Circ Cardiovasc Interv. 2024 Jul;17(7):e013729. doi: 10.1161/CIRCINTERVENTIONS.123.013729. Epub 2024 Apr 26. PMID: 38666384 Take-home Points: Percutaneous stent implantation for treatment of transverse aortic arch obstruction has high rates of technical and procedural success. The procedure demonstrates a favorable safety profile with a low incidence of serious complications. Despite initial success, a considerable number of patients (41%) required reinterventions over time. Commentary from Dr. Milan Prsa (Switzerland, Europe), section editor of Congenital Heart Disease Interventions Journal Watch: This retrospective, international, multicenter study evaluated the efficacy and safety of percutaneous stent implantation for treating transverse aortic arch (TAA) obstruction. Conducted from July 2002 to December 2017, the study included 146 patients (median age 14.3 [IQR 9.3-19] years, weight 53 [IQR 30-69] kg, follow-up 53 [IQR 12–120] months), analyzing technical outcomes, procedural success, complications, and the necessity for subsequent reinterventions and long-term hypertension management. Technical and procedural success was defined by successful stent placement and a residual aortic arch gradient of ≤10 mmHg, respectively. Most (74%) interventions were following a previous surgical or percutaneous procedure. The intervention exhibited a 100% technical success rate and an 88% procedural success rate. An arch vessel was overlapped by a stent in 81% of cases, most commonly the left subclavian artery (65%) and almost always (98%) intentionally. Balloon dilation of a stent side cell was performed in 22% of cases to improve flow to an arch vessel. Stent design, particularly the use of open cell stents, contributed to the overall success and adaptability of the procedure across varied anatomical challenges. Complications (e.g. aortic injury, stent migration/fracture, vascular injury) during and immediately after the procedure occurred in 14% of cases, and during follow-up in 12% of cases. Notably, 41% of patients underwent reinterventions (47% balloon angioplasty of stents and 47% additional stent implantation), indicating a significant recurrence of aortic obstruction or related complications over time. A residual gradient >10 mmHg was associated with increased odds of reintervention. Hypertension improved from baseline to most recent follow-up (68% to 46% of patients, p<0.05) with a concomitant increase in the use of antihypertensive medications (47% to 60% of patients, p<0.05). This study, which has the largest sample size and longest follow-up to date, underscores the procedural reliability and clinical efficacy of percutaneous stent implantation in managing TAA obstruction. Despite a lack of strict inclusion and exclusion criteria, as well as a standardized approach to clinical and imaging follow-up, the study shows substantial improvements in medium to long-term outcomes. Nevertheless, the high rate of reinterventions calls for ongoing surveillance and management strategies to address related complications and the progressive nature of TAA obstruction.

Radiation Reduction in Paediatric Cardiac Catheterization: We Can Go Even Lower. Finke T, Mainzer G, Yitzhak Y, Devadas S, Mroczek D, Benson LN, Borik S. CJC Pediatr Congenit Heart Dis. 2024 May 31;3(4):129-136. doi: 10.1016/j.cjcpc.2024.05.004. eCollection 2024 Aug. PMID: 39493664 Free PMC article. Commentary by Dr. Lahiri, section editor of Congenital Heart Disease Interventions Journal Watch: The authors state that the ALARA principle – "as low as reasonably achievable" – is essential for congenital cardiac catheterization, especially in children who need repeat procedures over their lifespan. The authors then compared the levels of radiation between two large tertiary care catheterization laboratories: one in Israel and one in Canada. The measures used were dose area product (DAP), DAP per body weight, total air kerma, and fluoroscopy time. The cath lab in Israel was labeled as unit A, and the cath lab in Canada was labeled as unit B. Unit A used AlluraClarity with ClarityIQ technology, which reduces noise and enhances image projection while using lower X-ray doses. Pulsed fluoroscopy was performed at 7.5 f/s, and cineangiograms were performed at 15 f/s. The data were compared with the most recently available (June 2011 to May 2014) data for the corresponding procedure types and radiation reduction protocol from the Hospital for Sick Kids, Canada. Radiation Safety Measures Implemented at Safra Children’s Hospital, Sheba Medical Center Fluoroscopy frame rate: 7.5 frames/s Air gap technique for all children below 30 kg Use of minimal magnification during procedures Limited field of view to the minimum necessary Use of “low” radiation preset with brief increases as clinically necessary Fluoroscopy image storage in place of digital imaging Weight-based reductions in preset frame rates Exposure to ionizing radiation as part of the consent process Use of Philips ClarityIQ technology High awareness of all team members to the “as low as reasonably achievable” principle Hiring of a radiation technician devoted to radiation reduction Regular updates to new systems Catheterizations in unit B were performed at 7.5 frames/s for fluoroscopy and 30 frames/s for cineangiography, using similar protocols to those in unit A, with removal of the anti-scatter grid for all patients <20 kg, allowing for data comparison. Unit B procedures were performed, and images were acquired on two Siemens biplane flat-panel detector digital angiographic systems (Artis zee [lab I] and Axiom Artis [lab II]; Siemens Medical Solutions). Center A analyzed 627 cases, and Center B had 2,033 cases. Below is the comparison of radiation between the two hospitals. A Few Interesting Findings: Ionizing radiation was not much different for PDA closures between the two centers. Fluoroscopy times were not different except for 4 procedures (shorter in Center A). The highest radiation exposure was seen, as expected, in pulmonary valve procedures, and the highest fluoroscopy times were in pulmonary valve perforation in both institutions. In summary, the authors show that there could be further reduction of radiation doses across 16 procedure types. This is achievable with newer technology, removal of anti-scatter grids for all patients <30 kg, and increasing awareness. It must be emphasized that fluoroscopy time in pediatrics does not correlate with median radiation doses, which are often used as a benchmark in adult labs. There are timers in pediatric labs built in for fluoroscopy time, which may serve as a good reminder for physicians to step off fluoroscopy during cases. However, these should not be the sole parameters on which to base hospital policies and protocols. In our lab, we use ultra-low fluoroscopy rates of 3.5 f/s and cine-rates of 7.5 f/s, along with increasing awareness among team members, which has resulted in significant improvement in radiation exposure for both us and the patients. Cardiac catheterization is heavily technology dependent. In this modern era of rapidly evolving technology, the safety of both operators and patients will likely improve over time, with an ever-changing goal of decreasing radiation, all while keeping in sync with the concept of ALARA.

Transcatheter pulmonary valve replacement after arterial switch operation. Nageotte S, Salavitabar A, Zablah JE, Ligon RA, Turner ME, El-Said H, Guyon P, Boucek D, Alvarez-Fuente M, McElhinney DB, Balzer D, Shahanavaz S. Catheter Cardiovasc Interv. 2024 Sep;104(3):531-539. doi: 10.1002/ccd.31152. Epub 2024 Jul 20. PMID: 39033329 Take Home Points: TPVR is a viable but challenging option for ASO patients, with a 66% success rate and relatively high risk of coronary compression or aortic root distortion (24% vs. 5–6% in the general TPVR population). Long-term durability concerns remain, with 32% of patients requiring reintervention within 5 years due to stent fracture, restenosis, or endocarditis. Pre-procedural imaging advancements (e.g., 3D CT, AI modeling) could improve patient selection and procedural success, reducing failure rates and complications. Commentary from Dr. Konstantin Averin (Cohen Children’s Heart Center), catheterization section editor of Pediatric Cardiology Journal Watch: The study by Nageotte et al. investigates the feasibility and safety of transcatheter pulmonary valve replacement (TPVR) in patients who have previously undergone an arterial switch operation (ASO) for D-transposition of the great arteries (D-TGA).  While TPVR is a well-established intervention for right ventricular outflow tract (RVOT) dysfunction, patients with prior ASO present unique anatomical and procedural challenges, particularly coronary compression and aortic root distortion. This retrospective multicenter study included 33 patients across nine centers of which TPVR was successfully performed in 22 patients (66%) - Melody (n=19) and SAPIEN (n=3) valves.  Pre-stenting was performed in nearly all cases.  In the cases that were technically successful TPVR significantly improved RVOT obstruction, reducing the RVOT peak gradient from 43 mmHg to 9 mmHg (p<0.001) and resolving pulmonary regurgitation (PR).  Coronary compression was the primary reason for inability to perform TPVR 8 patients (24%) and aortic root distortion with severe aortic regurgitation in 2 (6%).  One case was complicated by valve embolization requiring emergency surgical removal.  During a median follow-up of 4 years, 7 patients (32%) required RVOT reintervention, and 3 cases of endocarditis occurred (2 surgical explants and one being medically treated).  The study is limited by its retrospective design, small sample size, lack of long-term data and heterogeneous patient population. This study provides compelling evidence that TPVR can be an effective strategy for managing RVOT dysfunction after ASO, though higher procedural failure rates and mid-term reinterventions warrant careful patient selection and long-term monitoring.  The high rate of coronary compression and aortic root distortion raises an important question: Can we improve pre-procedural screening of ASO patients with RVOT dysfunction to identify those that will not be able to undergo TPVR?  Emerging computed tomography (CT) and three-dimensional (3D) modeling could eventually provide a non-invasive, pre-procedural risk assessment.  By optimizing selection criteria providers may ultimately be able to decrease the high procedural failure rate in ASO patients being considered for TPVR.

Excellent Survival With a Focus on Pulmonary Artery Reinterventions After the Arterial Switch Operation. Selcuk A, Ozturk M, Tongut A, Sterzbecher V, Park IH, Mehta R, Desai M, Yerebakan C, d'Udekem Y.World J Pediatr Congenit Heart Surg. 2024 Jul;15(4):421-429. doi: 10.1177/21501351241239307. Epub 2024 May 16.PMID: 38751363 Take Home Points The arterial switch operation (ASO) achieves a high survival rate in patients with dextro-transposition of the great arteries (d-TGA), with 96.6% surviving beyond the first year. One in five patients (21%) required reintervention, mainly due to pulmonary artery (PA) stenosis. Patients with Taussig-Bing anomaly (TBA) had a notably higher reintervention rate, identifying a high-risk subgroup within the d-TGA population Consistent, long-term follow-up is essential after the ASO, especially in patients with TBA, to monitor and manage PA complications Commentary from Dr. Milan Prsa (Switzerland, Europe), section editor of Congenital Heart Disease Interventions Journal Watch: The ASO is the standard corrective surgery for d-TGA. This study aimed to evaluate the effectiveness of ASO, focusing on survival rates and the incidence of reinterventions for PA stenosis, a common postoperative complication. This retrospective review included 180 patients who underwent ASO for d-TGA between 2002 and 2022 at a single center. Patients were divided into three groups: those with an intact ventricular septum (TGA-IVS), those with a ventricular septal defect (TGA-VSD), and those with Taussig-Bing anomaly (TBA). Kaplan-Meier survival analysis was used to assess overall survival and reintervention-free survival, while regression analyses identified risk factors for PA stenosis and intervention. The study found a one-year survival rate of 96.6%, underscoring the efficacy of ASO in managing d-TGA. However, reinterventions were necessary for 43 patients (24%), primarily due to PA stenosis (86%, 37/43). These 37 patients (21%) underwent 53 PA reinterventions, including 14 reoperations and 39 transcatheter angioplasties (33 ballon dilations and 6 stent implantations). Eight patients (22%, 8/37) required early (prior to discharge) PA reintervention, at a median postoperative day of 31 (IQR 8-39). The median time from ASO to PA angioplasty was six months (IQR 2-13), and from ASO to reoperation was one year (IQR 0.1-8). Freedom from PA reintervention decreased significantly over time, dropping from 97% at one year to 55% at 15 years, indicating a progressive risk for PA stenosis with age. Risk factors for PA reintervention were TBA (OR 6.4), mild PA stenosis at discharge (OR 6.1) and moderate or severe PA stenosis at discharge (OR 12.7). Despite limitations as a single-center retrospective review, this study highlights the long-term success of ASO for d-TGA and the challenges of managing postoperative complications, particularly PA stenosis. It provides valuable insights into the progression of PA stenosis over time, emphasizing the need for careful monitoring and individualized care, especially for patients with more complex anatomy like TBA. The authors suggest that the surgical techniques, such as the level of arterial transection and the type of patch used in neo-PA reconstruction (e.g. glutaraldehyde-treated pericardium) may contribute to PA stenosis. Future studies could focus on refining surgical techniques to reduce PA stenosis, thus improving patient outcomes and minimizing the need for reintervention.

Transcatheter Pulmonary Valve Replacement with the Harmony Valve in Patients Who Do Not Meet Recommended Oversizing Criteria on the Screening Perimeter Plot. McElhinney DB, Gillespie MJ, Aboulhosn JA, Cabalka AK, Morray BH, Balzer DT, Qureshi AM, Hoskoppal AK, Goldstein BH. Circ Cardiovasc Interv. 2024 May;17(5):e013889. doi: 10.1161/CIRCINTERVENTIONS.123.013889. Epub 2024 Apr 12. PMID: 38606564 Take Home Points The Harmony valve was FDA approved for treatment of post intervention pulmonary valve regurgitation in 2021 The stent Medtronic generates a screening report to help determine candidacy for a successful valve implantationis delivered by the Minima Delivery System which has an outer diameter equivalent to a 4 Fr sheath. Successful Harmony valve implantation with good results is possible in some patients that do not technically meet screen in criteria Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch:  The Harmony valve received FDA approval in 2021 for transcatheter pulmonary valve replacement (TPVR) for the treatment of post intervention pulmonary regurgitation. The Harmony valve is made of a covered self-expanding nitinol wire frame in an hourglass shape (rows 1 and 2 in the outflow/PA portion of the device, rows 5 and 6 the inflow/RV portion of the device) with a porcine pericardial valve in the center (rows 3 and 4). The inflow and outflow segments are designed to anchor the valve within the RVOT and prevent paravalvar leak. A pre procedure CT angiogram is performed and then analyzed by Medtronic using an algorithm designed to ensure adequate oversizing to secure the device in the RVOT. A screening report is generated and details various important anatomical features of the RVOT, including a perimeter plot (PP) that is generated based on measurements from the CT angiogram at end diastole and peak systole. A patient’s anatomy is typically considered a fit when the screening report predicts adequate oversizing of both the inflow and outflow portions of the device (approximately 70% of screened patients). While the screening report has been very useful with excellent specificity (unsuccessful valve implantation is extremely rare when fit predicted). However, the RVOT anatomy is complex, and it is unclear how many patients that don’t have a positive screening report could still undergo successful transcatheter pulmonary valve replacement. This retrospective multicenter study looked at patients with borderline or inadequate oversizing on the fit analysis who ultimately underwent successful Harmony valve implantation. Perimeter plot with green shading meeting criteria for minimum oversizing, yellow shading borderline oversizing (50-99% recommended), and red shading insufficient oversizing (<50% recommended).  The landing zone is the length for which this oversizing is met.   There were 22 patients at 8 different centers who underwent Harmony TPV25 implant despite not meeting recommended oversizing criteria; 13 of these were coded green-yellow and 9 green-red (meaning all had adequate oversizing on at least 1 end of the device). The RVOT anatomy of these patients were grouped into three different anatomic types with strategy for valve implantation being somewhat specific for each. The figures below show the PP on the left, diastole in the middle, and systole on the right. Type 1 (n=9): Long RVOT with a clear choke point (often at the level of the annulus) and large MPA that flared out toward the branch PAs. More than 50% of these patients had diagnoses other than TOF. The large, flared MPA did not allow for oversizing of both ends simultaneously. The valve was typically implanted in an annular position (valve housing/rows 3-4 at the level of the annulus). Type 2 (n=6): Short RVOT that was often pyramidal with a large degree of MPA expansion (in length and diameter) during systole. The RVOT length was too short during diastole for adequate oversizing of both ends and there was not usually a choke point. The valve was typically implanted high with the outflow rows flowering into the PA bifurcation or within the distensible distal MPA. Type 3 (n=7): Short and bulbous MPA with a discrete choke point that did not screen in because of the large MPA and short RVOT. More than 50% of these patients had diagnoses other than TOF. The valve was typically implanted high or at the annular level. The implant was annular in 15 patients and supra-annular in 7 patients. There was trivial pulmonary regurgitation via echocardiography in 5 patients, trivial paravalvar leak in 3 , and mild paravalvar leak in 2. 41% (9) of patients were started on antiarrhythmic medications for new non-sustained VT/frequent ventricular ectopy.  This study shows that patients with inadequate oversizing at one end of the device on the Harmony valve screening report may still be able to undergo successful Harmony TPVR with excellent short term results as long as there is adequate oversizing at one end of the device. This is possible because the anatomy of the RVOT in these cases allowed for device stability. Also, the anatomy of the RVOT is complex and while there may not be apposition of the device along the entire circumference of the RVOT that may not be necessary to ensure device stability. While it is challenging to draw broad conclusions from this study (it is unclear who screened out that could have undergone successful TPVR and who when attempted would have failed) this study highlights the importance of looking at the individual anatomical features when deciding whether or not to attempt TPVR with the Harmony valve.

Results of the multicenter early feasibility study (EFS) of the Renata Minima stent as treatment for branch pulmonary artery stenosis and coarctation of aorta in infants. Berman DP, Morray B, Sullivan P, Shahanavaz S, Zahn EM.Catheter Cardiovasc Interv. 2024 Jul;104(1):61-70. doi: 10.1002/ccd.31074. Epub 2024 May 12.PMID: 38736246 Take Home Points The Minima Stent is a symmetrical, closed cell cobalt-chromium stent premounted on either a 6 or 8 mm balloon with in-vitro dilation up to 24 mm in diameter The stent is delivered by the Minima Delivery System which has an outer diameter equivalent to a 4 Fr sheath. In this early feasibility study all 10 patients had successful stent implantation without serious adverse events Commentary from Dr. Jonathon Hagel (C.S. Mott Children’s Hospital, University of Michigan) Endovascular stent implantation for the treatment of branch pulmonary artery stenosis and coarctation of the aorta has become the mainstay of treatment for older children and young adults with stents that can be implanted with a final diameter that can reach adult size. Unfortunately, there remains a gap in the availability of a stent which can be implanted at a size appropriate for infants but that can also be dilated to adult size. Further, current stent technology requires delivery through large delivery sheaths leading to increased risk of vascular injury. The authors of this early feasibility study sought to address the safety and feasibility of the newly developed Renata Minima Stent and delivery system that were specifically designed to meet these needs.  The Minima Stent is a symmetrical, closed cell cobalt-chromium stent which is delivered by the Minima Delivery System which has an outer diameter equivalent to a 4 Fr sheath and can be advanced through a 6 Fr sheath if desired. The stent is premounted on either a 6 or 8 mm balloon with in-vitro dilation up to 24 mm in diameter while maintaining radial strength. The stent has a predictable shortening profile starting at 17mm fully crimped that shortens down to 5mm when dilated to 22mm.  The median age at implant was 9 months with a median weight of 7.6 Kg. The stent was successfully deployed in 10/10 patients and all patients met the predefined primary efficacy endpoint of successful relief of stenosis with >50% increase in vessel diameter and all were free of stent explant at 6 months post-implantation. Two patients treated for coarctation of the aorta developed pulse loss requiring low molecular weight heparin initiation and one patient had malposition of stent placement requiring a second stent to treat the lesion. Five patients have had elective stent re-dilation at a mean of 7 months post-implantation. In this early feasibility study, the Renata Minima Stent is safe and effective at treating infants and young children with native and recurrent branch pulmonary artery stenosis and coarctation of the aorta. This study, by nature of it design, was not able to describe in-human stent characteristics when dilated to adult diameters, though significant stent shortening and long-term radial strength without frame fracture remain uncertain. A multi-center pivotal trial is ongoing targeting the enrollment of 42 patients across 7 centers which will provide a larger cohort with longer follow-up to address some of these ongoing concerns.

Percutaneous Balloon-Expandable Stent Implantation to Treat Transverse Aortic Arch Obstruction: Medium- to Long-Term Outcomes of a Retrospective Multicenter Study. Salavitabar A, Eisner M, Armstrong AK, Boe BA, Chisolm JL, Cheatham JP, Cheatham SL, Forbes T, Jones TK, Krings GJ, Morray BH, Steinberg ZL, Akam-Venkata J, Voskuil M, Berman DP.Circ Cardiovasc Interv. 2024 Jul;17(7):e013729. doi: 10.1161/CIRCINTERVENTIONS.123.013729. Epub 2024 Apr 26.PMID: 38666384 Coronary artery fistulas are rare and are heterogeneous in their anatomy and presentation. Clinically asymptomatic CAFs can be managed conservatively without long-term complications. Commentary from Dr. Subhrajit Lahiri, section editor of Congenital Heart Disease Interventions Journal Watch: The authors begin by stating the importance of transverse arch coarctation and evidence of successful percutaneous treatment in small studies. The objective of this paper was to evaluate the technical, procedural, and mid- and long-term clinical outcomes of percutaneous TAA stent implantation. This was a retrospective, international, multicenter study including patients who had percutaneous stent implantation to treat TAA obstruction from July 2002 to December 2017 at 4 centers. Procedural success was defined as a residual transcatheter gradient of ≤10 mm Hg. The author reports the placement of transverse aortic stents in 146 patients aged 12 months to 120 months. Technical success was achieved in 146 (100%) patients. On univariable analyses, lower patient weight (P=0.018), body surface area (P=0.013), and smaller Minimum Diameter /Descending AO ratio (P<0.001) were associated with a higher baseline Peak Systolic Ejection Gradient (PSEG). Postintervention PSEG was not associated with any patient or anatomic characteristic but was inversely associated with implant balloon (P<0.001) and final dilation (P<0.001) diameters. Of note, most of the stents used in this study were open-celled stents which prevent obstruction of flow to the head and neck vessels that are jailed in most of these cases. The authors discussed the complications/risks in detail. The composite complication rate was 14%. This included stent embolization and intraprocedural aortic wall injuries. On univariable regression, the number of stents at the index procedure was the only variable associated with increased risk of intraprocedural complications (odds ratio, 4.58 [95% CI, 1.95–11.4]; P<0.001). The overall rate of postprocedural aortic wall injury and stent-related complications was 8.2% (n=12). There were no reports of abnormal brain imaging or cerebrovascular accidents immediately post-catheterization. Reintervention was reported in 60 (41%) patients at a median of 84 (22–148) months to first reintervention. Multivariate and univariate analysis showed that a residual gradient >10 mm Hg was associated with increased odds of reintervention at 1 year (odds ratio, 6.3 [95% CI, 1.5–26.8]; P=0.012) and from 1-year to most recent follow-up (odds ratio, 8.4 [95% CI, 2.2–56.1]; P=0.001). Interestingly, hypertension was present in 45% of patients at the latest follow up and the prescription of antihypertensive medications increased due to confidence that providers had to prescribe antihypertensive medications, once the coarctation was relieved by the intervention. This trend then plateaued.  The study can be criticized for the heterogeneity of the pathology, technique, and criteria of stent placement, the essence of which probably cannot be captured by the broad statistics performed. The blood pressure gradients reported were not granular to the level of arch vessels. Also, the lack of follow-up protocol probably fails to capture the exact prevalence of residual coarctation and long-term complications. Nevertheless, this is the largest of similar studies which encourages us to consider transverse aortic arch stent placement in the selected population assuring good technical success and low recurrence and complication rates.

Three-Decade Experience with Management of Coronary Artery Fistulas in Children. Haddad RN, Bonnet D, Malekzadeh-Milani S. Can J Cardiol. 2024 Jun 6:S0828-282X(24)00430-6. doi: 10.1016/j.cjca.2024.05.028. Online ahead of print. PMID: 38851390  Take home points: Coronary artery fistulas are rare and are heterogeneous in their anatomy and presentation. Clinically asymptomatic CAFs can be managed conservatively without long-term complications. Transcatheter closure is effective in appropriately selected patients but carries a relatively high risk of complications making it imperative that providers are prepared to deal them should they arise. Commentary from Dr. Konstantin Averin (Cohen Children’s Heart Center), catheterization section editor of Pediatric Cardiology Journal Watch: Coronary artery fistulas (CAFs) are rare anomalous connections from the normal coronary artery to another cardiac structure. These lesions range in severity from completely asymptomatic to those that can cause myocardial ischemia, primarily driven by the diameter of the orifice and length of the fistulous connection. Data on management and outcomes are limited so the authors sought to describe a 3-decade (1997-2023) single center experience with the management of CAFs in children.During the study period 94 CAFs in 78 patients (33 male) were identified, the median age at diagnosis was 3.4 years (IQR 0.9-6.6 years) and weight 15 kg (IQR 8.9-24.9 kg). Main closure indications were hemodynamically significant shunt, prevention of endocarditis or rupture in an aneurysmal feeder artery, or evidence of myocardial ischemia. Twenty-three patients did not have indications for closure and were managed conservatively, 8 had primary surgical ligation, and the rest (47) underwent trans-catheter closure. The catheterization procedural details are summarized in the table below. A wide variety of approaches (antegrade v retrograde) and devices (coils, vascular plugs, and nitinol occluders) were utilized. Antegrade approaches were utilized more commonly in the later part of the study period likely due to availability of smaller profile closure devices. Trans-catheter closure was successful in 44/47 patients. The rate of procedural complications was high with 31.9% experiencing complications, and almost half of these (6/15) being serious – CA pseudoaneurysm, myocardial infarction, air embolism, RCA dissection, and aortic valve regurgitation requiring surgical repair. There were no significant long-term complications in any of the treatment groups. The authors should be congratulated on a robust demonstration of the heterogeneous nature of CAFs and the various management strategies that can be applied. In the modern era transcatheter closure is effective in appropriately selected patients however the rate of serious complication is relatively high (12%) and requires upfront preparation and the availability of surgical back up. Smaller profile devices that can be delivered via microcatheters and 4-French diagnostic catheter may allow for treatment of more complex fistulas in smaller patients.

Incidence, risk factors, and management following cardiac catheterization via carotid and axillary artery approaches: A single-center experience on pseudoaneurysms in young infants. Takajo D, Newkirk B, Shahanavaz S. Catheter Cardiovasc Interv. 2024 Mar;103(4):580-586. doi: 10.1002/ccd.30966. Epub 2024 Feb 14.PMID: 38353500 Take-Home Points: Screening for pseudoaneurysms after procedures using carotid or axillary artery access aids in early detection and treatment. Longer sheath dwell times (in-to-out time) and higher activated clotting times (ACT) might be associated with pseudoaneurysm development. Commentary from Dr. Subhrajit Lahiri, section editor of Congenital Heart Disease Interventions Journal Watch: The authors accurately note that pseudoaneurysms following arterial access have been studied in adults. In these studies, interventional procedures, electrophysiology procedures, large sheath sizes, and left groin access were identified as risk factors. While Bauser-Heaton et al. reported pseudoaneurysms after carotid or axillary access in children, their lack of post-procedural complication screening limited the true incidence. This paper describes the authors' institutional practice of performing ultrasound screening 24 hours after every axillary or carotid access. They analyzed 29 young infants who underwent cardiac catheterization between 2013 and 2022. The median patient age was 6 days, with most having single ventricles. Procedures included PDA stenting, aortic valvuloplasty, and thrombectomy. Both carotid and axillary access were used, with ultrasound guidance for access establishment. Hemostasis was achieved using compression, and heparin was administered to maintain target ACT levels. The median procedure duration was 82 minutes, and the median compression time was 20 minutes. ACT values were recorded for most patients, with a median closing ACT of 208 seconds. All 29 patients underwent Doppler ultrasound within this timeframe. Four patients with carotid access and one with axillary access were diagnosed with access-related pseudoaneurysms. Bedside ultrasound compression in the ICU resolved the pseudoaneurysm in 3 patients. One patient underwent trans-arterial flow-diverting stent placement at 6 weeks, and another required embolization of the left common carotid artery. Comparing groups with and without pseudoaneurysms revealed significantly longer sheath dwell times (135 minutes vs. 75 minutes) and higher ACT (268 seconds vs. 200 seconds) in the pseudoaneurysm group. The authors acknowledge the lack of treatment guidelines for carotid or axillary pseudoaneurysms in children, with treatment depending on factors like size, location, and physician preference. However, they emphasize the importance of early detection. Limitations: Small sample size limits the statistical power of the conclusions. Lack of data on: Number of puncture attempts Bleeding after access Standardization in early cases Variability in post-procedural holding pressure Conclusion: This valuable study highlights a rare but important complication of carotid and axillary artery access, a common practice in cardiac catheterization labs. It encourages multicenter studies to establish guidelines for managing such complications.

Cardiac Catheterization Interventions in the Right Ventricular Outflow Tract and Branch Pulmonary Arteries Following the Arterial Switch Operation. Gritti MN, Farid P, Hassan A, Marshall AC. Pediatr Cardiol. 2024 Feb 10. doi: 10.1007/s00246-024-03408-w. Online ahead of print. PMID: 38341390 Take Home Points: Residual MPA/branch PA stenosis following the arterial switch operation can result in significant right ventricular hypertension. Branch PA angioplasty and branch PA stenting can improve RV hypertension, decrease gradients across the branch PAs, and improve the caliber of the vessel without major adverse events. More concrete indications for intervention and long term follow up, especially of stented branch PAs following ASO is needed to help guide optimal therapy. Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch: Dextro-transposition of the great arteries (d-TGA) is repaired in the neonatal period via the arterial switch operation (ASO) +/- closure of a ventricular septal defect if present. Pulmonary artery translocation with the LeCompte maneuver can results in the branch pulmonary arteries (PAs) both sitting on top of the ascending aorta. Branch PA stenosis is relatively common following this (up to 28% in previous studies) secondary to multiple factors. Additionally, pulmonary artery stenosis at the anastomotic site can also occur, though seem to be decreasing in frequency with improvement in surgical techniques. This, along with branch PA stenosis, can lead to RV hypertension. This study sought to describe the outcomes of transcatheter interventions in this patient population. A retrospective review of all patients who underwent both an ASO and cardiac catheterization (excluding balloon atrial septostomy) was performed at a single center from 1/2004-12/2020. Patients were excluded if they did not have a right heart catheterization (RHC) performed. A total of 544 patients had an ASO during this time. 110 patients had a cardiac catheterization performed, with 58 patients meeting inclusion criteria. 9 patients underwent a diagnostic RHC only. 49 patients underwent 76 right sided interventional cardiac catheterizations at a median age of 3 ± 3.9 years. Many patients had a cardiac catheterization performed for RV hypertension (42%), branch PA pressure gradient (29%), and significant branch PA size discrepancy (19%). The RV to systemic pressure ratio was higher in the interventional group vs the diagnostic group (0.68±0.21 vs 0.52±0.16, p<0.02). In the intervention group, 33% of patients had a significant RPA gradient and 33% LPA. 17% had a significant size discrepancy. In the 76 interventional catheterizations, balloon angioplasty of the RPA was performed 27, LPA in 42, and MPA in 10. Reduction in the RV hypertension was accomplished with angioplasty of the RPA (0.69±0.17 to 0.54±0.15, p<0.001) and LPA (0.66±0.17 to 0.54±0.17, p<0.001). The RPA gradient was reduced from a mean of 21.4 mmHg to 10.5 mmHg and LPA gradient from 22.8 mmHg to 13.3 mmHg. The size of both branch PAs increased following angioplasty as well (RPA 4.6 to 5.2 mm, LPA 4.4 to 6.8 mm). 15 patients had a stent placed in their RPA and 16 in their LPA with significant reduction in the RV pressure and gradients with near doubling in vessel caliber. 5 patients had stents placed in both branch PAs. There were no complications in the diagnostic RHC cohort and 9 (12%) in the interventional cohort. None of these complications were considered high severity. This study showed that branch PA interventions in young children following ASO can result in a significant decrease in RV hypertension with an acceptable risk profile. Unfortunately, this study was not able to clearly delineate indications for intervention as determined by noninvasive imaging. I expect there is still significant practice variation across centers given this. Long term follow-up of this population is needed, especially following branch PA stenting, given the known risk of late aortopulmonary fistula formation. Additionally, it is unclear what degree of RV hypertension and/or branch PA flow discrepancies are clinically significant in patients post ASO.

Comparison of ductus stent versus surgical systemic-to-pulmonary shunt as initial palliation in patients with univentricular heart. Grozdanov D, Osawa T, Borgmann K, Schaeffer T, Staehler H, Di Padua C, Heinisch PP, Piber N, Georgiev S, Hager A, Ewert P, Hörer J, Ono M. Eur J Cardiothorac Surg. 2024 Mar 1;65(3):ezae011. doi: 10.1093/ejcts/ezae011.PMID: 38212978 Take home points: In patients with single ventricle physiology and ductal-dependent pulmonary blood flow, initial palliation with either a surgical systemic-to-pulmonary artery shunt or interventional ductal stenting had comparable survival rates, with no significant difference in the probability of reaching stage II and III palliation. Patients undergoing ductal stenting experienced shorter ICU and hospital stays, while having higher rates of acute complications, needing more frequent reinterventions. Commentry from Dr. Milan Prsa (Switzerland, Europe), section editor of Congenital Heart Disease Interventions Journal Watch : In patients with single ventricle (SV) physiology and ductal-dependent pulmonary blood flow (DD-PBF), an initial palliation during the neonatal period is necessary to establish a stable source of PBF. This can be achieved through a surgical systemic-to-pulmonary artery shunt (SPS) or percutaneous ductal stenting (DS). The authors sought to compare survival rates between SPS and DS in patients with SV physiology and DD-PBF. Additionally, they aimed to compare the two groups in terms of hospital recovery, rate of complications, pulmonary artery (PA) development and outcomes for stage II and stage III palliation. This was a retrospective, observational study conducted at a single center from 2009 to 2022. A total of 130 patients were identified, with 81 undergoing SPS (62 modified Blalock-Taussig shunt and 19 central aortopulmonary shunt) and 49 undergoing DS as their initial palliation. The only significant difference between the groups was more patients with pulmonary atresia and intact ventricular septum were palliated with DS (22.4% vs. 9.9%, p = 0.049). The results showed comparable survival rates between the two groups, with no significant difference in reaching stage II or stage III palliation. Patients with DS had significantly shorter ICU and overall hospital stays compared to SPS (median 1 vs. 7 days in the ICU; 7 vs. 17 days in the hospital). Acute complications, including stent dysfunction and dislocation, were more common in the DS group (20.4% vs. 6.2% in the SPS group), with all 10 of these patients in the DS group needing a SPS. Pulmonary artery growth was generally similar between the two groups, though patients with DS showed a lower ratio of left-to-right PA index compared to those with SPS, indicating potentially less balanced PA development. Despite its shortcomings as a single-center retrospective review with inherent patient-level differences, this study supports the use of DS as a viable initial palliative option for patients with SV physiology and DD-PBF, particularly given the reduced hospitalization time and comparable survival rates to SPS. However, clinicians should weigh the benefits of shorter ICU and hospital stays against the potentially higher risk of reintervention associated with DS, including emergent conversion to SPS. The study also underscores the need for a prospective randomized trial to determine if one palliative approach offers a clear therapeutic advantage. Hopefully, the future large multicenter COMPASS trial will settle the debate.1 References Petit CJ, Romano JC, Zampi JD, et al. Rationale and Design of the Randomized Comparison of Methods for Pulmonary Blood Flow Augmentation: Shunt Versus Stent (COMPASS) Trial: A Pediatric Heart Network Study. World Journal for Pediatric and Congenital Heart Surgery. 2024;0(0). doi:10.1177/21501351241266110

Transcatheter Pulmonary Valve Replacement with Balloon-Expandable Valves: Utilization and Procedural Outcomes from the IMPACT Registry. Stefanescu Schmidt AC, Armstrong AK, Aboulhosn JA, Kennedy KF, Jones TK, Levi DS, McElhinney DB, Bhatt AB. JACC Cardiovasc Interv. 2024 Jan 22;17(2):231-244. doi: 10.1016/j.jcin.2023.10.065. PMID: 38267137 Take Home Points Melody valves were used more often over the entire study period (57%) though there was an evolution in valve type with Sapien valves contributing to more than 50% of implants by 2020. Melody valves were used more often in younger patients, patients with conduits and patients with RVOT stenosis whereas Sapien valves were more commonly used in patients with predominant PR and those with native/patched RVOTs Center experience with the TPVR procedure varied widely with most centers reporting <10 cases per year Commentary from Dr. Jonathon Hagel (C.S. Mott Children’s Hospital, University of Michigan) After its initial commercial approval in the United States in 2010, transcatheter pulmonary valve replacement (TPVR) has expanded and evolved. The authors sought to examine real world patient and procedural characteristics of TPVR using data from the IMPACT (Improving Pediatric and Adult Congenital Treatment) registry which includes 106 participating sites. Their secondary objectives were to describe acute hemodynamic outcomes and major adverse events (MAEs) associated with the procedure.             Patients who had a TPVR procedure entered in the IMPACT registry with an implant date between April 2016 and March 2021 were included in the study. This timeframe represents the only approved commercially available devices at the time being the Melody and Sapien transcatheter pulmonary valve (TPV). Notably, this timeframe excludes newer self-expanding TPV platforms designed specifically for large native/patched RVOTs. Those in whom a device was not implanted, were treated with a self-expanding TPV or who had no data entered for valve type were excluded from analysis. Over the 5-year study period, 4936 TPVR procedures were attempted of which 4513 met the inclusion criteria. The average yearly volume was <10 cases at more than two-thirds of centers. The median age at implant was 19 years (13, 31) with 10% of patients weighing <30 Kg and 3% of patients <20 Kg. Acute success was achieved in 95% of patients however an optimal hemodynamic outcome with peak-to-peak invasive gradient of <15 mmHg was only achieved in 83% of patients. MAEs were reported in 2.4% of cases and were significantly less common in patients with a BPV (1.4%) compared to those with a homograft (2.9%) or native/patched RVOT (3.4%) (P=0.004). In multivariable analysis, age (10-19 yrs vs. 19-40 yrs), RVOT type (BPV vs. Homograft) and femoral venous access were significantly associated with lower risk of MAEs after adjusting for valve type, year or procedure and TPVR annual center volume. Using this large national registry of children and adults with congenital heart disease there were several key findings. First, one quarter of implants were performed into native/patched outflow tracts which is an off-label application of these devices. Second, patients weighing <30Kg (who were excluded from the initial Melody and Sapien clinical trials) represented 10% of this cohort. Emergent/urgent TPVR cases were rare but more likely to be associated with MAEs and less likely to be successful. MAEs were uncommon with one reported procedural death, a small number of cardiac arrests, ECMO and unplanned cardiac or vascular surgery.