Thrombocytopenia is Associated with Higher Fontan Pressure and Increased Morbidity in Patients with Fontan Circulation.

After the Fontan procedure, patients require lifelong follow-up due to significant late morbidity and mortality. Thrombocytopenia is seen frequently post-Fontan, likely due to secondary hypersplenism from elevated Fontan pressure. We investigated platelet counts in patients with a Fontan circulation and assessed associations with catheterization data and clinical outcomes. This retrospective study included 92 patients (33% female) post-Fontan who had a complete blood count performed between January 2011 and July 2023. The age at evaluation was 24.0 ± 8.9 years. Outcomes measured included elevated Fontan pressure (≥ 15 mmHg), Fontan-associated liver disease (FALD), unscheduled admissions, transplant, and death. Participants with thrombocytopenia (≤ 150,000/µL) had significantly higher rates of elevated Fontan pressure (OR 8.1, 95% CI 1.3-52.7, p = 0.03), FALD (OR 4.1, 95% CI 1.6-10.6, p = 0.004), and unscheduled admissions (362 ± 577 versus 115 ± 185 admissions per 1000 patient-years, p = 0.02). Thrombocytopenia post-Fontan is associated with elevated Fontan pressure, FALD, and increased morbidity. Platelet count could serve as a non-invasive factor in identifying patients at risk of decompensation.

Augmented Biphasic Breathing Using Sniff and an Oral Positive Expiratory Pressure Device (Sniff-PEP) in Fontan Patients.

The use of an oral positive expiratory pressure device (oPEP) with sniff breathing (Sniff-PEP) mimics biphasic ventilation. Biphasic ventilation increases pulmonary blood flow and cardiac output in Fontan patients. The aim of this study was to assess the effect of Sniff-PEP on Fontan flow velocities. A single-center, pilot, prospective study was carried out in 15 subjects with Fontan circulation enrolled to use the oPEP device for 1 month. Subjects were instructed on Sniff-PEP and to use the device for 10-15 min 3-4 times a day. Measurements of flow velocity and cardiac output were measured via echocardiogram and quality of life assessments were performed at baseline and 4-6 weeks later. The mean age at enrollment was 19.9 ± 8.7 years (age range of 10-37 years). 7 patients (47%) had dominant left ventricle and 8 (53%) had an open fenestration. There was a statistically significant increase in flow velocities in the hepatic vein from 27.5 ± 7.6 to 35.1 ± 11.3 cm/s (p = 0.003), left pulmonary artery from 51.6 ± 16.6 to 57.6 ± 21.1 cm/s (p = 0.01), and right pulmonary artery from 43.1 ± 14.2 to 45.8 ± 17.2 cm/s (p = 0.04). With chronic use, the mean fenestration gradient slightly decreased from 4.5 ± 1.6 to 4.1 ± 1.9 mmHg but the difference was not statistically significant (p = 0.14). oPEP device therapy increased flow velocity in several areas in the Fontan circulation with acute use. Further studies are needed to assess the effects long term.Clinical Trial Registration: URL: https://clinicaltrials.gov . Unique identifier: NCT03251742.

Persistent Patent Vertical Vein After Repair of Total Anomalous Pulmonary Venous Connection (TAPVR): A Rare Cause of Hypoxemia Post-Fontan Procedure.

Vertical vein (VV) ligation during total anomalous pulmonary venous return (TAPVR) repair is controversial. While some surgeons prefer ligation of the VV to prevent adverse sequelae of shunting across it and to promote flow through the newly created anastomosis, others leave it to serve as a "pop off valve" to the left heart structures, which are believed to be hypoplastic and noncompliant, presumably contributing to a more favorable post-operative outcome. We report two patients post-Fontan procedure, who underwent cardiac catheterization to explore the etiology of hypoxia and were found to have a persistent VV responsible for right to left shunting. Both patients underwent closure of the VV with improvement in the cyanosis and clinical course. These cases provide evidence supporting surgical ligation of the VV at the time of TAPVR repair, especially in patients with single ventricle.

Occlusion of the os of the left coronary artery by dysplastic aortic valve tissue presenting as progressive mitral insufficiency and cardiac arrest.

Mitral regurgitation in the neonatal period is relatively rare. It can be secondary to a congenital malformation of the valve apparatus or mitral valve dysfunction and deformation secondary to myocardial dysfunction or volume load of the left ventricle. Less commonly, it can be due to coronary artery abnormalities leading to mitral valve papillary muscle ischaemia and subsequent dysfunction. Such coronary artery abnormalities include anomalous left coronary artery from pulmonary artery, left main coronary artery atresia, or a thromboembolic phenomenon. In this study, we describe a newborn with a dysplastic aortic valve causing obstruction of the os of the left coronary artery leading to progressive mitral insufficiency.

Cardiac MRI-Derived Inferior Vena Cava Cross-Sectional Area Correlates with Measures of Fontan-Associated Liver Disease.

There is currently no clear consensus on screening techniques to evaluate the presence or severity of Fontan-associated liver disease (FALD). Cardiac MRI (CMR) is used routinely for post-Fontan surveillance, but CMR-derived measures that relate to the severity of FALD are not yet defined. This was a cross-sectional single-center study of post-Fontan patients who underwent a CMR. CMR exams were re-analyzed by a single pediatric cardiologist. Surrogates of FALD included Gamma-Glutamyl Transferase (GGT), Fibrosis-4 laboratory score (FIB-4), and imaging findings. Findings consistent with cirrhosis on liver ultrasound included increased liver echogenicity and/or nodularity. Statistical analyses were performed to investigate potential relationships between CMR parameters and markers of FALD. Sixty-one patients were included. A larger inferior vena cava cross-sectional area (IVC-CSA) indexed to height was significantly associated with a higher FIB-4 score (Spearman's ρ = 0.28, p = 0.04), a higher GGT level (Spearman's ρ = 0.40, p = 0.02), and findings consistent with cirrhosis on liver ultrasound (OR 1.17, 95% CI: (1.01, 1.35), p = 0.04). None of the other CMR parameters were associated with markers of FALD. A larger indexed IVC-CSA was associated with higher systemic ventricle end-diastolic pressure (EDP) on cardiac catheterization (Spearman's ρ = 0.39, p = 0.018) as well as older age (Spearman's ρ = 0.46, p = < 0.001). Indexed IVC-CSA was the only CMR parameter that was associated with markers of FALD. This measure has the potential to serve as an additional non-invasive tool to improve screening strategies for FALD. Visual abstract summarizing the primary findings of this paper.

Comparison of the investigational device exemption and post-approval trials of the Melody transcatheter pulmonary valve.

OBJECTIVE: We compared 5-year outcomes of transcatheter pulmonary valve (TPV) replacement with the Melody TPV in the post-approval study (PAS) and the investigational device exemption (IDE) trial. BACKGROUND: As a condition of approval of the Melody TPV after the IDE trial, the Food and Drug Administration required that a PAS be conducted to evaluate outcomes of TPV replacement in a "real-world" environment. The 5-year outcomes of the PAS have not been published, and the IDE and PAS trials have not been compared. METHODS: The cohorts comprised all patients catheterized and implanted at 5 IDE sites and 10 PAS sites. Differences in trial protocols were detailed. Time-related outcomes and valve-related adverse events were compared between the two trials with Kaplan-Meier curves and log-rank testing. RESULTS: 167 patients (median age, 19 years) were catheterized and 150 underwent TPV replacement in the IDE trial; 121 were catheterized (median age, 17 years) and 100 implanted in the PAS. Freedom from hemodynamic dysfunction (p = .61) or any reintervention (p = .74) over time did not differ between trials. Freedom from stent fracture (p = .003) and transcatheter reintervention (p = .010) were longer in PAS, whereas freedom from explant (p = .020) and TPV endocarditis (p = .007) were shorter. Clinically important adverse events (AEs) were reported in 14% of PAS and 7.2% of IDE patients (p = .056); the incidence of any particular event was low in both. CONCLUSIONS: Hemodynamic and time-related outcomes in the PAS and IDE trials were generally similar, confirming the effectiveness of the Melody TPV with real-world providers. There were few significant complications and limited power to identify important differences in AEs. The lack of major differences in outcomes between the two studies questions the usefulness of mandated costly post-approval studies as part of the regulatory process for Class III medical devices.

Radiation Risk Categories in Cardiac Catheterization for Congenital Heart Disease: A Tool to Aid in the Evaluation of Radiation Outcomes.

To stratify diverse procedure types into categories with similar radiation exposure in cardiac catheterization for congenital heart disease. Radiation exposures for a comprehensive list of specific procedure types and stratification of outcomes based on radiation risk are not currently available. Data between January 2014 and December 2015 were collected on all cases performed at sites participating in C3PO-QI (Congenital Cardiac Catheterization Outcomes Project-Quality Improvement Initiative) and 9 centers were included. Using expert consensus, 40 unique procedure types were defined by diagnostic characteristics or the intervention(s) performed, and dose area product (DAP) per kilogram of body weight (µGy × m2/kg) was summarized. Using empiric and consensus methods, three radiation risk categories were created. A total of 11,735 cases were included for analysis. Thirteen (n = 7918) procedure types with median DAP/kg < 100 were categorized in the low radiation exposure category (median DAP/kg 39). The medium exposure category (n = 1807) consisted of 16 procedure types with median DAP/kg values ranging 100 to < 200 (overall median DAP/kg 131). Finally, the high radiation exposure category (n = 1073) consisted of 11 procedure types with median DAP/kg ≥ 200 (overall median DAP/kg of 231). The radiation exposure risk categories created in this multi-center dataset are a critical step towards the development of a robust risk adjustment methodology for radiation exposure in catheterization for congenital heart disease.

Implementation of Methodology for Quality Improvement in Pediatric Cardiac Catheterization: A Multi-center Initiative by the Congenital Cardiac Catheterization Project on Outcomes-Quality Improvement (C3PO-QI).

The Congenital Cardiac Catheterization Project on Outcomes (C3PO) launched in 2007 as a multi-center collaborative to establish standardized and comparable metrics for pediatric cardiac catheterization procedures. The limitations of larger registries at the time led to the development of the next phase in 2013, C3PO-Quality Improvement (C3PO-QI), focusing on instituting QI initiatives within the field. The objective of this manuscript is to provide a detailed overview of C3PO-QI and report data on case characteristics and outcome metrics being explored. C3PO-QI was designed to cultivate institutional collaboration during implementation of its initiatives. A database and website were developed to support data entry and on-demand reporting. The registry prospectively captures pediatric cardiac catheterization data among 15 hospitals. The present study includes case demographic data (n) and quality metric reporting by case type, age, and radiation dose variables. This dataset includes 13,135 cases entered into the database between 1/1/2014 and 12/31/2015. Interventional cases make up the highest percentage by case mix distribution (48 %), and patients <1 years make up the highest percentage by age distribution (26 %). The ratio of diagnostic and interventional procedures performed changes by age group. Application of QI metric shows all procedure types surpassing metric goals. Large volume data collection, such as in C3PO-QI, allows for meaningful interpretation of data. C3PO-QI is uniquely poised to deliver fast-paced changes in the field. Although the project initiatives are specific to pediatric cardiac catheterization, the implementation of the project and utilization of real-time reporting is generalizable to other specialties and multi-center collaboratives.

Transcatheter management of mid-aortic syndrome secondary to myofibroma presenting in infancy with severe left ventricular dysfunction: a case report.

In this study, we summarise a case of a myofibroma causing mid-aortic syndrome due to obstruction of the distal thoracic and abdominal aorta leading to severe left ventricular dysfunction. The patient was managed with percutaneous intervention via balloon dilation and stent placement. On follow-up, the patient has normalisation of ventricular function, is off anti-hypertensives, and is being monitored for re-stenosis.

NuMED Covered Cheatham-Platinum Stent™ for the treatment or prevention of right ventricular outflow tract conduit disruption during transcatheter pulmonary valve replacement.

OBJECTIVE: Retrospectively assess the frequency of right ventricular outflow tract (RVOT) conduit disruption during transcatheter pulmonary valve replacement (TPVR) and the effectiveness and safety of NuMED Covered Cheatham-Platinum Stents™ (CCPS) for its prevention or treatment. BACKGROUND: There have been no published reports to date describing the safety and effectiveness of covered stents to prevent or treat RVOT conduit disruption during TPVR. METHODS: Data regarding 251 TPVR procedures performed at multiple US investigational sites were retrospectively reviewed to explore the incidence and potential predictors of conduit disruption. In addition, data on the use of 69 CCPS implanted in 50 patients during TPVR was reviewed. RESULTS: The overall incidence of conduit disruption requiring intervention was 6%. The only predictor identified was a very elevated RVOT conduit systolic pressure gradient. A pre-existing conduit tear was present in nine, while 31 developed tears after conduit dilation and three, after TPVR. The CCPS was used prophylactically in seven. Conduit tears were prevented or repaired in 49/50 patients. No CCPS-related acute complications were reported. At 6-month follow-up, no patient had more than mild pulmonary regurgitation and the mean Doppler RVOT gradient (12.7 ± 5.8 mm Hg) comparing favorably with that reported in the Melody TPV® IDE trial (20.0 ± 8.6 mm Hg). CONCLUSION: CCPS implantation can successfully treat RVOT conduit disruption without negative impact on the TPV function. This retrospective analysis suggests high RVOT conduit systolic pressure gradient is a risk factor for conduit tears during TPVR.

Device therapy for atrial septal defects in a multicenter cohort: acute outcomes and adverse events.

BACKGROUND: Secundum atrial septal defect (ASD) closure devices were granted approval based on industry-sponsored, prospective, nonrandomized, single device studies, demonstrating acceptable efficacy and safety in selected patients. We sought to report community practice and outcomes. METHODS AND RESULTS: Procedure specific data was collected on cases considered for ASD closure in the congenital cardiac catheterization project on outcomes (C3PO) between February 1, 2007 and June 31, 2010. Eight centers contributed data during this time period. All adverse events (AE) were independently reviewed and classified by a five level severity scale. In 40 months (2/07-6/10), 653 of 688 ASDs were occluded with a single device using an AMPLATZER(®) Septal Occluder (ASO) in 566 (87%), GORE(®) HELEX(®) Septal Occluder (HSO) in 33 (5%), and a CardioSEAL(®) or STARFlex™ device (CSD) in 54 (8%). Most patients had an isolated ASD (93%). 85% were >2 years of age. The ASD median diameter was 12 mm [8,16] for ASO, with smaller diameters in HSO 8 mm [7,10] and CSD 8 mm [5,10] (P < 0.001). AE (n = 82) were recorded in 76 cases, 11.5% (95% CI 9.2%, 14.1%) and classified as high severity in 4.7% (95% CI 3.2%, 6.5%), with no mortality. A new conduction abnormality was detected during 15 cases and did not resolve in one. Transcatheter device retrieval was possible in 7 of 10 device embolizations. Device erosion occurred in 3 of 566, 0.5% (95% CI 0.1%, 1.5%), ASO implants. CONCLUSION: Although device closure of ASDs is associated with low morbidity and rare mortality, ongoing assessment of device safety profiles are warranted, and registries offer opportunities to facilitate the required surveillance.

Outcomes of pediatric patients undergoing cardiac catheterization while on extracorporeal membrane oxygenation.

The aim of the study is to explore the indications for cardiac catheterization while on extracorporeal membrane oxygenation (ECMO) and the various catheter interventions performed as well as assess the safety profile and determine the short- and intermediate-term survival. ECMO is a lifesaving intervention for pediatric patients with respiratory and/or cardiovascular failure. There is limited recent literature discussing the survival and outcomes of patients undergoing cardiac catheterization while on ECMO. A retrospective review of consecutive patients undergoing catheterization while on ECMO from 2004 to 2013 was performed. Thirty-six patients who underwent 40 cardiac catheterizations were identified. Indications for catheterization included hemodynamic/anatomic assessment of postoperative (16) and non-operative patients (7), planned catheter interventions (CI) (12), and cardiomyopathy assessment (5). CI were performed during 18 (45 %) catheterizations, including stenting of vessels/surgical shunts (9), balloon atrial septostomy (4), device closure of septal defects/vessels (3), thrombolysis of vessels (2), endomyocardial biopsy (2), and temporary pacer wire placement (1). Unexpected diagnostic information was found in 21 (52 %), and 13 patients were referred for surgical intervention. Successful decannulation was achieved in 86 % of patients. Survival to discharge was 72 % and intermediate survival was 69 % (median = 29 months). Survival was 88 % (15/17) among patients who underwent CI. There were six procedural complications (15 %); five vascular and one non-vascular. There were no complications related to patient transport. Cardiac catheterization and interventions while on ECMO are safe, with a survival to discharge of 72 %. Diagnostic information obtained from catheterization leads to management decisions which may impact survival.

SCAI expert consensus statement for advanced training programs in pediatric and congenital interventional cardiac catheterization.

Pediatric and Congenital Interventional Cardiology is the practice of catheter-based techniques that improve cardiac physiology and circulation through the treatment of heart disease in children and adults with congenital or acquired heart defects. Over the last decade, and since last published training guidelines for pediatric cardiac catheterization and interventional cardiology were published in 2005 [1] the field of Pediatric and Congenital Cardiac Catheterization has evolved into a predominantly interventional discipline. As there is no sub-specialty certification for interventional cardiac catheterization in pediatrics, the Congenital Heart Disease Committee of the Society of Cardiovascular Angiography and Interventions has put together this consensus statement for advanced training in pediatric and congenital interventional cardiac catheterization. The statement puts forth recommendations for program infrastructure in terms of teaching, personnel, equipment, facilities, conferences, patient volume and trainee assessment. This is meant to set a standard for training programs as well as giving applicants a basis on which to judge and compare programs.

Living to Tell the Tale: A First-Person Chronicle of the Development of the Fontan-Kreutzer Procedure.

The current surgical approach for patients with a single ventricle is the culmination of decades of dedicated research and groundbreaking innovation. From 1971 to the present day, a series of incremental advancements have significantly extended the life expectancy of these patients. Since the very beginning, Dr Guillermo Kreutzer and his team have pioneered different techniques with the ultimate goal of improving outcomes for these individuals. This is, narrated by him, the story of how it all began.

Participation in Competitive Sports by Patients With Congenital Heart Disease: AHA/ACC and EAPC/ESC/AEPC Guidelines Comparison.

Sports participation in patients with congenital heart disease is an evolving subject. The American Heart Association/American College of Cardiology released a set of guidelines that advise the type and level of sports participation based primarily on anatomical defects with secondary consideration given to hemodynamic effects. Recently, the European Association of Preventive Cardiology/European Society of Cardiology/Association for European Paediatric and Congenital Cardiology offered a contrasting approach to sports participation that is based on hemodynamic and electrophysiological profiles of each patient, regardless of anatomical consideration. These guidelines are drastically different in their approaches but do have some similarities. In this review, we compare both documents, focusing on the aim, population, classification of sports, and the methodology of making recommendations. This review aims to assist practicing cardiologists in integrating the available published data and recommendations when counseling patients for sports participation.

A probabilistic neural twin for treatment planning in peripheral pulmonary artery stenosis.

The substantial computational cost of high-fidelity models in numerical hemodynamics has, so far, relegated their use mainly to offline treatment planning. New breakthroughs in data-driven architectures and optimization techniques for fast surrogate modeling provide an exciting opportunity to overcome these limitations, enabling the use of such technology for time-critical decisions. We discuss an application to the repair of multiple stenosis in peripheral pulmonary artery disease through either transcatheter pulmonary artery rehabilitation or surgery, where it is of interest to achieve desired pressures and flows at specific locations in the pulmonary artery tree, while minimizing the risk for the patient. Since different degrees of success can be achieved in practice during treatment, we formulate the problem in probability, and solve it through a sample-based approach. We propose a new offline-online pipeline for probabilistic real-time treatment planning which combines offline assimilation of boundary conditions, model reduction, and training dataset generation with online estimation of marginal probabilities, possibly conditioned on the degree of augmentation observed in already repaired lesions. Moreover, we propose a new approach for the parametrization of arbitrarily shaped vascular repairs through iterative corrections of a zero-dimensional approximant. We demonstrate this pipeline for a diseased model of the pulmonary artery tree available through the Vascular Model Repository.

Impact of guideline directed medical therapy on myocardial function in adults with congenital heart disease.

BACKGROUND: Guideline-directed heart failure therapy with angiotensin receptor blocker/neprilysin inhibitor (ARNi) and sodium-glucose transporter inhibitors (SGLT2i) has been incrementally beneficial in improving outcomes in heart failure patients. OBJECTIVE: Evaluate the feasibility and efficacy of guideline-directed medical therapy (GDMT) in adults congenital heart disease (ACHD) patients. METHODS: In a retrospective cohort study, ACHD patients with either New York Heart Association (NYHA) Class II symptoms or systemic ejection fraction (EF) <45%, optimized on a combination of beta-blocker (BB), ARNi, mineralocorticoid receptor antagonist (MRA) and SGLT2i were evaluated. RESULTS: Forty-six patients with a mean age 42.6 ± 12.1 years prescribed GDMT were identified. Twenty-eight (61%) were male, 20 (43%) had a systemic right ventricle (RV) and 9 (20%) had single-ventricle physiology. Over the optimization period, 20 (43%) were sustained on ARNi and 42 (91%) on SGLT2i in addition to treatment with BB and MRA. Over a period of 45 weeks, echocardiography parameters for left ventricle (LV) ejection fraction (EF) (+7.5%, p = 0.006), systemic ventricle (SV) velocity time integral (VTI) (+1.9 cm, p = 0.012) and LV global longitudinal strain (GLS) (-2.5%, p = 0.005) improved when 3-4 medications were used versus 1-2 medications alone. The use of either ARNi or SGLT2i (+8.1%, p = 0.017) or in combination (+7.0%, p = 0.043) increased LVEF compared to the use of neither medication. CONCLUSION: Combination GDMT is beneficial in improving myocardial characteristics in ACHD patients with systemic RV and LV.

Relationship between procedural adverse events associated with cardiac catheterization for congenital heart disease and operator factors: results of a multi-institutional registry (C3PO).

BACKGROUND: Data examining the effect of operator years in practice and volume on adverse events (AE) after cardiac catheterization in patients with congenital heart disease is limited. METHODS AND RESULTS: Data were prospectively collected using a multi-center registry (C3PO). 10,885 catheterizations performed between 02/07 and 06/10 at eight institutions were included. AE rates were risk-adjusted for hemodynamic vulnerability, procedure type risk group, and age and compared between operators with different years in practice (YIP) and volume. AE occurred in 13% of procedures. Operators with less than five YIP had higher adjusted odds of any AE (OR 1.42, 95% CI 1.14-1.77) or a high severity AE (OR 1.35, 95% CI 1.04-1.75), when compared with operators with 5 to less than 25 YIP (5 < 25), while operators with ≥25 YIP had higher odds of a high severity (but not any) AE (OR 1.39, 95% CI 1.08-1.80). Operators with <5 YIP had a higher percentage of preventable AE (out of all AE, 16% vs. 8%, P < 0.001) as well as higher odds of vascular or cardiac trauma (OR 1.81, 95% CI 1.11-2.97), or technical AE (OR 1.98, 95% CI 1.31-2.99) when compared with operators with 5 < 25 YIP. There was no consistent relationship between operator volume, and incidence of AE. CONCLUSIONS: Operators with less than 5 years in practice have higher risk-adjusted AE rates. While an important consideration in guiding and mentoring operators with fewer years in practice, it is important to emphasize that reporting adverse events does not take into account procedural efficacy.

Low weight as an independent risk factor for adverse events during cardiac catheterization of infants.

BACKGROUND: Studies have documented the importance of procedure type and hemodynamic variables on the incidence of procedure related adverse events (AE) after cardiac catheterization. However, little is known about the impact of low weight on the incidence and severity of AE. METHODS: Data were prospectively collected using a multicenter registry (C3PO). Infants <1 year were divided into four weight categories: <2 kg, 2-3 kg, 3-5 kg, ≥5 kg. AE severity was classified as level 1-5 (none, minor, moderate, major, death). RESULTS: Eight centers submitted details on 3,679 cases (34% diagnostic) performed in infants <1 year from 2/07 to 6/10: <2 kg: 57 (1.5%), 2-3 kg: 403 (11%), 3-5 kg: 1,527 (41.5%), ≥5 kg: 1,692 (46%). AE occurred in 20% of cases (<2 kg: 28%, 2-3 kg: 25%, 3-5 kg: 23%, ≥5 kg: 16%) with 41% of all AE being level 3-5 AE. Death occurred more frequently in the <2 kg group (12%), 71% of which were interventional cases. The case-related mortality in all other weight groups was <1%. By multivariable analysis, weight <2 kg, 2-3 kg, and 3-5 kg were independent risk factors for high severity (level 3-5) AE (<2 kg: OR 2, 95%CI 1.1-3.6; 2-3 kg: OR 1.4, 95%CI 1-1.8; 3-5 kg: OR 1.3, 95%CI 1.1-1.5), with similar findings for all AE. Blood transfusions were more common in lower weight categories (<2 kg: 42%, 2-3 kg: 29%, 3-5 kg: 25%, ≥5 kg: 15%, p<0.001). CONCLUSIONS: The risk of AE during cardiac catheterization of infants increases with lower weight. Infants who weigh less than 2 kg have a significantly higher risk of adverse events (most notably death) even after correcting for hemodynamic vulnerability and procedure type risk group.