Magnetic resonance three-dimensional steady-state free precession imaging of the thoracic duct in patients with Fontan circulation and its relationship to outcomes.

BACKGROUND: Lymphatic complications are common in patients with Fontan circulation. Three-dimensional balanced steady-state free precession (3D bSSFP) angiography by cardiovascular magnetic resonance (CMR) is widely used for cardiovascular anatomical assessment. We sought to determine the frequency of thoracic duct (TD) visualization using 3D bSSFP images and assess whether TD characteristics are associated with clinical outcomes. METHODS: This was a retrospective, single-center study of patients with Fontan circulation who underwent CMR. Frequency matching of age at CMR was used to construct a comparison group of patients with repaired tetralogy of Fallot (rTOF). TD characteristics included maximum diameter and a qualitative assessment of tortuosity. Clinical outcomes included protein-losing enteropathy (PLE), plastic bronchitis, listing for heart transplantation, and death. A composite outcome was defined as presence of any of these events. RESULTS: The study included 189 Fontan patients (median age 16.1 years, IQR 11.0-23.2 years) and 36 rTOF patients (median age 15.7 years, IQR 11.1-23.7 years). The TD diameter was larger (median 2.50 vs. 1.95 mm, p = 0.002) and more often well visualized (65% vs. 22%, p < 0.001) in Fontan patients vs. rTOF patients. TD dimension increased mildly with age in Fontan patients, R = 0.19, p = 0.01. In Fontan patients, the TD diameter was larger in those with PLE vs. without PLE (age-adjusted mean 4.11 vs. 2.72, p = 0.005), and was more tortuous in those with NYHA class ≥ II vs. class I (moderate or greater tortuosity 75% vs. 28.5%, p = 0.02). Larger TD diameter was associated with a lower ventricular ejection fraction that was independent of age (partial correlation = - 0.22, p = 0.02). More tortuous TDs had a higher end-systolic volume (mean 70.0 mL/m2 vs. 57.3 mL/m2, p = 0.03), lower creatinine (mean 0.61 mg/dL vs. 0.70 mg/dL, p = 0.04), and a higher absolute lymphocyte count (mean 1.80 K cells/µL vs. 0.76 K cells/µL, p = 0.003). The composite outcome was present in 6% of Fontan patients and was not associated with TD diameter (p = 0.50) or tortuosity (p = 0.09). CONCLUSIONS: The TD is well visualized in two-thirds of patients with Fontan circulation on 3D-bSSFP images. Larger TD diameter is associated with PLE and increased TD tortuosity is associated with an NYHA class ≥ II.

Real-world use of apixaban for the treatment and prevention of thrombosis in children with cardiac disease.

BACKGROUND: Direct oral anticoagulants use in pediatric cardiology is poorly defined. OBJECTIVE: We present the largest experience of apixaban use in children with heart disease, using weight- and level-based dosing. METHODS: Retrospective single-center analysis of cardiac patients ≤19 years treated with apixaban. Patients were evaluated for safety (clinically relevant non-major [CRNM] or major bleeding; thrombotic events) and effectiveness (thrombus improvement by imaging). Peak drug-specific anti-Xa chromogenic assay results ("apixaban levels") were analyzed. RESULTS: Over 3 years (5/2018-9/2021), 219 children, median age 6.8 years (0.3-19), median weight 20.8 kg (4.8-160) received apixaban, totaling 50,916 patient days. Of them, 172 (79%) warranted thromboprophylaxis and 47 (21%) thrombosis treatment (with 10 arterial, 19 venous, 15 intracardiac, and 3 pulmonary). The median initial peak apixaban level was 165 ng/mL (23-474; n = 125) in the prophylaxis subgroup and 153 ng/mL (30-450; n = 33) in the treatment subgroup; dosage was adjusted in response to levels in 25% of the patients. There were 4 bleeding safety events (3 CRNM; 1 major, hemoptysis complicating empyema); the serious bleeding event rate was 2.9 per 100 patient-years of apixaban. Minor bleeding events (42) were noted in 18 patients, with an additional 2 having leukopenia, 1 transaminitis, and 3 rashes. An improvement in thrombosis was seen in 95% of the treated patients with available follow-up imaging (37/39 patients). CONCLUSION: Apixaban use was feasible with a low rate of adverse events across a diverse pediatric cardiac population using commercially available tablets dosed to weight and adjusted based on peak apixaban levels.

Predictors of Serious Adverse Events and High-Level Cardiorespiratory Support in Patients Undergoing Transcatheter Pulmonary Vein Interventions.

Patients with pulmonary vein stenosis (PVS) often require frequent transcatheter pulmonary vein (PV) interventions for management of restenosis. Predictors of serious adverse events (AEs) and need for high-level cardiorespiratory support (mechanical ventilation, vasoactive support, and/or extracorporeal membrane oxygenation) 48 h after transcatheter PV interventions have not been reported. This is a single-center retrospective cohort analysis of patients with PVS who underwent transcatheter PV interventions from 3/1/2014 to 12/31/2021. Univariate and multivariable analyses were performed using generalized estimating equations to account for within-patient correlation. 240 patients underwent 841 catheterizations involving PV interventions (median 2 catheterizations per patient [1,3]). At least one serious AE was reported in 100 (12%) cases, the most common of which were pulmonary hemorrhage (n = 20) and arrhythmia (n = 17). There were 14 severe/catastrophic AEs (1.7% of cases) including three strokes and one patient death. On multivariable analysis, age less than 6 months, low systemic arterial saturation (< 95% in patients with biventricular [BiV] physiology, < 78% in single ventricle [SV] physiology), and severely elevated mean PA pressure (≥ 45 mmHg in BiV, ≥ 17 mmHg in SV) were associated with SAEs. Age less than 1 year, hospitalization prior to catheterization, and moderate-severe RV dysfunction were associated with high-level support after catheterization. Serious AEs during transcatheter PV interventions in patients with PVS are common, although major events such as stroke or death are uncommon. Younger patients and those with abnormal hemodynamics are more likely to experience serious AEs and require high-level cardiorespiratory support after catheterization.

Factors associated with morbidity, mortality, and hemodynamic failure after biventricular conversion in borderline hypoplastic left hearts.

OBJECTIVE: A subset of patients with borderline hypoplastic left heart may be candidates for single to biventricular conversion, but long-term morbidity and mortality persist. Prior studies have shown conflicting results regarding the association of preoperative diastolic dysfunction and outcome, and patient selection remains challenging. METHODS: Patients with borderline hypoplastic left heart undergoing biventricular conversion from 2005 to 2017 were included. Cox regression identified preoperative factors associated with a composite outcome of time to mortality, heart transplant, takedown to single ventricle circulation, or hemodynamic failure (defined as left ventricular end-diastolic pressure >20 mm Hg, mean pulmonary artery pressure >35 mm Hg, or pulmonary vascular resistance >6 international Woods units). RESULTS: Among 43 patients, 20 (46%) met the outcome, with a median time to outcome of 5.2 years. On univariate analysis, endocardial fibroelastosis, lower left ventricular end-diastolic volume/body surface area (when <50 mL/m2), lower left ventricular stroke volume/body surface area (when <32 mL/m2), and lower left:right ventricular stroke volume ratio (when <0.7) were associated with outcome; higher preoperative left ventricular end-diastolic pressure was not. Multivariable analysis demonstrated that endocardial fibroelastosis (hazard ratio, 5.1, 95% confidence interval, 1.5-22.7, P = .033) and left ventricular stroke volume/body surface area 28 mL/m2 or less (hazard ratio, 4.3, 95% confidence interval, 1.5-12.3, P = .006) were independently associated with a higher hazard of the outcome. Approximately all patients (86%) with endocardial fibroelastosis and left ventricular stroke volume/body surface area 28 mL/m2 or less met the outcome compared with 10% of those without endocardial fibroelastosis and with higher stroke volume/body surface area. CONCLUSIONS: History of endocardial fibroelastosis and smaller left ventricular stroke volume/body surface area are independent factors associated with adverse outcomes among patients with borderline hypoplastic left heart undergoing biventricular conversion. Normal preoperative left ventricular end-diastolic pressure is insufficient to reassure against diastolic dysfunction after biventricular conversion.

Apixaban for treatment of intracardiac thrombosis in children with congenital heart disease.

Apixaban is well studied in adults; paediatric data are extremely limited. We describe 3 children (age 2-6 years, weight 13-17 kg) with congenital heart disease who developed intracardiac thrombosis, and in whom typical treatments had failed (in 1) or were considered impractical (in 2). All were treated with apixaban 2.5 mg orally twice daily with complete (in 2) or partial (in 1) thrombus resolution and no clinical bleeding events.

A geometrically adaptable heart valve replacement.

Congenital heart valve disease has life-threatening consequences that warrant early valve replacement; however, the development of a growth-accommodating prosthetic valve has remained elusive. Thousands of children continue to face multiple high-risk open-heart operations to replace valves that they have outgrown. Here, we demonstrate a biomimetic prosthetic valve that is geometrically adaptable to accommodate somatic growth and structural asymmetries within the heart. Inspired by the human venous valve, whose geometry is optimized to preserve functionality across a wide range of constantly varying volume loads and diameters, our balloon-expandable synthetic bileaflet valve analog exhibits similar adaptability to dimensional and shape changes. Benchtop and acute in vivo experiments validated design functionality, and in vivo survival studies in growing sheep demonstrated that mechanical valve expansion accommodated growth. As illustrated in this work, dynamic size adaptability with preservation of unidirectional flow in prosthetic valves thus offers a paradigm shift in the treatment of heart valve disease.

Value of Troponin Testing for Detection of Heart Disease in Previously Healthy Children.

Background Troponin levels are frequently obtained in pediatric patients, but the benefit remains unclear. Methods and Results This retrospective study included 1993 patients aged 0 to 21 years without history of cardiac disease in whom troponin levels were obtained during clinical evaluation of cardiac and noncardiac presentations. Troponin was elevated (≥0.1 ng/mL) in 182 patients (9%). A cardiac diagnosis was made in 109 (60%) of those with elevated troponin and in 208 (12%) of those without (P<0.001). The positive predictive value of elevated troponin for a cardiac diagnosis was 60% for the entire cohort and 85% for patients with a cardiac presentation. The negative predictive value of nonelevated troponin was 89% for the entire cohort and 96% in patients without a cardiac presentation. Serial testing did not improve these predictive values. However, among 404 patients with initially nonelevated levels who had serial measurements, subsequent elevation was found in 80 (20%), of whom 15 (19%) had a cardiac diagnosis. The optimal troponin cutoff value to differentiate cardiac from noncardiac diagnosis was higher in children aged <3 months (0.045 ng/mL) compared with those aged ≥3 months (0.005 ng/mL). Conclusions Troponin can be a useful adjunctive test in the evaluation of children when the differential diagnosis includes cardiac etiologies. Serial measurement was not helpful when troponin was elevated at presentation but may merit consideration when the initial level is not elevated and there is ongoing concern about cardiac involvement. Lower reference values may be appropriate when evaluating children in contrast to adults.

Systemic Sirolimus to Prevent In-Stent Stenosis in Pediatric Pulmonary Vein Stenosis.

Evaluate the efficacy of systemic sirolimus (rapamycin) in preventing in-stent stenosis (ISS) in pediatric intraluminal pulmonary vein stenosis (PVS). Report the adverse events related to sirolimus therapy. There is a high incidence of ISS following stent implantation in PVS. The use of sirolimus in preventing ISS has not been reported. Retrospective review of all patients who received sirolimus (8 week course) for treatment of ISS for PVS between January 2013 and June 2018. Forty stents (37 bare metal, 3 drug-eluting) in 20 patients were treated with sirolimus; 20 at the time of implantation (primary prevention [1P]) and 20 following documented ISS requiring transcatheter reintervention (secondary prevention [2P]). Treated patients were young (median 2 y/o [0.7-5.7]) and most had PVS associated with congenital heart disease (75%, 15/20; 4/15 with TAPVC). In the 1P group, 85% (17/20) of stents were without significant (< 50%) ISS at median of 102 days (range 56-527); the growth rate of ISS in this group was 7.5 ± 7.1%/month. In the 2P group, most stents had a slower growth rate of ISS after sirolimus therapy compared to pre-treatment (median 3.7 [- 0.2 to 13.1] vs. 10.4 [1.3 to 19.5] %/month; p < 0.001). One patient developed pneumonia on drug while concurrently taking another immunosuppressive agent. No other serious adverse events were related to sirolimus therapy. Systemic sirolimus slows the growth rate of ISS following stent implantation in PVS compared to pre-treatment rates and was administered safely in a small number of pediatric patients with complex heart disease.

A Novel Biological Strategy for Myocardial Protection by Intracoronary Delivery of Mitochondria: Safety and Efficacy.

Mitochondrial dysfunction is the determinant insult of ischemia-reperfusion injury. Autologous mitochondrial transplantation involves supplying one's healthy mitochondria to the ischemic region harboring damaged mitochondria. The authors used in vivo swine to show that mitochondrial transplantation in the heart by intracoronary delivery is safe, with specific distribution to the heart, and results in significant increase in coronary blood flow, which requires intact mitochondrial viability, adenosine triphosphate production, and, in part, the activation of vascular KIR channels. Intracoronary mitochondrial delivery after temporary regional ischemia significantly improved myocardial function, perfusion, and infarct size. The authors concluded that intracoronary delivery of mitochondria is safe and efficacious therapy for myocardial ischemia-reperfusion injury.

Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals: collateral vessel disease burden and unifocalisation strategies.

IntroductionThe optimal approach to unifocalisation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (pulmonary artery/ventricular septal defect/major aortopulmonary collaterals) remains controversial. Moreover, the impact of collateral vessel disease burden on surgical decision-making and late outcomes remains poorly defined. We investigated our centre's experience in the surgical management of pulmonary artery/ventricular septal defect/major aortopulmonary collaterals.Materials and methodsBetween 1996 and 2015, 84 consecutive patients with pulmonary artery/ventricular septal defect/major aortopulmonary collaterals underwent unifocalisation. In all, 41 patients received single-stage unifocalisation (Group 1) and 43 patients underwent multi-stage repair (Group 2). Preoperative collateral vessel anatomy, branch pulmonary artery reinterventions, ventricular septal defect status, and late right ventricle/left ventricle pressure ratio were evaluated. RESULTS: Median follow-up was 4.8 compared with 5.7 years for Groups 1 and 2, respectively, p = 0.65. Median number of major aortopulmonary collaterals/patient was 3, ranging from 1 to 8, in Group 1 compared with 4, ranging from 1 to 8, in Group 2, p = 0.09. Group 2 had a higher number of lobar/segmental stenoses within collateral vessels (p = 0.02). Group 1 had fewer catheter-based branch pulmonary artery reinterventions, with 5 (inter-quartile range from 1 to 7) per patient, compared with 9 (inter-quartile range from 4 to 14) in Group 2, p = 0.009. Among patients who achieved ventricular septal defect closure, median right ventricle/left ventricle pressure was 0.48 in Group 1 compared with 0.78 in Group 2, p = 0.03. Overall mortality was 6 (17%) in Group 1 compared with 9 (21%) in Group 2.DiscussionSingle-stage unifocalisation is a promising repair strategy in select patients, achieving low rates of reintervention for branch pulmonary artery restenosis and excellent mid-term haemodynamic outcomes. However, specific anatomic substrates of pulmonary artery/ventricular septal defect/major aortopulmonary collaterals may be better suited to multi-stage repair. Preoperative evaluation of collateral vessel calibre and function may help inform more patient-specific surgical management.

Hemodynamic parameters predict adverse outcomes following biventricular conversion with single-ventricle palliation takedown.

OBJECTIVE: Patients with a borderline left ventricular hypoplasia in the hypoplastic left heart syndrome variant or an unbalanced atrioventricular canal who undergo initial single-ventricle palliation may be candidates for biventricular (BiV) conversion following left ventricle (LV) recruitment procedures. We investigated associations among preoperative parameters and postoperative outcomes in patients undergoing BiV conversion. METHODS: We performed a retrospective review of patients who underwent BiV conversion to determine variables associated with clinical outcomes. Predictor variables included cardiac diagnosis, age and weight, LV dimension, LV end diastolic volume, LV mass, preoperative LV end diastolic pressure (LVEDP), and preoperative left atrial pressure. Primary outcome was a composite of death, heart transplant, or BiV takedown. RESULTS: Of 51 patients, 11 experienced primary outcome (22%). Patients with hypoplastic left heart syndrome variant were more likely to experience primary outcome than those with an unbalanced atrioventricular canal (30% vs 6%; P = .03). Receiver operating characteristic analysis demonstrated that preoperative LVEDP had good predictive accuracy in classifying patients with and without the primary outcome (area under the curve, 0.757; 95% confidence interval, 0.594-0.919; P = .012). The Youden J-index indicated a cutoff of LVEDP ≥ 13 mm Hg as optimal for predicting the primary outcome. Multivariable Cox regression demonstrated that LVEDP ≥ 13 mm Hg (adjusted hazard ratio, 4.00; P = .037) and postoperative right ventricle pressure > 3/4 (adjusted hazard ratio, 21.75; P < .001) were significantly associated with primary outcome, independent of age, weight, and diagnosis. CONCLUSIONS: Elevated preoperative LVEDP is a risk factor for suboptimal postoperative hemodynamic parameters and adverse outcome following BiV conversion from single-ventricle palliation.

Mechanism of valve failure and efficacy of reintervention through catheterization in patients with bioprosthetic valves in the pulmonary position.

BACKGROUND: Surgical and transcatheter bioprosthetic valves (BPVs) in the pulmonary position in patients with congenital heart disease may ultimately fail and undergo transcatheter reintervention. Angiographic assessment of the mechanism of BPV failure has not been previously described. AIMS: The aim of this study was to determine the mode of BPV failure (stenosis/regurgitation) requiring transcatheter reintervention and to describe the angiographic characteristics of the failed BPVs and report the types and efficacy of reinterventions. MATERIALS AND METHODS: This is a retrospective single-center review of consecutive patients who previously underwent pulmonary BPV placement (surgical or transcatheter) and subsequently underwent percutaneous reintervention from 2005 to 2014. RESULTS: Fifty-five patients with surgical (41) and transcutaneous pulmonary valve (TPV) (14) implantation of BPVs underwent 66 catheter reinterventions. The surgically implanted valves underwent fifty reinterventions for indications including 16 for stenosis, seven for regurgitation, and 27 for both, predominantly associated with leaflet immobility, calcification, and thickening. Among TPVs, pulmonary stenosis (PS) was the exclusive failure mode, mainly due to loss of stent integrity (10) and endocarditis (4). Following reintervention, there was a reduction of right ventricular outflow tract gradient from 43 ± 16 mmHg to 16 ± 10 mmHg (P < 0.001) and RVp/AO ratio from 0.8 ± 0.2 to 0.5 ± 0.2 (P < 0.001). Reintervention with TPV placement was performed in 45 (82%) patients (34 surgical, 11 transcatheter) with no significant postintervention regurgitation or paravalvular leak. CONCLUSION: Failing surgically implanted BPVs demonstrate leaflet calcification, thickness, and immobility leading to PS and/or regurgitation while the mechanism of TPV failure in the short- to mid-term is stenosis, mainly from loss of stent integrity. This can be effectively treated with a catheter-based approach, predominantly with the valve-in-valve technique.

Noninvasive Cardiac Output Estimation by Inert Gas Rebreathing in Mechanically Ventilated Pediatric Patients.

OBJECTIVE: To assess the feasibility and accuracy of inert gas rebreathing (IGR) pulmonary blood flow (Qp) estimation in mechanically ventilated pediatric patients, potentially providing real-time noninvasive estimates of cardiac output. STUDY DESIGN: In mechanically ventilated patients in the pediatric catheterization laboratory, we compared IGR Qp with Qp estimates based upon the Fick equation using measured oxygen consumption (VO2) (FickTrue); for context, we compared FickTrue with a standard clinical short-cut, replacing measured with assumed VO2 in the Fick equation (FickLaFarge, FickLundell, FickSeckeler). IGR Qp and breath-by-breath VO2 were measured using the Innocor device. Sampled pulmonary arterial and venous saturations and hemoglobin concentration were used for Fick calculations. Qp estimates were compared using Bland-Altman agreement and Spearman correlation. RESULTS: The final analysis included 18 patients aged 4-23 years with weight >15 kg. Compared with the reference FickTrue, IGR Qp estimates correlated best and had the least systematic bias and narrowest 95% limits of agreement (results presented as mean bias ±95% limits of agreement): IGR -0.2 ± 1.1 L/min, r = 0.90; FickLaFarge +0.7 ± 2.2 L/min, r = 0.80; FickLundell +1.6 ± 2.9 L/min, r = 0.83; FickSeckeler +0.8 ± 2.5 L/min, r = 0.83. CONCLUSIONS: IGR estimation of Qp is feasible in mechanically ventilated patients weighing >15 kg, and agreement with FickTrue Qp estimates is better for IGR than for other Fick Qp estimates commonly used in pediatric catheterization. IGR is an attractive option for bedside monitoring of Qp in mechanically ventilated children.

Systemic rapamycin to prevent in-stent stenosis in peripheral pulmonary arterial disease: early clinical experience.

OBJECTIVES: We have taken a novel approach using oral rapamycin - sirolimus - as a medical adjunct to percutaneous therapy in patients with in-stent stenosis and high risk of right ventricular failure. BACKGROUND: Peripheral pulmonary artery stenosis can result in right ventricular hypertension, dysfunction, and death. Percutaneous pulmonary artery angioplasty and stent placement acutely relieve obstructions, but patients frequently require re-interventions due to re-stenosis. In patients with tetralogy of Fallot or arteriopathy, the problem of in-stent stenosis contributes to the rapidly recurrent disease. METHODS: Rapamycin was administered to 10 patients (1.5-18 years) with peripheral pulmonary stenosis and in-stent stenosis and either right ventricular hypertension, pulmonary blood flow maldistribution, or segmental pulmonary hypertension. Treatment was initiated around the time of catheterisation and continued for 1-3 months. Potential side-effects were monitored by clinical review and blood tests. RESULTS: Target serum rapamycin level (6-10 ng/ml) was accomplished in all patients; eight of the nine patients who returned for clinically indicated catheterisations demonstrated reduction in in-stent stenosis, and eight of the 10 patients experienced no significant side-effects. Among all, one patient developed diarrhoea requiring drug discontinuation, and one patient experienced gastrointestinal bleeding while on therapy that was likely due to an indwelling feeding tube and this patient tolerated rapamycin well following tube removal. CONCLUSIONS: Our initial clinical experience supports that patients with peripheral pulmonary artery stenosis can be safely treated with rapamycin. Systemic rapamycin may provide a novel medical approach to reduce in-stent stenosis.

Acute kidney injury after Fontan completion: Risk factors and outcomes.

OBJECTIVE: Acute kidney injury (AKI) is a predictor of outcomes in heterogeneous populations of children undergoing cardiac surgery. We investigated its causes and consequences in a cohort undergoing Fontan completion, hypothesizing that central venous pressure is independently associated with development of AKI. METHODS: In this retrospective cohort study of patients undergoing Fontan (n = 211), univariable and multivariable analyses identified factors associated with AKI within 3 days of surgery. Secondary analyses identified factors associated with hospital length of stay, and examined effects of perioperative kidney injury on follow-up renal function. RESULTS: Acute kidney injury occurred in 42% of cases (n = 89), with the following independent risk factors: mean renal perfusion (mean arterial minus central venous) pressure on postoperative day zero (per mm Hg; adjusted odds ratio [AOR] 0.83; P < .001); preoperative atrioventricular valve regurgitation > mild (AOR 6.78; P = .02); bypass time (per 10 minutes, AOR 1.08; P = .04); peak inotrope score on postoperative day zero (per point, AOR 1.17; P < .001); and preoperative pulmonary vascular resistance (per Wood unit, AOR 1.69; P = .04). Central venous pressure was not independently associated with AKI. Moderate and severe (but not mild) AKI were independently associated with prolonged hospital length of stay (adjusted hazard ratios, 0.56; P = .004, and .41; P = .006, respectively). Perioperative injury was not associated with longer-term renal dysfunction. CONCLUSIONS: Acute kidney injury is common after Fontan completion and has several potentially modifiable risk factors. Moderate-to-severe injury is associated with longer hospital length of stay but not with renal dysfunction at follow-up.

Systemic Embolic Complications of Pulmonary Vein Angioplasty in Children.

Pulmonary vein stenosis (PVS) carries significant morbidity and mortality for affected children, and its management often requires multiple angioplasty procedures. PVS angioplasty can be complicated by systemic embolic events such as stroke, but incidence and risk factors are poorly understood. We reviewed pediatric catheterizations involving PVS angioplasty and/or stent placement performed at Boston Children's Hospital between July 2005 and February 2014. A total of 406 cases were performed in 144 distinct patients. Patients underwent a median of two catheterizations, at median age 1 year and weight 6.9 kg. Eleven (2.7 %) catheterizations were complicated by clinically apparent systemic embolic events, comprising 10 strokes (one with associated hepatic embolism) and 1 renal infarct. Prevalence of clinically evident stroke among this cohort was 7.6 %. Using a prior (uncomplicated) catheterization to allow each patient to serve as their own control, we sought to identify potentially modifiable risk factors for systemic embolic events. Although this analysis was limited by low power, complicated and uncomplicated angioplasties did not appear to differ in case time, contrast dose, anticoagulation management, use of cutting balloons, number of catheter exchanges, or size of long sheath used. Significant non-embolic adverse events were common, occurring in 25 % of catheterizations. Systemic embolism appears to complicate PVS angioplasty at a rate much higher than that described for other congenital catheterizations. This risk may be inherent to the procedure rather than related to any modifiable or operator-dependent factors.

Transcatheter brachial fistula creation for treatment of pulmonary arteriovenous malformations.

Pulmonary arteriovenous malformations (PAVMs) are thought to form as a result of exclusion of hepatic venous blood from part of the pulmonary circulation. Surgical arteriovenous (AV) fistula creation has demonstrated therapeutic potential to reverse PAVM formation. We sought to demonstrate the feasibility and safety of transcatheter AV fistula creation for this indication. Fluoroscopically guided puncture from the basilic vein into the brachial artery using a Brockenbrough needle and sharpened 0.014" wire created a tract between these vessels. After balloon dilation of the tract, a covered stent was deployed, resulting in a functioning brachial AV fistula. The procedure was technically successful, with no clinical complications at 4 months follow-up. Repeat diagnostic catheterization revealed marked improvement in systemic saturation and near-resolution of PAVMs in the pilot patient. This report suggests that transcatheter brachial arteriovenous fistula formation is technically feasible, and may be effective in managing PAVMs in select single-ventricle patients.

Acute outcomes after introduction of a standardized clinical assessment and management plan (SCAMP) for balloon aortic valvuloplasty in congenital aortic stenosis.

INTRODUCTION: Standardization of care can reduce practice variation, optimize resource utilization, and improve clinical outcomes. We have created a standardized clinical assessment and management plan (SCAMP) for patients having balloon aortic valvuloplasty (BAV) for congenital aortic stenosis (AS). This study compares acute outcomes of BAV at our institution before and after introduction of this SCAMP. METHODS: In this retrospective matched cohort study, each SCAMP patient was matched to four historical controls. Outcomes were categorized based on the combination of residual AS and aortic regurgitation (AR) as: (1) Optimal: gradient ≤ 35 mm Hg and trivial or no AR; (2) Adequate: gradient ≤ 35 mm Hg and mild AR; (3) Inadequate: gradient > 35 mm Hg and/or moderate or severe AR. RESULTS: All 23 SCAMP patients achieved a residual AS gradient ≤ 35 mm Hg; the median residual AS gradient for the SCAMP group was lower (25 [10-35] mm Hg) than in matched controls (30 [0-65] mm Hg; P = 0.005). The two groups did not differ with regard to degree of AR grade after BAV. Compared with controls, SCAMP patients were more likely to have an optimal result and less likely to have an inadequate result (52% vs. 34% and 17% vs. 45%, respectively; P = 0.02) CONCLUSIONS: A SCAMP for BAV resulted in optimal acute results in half of the initial 23 patients enrolled, and outcomes in this group were better than those of matched historical controls. Whether these improved acute outcomes translate into better long-term outcomes for this patient population remains to be seen.

Bloodstream infections occurring in patients with percutaneously implanted bioprosthetic pulmonary valve: a single-center experience.

BACKGROUND: Percutaneous pulmonary valve implantation using a stent-based bioprosthetic valve provides an alternative to surgery in select patients. Systemic infections in Melody valve-implanted patients with and without identified valve involvement have been reported, yet the incidence is unknown, and risk factors remain unidentified. METHODS AND RESULTS: Between 2007 and 2012, a total of 147 consecutive patients with congenital heart disease underwent Melody percutaneous pulmonary valve implantation at our institution. Demographic and clinical variables were collected at baseline and at follow-up and analyzed as predictors. The occurrence of bloodstream infection (BSI), defined as a bacterial infection treated with ≥4 weeks of antibiotics, served as our primary outcome. The mean age at implantation for the study population was 21.5±11 years, and tetralogy of Fallot was the cardiac condition in 59%. During a median follow-up of 19 months, 14 patients experienced BSI (9.5%; 95% confidence interval, 5.3%-15%). Of these, 4 (2.7%) patients had Melody valve endocarditis. Two patients died during the event, neither of whom had known valve involvement. The median procedure to infection time was 15 months (range, 1-56). In univariate analysis, male sex, previous endocarditis, in situ stents in the right ventricular outflow tract, and presence of outflow tract irregularities at the implant site were associated with BSI occurrence. CONCLUSIONS: In this cohort, 9.5% of patients who underwent Melody percutaneous pulmonary valve implantation experienced subsequent BSI, occurring 1 to 56 months after implant, and 2.7% of patients had prosthetic endocarditis. Our findings suggest that patient and nonvalve anatomic factors may be associated with BSI after percutaneous pulmonary valve implantation.

Transcatheter Potts shunt creation in patients with severe pulmonary arterial hypertension: initial clinical experience.

BACKGROUND: Patients with severe pulmonary arterial hypertension (PAH) face significant morbidity and death as a consequence of progressive right heart failure. Surgical shunt placement between the left PA and descending aorta (Potts shunt) appears promising for PAH palliation in children; however, surgical mortality is likely to be unacceptably high in adults with PAH. METHODS: We describe a technique for transcatheter Potts shunt (TPS) creation by fluoroscopically guided retrograde needle perforation of the descending aorta at the site of apposition to the left PA to create a tract for deployment of a covered stent between these vessels. This covered stent-anchored by the vessel walls and surrounding tissue-serves as the shunt. RESULTS: TPS creation was considered in 7 patients and performed in 4. The procedure was technically successful in 3 patients; 1 patient died during the procedure as a result of uncontrolled hemothorax. One acute survivor, critically ill at the time of TPS creation, later died of comorbidities. The 2 mid-term survivors (follow-up of 10 and 4 months) are well at home, with symptomatic improvement and no late complications. The 3 candidate patients in whom the procedure was not performed died within 1 month of consideration, underscoring the tenuous nature of this population. CONCLUSIONS: TPS creation is feasible and may offer symptomatic relief to select patients with refractory PAH. Further study of this innovative approach is warranted.