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Introduction Cardiac perforation is a rare life-threatening complication of cardiac catheterization. There is very little published literature detailing risk factors for cardiac perforation and outcomes from this complication in children. Materials and Methods This was a retrospective study analyzing the cardiac catheterization case registry of the Congenital Cardiovascular Interventional Study Consortium. Children aged Results Cardiac perforation occurred in 50 patients from a total of 36,986 (0.14%). Cardiac perforation was more likely to occur in younger, smaller patients undergoing urgent /emergent and interventional procedures (pppConclusions Cardiac perforation during cardiac catheterization is a life-threatening complication with a range of associated secondary complications. Higher CRISP score, lower age and radio-frequency perforation of pulmonary valve are independent predictors.

Pulmonary endarterectomy (PEA) is the main treatment for chronic thromboembolic pulmonary hypertension (CTEPH). Postoperative unfractionated heparin dosing can be monitored by activated partial thromboplastin time (APTT) or by anti-factor Xa activity (anti-Xa). In pseudo heparin resistance, APTT response to heparin is blunted due to elevated Factor VIII (FVIII) which can underestimate anticoagulation. We examined possible pseudo heparin resistance after PEA and assessed the impact of FVIII. APTT response to heparin before and after operation was determined in 13 PEA patients anticoagulated with unfractionated heparin. APTT and anti-Xa concordance was analyzed from paired postoperative samples, and antithrombin, fibrinogen and FVIII levels were measured. Single-cell RNA sequencing was used to characterize FVIII gene expression in PEA specimens of 5 patients. APTT response to heparin was blunted after PEA. APTT and anti-Xa were discordant in 36% of postoperative samples and most common discordant patterns were subtherapeutic APTT with therapeutic (16%) or supratherapeutic (11%) anti-Xa. Overall, APTT underestimated anticoagulation relative to anti-Xa in one-third of the samples. FVIII levels were elevated before surgery, increased substantially 1 and 3 days (median 4.32 IU/mL) after PEA, and were higher in discordant than concordant samples. Single-cell RNA sequencing showed FVIII gene expression in PEA specimen endothelial cells. Pseudo heparin resistance is common after PEA likely due to highly elevated postoperative FVIII levels indicating that anti-Xa reflects postoperative heparinization better than APTT in these patients. FVIII production by the pulmonary artery endothelium may participate in local prothrombotic processes important for CTEPH pathogenesis.

Objectives Characterize the safety and effectiveness of the Amplatzer Piccolo Occluder for patent ductus arteriosus (PDA) closure. Background The presence of a hemodynamically significant PDA has been associated with an increased risk of morbidity and mortality in children born premature. Methods This was a single arm, prospective, multicenter, non-randomized study to evaluate the Amplatzer Piccolo Occluder to treat PDA in patients ≥700 g. From June 2017 to February 2019, 200 patients were enrolled at nine centers, with 100 patients weighing ≤2 kg. Primary effectiveness endpoint was the rate of PDA closure at 6-month follow-up. Primary safety endpoint was the rate of major complications through 6 months. Secondary endpoint was rate of significant pulmonary or aortic obstruction through 6 months' follow-up. Results The implant success rate was 95.5% (191/200) overall and 99% in patients ≤2 kg (99/100). The primary effectiveness endpoint was achieved in 99.4% of implanted patients. Four patients experienced a primary safety endpoint event (2 transfusions, 1 hemolysis, and 1 aortic obstruction). There were no branch pulmonary artery obstructions. Five patients, all ≤2 kg, were noted to have worsening of tricuspid regurgitation (TR) after the procedure. None of the TR incidences manifested clinically. The Amplatzer Piccolo Occluder received FDA approval in January 2019 and became the first device approved for PDA closure in patients ≥700 g. Conclusions This study supports the safety and effectiveness of the Amplatzer Piccolo Occluder, particularly in patients between 700 g and 2 kg where there is currently a significant unmet need in the United States. ClinicalTrials.gov identifier: NCT03055858.

OBJECTIVES To externally validate the CRISP score, and determine if refinements might improve clinical utility. BACKGROUND The CRISP score estimates risk of serious adverse events (SAEs) for pediatric catheterization. METHODS Pediatric (age < 18) procedures reported to the Congenital Cardiovascular Interventional Study Consortium registry from 05/08 to 09/17 (n = 29,830, 27 centers) were divided into a development dataset of 14,784 earlier procedures, and a validation dataset of 15,046 more recent procedures. The development dataset was used to refit the original CRISP model, and to develop a revised(r) CRISP score, consisting of entirely pre-procedurally collected data. The validation dataset was then used to compare model fit and risk prediction between CRISP, rCRISP and two existing risk scores using Akaike's (AIC), Schwarz's (BIC) Bayes Information Criteria, -log Likelihood (N2LL), area under the receiver operator curve and chi-square goodness-of-fit statistic (across 5 risk categories). RESULTS Overall 4.31% of patients experienced at least one SAE with frequency increasing from 1.08% in CRISP category 1 to 27.34% in category 5. Both CRISP and rCRISP (entirely pre-procedural) predicted risk of SAEs well, with observed to predicted ratios ranging from 0.71 to 1.18 across the 5 risk categories. Compared to the original CRISP score, rCRISP demonstrated less optimal model fit (higher AIC, BIC, and N2LL) but similar risk prediction (C-statistic = 0.71 vs. 0.70; chi-squared statistic = 6.77 vs. 6.85). CONCLUSION The CRISP score accurately predicts procedural risk. With minor modifications, the revised version (rCRISP) performed well with arguably greater clinical utility as an entirely preprocedural risk model.

During transcatheter pulmonary valve placement, coronary compression observed during simultaneous right ventricular outflow tract angioplasty and coronary angiography typically contraindicates valve implantation. We present a unique patient with tetralogy of Fallot who underwent successful transcatheter Melody valve placement despite coronary compression observed during right ventricular outflow tract balloon angioplasty.

Systemic ventricular end-diastolic pressure (SVEDP) is an important determinant of pulmonary artery pressure in those with a Fontan circulation. Predictors of an elevated SVEDP have been incompletely identified in this population. All who underwent the Fontan operation at our center between 1/2009 and 12/2013 were retrospectively identified. SVEDP at the pre-Fontan catheterization and other patient variables were extracted. We identified 61 patients. Pre-Fontan SVEDP was positively associated with systemic ventricular systolic pressure (β = 0.4, p = 0.004), aortic systolic pressure (β = 0.3, p = 0.007), aortic mean pressure (β = 0.3, p = 0.02), and decreased ventricular systolic function (p = 0.03). Compared to those with pre-Fontan SVEDP ≤ 7 mmHg, patients with SVEDP > 7 mmHg had higher average ventricular systolic pressure (85.0 ± 7.5 vs. 78.7 ± 8.3 mmHg, p = 0.003), higher average descending aorta mean pressure (62.4 ± 4.9 vs. 58.6 ± 8.1 mmHg, p = 0.03), and a higher incidence of decreased ventricular systolic function (36 vs. 15%, p = 0.07). For those with a systemic right ventricle, the SVEDP decreased significantly from the pre-Stage 2 to pre-Fontan measurements (8.7 ± 2.6 vs. 7.3 ± 2.0 mmHg, p = 0.02), but not for those with a systemic left ventricle (7.8 ± 2.0 vs. 7.2 ± 1.8 mmHg, p = 0.3). At pre-Fontan catheterization, decreased ventricular systolic function and markers of systemic afterload were positively associated with the SVEDP. SVEDP decreased significantly after Stage 2 for those with a systemic right ventricle, but not for those with a systemic left ventricle; the systemic right ventricle may be particularly vulnerable to pre-Stage 2 volume loading.

Aims We sought to identify factors associated with major adverse events (MAE) after cardiac catheterization in adolescents and adults with congenital heart disease (CHD), and create the first model to individualize risk discussions in this growing population. Methods and results Improving Pediatric and Adult Congenital Treatment (IMPACT), a National Cardiovascular Data Registry, contains congenital catheterization data from over 87 hospitals in the United States. Demographics, pre-procedure, and procedural variables were collected for patients over age 10. Multivariable logistic regression was used to identify significant predictors of MAE, a composite of death, urgent surgery or procedure due to a catheterization complication, transfusion, embolic stroke, tamponade, extracorporeal membrane oxygenation or ventricular assist device placement, and device embolization, malposition or thrombosis requiring surgical intervention. A risk score was built based on the effect sizes of each predictor and validated in a split sample. A MAE occurred in 686 (2.5%) of the 27 293 index procedures meeting inclusion criteria. The independent multivariate predictors of MAE were older age, pre-procedural anticoagulation use, renal disease, lower haemoglobin, lower oxygen saturation, non-elective procedure, higher index procedure risk and having had no prior cardiac procedures. Being underweight or overweight had borderline significance and was added to the model. The C-statistic for the model was robust at 0.787 in the derivation and 0.773 in the validation cohort. Conclusion The factors predicting adverse events after cardiac catheterization in adolescents and adults with CHD are different than in the general population. Validation of this model in other national or multi-institutional datasets is the next step.

Purpose The majority of potential donor lungs are not being used. The primary reason for underutilization is the concern for primary graft dysfunction (PGD). There is currently no clinically available therapy for PGD. Alpha 1 antitrypsin (A1AT) is a serine protease inhibitor with anti-inflammatory and cytoprotective properties. We and others have shown benefits of A1AT in small and large animal lung transplant studies. Before performing clinical trials, evidence of therapeutic efficacy in human lungs would be valuable. We tested the effect of A1AT given during ex vivo lung perfusion (EVLP) to human lungs rejected for transplantation. Methods Double lung blocks rejected for transplantation (n=8) were divided and placed on separate EVLP circuits for 12h. Lungs were randomly assigned to receive A1AT or placebo, with the contralateral lung serving as control for the treated lung. Outcome measures included: hourly physiologic lung function, perfusate loss, wet-dry weight ratio, inflammatory mediators, endothelin-1 (ET-1), and zonula occludens tight junction protein‐1 (ZO‐1, immunofluorescence staining). Results The A1AT-treated group demonstrated significantly better lung function: higher pO2 and compliance (Fig A), lower pulmonary artery pressure (-0.4 mmHg p= 0.04) and vascular resistance (-30.4 dynes·s cm−5 p= 0.01). Perfusate loss, a surrogate for lung permeability, was lower in the A1AT group, as was the wet-dry ratio (Fig B). A1AT also decreased ET-1 levels in perfusate (Fig C) and increased ZO-1 expression on endothelial cells (Fig D). Conclusion In this study we demonstrated that human A1AT was able to improve the quality of severly injuried human lungs, likely through endothelial cell protection. The encouraging results justify a clinical trial, in order to improve donor lung quality and clinical outcomes in lung transplantation. Our study also illustrates that testing selected drugs on injured human lungs on EVLP is a viable strategy prior to clinical application.

Purpose Ex-vivo lung perfusion (EVLP) maintains marginal donor lungs at body temperature with ventilation and circulating perfusate, allowing for functional assessment prior to transplantation. Prolonged EVLP would allow for advanced time-dependent therapies for donor lung repair and reconditioning. We hypothesized that the addition of a dialysis machine to the EVLP circuit would maintain homeostasis of the donor lung and prolong EVLP duration. Methods Porcine donor lungs (n=3) were extracted and placed on the EVLP platform for 36 hours or until termination criteria (dynamic compliance Results Dialysis successfully prevented an increase in electrolyte levels (Fig 1C) and maintained glucose and lactate levels at baseline (1C). EVLP was prolonged in the dialysis group with a mean duration of EVLP reaching 32±6.93 h in the E+D group compared to 18.67±3.27 h in the historical control group (Fig 1D). Percent lung survival at 24h of perfusion was 100% in the E+D group, while only 20% was seen in historical controls (Fig 1B). Both lungs which survived to 36h of EVLP presented excellent lung function based on assessment by EVLP. Conclusion Dialysis may preserve lung function and length of EVLP by maintaining homeostasis of the lung. Following the results of this encouraging pilot study, a formal blinded experiment is being performed and is underway.

Purpose Ex-vivo lung perfusion (EVLP) maintains marginal donor lungs at body temperature with ventilation and circulating perfusate, allowing for functional assessment prior to transplantation. Prolonged EVLP would allow for advanced time-dependent therapies for donor lung repair and reconditioning. We hypothesized that the addition of a dialysis machine to the EVLP circuit (dEVLP) would maintain homeostasis of the donor lung and prolong EVLP duration. Methods Porcine donor lungs (n=6) were extracted and placed on the EVLP platform for 36 hours or until termination criteria (dynamic compliance Results EVLP was prolonged in the dialysis group with a mean duration of EVLP reaching 30.83±0.57 h in the dEVLP group compared to 19.6±2.61 h in the historical control group (Fig 1D). Percent lung survival at 24h of perfusion was 100% in the dEVLP group, while only 20% was seen in historical controls (Fig 1B). Dialysis successfully prevented an increase in electrolyte levels (Fig 1C), maintained glucose and lactate levels at baseline (1C), and maintained physiological parameters (Fig 1D). Both lungs which survived to 36h of EVLP presented excellent lung function based on assessment by EVLP. Conclusion Dialysis may preserve lung function and length of EVLP by maintaining homeostasis of the lung. Following the results of this encouraging proof of concept study, a formal blinded experiment is underway.

Current practice of sedation and anesthesia for patients undergoing pediatric congenital cardiac catheterization laboratory (PCCCL) procedures is known to vary among institutions, a multi-society expert panel with representatives from the Congenital Heart Disease Council of the Society for Cardiovascular Angiography and Interventions (SCAI), the Society for Pediatric Anesthesia (SPA) and the Congenital Cardiac Anesthesia Society (CCAS) was convened to evaluate the types of sedation and personnel necessary for procedures performed in the PCCCL. The goal of this panel was to provide practitioners and institutions performing these procedures with guidance consistent with national standards and to provide clinicians and institutions with consensus-based recommendations and the supporting references to encourage their application in quality improvement programs. Recommendations can neither encompass all clinical circumstances nor replace the judgment of individual clinicians in the management of each patient. The science of medicine is rooted in evidence, and the art of medicine is based on the application of this evidence to the individual patient. This expert consensus statement has adhered to these principles for optimal management of patients requiring sedation and anesthesia. What follows are recommendations for patient monitoring in the PCCCL regardless of whether minimal or no sedation is being used or general anesthesia is being provided by an anesthesiologist. © 2016 Wiley Periodicals Inc.

Background Transcatheter patent ductus arteriosus (PDA) occlusion is feasible in small infants and may improve lung function in symptomatic patients. We aimed to describe transcatheter PDA closure in small infants including predictors of technical success and rate of complication and to identify factors associated with improved respiratory status after closure. Methods All patients in the NICU at our center who were referred for transcatheter PDA occlusion between 1/2010 and 11/2014 were retrospectively identified. Relevant details were extracted. Additionally, a modification of the respiratory severity score (RSS) (FiO2 × mean airway pressure) was used to characterize degree of pulmonary support before and at intervals after catheterization. Results Twenty patients were identified with median age of 96 days (13–247) and weight of 3.1 kg (1.7–4.7). The PDA was type F morphology in 14 (70%) patients. The PDA was successfully occluded in 16 (80%) patients. Ratio of minimum PDA diameter/length was >0.5 in all unsuccessful attempts and

Background: Stenosis of the retroaortic pulmonary artery is common in patients with single ventricle heart disease. Intraoperative hybrid stenting at the bidirectional Glenn or Fontan operation can treat this lesion and avoid a complex surgical arterioplasty. Methods: Patients who underwent intraoperative stent implantation to the retroaortic pulmonary artery during the bidirectional Glenn or Fontan operation at our center between January 2005 and July 2014 were retrospectively identified. Results: Thirteen patients were included with a median weight of 8 kg (5.6-14.4 kg) and age of 6 months (4 months-3.8 years). All had undergone Norwood operation, and eight (62%) had hypoplastic left heart syndrome. Eight (62%) underwent stent placement during bidirectional Glenn and five (38%) during Fontan operation. Ten patients had one stent placed, and three had two overlapping stents. The median diameter of the stenotic vessel was 3 mm (2.0-5.5 mm) and diameter of the balloon used for stent expansion was 7 mm (5-10 mm). Two complications occurred including pulmonary hemorrhage from presumed wire perforation and left main stem bronchus compression requiring stent removal. No patient required stent intervention in the postoperative period, and all were discharged from the hospital. At a median follow-up of 1.3 years (2 months-7.1 years), six patients underwent interval dilation to account for somatic growth. Conclusions: Hybrid stenting of the retroaortic pulmonary artery at the bidirectional Glenn or Fontan operation is an effective treatment of pulmonary artery stenosis and prevents the need for a complex surgical arterioplasty.

Purpose Improved real-time assessment of donor lung quality during Ex Vivo Lung Perfusion (EVLP) could enhance safe utilization of lungs for transplantation. Near-infrared (NIR) fluorescent imaging with indocyanine green (ICG) has been used in various clinical intraoperative applications to evaluate tissue perfusion. We investigated the feasibility of NIR imaging during EVLP and aimed to detect and quantify lung perfusion and permeability. Methods Pig lungs with extended 24-hour cold ischemia (n=4) and human lungs rejected from clinical transplantation (n=2) were assessed with NIR imaging during EVLP. Serial NIR imaging was performed with SPY Elite imaging system after ICG (0.3, 0.6 or 1.0 mg) administration through pulmonary artery (Fig A). Tissue perfusion was quantified using SPYQ analysis software, and tissue ICG accumulation was correlated with lung damage. Results Strong NIR signal was detected immediately after ICG administration with 0.6 mg (pig lungs) or 1.0 mg (human lungs) doses resulting in optimal fluorescence for tissue perfusion evaluation. In contrast to the transient kinetics and fast liver metabolism during clinical in vivo ICG administration, a single ICG dose during EVLP resulted in stable NIR signal for over 10 hours. Perfusion quantification of pig lungs with extended cold preservation revealed peripheral areas with compromised tissue perfusion that gradually recovered over time with recruitment of additional pulmonary vascular beds (Fig B). ICG accumulation was detected in sites with damage and increased vascular permeability in pig and human lungs (Fig C and D). Conclusion NIR imaging with a clinically-approved intravascularly-delivered ICG fluorescent probe can dynamically quantify tissue perfusion and detect damage-induced vascular permeability. This novel and promising imaging modality could be used during EVLP to assess lung quality, or to determine effects of therapeutics that target tissue perfusion and vascular permeability.

Purpose Pulmonary endarterectomy (PEA) is curative for suitable chronic thromboembolic pulmonary hypertension (CTEPH) patients. Careful anticoagulation prevents postoperative bleeding and thromboembolic recurrence. Heparinization is often guided by aPTT but it can be influenced by Factor VIII - a coagulation factor elevated in CTEPH. Anti-Xa-guided anticoagulation is less affected by other factors. We investigated the correlation between aPTT and Anti-Xa after PEA and the impact of coagulation factors. Methods 55 paired perioperative aPTT and Anti-Xa samples from 14 PEA patients were analyzed. aPTT guidance was used for postoperative unfractioned heparin titration. Samples were considered concordant if aPTT (target 45-65sec) and Anti-Xa (target 0.3-0.5UI/ml) were in the same category (subtherapeutic, therapeutic or supratherapeutic) defined by our clinical practice. Antithrombin activity, Factor VIII and fibrinogen were concomitantly measured. Single-cell RNA sequencing of PEA specimens (n=5) was used to screen for coagulation factor transcription. Results aPTT and Anti-Xa were concordant in 64% of the postoperative sample pairs. Most common discordant pattern was subtherapeutic aPTT with therapeutic (15.6%) or supratherapeutic (11.1%) Anti-Xa. Compared to pre-operative levels, plasma Factor VIII increased on day 1 (p=0.04) and day 3 (p=0.0003), and fibrinogen on day 3 after PEA (p=0.008). Discordant aPTT and Anti-Xa samples had higher antithrombin (p Conclusion aPTT monitoring underestimates anticoagulation after PEA compared to Anti-Xa and is possibly influenced by elevated postoperative Factor VIII levels. Local Factor VIII production by thrombus endothelium may contribute to CTEPH pathogenesis.

Purpose We have recently showed the superiority of 10°C cold static preservation (CSP) compared to standard 4°C. Despite that, CSP cannot be prolonged unlimited. Here, we hypothesized that combining CSP at 10°C with 2 short cycles of normothermic EVLP (a “recharge” period) would further extend donor lung preservation. Methods Donor lungs (n=3) from Yorkshire pigs (28-35kg) were flushed with 4°C LPD and subsequently preserved using 10°C CSP and intermittent normothermic EVLP (Fig 1A). After a total of 72h of preservation, a left lung transplant was performed followed by 4h of reperfusion. At 4h of reperfusion, isolated graft assessment was performed by clamping the contralateral pulmonary artery and bronchus. To evaluate the contribution of the EVLP recharge periods, 2 control lungs were preserved solely with 10°C CSP for 72h and assessed using normothermic EVLP. Results After 3-days of preservation, post-transplant graft function was excellent. Systemic P/F ratio after excluding the contra-lateral lung was 430 ± 57 mmHg. Lung function was also stable during the intermittent EVLP periods (Fig 1B) and after transplantation (Fig 1C). No pulmonary edema was observed in the bronchoscopic assessment after transplant. Lungs preserved purely in CSP for 72h were assessed on EVLP and failed immediately with the development of massive pulmonary edema. Conclusion We demonstrate for the first time the feasibility of 3-day lung preservation leading to excellent early post-transplant outcomes. Further experiments are being performed to confirm these positive findings and underlying mechanisms. The combination of a modified CSP method (10°C) and intermittent EVLP can open new opportunities to further prolong organ preservation and provide time for advanced lung treatments and repair.

The purpose of this study was to define the risk for adults with congenital heart disease who underwent cardiac catheterization and to propose a precatheterization risk scoring system. Data were prospectively collected using a multicenter registry of the Congenital Cardiovascular Interventional Study Consortium. The occurrence of serious adverse events (SAE) was correlated with 12 predefined variables. Catheterization RISk in Adult patients (CRISA) score was derived using multivariate logistic regression with backward elimination model selection method. The CRISA score was compared with the American Society of Anesthesiology score and a consensus-derived, 20-point risk score based on their ability to predict SAE. From June 2008 to September 2017, 300 adjudicated SAE's occurred in 7317 catheterization procedures (overall SAE rate 4.1%) performed in adults over 18 years of age at 27 contributing centers. Nine of the 12 tested variables were ultimately included in the CRISA score. CRISA score positively correlated with risk of SAE, and was superior to American Society of Anesthesiology and the 20-point risk score in predicting SAE. Minimal (CRISA score 0 to 2), low (3 to 7), moderate (8 to 10) and high (≥11) risk categories were identified, corresponding to 0.5%, 3.2%, 7.9%, and 16.7% risk of SAE, respectfully. In conclusion, the CRISA score reliably predicts risk of SAE in adults with congenital heart disease who underwent cardiac catheterization and may be useful for preprocedural risk assessment.

Purpose Ex vivo lung perfusion (EVLP) enables novel therapeutic approaches to repair damaged lungs for transplantation. We investigated the concept and feasibility of elective cell therapy for donor lungs. Dosing, efficacy and transgene expression kinetics of engineered mesenchymal stromal cell therapy were examined in pig EVLP and transplantation. Methods Human umbilical cord perivascular mesenchymal stromal/stem cells were transduced with an adenoviral vector encoding human IL-10 (MSC-hIL-10 cells), cryopreserved and recovered 1h before use. Pig lungs with 4 to 24-hour cold ischemia (n=5) were connected to EVLP for 6 (n=3) or 12 hours (n=2) and MSC-hIL-10 cells (40-150 × 106) were administered through the pulmonary artery after 1h of EVLP. Left single lung transplantation was performed after EVLP and the grafts were monitored up to 4h (n=4) and 3d (n=1) after reperfusion. Human IL-10 levels were determined by ELISA and fluorescence in situ hybridization with human-specific ALU probes was used to track MSC-hIL-10 cells. Results Supra-therapeutic levels of hIL-10 were present in EVLP perfusate within minutes after MSC-hIL10 cell administration and the levels consistently increased during EVLP (Figure 1A). Recipient plasma hIL-10 levels were elevated 1h after lung transplantation, remained high for 4h and gradually decreased to low levels by 3d after transplantation (Figure 1C). Elevated tissue and bronchoalveolar lavage hIL-10 levels were observed in the transplanted lung and remained low in the recipient native lung. MSC-hIL-10 cells were detected in the donor lung during EVLP and after transplantation (Figure 1B). Conclusion Engineered mesenchymal stromal cell therapy during EVLP is a novel and practical “off-the-shelf” strategy to achieve rapid transient therapeutic levels of soluble cytokines such as IL-10 for pre-transplant lung repair and protection. Ongoing studies will determine the therapeutic effect and longer-term fate of MSC-hIL-10 cells delivered during EVLP.

Objectives We sought to develop a scoring system that predicts the risk of serious adverse events (SAE's) for individual pediatric patients undergoing cardiac catheterization procedures. Background Systematic assessment of risk of SAE in pediatric catheterization can be challenging in view of a wide variation in procedure and patient complexity as well as rapidly evolving technology. Methods A 10 component scoring system was originally developed based on expert consensus and review of the existing literature. Data from an international multi-institutional catheterization registry (CCISC) between 2008 and 2013 were used to validate this scoring system. In addition we used multivariate methods to further refine the original risk score to improve its predictive power of SAE's. Results: Univariate analysis confirmed the strong correlation of each of the 10 components of the original risk score with SAE attributed to a pediatric cardiac catheterization (P

Objective The objective of a hybrid approach to staged palliation of single-ventricle anomalies is designed to minimize the trauma of the first stage. However, the second stage is a complex procedure that may negate the advantages of the first stage. We sought to devise a "hybrid" approach to the second stage when aortic outflow is expected to remain unobstructed. Methods The procedure involves a simple incision into the main pulmonary artery, dilation/stenting of the ductal continuation, formation of a stented baffle between the branch pulmonary arteries' orifices, and a bidirectional Glenn connection. It avoids dissection of the distal arch and ductal continuation and obviates the need for a Damus-Kaye-Stansel connection. We carried out this procedure in 2 patients, one with unbalanced atrioventricular canal and the other with mitral atresia. Results Both patients underwent an uncomplicated operative procedure. Both patients were successfully weaned from the ventilator, with no clinically evident neurologic injury. The first patient died of complications related to thrombosis of the left pulmonary artery before initiation of anticoagulation. The second patient is alive and well 1 year postoperation with no obstruction to either systemic or pulmonary flow and no baffle leak and good right ventricle function. Conclusions This hybrid comprehensive stage II operation appears feasible and technically simpler than the conventional comprehensive stage II procedure. It is applicable to a subset of single-ventricle cases in which aortic outflow is anticipated to remain unobstructed. We recommend early postoperative anticoagulation to avoid early left pulmonary artery thrombosis.

Background: Risk standardization for adverse events after congenital cardiac catheterization is needed to equitably compare patient outcomes among different hospitals as a foundation for quality improvement. The goal of this project was to develop a risk-standardization methodology to adjust for patient characteristics when comparing major adverse outcomes in the NCDR’s (National Cardiovascular Data Registry) IMPACT Registry (Improving Pediatric and Adult Congenital Treatment). Methods: Between January 2011 and March 2014, 39 725 consecutive patients within IMPACT undergoing cardiac catheterization were identified. Given the heterogeneity of interventional procedures for congenital heart disease, new procedure-type risk categories were derived with empirical data and expert opinion, as were markers of hemodynamic vulnerability. A multivariable hierarchical logistic regression model to identify patient and procedural characteristics predictive of a major adverse event or death after cardiac catheterization was derived in 70% of the cohort and validated in the remaining 30%. Results: The rate of major adverse event or death was 7.1% and 7.2% in the derivation and validation cohorts, respectively. Six procedure-type risk categories and 6 independent indicators of hemodynamic vulnerability were identified. The final risk adjustment model included procedure-type risk category, number of hemodynamic vulnerability indicators, renal insufficiency, single-ventricle physiology, and coagulation disorder. The model had good discrimination, with a C-statistic of 0.76 and 0.75 in the derivation and validation cohorts, respectively. Model calibration in the validation cohort was excellent, with a slope of 0.97 (standard error, 0.04; P value [for difference from 1] =0.53) and an intercept of 0.007 (standard error, 0.12; P value [for difference from 0] =0.95). Conclusions: The creation of a validated risk-standardization model for adverse outcomes after congenital cardiac catheterization can support reporting of risk-adjusted outcomes in the IMPACT Registry as a foundation for quality improvement.

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OBJECTIVES We examine normalized air Kerma area product (PKA ) by body weight (PKA /BW) as a reference value of radiation dose and benchmark PKA /BW in pediatric laboratories using a multicenter registry database. BACKGROUND Reduction of radiation dose is an important quality improvement task in pediatric cardiac catheterization laboratories. Physicians need to agree on a standard method of reporting radiation dose that would allow comparisons to be made between operators and institutions. METHODS This was a multicenter observational study of radiation dose in pediatric laboratories. Patient demographic, procedural and radiation data including fluoroscopic time and PKA (µGy m(2) ) were analyzed. PKA /BW was obtained by indexing PKA to body weight. RESULTS A total of 8,267 pediatric catheterization procedures (age

Branch pulmonary artery stenosis (BPAS) in the setting of systemic-pulmonary artery shunts (SPS) may result in significant sequelae. Limited information exists regarding the safety and efficacy of pulmonary artery balloon angioplasty and stent implantation via SPS in neonates and infants. This study aimed to examine the feasibility, safety, and efficacy of balloon angioplasty/stent implantation for BPAS performed via SPS in neonates and infants. A single-center retrospective analysis of all patients weighing 10 kg or less who underwent angioplasty for BPAS via SPS was performed. Systemic oxygen saturations and vessel diameter before, during, and after the procedure were compared. Between July 1996 and February 2008, 15 patients underwent 20 catheterizations for the treatment of 27 BPAS via SPS. The patients had a mean weight of 5.6 kg (range, 2.6–10 kg) and a mean age of 7.6 months (range, 7 days to 33 months). The SPS diameter ranged between 2 and 5 mm (median, 3.5 mm). Angioplasty was performed for all 27 lesions, and an additional stent was placed in 5 of these. The average lesion diameter increased from 2.3 ± 1.5 to 4.7 ± 1.7 mm (p < 0.05), and 25 (93 %) of the 27 lesions met the predetermined criteria for success. Systemic oxygen saturation increased from 73 ± 9.5 % to 82 ± 6.8 % immediately after intervention and was 83 ± 7.9 % at discharge (p < 0.05). There were no instances of shunt thrombosis. Two patients experienced transient hypotension during the procedure. No procedural deaths occurred. The study findings suggest that balloon angioplasty or stent implantation performed via SPS appears to be safe and effective treatment for BPAS in neonates and infants.

Staged palliation to achieve a total cavopulmonary connection is a common treatment strategy in patients with single ventricle congenital heart disease. Patients with bilateral superior caval veins (bilateral SVC) often require the creation of bilateral superior cavopulmonary connections as part of the staged palliation, and these patients are at increased risk of morbidity. We describe a novel technique used in two patients with bilateral SVC and very small (1-2 mm) bridging vein that encouraged bridging vein growth and facilitated creation of a unilateral superior cavopulmonary connection.

Objectives The purpose of this study was to compare the safety and efficacy of surgical, stent, and balloon angioplasty (BA) treatment of native coarctation acutely and at follow-up. Background Controversy surrounds the optimal treatment for native coarctation of the aorta. This is the first multicenter study evaluating acute and follow-up outcomes of these 3 treatment options in children weighing >10 kg. Methods This is a multicenter observational study. Baseline, acute, short-term (3 to 18 months), and intermediate (>18 months) follow-up hemodynamic, imaging data, and complications were recorded. Results Between June 2002 and July 2009, 350 patients from 36 institutions were enrolled: 217 underwent stent, 61 underwent BA, and 72 underwent surgery. All 3 arms showed significant improvement acutely and at follow-up in resting systolic blood pressure and upper to lower extremity systolic blood pressure gradient (ULG). Stent was superior to BA in achieving lower ULG acutely. Surgery and stent were superior to BA at short-term follow-up in achieving lower ULG. Stent patients had shorter hospitalization than surgical patients (2.4 vs. 6.4 days; p Conclusions Stent patients had significantly lower acute complications compared with surgery patients or BA patients, although they were more likely to require a planned reintervention. At short-term and intermediate follow-up, stent and surgical patients achieved superior hemodynamic and integrated aortic arch imaging outcomes compared with BA patients. Because of the nonrandomized nature of this study, these results should be interpreted with caution.

The long-term outcome of patients with congenitally malformed hearts involving abnormal right ventricular morphology and haemodynamics is variable. In most instances, the patients are at risk for right ventricular failure, in part due to morphological differences between the right and left ventricles and their response to chronic volume and pressure overload. In patients after repair of tetralogy of Fallot, and after balloon valvotomy for valvar pulmonary stenosis, pulmonary regurgitation is the most significant risk factor for right ventricular dysfunction. In patients with a dominant right ventricle after Fontan palliation, and in those with systemic right ventricles in association with surgically or congenitally corrected transposition, the right ventricle is not morphologically capable of dealing with chronic exposure to the high afterload of the systemic circulation. In patients with Ebstein’s malformation of the tricuspid valve, the degree of atrialisation of the right ventricle determines how well the right ventricle will function as the pump for the pulmonary vascular bed.

Objective The objective of this study is to examine the safety/efficacy of alternative routes of vascular access (ARVA) for successful performance of interventions. Background Complex interventional catheterizations may be required in children with limited vascular access, vascular constraints relative to size, and hemodynamic instability. Our approach has been to utilize ARVA in selected cases. Methods ARVA pertains to any vessel excluding femoral, jugular/subclavian veins, or umbilical access. A retrospective review performed on patients with an intervention utilizing ARVA between August 1995 and January 2004 was performed. Patients were divided by clinical status: critically ill/emergent (A), elective cases (B). Procedural success was based on previously published criteria. Results Sixty-four interventions were performed in 50 patients using 54 ARVA. ARVA utilized: radial (1), axillary (2), brachial (2), carotid arteries (25); brachial (2) hepatic (9) veins; and open chest/direct cardiac puncture (13). ARVA provided successful access to target lesions. Interventions included stents (30), valvuloplasty (16), angioplasty (14), and one each of vascular occlusion, septal occlusion, accessory pathway ablation, and septostomy. Group A patients were smaller (P Conclusions ARVA may provide a strategic advantage that may be safely applied to a variety of interventions regardless of patient size or degree of illness. These techniques may further extend the scope of successful interventions in children.

BACKGROUND Stents implantation in infants has been shown to be feasible, however, there are no published reports examining long-term outcomes. Concerns exist regarding creation of fixed obstructions secondary to the stent if expansion to larger diameters over time is not possible. METHODS A retrospective analysis of the earliest consecutive series of infants who underwent stent placement at our institution between October 1995 and December 1999. RESULTS Implantation of 33 stents were attempted in 27 infants, median age = 10 (25-24) months, wt = 8.1 (3.4-14.5) kg. Stents used were as follows: 16 large, 13 medium, and 4 coronary. Acute implant success was 94%. There were three nonprocedure-related deaths within 30 days of implantation, 1 patient was lost to follow-up and 1 had acute stent thrombosis. The remaining 22 patients (26 stents) form the long-term follow-up study group. Nineteen stents underwent 33 redilations. Following latest redilation, 67.0 (37-113) months postimplantation, minimal luminal diameter increased from 7.0 +/- 1.8 mm immediately following implantation to 8.7 +/- 2.3 mm (P < 0.001). Seven stents were electively removed/ligated during a planned surgery. All 18 remaining in situ stents are patent without significant obstruction 102 (84-116) months following implantation. There was one late death 51 months after stent implantation. The remaining 21 patients are alive and well. CONCLUSIONS Stent implantation in infants is safe and effective. Serial redilation is possible to keep pace with somatic growth; however, efforts should be made to implant stents with adult diameter potential in children who will not require further cardiac surgery. Implantation of small- and medium-sized stents can provide effective palliation and should be considered in carefully selected infants who will ultimately require future surgery.

The coronary arteries, the vessels through which both substrate and oxygen are provided to the cardiac muscle, normally arise from paired stems, right and left, each arising from a separate and distinct sinus of the aortic valve. The right coronary artery runs through the right atrioventricular groove, terminating in the majority of instances in the inferior interventricular groove. The main stem of the left coronary artery bifurcates into the anterior descending, or interventricular, and the circumflex branches. Origin of the anterior descending and circumflex arteries from separate orifices from the left sinus of Valsalva occurs in about 1% of the population, while it is also frequent to find the infundibular artery arising as a separate branch from the right sinus of Valsalva.Anomalies of the coronary arteries can result from rudimentary persistence of an embryologic coronary arterial structure, failure of normal development or normal atrophy as part of development, or misplacement of connection of a an otherwise normal coronary artery. Anomalies, therefore, can be summarized in terms of abnormal origin or course, abnormal number of coronary arteries, lack of patency of the orifice of coronary artery, or abnormal connections of the arteries.Anomalous origin of the left coronary artery from the pulmonary trunk occurs with an incidence of approximately 1 in 300,000 children. The degree of left ventricular dysfunction produced likely relates to the development of collateral vessels that arise from the right coronary artery, and provide flow into the left system. Anomalous origin of either the right or the left coronary artery from the opposite sinus of Valsalva can be relatively innocuous, but if the anomalous artery takes an interarterial course between the pulmonary trunk and the aorta, this can underlie sudden death, almost invariably during or immediately following strenuous exercise or competitive sporting events. Distal anomalies of the coronary arteries most commonly involve abnormal connections, or fistulas, between the right or left coronary arterial systems and a chamber or vessel.We discuss the current techniques available for imaging these various lesions, along with their functional assessment, concluding with a summary of current strategies for management.

Background: We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques. Methods and Results: Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5–92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up. Conclusions: Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA. © 2007 Wiley-Liss, Inc.

Background: We report a multi-institutional experience with intravascular stenting (IS) for treatment of coarctation of the aorta. Methods and Results: Data was collected retrospectively by review of medical records from 17 institutions. The data was broken down to prior to 2002 and after 2002 for further analysis. A total of 565 procedures were performed with a median age of 15 years (mean = 18.1 years). Successful reduction in the post stent gradient ( 0.8 was achieved in 97.9% of procedures. There was significant improvement (P < 0.01) in pre versus post stent coarctation dimensions (7.4 mm ± 3.0 mm vs. 14.3 ± 3.2mm), systolic gradient (31.6 mm Hg ± 16.0 mm Hg vs. 2.7 mm Hg ± 4.2 mm Hg) and ratio of the coarctation segment to the DAo (0.43 ± 0.17 vs. 0.85 ± 0.15). Acute complications were encountered in 81/565 (14.3%) procedures. There were two procedure related deaths. Aortic wall complications included: aneurysm formation (n = 6), intimal tears (n = 8), and dissections (n = 9). The risk of aortic dissection increased significantly in patients over the age of 40 years. Technical complications included stent migration (n = 28), and balloon rupture (n = 13). Peripheral vascular complications included cerebral vascular accidents (CVA) (n = 4), peripheral emboli (n = 1), and significant access arterial injury (n = 13). Older age was significantly associated with occurrence of CVAs. A significant decrease in the technical complication rate from 16.3% to 6.1% (P < 0.001) was observed in procedures performed after January 2002. Conclusions: Stent placement for coarctation of aorta is an effective treatment option, though it remains a technically challenging procedure. Technical and aortic complications have decreased over the past 3 years due to, in part, improvement in balloon and stent design. Improvement in our ability to assess aortic wall compliance is essential prior to placement of ISs in older patients with coarctation of the aorta. © 2007 Wiley-Liss, Inc.

Background: Risk-standardization for adverse events following congenital cardiac catheterization is needed to equitably compare patient outcomes among different hospitals as a foundation for quality improvement. We sought to refine and update the risk-standardization methodology for the NCDR ® IMPACT TM (Improving Pediatric and Adult Congenital Treatment) Registry. Methods: We identified 39,725 consecutive patients within IMPACT undergoing cardiac catheterization between January 2011 and March 2014. New procedure type risk categories were derived by empiric data and expert opinion and markers of hemodynamic vulnerability were empirically explored and identified. A multivariable hierarchical logistic regression model to identify patient and procedural characteristics predictive of a major adverse event (MAE) or death following cardiac catheterization was derived in 70% of the cohort and validated in the remaining 30%. Results: The rate of MAE or death was 7.1% and 7.2% in the derivation and validation cohorts, respectively. Six independent indicators of hemodynamic vulnerability and six procedure-type risk groups were identified. The final risk adjustment model included procedure type risk group, hemodynamic vulnerability, renal insufficiency, single-ventricle physiology, and coagulation disorder (See Figure). The model had good discrimination with a C-statistic of 0.76 and 0.75 in the derivation and validation cohorts, respectively. Model calibration was excellent with a slope of 0.97 (standard error [SE] 0.04; p-value [for difference from 1]= 0.53) and an intercept of 0.007 (SE 0.12; p-value [for difference from 0]= 0.95). Conclusion: We updated and refined a risk-standardization model for outcomes following congenital cardiac catheterization using the large, multicenter IMPACT Registry. Our model can be used for quality reporting back to sites participating in IMPACT to guide quality improvement initiatives.

Objectives:To determine the long-term outcomes and risk factors for, reintervention after balloon dilation of congenital aortic stenosis in children aged 6 months or older.Background:Although balloon dilation of congenital aortic stenosis has become a primary therapeutic strategy, few data are available regarding long-term outcomes.Methods:We carried out a retrospective review of 87 children who had undergone balloon dilation of the aortic valve at median age of 6.9 years.Results:The procedure was completed in 98% of the children, with an average reduction in the gradient across the valve of 64 ± 28%, and without mortality. Of the children, 76 had been followed for a mean of 6.3 ± 4.2 years. Reintervention on the aortic valve was required in 32 children, with 12 undergoing reintervention within 6 months, with 1 death. Another patient had died over the period of follow-up due to a non-cardiac event. Estimated freedom from reintervention was 86% at 1 year, 67% at 5 years, and 46% at 12 years. Parametric modeling of the hazard function showed a brief early phase of increased risk, superimposed on an ongoing constant risk. The only incremental risk factor for the early phase was a residual gradient immediately subsequent to the procedure greater than 30 mmHg. Incremental risk factors for the constant phase included the presence of symmetric valvar opening, and greater than moderate regurgitation immediately after dilation.Conclusion:Long-term survival was excellent, albeit that the need for further reintervention was high due to the palliative nature of the procedure.

In cardiac transplantation, the donor organ is not initially innervated and demonstrates decreased heart rate variability (HRV). However, HRV may improve after several months. The mechanism for HRV improvement has not been elucidated; autonomic "reinnervation" of the donor heart has been proposed. The role of atrioatrial conduction from recipient to donor organ has not been evaluated. We prospectively evaluated cardiac transplant patients with a limited electrophysiology study at the time of their surveillance biopsies. Recordings were made of recipient and donor signals, observing conduction properties between recipient and donor atria. Holter recordings were analyzed and HRV was determined using spectral analysis techniques, recording mean RR interval, low-frequency power (LF), high-frequency power (HF), and the LF/HF ratio. These were compared to published norms. From November 1999 to May 2000, 21 patients (6 female) who underwent cardiac transplantation participated at a median age of 101 months (range, 4.1-217 months). Time posttransplant ranged from 26 days to 71 months. Holter data were available for 20 patients and demonstrated dissociated P waves in 13 (65%). The mean heart rate on Holter was 111 beats per minute (bpm) (range, 85-161 bpm). We were able to record distinct recipient atrial signals in 16 of 21 (76%) patients. The average recipient tissue heart rate was 55% that of the donor heart rate. We documented atrioatrial association in only 1 patient. HRV did not reach normal values for most patients and did not increase with time posttransplantation. The LF values were in the normal range for most patients, whereas 3 patients had normal HF values and 2 patients had values just below normal. Recipients of heart transplantation have a predominantly sympathetic influence of HRV. These preliminary data suggest that atrioatrial conduction does not play a role in reestablishing normal heart rate control following pediatric cardiac transplantation.

OBJECTIVES The purpose of this study was to examine the safety and efficacy of interventional catheterization performed early after congenital heart surgery. BACKGROUND Transcatheter interventions performed in the early postoperative period are viewed as high risk. To date, there have been limited published data regarding these procedures. METHODS All catheterizations performed within six weeks after congenital heart surgery between August 1995 and January 2001 were retrospectively reviewed. A cardiac anesthesiologist, cardiac intensivist, cardiac surgeon, and operating room team were available for all cases. Interventional procedures were performed based on clinical indications, regardless of the time elapsed from surgery. RESULTS Sixty-two patients, median age four months (2 days to 11 years), weight 4.7 kg (2.3 to 45 kg), underwent 66 catheterizations on median postoperative day 9 (0 to 42 days). Thirty-five cases involved 50 interventional procedures. Nine patients required extracorporeal cardiopulmonary support. Success rates by procedure were: angioplasty, 100%; stent implantation, 87%; vascular/septal occlusion, 100%; and palliative pulmonary valvotomy, 75%. Complications included stent migration (one patient), cerebral vascular injury (one patient), and left pulmonary artery stenosis (one patient). Thirty procedures involved angioplasty or stent implantation, including 26 involving a recently created suture line. Suture disruption or trans-mural vascular tears were not observed. There was no procedural mortality. Thirty-day survival for patients undergoing intervention was 83%. CONCLUSIONS Transcatheter interventions can be successfully performed in the early postoperative period. These procedures can have a positive impact on patient outcome; however, they should be performed only by a pediatric interventional cardiologist supported by a multi-disciplinary team.

Background— Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare congenital lesion with high mortality. Therapy was exclusively surgical until recently, when the use of radiofrequency-assisted perforation of the atretic valve was introduced as a treatment option. This study analyzes the outcomes and morphological changes to right heart structures after percutaneous perforation and balloon dilation of the atretic valve. Methods and Results— Between April 1992 and August 2000, 30 patients with PA-IVS underwent attempted percutaneous valve perforation and balloon dilation of the pulmonary valve. Longitudinal echocardiographic measurements of the tricuspid valve diameter, right ventricular length and area were recorded. Z scores were calculated according to published formulas. Perforation was achieved in 27 patients. In 14 patients a modified Blalock-Taussig shunt was performed between 2 and 24 days after valve dilation. There were 3 early and 2 late deaths. Among the survivors (follow-up time of 1 to 87 months), 16 patients had a biventricular circulation, 3 a 1 ½-ventricle circulation, and 1 a Fontan operation. Four patients are awaiting further palliation. There was no significant change of the tricuspid valve Z score or right ventricular length Z score with time. Conclusions— Percutaneous balloon valvotomy is an effective treatment strategy for patients with PA-IVS provided that there is a patent infundibulum and a lack of a right ventricle–dependent coronary circulation. Despite the observation that right heart growth does not increase with body growth in early follow-up, it appears adequate to maintain a biventricular circulation in many patients.

The management of uncomplicated aortic valve stenosis presenting with critical obstruction in infants continues to be associated with significant morbidity and mortality. However, not all infants have critical obstruction, and outcomes spanning the broader spectrum of disease severity are less well defined.In a 12-year period, 55 infants (3 months of age) were seen with aortic valve stenosis and with anatomy suitable for biventricular repair. Clinical, echocardiographic, angiographic, management, and outcome data were reviewed.Status at presentation (median age 6 days) included signs of congestive heart failure in 20 patients, cardiovascular collapse in 5 patients, and an asymptomatic heart murmur in 30 patients. The initial echocardiogram showed reduced left ventricular function in 26% of patients, with a mean peak instantaneous gradient of 69 +/- 30 mm Hg in patients with normal function. There were 5 deaths (9%), all in patients with poor ventricular function. The initial intervention was balloon valvotomy in 24 patients and surgical valvotomy in 20 patients, with 11 patients having no intervention to date. The freedom-from-intervention rate was 69% at age 1 week, 58% at 1 month, 36% at 3 months, and 28% at 1 year. Patients without cardiovascular collapse, normal left ventricular function, and gradients60 mm Hg at presentation (n =1 9) had better survival and longer freedom from intervention than patients with poor ventricular function or gradientsor=60 mm Hg (n = 36, P =.0001).Most infants with aortic valve stenosis receive intervention, although this may be safely delayed in selected patients with lower initial gradients and good left ventricular function.

The Helex Septal Occluder is a new device used to close atrial septal defects via interventional catheterization. In order to study the role of echocardiography during its use, and to describe the morphologic variants of defects suitable for closure with this occluder, we evaluated all patients undergoing intended closure of an atrial septal defect with the Helex occluder. A combination of transthoracic, transesophageal, three-dimensional, and intracardiac echocardiography were used before, during, and after the procedure to characterize anatomy, assess candidacy for closure, guide the device during its deployment, and evaluate results. Among the 60 candidates included in the study, 11 were excluded because of transesophageal echocardiographic and/or catheterization data obtained in the laboratory. Attempts at closure were successful in 46 patients, and unsuccessful in 3. We successfully treated four types of defects. These were defects positioned centrally within the oval fossa with appreciable rims along the entire circumference of the defect, defects with deficient or absent segments of the rim, defects with aneurysm of the primary atrial septum, and defects with multiple fenestrations. Follow-up transthoracic echocardiograms taken at a median of 7 months demonstrated no residual defects in 21, trivial residual defects in 17, and small residual defects in 8 patients. In 20 patients, three-dimensional reconstructions were used to characterize the morphology of the defect and the position of the device. Because transesophageal echocardiography was often limited by acoustic interference from the device, intracardiac echocardiography was utilized in 3 cases to overcome this limitation.

Catheter-directed perforation of cardiac tissue with radiofrequency (RF) energy has expanded the horizon of the interventional cardiologist dealing with congenital heart disorders. The focus of the following discussion will be to detail the biophysical basis behind RF perforation and review its application in the management of congenital heart lesions.

A trial of 11 video-conferenced teaching sessions for residents in pediatric cardiology was performed by the 7 training programs in Canada in order to share expertise in specialized areas, to expose trainees to educational telemedicine, and to acquaint residents with other programs and personnel. Topics included cardiac pathology, arrhythmias, magnetic resonance imaging, fetal physiology, pulmonary hypertension, and cardiomyopathy. The sessions were evaluated by 93 residents by questionnaire for content and technology. Session content was highly rated. Videoconference picture quality was highly rated, but sound quality and visual aids were rated as neutral or unsatisfactory by a significant minority,related to problems with several early sessions, subsequently corrected. 60% of respondents rated the videoconferences as good as live presentations. Presenters were generally satisfied although they required some adjustments to videoconferencing. The average cost per session was $700 Canadian. Videoconferencing of resident educational sessions was generally well accepted by most presenters and residents, and the trial has formed the basis for a national network. Adequate organizational time, and careful attention to audiovisual needs, are most important. Videoconference guidelines are suggested for presenters based on this experience.

Thirteen children (seven male) with coronary artery fistula underwent percutaneous transcatheter occlusion. The age range was 8 months to 14 years (mean, 6.3 years). The fistulas had their origins from the right coronary artery (six), from the left anterior descending coronary artery (three), and from the left circumflex coronary artery (four). Drainage was to the right ventricle (seven), the right atrium (three), and one each to the pulmonary artery, left atrium, and superior caval vein. The fistulas were closed with coils in 10 patients, a Rashkind double-umbrella device in 1 patient, and an Amplatzer Duct Occluder in 2 patients. Complete occlusion was achieved in 9 of 13 patients. Complications consisted of migration of coils in four and transient arrhythmias or changes in the resting electrocardiogram in four patients. Follow-up studies 1 to 31 months (mean, 14.6 months) after occlusion noted only four patients with trivial (clinically insignificant) residual shunts. Owing to various coronary fistula morphologies, transcatheter occlusion requires availability of different embolization techniques. Short-term follow-up supports persistent clinical efficacy and transcatheter closure techniques as the initial form of therapy.

A randomized trial of arterial duct occlusion with a double umbrella (DU) or wire coil (WC) was undertaken for patients18 years of age, weighing10 kg with isolated ductsor = 3 mm in diameter. Baseline, procedural, and outcome characteristics were compared in an intention-to-treat analysis according to randomization group. From 40 consecutively screened patients, 2 were not enrolled due to a ductal diameter of3 mm on initial aortography, 38 patients were randomized to either the DU (n = 20) or WC (n = 18) groups. The groups did not differ significantly with respect to age, weight, gender, duct size, type, or branch pulmonary artery diameters. Crossover occurred only in the DU group, where 4 patients (20%) had a ductal diameter ofor = 1 mm and could not be entered for umbrella placement. All remaining DU group patients had ductal diameters ofor = 1.3 mm (p0.0001). There were no embolizations or secondary implants in the DU group, but in the WC group there was 1 early and 1 late embolization, with 6 patients (33%) withor = 2 coils. Mean times for the procedure (DU 68+/-19 minutes; WC 65+/-27 minutes; p = 0.70) and fluoroscopy (DU 14+/-4 minutes; WC 11+/-6 minutes; p = 0.22) did not differ significantly. Angiographic duct closure was documented in 4 of 13 patients (31%) of the DU group and 4 of 18 patients (22%) of the WC group (p = 0.69). Combined with an echocardiogram, closure in 11 of 17 patients with DU (65%) and 13 of 18 patients with WC (72%) (p = 0.64) was documented before hospital discharge. One WC group patient received thrombolytic therapy for a femoral artery thrombus. Follow-up at a median of 6.5 months (range 3.2 to 37) showed closure by Doppler echocardiography in 15 of 19 patients with DU (79%) versus 14 of 18 patients with WC (78%) (p = 1.0). Thus, with a tendency toward similar procedural characteristics and outcomes, the higher cost of the DU system compared with coil implants favors the use of coils for closure of the small arterial duct.