Transcatheter closure is becoming the standard of care for definitive closure of patent ductus arteriosus (PDA) in premature infants. To avoid risks associated with the transportation of a fragile neonate, the intervention can be performed as a bedside procedure within the neonatal intensive care unit, even in extremely low birth weight (ELBW) infants. Limited evidence-based guidelines are available for transcatheter PDA closure in premature infants in general and for bedside PDA closure specifically. This framework represents an expert consensus regarding bedside PDA closure in ELBW infants and guidance for procedural implementation. Recommendations for patient eligibility, pre-procedural planning, staff requirements, procedural aspects, imaging and follow-up and a stepwise implementation plan for a bedside PDA closure program are presented. IMPACT: Extremely low birth weight (ELBW) infants with a patent ductus arteriosus (PDA) may be considered for transcatheter PDA closure. An expert consensus is provided on bedside transcatheter PDA closure performed within the neonatology intensive care unit, thereby mitigating the risks associated with transportation of these highly vulnerable infants outside of the neonatology intensive care unit. Guidance is provided regarding procedural aspects, including staff requirements, planning, setting, and imaging, and implementation of a bedside transcatheter PDA closure program.

This review examines the incidence, mechanisms, and management of branch pulmonary artery stenosis following the arterial switch operation (ASO) for transposition of the great arteries. We sought to clarify how surgical techniques and anatomical factors contribute to this complication and evaluate the outcomes of different interventional strategies, including balloon angioplasty and stent implantation. Branch pulmonary artery stenosis is a frequent long-term complication after the ASO, particularly associated with the LeCompte maneuver. Advances in imaging techniques have improved detection, while transcatheter approaches represent the mainstay of treatment. Balloon angioplasty can provide short-term relief but is often limited by restenosis and external compression. Stent implantation has shown higher procedural success and lower reintervention rates, although it carries specific risks in younger patients and requires adaptation to growth. Pulmonary artery stenosis after an ASO remains a major clinical challenge. Individualized anatomical assessment, early recognition, and tailored interventional strategies are critical for optimizing outcomes. Future research should focus on refining stent technology, hybrid techniques, and long-term surveillance to reduce complications and improve quality of life in this growing patient population.

BACKGROUND:Transcatheter patent ductus arteriosus (PDA) occlusion outcomes in premature and low birth weight infants have improved with advances in procedural technique and availability of low-profile devices. We describe our clinical experience with the Azur Vascular Plug (Terumo Medical Corporation, NJ, USA) for PDA occlusion. AIMS:To assess procedural success, safety and short-term outcomes of the Azur Vascular Plug for PDA occlusion in premature and low birth weight infants. METHODS:Single-center observational study of all preterm and low birth weight infants who underwent a transcatheter PDA occlusion procedure involving the Azur Vascular Plug between June 2024 and October 2025. RESULTS:The Azur Plug was used in 13 infants. The median (range) procedural age was 44 days (17-93 days) and weight 1344 g (855-3900 g). Successful implantation with microcatheter deployment occurred in 12/13 infants. In 11 cases, the 8 mm Azure device was deployed. The ratio of the unconstrained device to the minimal PDA diameter ranged from 2:1 to 4:1 and decreased with experience. The minimal ductal length for deployment was 9.0 mm (lateral angiography). Mean (range) follow-up was 5.8 months (1.5-15.7 months). Complete ductal occlusion prior to 6-month follow-up occurred in 11/12 infants. No aortic obstruction, left pulmonary artery obstruction, or tricuspid valve injury was noted in follow-up. CONCLUSION:The Azur Vascular Plug is a safe and effective option for PDA device occlusion in premature and low birth weight infants. The sizing limits in premature ducts are under evolution. The Azur device appears suitable for ducts with a minimal length of 9.0 mm and, conservatively, a diameter up to 5.0 mm.

We discuss a case of symptomatic atrial arrhythmia in a 31 year old man who had previously undergone extra-cardiac Fontan surgery and a MAZE procedure. Besides the peculiar anatomy that restricted percutaneous atrial access only by perforation through the extra-cardiac tunnel, changing cycle lengths of the tachycardua necessitated innovative mapping to define the electro-morphology of the arrhythmia.

Background A methodology for predicting pediatric cardiac catheterization-related complications can assist interventionists in planning treatment strategies, obtaining informed consent, and allocating medical resources. We aimed to perform an external validation of the Catheterization Risk Score for Pediatrics (CRISP). Methods We retrospectively reviewed 3093 consecutive catheterizations performed between January 2016 and March 2021 to calculate the CRISP. Model performance was assessed using discrimination (area under the receiver operating characteristic curve [AUC]) and calibration (observed and predicted risk). Results Serious adverse events (SAE) occurred in 200 procedures (6.5%, 208 events). The most frequent complication was arterial occlusive thrombosis at the access site (1.8%). Nine catheterization-related deaths were identified. The mean CRISP score was 5.74 ± 3.43. SAE incidence increased across categories, ranging from 1.5% in category 1 to 36.4% in category 5. The CRISP score and categories demonstrated good discriminative power (AUC, 0.729; 95% CI, 0.695-0.764; AUC, 0.717, 95% CI, 0.682-0.752). Conclusions The CRISP scoring method demonstrated good predictive performance in identifying SAE. This external validation supports procedural planning and may improve communication with patients and families, thereby enhancing safety and quality of care.

Advances in imaging diagnostics, surgical techniques and transcatheter interventions for paediatric patients with severe congenital heart disease (CHD) have substantially reduced mortality, thereby extending the lifespan of these individuals and increasing the number of adults with complex CHD. Transcatheter interventions have emerged as an alternative to traditional open-heart surgery to mitigate congenital defects. The evolution of techniques, the introduction of new devices and the growing experience of operators have enabled the treatment of patients with progressively more complex conditions. The general cardiology community might be less aware of contemporary interventions for adult CHD, their clinical indications and associated outcomes than interventional cardiologists and congenital heart specialists. In this Review, we provide a comprehensive evaluation of the available transcatheter interventions for adult patients with CHD. The past 20 years have witnessed remarkable progress in the evolution of transcatheter procedures for the treatment of adult patients with congenital heart disease. In this Review, Rodés-Cabau and colleagues provide a comprehensive overview of the available transcatheter interventions for these patients, focusing on their current indications and associated outcomes.

Transposition of the great arteries (TGA) is a complex congenital heart defect with two primary anatomical subtypes: dextro-TGA and levo-TGA. Advances in neonatal surgical techniques, particularly the arterial switch operation, have significantly improved survival rates. However, as this population ages, late complications such as heart failure and valve dysfunction present new clinical challenges. Transcatheter interventions have emerged as valid alternatives to surgical reintervention for these patients, providing effective symptom relief and improved quality of life, reducing the need for repeated sternotomies. As more adults with repaired TGA reach advanced ages, long-term studies are needed to assess the durability and safety of transcatheter therapies. Expanding the indications, refining procedural techniques, and developing specialized devices will be essential in optimizing outcomes for this growing patient population.

BACKGROUND:Covered stent correction for a sinus venosus atrial septal defect (SVASD) was first performed in 2009. This innovative approach was initially viewed as experimental and was reserved for highly selected patients with unusual anatomic variants. In 2016, increasing numbers of procedures began to be performed, and in several centers, it is now offered as a standard of care option alongside surgical repair. However, covered stent correction for SVASD is not recognized by regulatory authorities, and in the minds of many pediatric and adult congenital cardiologists and surgeons, the condition is viewed as treatable only by cardiac surgery with cardiopulmonary bypass. METHODS:In April 2023, all centers identified from international conferences, publications, and colleague networks to be undertaking covered stent correction for SVASD were invited to participate in a retrospective audit of their procedures. RESULTS:Data were received on 381 patients from 54 units over a 12-year period with 90% of procedures being performed over the past 5 years. Balloon-expandable stents (8 types) were used in the majority; self-expanding stents (4 types) were used in 4.5%. The commonest stent was the 10-zig covered Cheatham Platinum stent in 62% of cases. In 10 procedures, the stent embolized requiring surgical retrieval and repair of the defect, resulting in technically successful implantation in 371 of 381 (97.4%). Major complications (surgical drainage of tamponade, pacemaker implantation, surgery for pulmonary vein occlusion, and late stent removal) occurred in 5 patients (1.3%). Repeat catheterization to correct residual leaks was required in 7 patients (1.8%). Thus, 359 of 381 patients (94.2%) had successful correction without major complications or additional catheter interventions. CONCLUSIONS:This article details the exponential uptake of covered stent correction for SVASD during the past 5 years. Cardiopulmonary bypass was avoided in the majority of patients, and major complications were infrequent. Prospective registries with standardized definitions, inclusion criteria, and follow-up and comparative studies with surgery are now required to help support the extension of covered stent correction as an alternative standard-of-care option for patients with an SVASD.

We present an 18-year-old male with Fallot's tetralogy (ToF) repaired with a transannular and main pulmonary artery (PA) patch, who suffered an acute coronary artery compression after a Harmony-TPV deployment. Left main coronary artery compression was confirmed with angiography and IVUS. He underwent emergent surgery, with a bioprosthetic valve replacement.

BACKGROUND:The persistently patent arterial duct accounts for ~12% of congenital heart lesions. Untreated, it may result in heart failure due to volume loading of the left heart, pulmonary hypertension, and infective endarteritis. Percutaneous device closure is the preferred occlusion technique, with the standard approach consisting of femoral artery access for angiography and venous access for device delivery (AA). A venous-only strategy (VA) for angiography and device delivery can also be employed. HYPOTHESIS:We hypothesized that VA would eliminate the need of arterial entry, reduce procedure times and radiation exposure compared to standard AA. METHODS:This is a retrospective cohort study of isolated arterial duct device closure at the Hospital for Sick Children from January 1, 2011, through December 31, 2022. Exclusions included premature neonates, children requiring arterial access for monitoring, and those who underwent other procedures. Children were categorized based upon initial access determined by operator preference into VA or AA groups. RESULTS:The cohort consisted of 405 children, 252 (62.2%) females, with a median age of 3.1 years (IQR 1.30-5.84), median weight 13.2 kg (IQR 9.0-19.5), and duct diameter of 2.9 mm (IQR 2.0-3.5) with no significant differences between the groups. Type A ducts were more frequent in the AA group (90% vs. 72%). The VA group included 106 children, of which 14 (13.2%) required AA conversion for angiography due to complex ductal anatomy, to assess device position before release, but remained in the VA group for analysis. Children in the VA group had lower dose area product (DAP) (p < 0.001), fluoroscopy times (p = 0.025), contrast volumes (p < 0.001), procedure times (p < 0.001), and recovery room lengths of stay (LOS) (p < 0.001). Six (5.7%) VA children required admission compared to 44 (14.7%) in the AA group (p = 0.015) with no difference in reintervention rates. Weighted regression analysis showed VA was associated with reduced admission likelihood (OR: 0.354 [0.131, 0.822], p = 0.024), DAP (coef -126.4 [-213.3, -39.4], p = 0.004), and contrast volumes (coef 31.2 [-36.6, -25.9], p < 0.001) compared to AA. CONCLUSIONS:Venous-only access was associated with lower DAP and recovery room LOS. Additionally, VA was associated with a lower likelihood of admission with no difference in reintervention rates, suggesting procedural safety. These findings support the consideration of VA as a preferred approach for appropriate cases.

Valsartan has been shown to attenuate phenotypic progression among individuals with early-stage sarcomeric hypertrophic cardiomyopathy (HCM). Myocardial tissue characterization by cardiac magnetic resonance (CMR) imaging may enhance mechanistic insights, but whether valsartan influences these parameters remains uncertain. To evaluate the treatment effects of valsartan on myocardial structure, function, and tissue parameters in early-stage sarcomeric HCM. This prespecified CMR substudy of the VANISH (Valsartan for Attenuating Disease Evolution in Early Sarcomeric Hypertrophic Cardiomyopathy) randomized clinical trial evaluated treatment effects of valsartan vs placebo on myocardial structure, function, and tissue parameters and was conducted from April 2014 through July 2019 at 17 international sites. Individuals aged 8 to 45 years with early-stage HCM aged between 8 and 45 years and with no or minimal symptoms were eligible for inclusion. Treatment with placebo or valsartan (80 mg per day for children weighing <35 kg, 160 mg per day for children weighing ≥35 kg, or 320 mg per day for adults aged 18 years or older). The primary outcome was mean change in CMR parameters between baseline and year 2, including indexed extracellular volume (iECV), indexed intracellular volume (iICV), and late gadolinium enhancement (LGE). Mean between-group differences in CMR parameters between baseline and year 2 were evaluated using multivariable mixed-effects linear regression models. Overall, 137 of 178 VANISH participants (77.0%) underwent CMR imaging at baseline and year 2. Among these participants, mean (SD) age was 23 (10) years, and 51 participants (37.2%) were female. Baseline characteristics and CMR parameters were well balanced between treatment groups. Higher LGE, iECV, and iICV at baseline were associated with higher cardiac biomarker levels and more pronounced cardiac remodeling. Between baseline and year 2, valsartan appeared to increase left ventricular (LV) end-diastolic volume index (mean difference [MD], 3.3 mL/m2; 95% CI, 0.4-6.2; P = .03), suggesting treatment benefit, but did not significantly impact LV mass index (MD, −2.9 g/m2; 95% CI, −6.1 to 0.2; P = .07) or LV ejection fraction. Similarly, valsartan appeared to reduce decline in right ventricular volumes. Valsartan appeared to significantly reduce iICV progression (MD, −5.0 mL/m2; 95% CI, −9.7 to −0.4; P = .03), but did not impact iECV (MD, 0.0 mL/m2; 95% CI, −1.4 to 1.3; P = .95) or LGE progression (MD, 0.5%; 95% CI, −0.4 to 1.3; P = .30). These findings enhance mechanistic insights into the effect of valsartan in early-stage HCM, showing potential benefits on biventricular remodeling and myocardial intracellular volume. Further research to identify cellular mechanisms of valsartan on HCM progression is needed. ClinicalTrials.gov Identifier: NCT01912534

BACKGROUND:Sex differences in congenital heart disease are known to effect outcomes, however, there is limited data on its role in atrial septal defect (ASD) closure. AIMS:We aimed to investigate sex differences in baseline characteristics, procedural and long-term outcomes of patients who underwent transcatheter ASD closure. METHODS:This single-center, retrospective cohort study enrolled adult patients undergoing ASD closure between 2005 and 2016 at the Toronto General Hospital, Canada. Information on index procedure and follow-up was extracted from the hospital medical records. RESULTS:Of the 853 patients included, 281 (32.9%) were male and 572 (67.1%) were female. Females more frequently presented with dyspnea or palpitations, whereas males had more cardiovascular comorbidities. More males presented with right ventricular (RV) dysfunction than females. Females had higher RV systolic pressures and a higher prevalence of moderate-to-severe tricuspid regurgitation (TR). Procedure-related complications were rare and not different by sex. At 12-month follow-up, both males and females showed comparable decreases in RV diameter, RV systolic pressure, and TR severity. After a mean follow-up of 3 years (SD = 5), no significant differences were observed in the incidence of death (adjusted hazard ratio (HR) = 1.48 [95% CI 0.38-5.74]; p = 0.57), need for cardioversion or ablation, cerebrovascular events, and pacemaker implantation. Females had a lower hazard of new-onset atrial fibrillation than males (HR = 0.63 [95% CI 0.41-1.00]; p = 0.05). CONCLUSION:Although patient profiles differed by sex, procedural and long-term outcomes were comparable, suggesting that females and males benefit equally from transcatheter ASD closure.

ObjectiveMachine learning (ML) can facilitate prediction of major adverse cardiovascular events (MACEs) in repaired tetralogy of Fallot (rTOF). We sought to determine the incremental value of ML above expert clinical judgement for risk prediction in rTOF.MethodsAdult congenital heart disease (ACHD) clinicians (≥10 years of experience) participated (one cardiac surgeon and four cardiologists (two paediatric and two adult cardiology trained) with expertise in heart failure (HF), electrophysiology, imaging and intervention). Clinicians identified 10 high-yield variables for 5-year MACE prediction (defined as a composite of mortality, resuscitated sudden death, sustained ventricular tachycardia and HF). Risk for MACE (low, moderate or high) was assigned by clinicians blinded to outcome for adults with rTOF identified from an institutional database (n=25 patient reviews conducted by five independent observers). A validated ML model identified 10 variables for risk prediction in the same population.ResultsPrediction by ML was similar to the aggregate score of all experts (area under the curve (AUC) 0.85 (95% CI 0.58 to 0.96) vs 0.92 (0.72 to 0.98), p=0.315). Experts with ≥20 years of experience had superior discriminative capacity compared with <20 years (AUC 0.98 (95% CI 0.86 to 0.99) vs 0.80 (0.56 to 0.93), p=0.027). In those with <20 years of experience, ML provided incremental value such that the combined (clinical+ML) AUC approached ≥20 years (AUC 0.85 (95% CI 0.61 to 0.95), p=0.055).ConclusionsRobust prediction of 5-year MACE in rTOF was achieved using either ML or a multidisciplinary team of ACHD experts. Risk prediction of some clinicians was enhanced by incorporation of ML suggesting that there may be incremental value for ML in select circumstances.

Introduction: Children with significant left-to-right shunting across an isolated atrial septal defect (ASD) may have important right ventricular (RV) dilation. We sought to determine factors associated with RV recovery after percutaneous device closure. Methods: Children who underwent transcatheter device closure of an isolated ASD were included if they had no underlying genetic defect and echocardiography from prior to, immediately after and at follow-up. General linear regression modeling was used to determine factors associated with time-related RV dimensional recovery. Results: Inclusion criteria were met for 385 children (62% females; mean age 8.9 + 4.3 years) whose procedure occurred from 11/1985 to 11/2012. A single defect was present for 85%, with a mean size indexed to BSA of 14.9 + 6.6 mm/m 2 . A single device (Amplatzer for 80%) was used for 97% of the children, with a mild residual shunt present in 14% at the procedure. Mean BSA-indexed RV end-diastolic dimension (RVEDD) immediately post-closure was 2.20 + 0.66 cm/m 2 and decreased at a median follow-up of 1.8 years (range up to 13 years) to 1.71 + 0.48 cm/m 2 (p<0.001), corresponding to a mean BSA-adjusted Z score of +1.51 at follow-up (>+2 for 47% of children). Significant factors associated with a greater reduction in BSA-indexed RV size ( Figure ) included younger age at closure (p<0.001), larger indexed ASD size (p<0.001), greater RV size at closure (p<0.001) and longer follow-up time (p<0.001). Reduction was not associated with the presence of any residual shunt post-closure. QRS duration on ECG did not change significantly from pre-closure (mean 90 + 12 mmsec) to latest ECG (mean 89 + 12; p=035). Conclusions: Despite progressive reductions in RV size after ASD device closure, some children may continue to have RV enlargement. Earlier closure is associated with greater improvements.

Introductions: Pulmonary regurgitation is a diastolic phenomenon but little is known of the impact of RV-PA conduit interventions on RV diastolic function. We measured the acute effects of PPVI or stent implantation on RV diastolic relaxation with high-fidelity pressure catheters. Methods: Right and left heart pressure measurements with Millar Mikro-Cath pressure catheters in children undergoing RV-PA conduit intervention, who had also had an MRI. The relaxation time constant (RV-tau) was calculated as the time constant of the monoexponential pressure decay in the interval between the pressure at dP/dt min (P 0 ) to when the pressure fell to 10% of P 0 . Result: The age for PPVI (n=29) or stent (n=21) implantations were (mean ± sd): 14 ± 2.8 and 11.8 ± 4.2 years, respectively. RV-tau decreased 33% in the PPVI group and increased 11% in the Stent group (Table 1). The absolute value of RV dP/dt min decreased 9% in the Stent but not the PPVI group. The absolute value of LV dP/dt min increased 12% in the PPVI but not the Stent group. There was a small increase in peak VO 2 at the last follow-up (median 1.04 years, range 0.15-4.69 years) in the PPVI but not the Stent group compared to baseline (from 27.1 to 31.6 ml/kg/min, p = 0.01). The Δpeak VO 2 correlated with ΔRV-tau (r = 0.75, p = 0.01, n = 10) but not with ΔRV-PA gradient or pre pulmonary regurgitation fraction. Conclusions: PPVI results in faster RV diastolic relaxation. This may contribute to post-procedure enhanced exercise capacity more than either RV pressure and volume unloading alone.

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

OBJECTIVE:There is a high burden of reintervention after repair of tetralogy of Fallot (TOF). We compare procedural burden and late outcomes in valve-sparing repair (VSR) and transannular patch (TAP) cohorts over 30 years. METHODS:Patients undergoing TOF repair (1990-2021, excluding complex TOF) were included in this study (n = 1239) with subsequent comparisons between TAP (n = 550) and VSR (n = 648) cohorts. Descriptive statistics, cumulative incidence frequencies, survival analysis, and propensity matching (n = 425) were used to analyze reintervention burden and survival. RESULTS:Overall survival of the cohort was 96.7% at 15 years and 95.6% at 25 years, with similar survival between TAP and VSR cohorts (P = .22). The TAP cohort had increased incidence of procedural burden at 25 years (TAP 69.8% vs VSR 37.2%; P < .001), with 34.6% undergoing ≥2 reinterventions. The TAP cohort had higher incidence of surgical pulmonary valve replacement at 15 years (TAP 20.7% vs VSR 7.6%; P < .001) and placement of pulmonary artery stents (TAP 20.2% vs VSR 4.9%; P < .001). By contrast, VSR had higher incidence of right ventricular outflow tract (RVOT) reoperation at 15 years (VSR 7.3% vs TAP 3.6%; P = .047). After propensity score matching there was no survival advantage between the VSR and TAP cohorts (Era 2), whereas the need for RVOT reoperation was not different between the 2 cohorts (P = .060). CONCLUSIONS:The procedural burden remains high following TOF repair. TAP is associated with higher procedural burden in matched and nonmatched cohorts. VSR has increased risk of reoperation for RVOT obstruction only in nonmatched comparisons. Anatomical complexity and surgical repair strategy influence procedural burden following TOF repair.