Incremental reduction in the incidence of stroke in children supported with the Berlin EXCOR ventricular assist device.

BACKGROUND: Cerebrovascular events (CVEs) are common among children supported with the Berlin EXCOR (Berlin Heart GmbH, Berlin, Germany) ventricular assist device (VAD). Given the high incidence of CVEs associated with this device, we sought to describe our institutional experience in incrementally reducing CVEs in children supported with the Berlin EXCOR VAD. METHODS: We collected pertinent data on 39 consecutive patients who underwent Berlin EXCOR VAD implantation at a single center. Frequency of CVEs was described in risk per implantation, per day, and in reference to the time of therapeutic anticoagulation. Risk factors were analyzed for association with CVEs. RESULTS: Of the initial 39 Berlin EXCOR VAD implantations, 16 CVEs occurred in 12 patients. The incidence of CVEs decreased with institutional experience per patient (R(2) = 0.6909, p = 0.007) and per patient-day (R(2) = 0.8051, p = 0.002). CVEs occurred more frequently before therapeutic anticoagulation targets were achieved (4.1%/day) compared with after therapeutic anticoagulation targets were achieved (0.9%/day; p = 0.044). CONCLUSIONS: Incidence of CVEs decreased with institutional experience. The risk of CVE is highest in the immediate postoperative period before therapeutic anticoagulation is achieved. Further studies are warranted in pediatric patients supported with the Berlin EXCOR VAD to confirm our findings in a larger cohort.

Parvovirus B19 myocarditis causes significant morbidity and mortality in children.

Although parvovirus B19 (PVB19) currently is the most common cause of viral myocarditis, limited pediatric data exist. Whereas other viruses infect cardiomyocytes, PVB19 targets coronary endothelium, leading to myocardial ischemia and dysfunction. A retrospective review investigated patients with polymerase chain reaction (PCR)-verified PVB19 myocarditis at Texas Children's Hospital and Arkansas Children's Hospital (January 2005 to August 2008). The primary end points of the study were transplant-free survival and circulatory collapse (death, mechanical support, or transplantation). For the 19 patients identified (age, 6 months to 15 years), the most common presenting symptoms were respiratory and gastrointestinal. At admission, all the patients demonstrated ventricular dysfunction requiring inotropic support (median ejection fraction, 24 %; median left ventricle end-diastolic diameter [LVEDD] z-score, 4.6). Whereas T-wave abnormalities were common, ST elevation was evident in five patients (two died and three required transplantation). Serum B-type natrietic peptide was elevated in all 12 patients tested (range, 348-8,058 pg/ml), and troponin I was high in 7 of 9 patients (range, 0.04-14.5 ng/ml). Of the 15 patients with circulatory collapse, nine received mechanical support, eight underwent successful transplantation, and five died. Only six patients (32 %) experienced transplant-free survival, and five patients had full recovery of function at discharge. In the transplant-free survival group, ST changes on presenting electrocardiography were less likely (p = 0.03), and the admission LVEDD z-score tended to be lower (3.3 vs 5.6; p = 0.08). In children, PVB19 myocarditis causes significant mortality and morbidity. Although mechanical intervention can support patients in the initial stage of decompensated heart failure, patients with PVB19 myocarditis often demonstrate persistent dysfunction requiring medical therapy and transplantation.

Extracorporeal membrane oxygenation support for intractable primary arrhythmias and complete congenital heart block in newborns and infants: short-term and medium-term outcomes.

OBJECTIVES: To describe the experience with extracorporeal membrane oxygenation support for intractable primary arrhythmias in newborns and infants. DESIGN: Retrospective study. SETTING: A tertiary care pediatric hospital. PATIENTS: Patients younger than 1 yr supported with extracorporeal membrane oxygenation for primary cardiac arrhythmias were identified from the institutional extracorporeal membrane oxygenation registry. INTERVENTIONS: Extracorporeal membrane oxygenation support. MEASUREMENTS AND MAIN RESULTS: Clinical characteristics and outcomes were investigated for patients with primary cardiac arrhythmia supported with extracorporeal membrane oxygenation. Outcomes investigated were time from initiation of extracorporeal membrane oxygenation support to arrhythmia control, duration of extracorporeal membrane oxygenation support, and results of interventions performed while supported with extracorporeal membrane oxygenation. We summarized the independent categorical and continuous variables using frequencies, percentages, and medians and ranges, respectively. Extracorporeal membrane oxygenation support was used in nine patients for rescue therapy for primary tachyarrhythmia and bradycardia. The primary arrhythmias were: focal atrial tachycardia (n = 2); reentrant supraventricular tachycardia (n = 3); junctional ectopic tachycardia (n = 2); and congenital complete atrioventricular block (n = 2) patients. Seven patients presented with severe hemodynamic compromise, with six patients requiring extracorporeal cardiopulmonary resuscitation. All patients required extracorporeal membrane oxygenation within 24 hrs of initial presentation. Balloon atrial septostomy was performed in three patients and ablation was performed in two patients. Sinus rhythm was achieved in all reentrant supraventricular tachycardia and rate control was established in both patients with focal atrial tachycardia and in one patient with junctional ectopic tachycardia while using extracorporeal membrane oxygenation support. All patients survived to hospital discharge, and median follow-up for the cohort was 5 yrs. There was one late death; all survivors had good overall and neurologic outcomes. CONCLUSIONS: The requirement of extracorporeal membrane oxygenation support in newborns and infants with intractable arrhythmia is rare. Extracorporeal membrane oxygenation support does potentially carry morbidity; however, to prevent arrhythmia-related mortality, extracorporeal membrane oxygenation support and/or extracorporeal cardiopulmonary resuscitation should be considered in the management of hemodynamically unstable primary arrhythmias as an emergent lifesaving procedure.

The technology path to deep greenhouse gas emissions cuts by 2050: the pivotal role of electricity.

Several states and countries have adopted targets for deep reductions in greenhouse gas emissions by 2050, but there has been little physically realistic modeling of the energy and economic transformations required. We analyzed the infrastructure and technology path required to meet California's goal of an 80% reduction below 1990 levels, using detailed modeling of infrastructure stocks, resource constraints, and electricity system operability. We found that technically feasible levels of energy efficiency and decarbonized energy supply alone are not sufficient; widespread electrification of transportation and other sectors is required. Decarbonized electricity would become the dominant form of energy supply, posing challenges and opportunities for economic growth and climate policy. This transformation demands technologies that are not yet commercialized, as well as coordination of investment, technology development, and infrastructure deployment.

The impact of heart failure severity at time of listing for cardiac transplantation on survival in pediatric cardiomyopathy.

BACKGROUND: The survival benefit of heart transplantation in adult heart failure is greatest for the sickest patients and negligible for patients not requiring inotropic or mechanical support. We hypothesized a similar survival benefit of heart transplantation for childhood cardiomyopathies with heart failure. METHODS: A merged data set of children registered in both the Pediatric Cardiomyopathy Registry and the Pediatric Heart Transplant Study was used to assess differences in mortality before and after transplant in patients with different levels of heart failure severity. Severity was scored 2 if mechanical ventilatory or circulatory support was required, 1 if intravenous inotropes were required, or 0 if no support was required. RESULTS: For 332 eligible children, 12-month mortality after listing was 9% for those with a severity score of 0 (n = 105), 16% with a score of 1 (n = 118), and 26% with a score of 2 (n = 109; p = 0.002) with a 3%, 8%, and 20% mortality with severity scores at listing of 0, 1, and 2, respectively, occurring before transplant. Patients listed with a score of 0 frequently deteriorated: 50% received an allograft or died before transplant with severity scores of 1 or 2. The risk of deterioration increased with previous surgery (relative risk, 3.84; p = 0.03) in the short-term and with lower left ventricular mass z-score at time of presentation (relative risk, 1.74; p = 0.003) in the longer-term. CONCLUSION: Pediatric cardiomyopathy patients who require high levels of support receive a survival benefit from heart transplantation that is not shared by patients not requiring intravenous inotropic or mechanical support.

Cardiopulmonary bypass flow rate: a risk factor for hyperlactatemia after surgical repair of secundum atrial septal defect in children.

OBJECTIVE: Early postoperative hyperlactatemia is seen in some children after surgical repair of secundum atrial septal defect despite apparently normal cardiac output. The objective of the study was to investigate the intraoperative risk factors for hyperlactatemia in patients undergoing atrial septal defect repair. METHODS AND RESULTS: A retrospective review of 68 consecutive patients who underwent isolated atrial septal defect repair at Arkansas Children's Hospital between January 2001 and March 2006 was performed. Perioperative factors in the high lactate group (lactate >3 mmol/L, n = 26) were compared with those in the low lactate group (n = 42). Early hyperlactatemia was seen in 38% of the cohort. The high lactate group showed significantly lower weight-indexed cardiopulmonary bypass flow rate (101 + or - 6.5 mL/kg(-1)/min(-1) vs 131 + or - 6.0 mL/kg(-1)/min(-1), P = .0013), oxygen delivery during cardiopulmonary bypass (mean 12.7 + or - 0. 7 mL/kg(-1)/min(-1) vs 17.0 + or - 1 mL/kg(-1)/min(-1), P = .0009), and higher postoperative glucose (191 + or - 8.6 mg/dL vs 151 + or - 5.4 mg/dL, P = .003) compared with the LL group. Multivariate logistic regression analysis showed that weight-indexed cardiopulmonary bypass flow rate (P = .007) and average mean arterial blood pressure during cardiopulmonary bypass (P = .009) were independent risk factors for postoperative hyperlactatemia. Cardiopulmonary bypass flow rate less than 100 mL/kg(-1)/min(-1) was associated with an odds ratio of 7.67 (95% confidence interval, 1.28-45.86; P = .026) for postoperative hyperlactatemia. CONCLUSION: Lower weight-indexed cardiopulmonary bypass flow rate is an independent risk factor for early postoperative hyperlactatemia in children after atrial septal defect repair.

The effect of age, diagnosis, and previous surgery in children and adults undergoing heart transplantation for congenital heart disease.

OBJECTIVES: We sought to evaluate the outcomes and identify risk factors for mortality after heart transplantation (HT) for congenital heart disease (CHD) in infants, children, and adults. BACKGROUND: CHD is considered a risk factor for mortality after HT, yet this unique group of patients represents a spectrum of complexity. METHODS: There were 488 patients transplanted for CHD from the combined Pediatric Heart Transplant Study (1993 to 2002, n = 367) and the Cardiac Transplant Registry Database (1990 to 2002, n = 121) who were analyzed. RESULTS: The median age at HT was 12.4 years. Primary diagnosis included single ventricle (36%), d-transposition of the great arteries (12%), right ventricular outflow tract lesions (10%), l-transposition of the great arteries (8%), ventricular/atrial septal defects (8%), left ventricular outflow obstruction (8%), and other (18%). Ninety-three percent of patients had at least 1 operation before HT. Survival at 3 months post-HT was significantly worse in CHD patients versus children with cardiomyopathy, but not adults with cardiomyopathy (86%, 94%, and 91%, respectively). There was no difference in conditional 3-month survival among the 3 groups. Five-year survival was 80%. Risk factors for early mortality were older recipient age, older donors with longer ischemic times, and pre-HT Fontan operations. Predicted survival in Fontan patients was lower (77% and 70% at 1 and 5 years) versus non-Fontan patients (88% and 81% at 1 and 5 years). Risk factors for constant phase mortality included younger recipient age, higher transpulmonary gradient, cytomegalovirus mismatch at HT, and earlier classical Glenn operation. CONCLUSIONS: Patients undergoing transplantation for CHD have a good late survival if they survive the early post-operative period. Risk factors for reduced survival are older age at transplant and a previous Fontan operation.

National-level infrastructure and economic effects of switchgrass cofiring with coal in existing power plants for carbon mitigation.

We update a previously presented Linear Programming (LP) methodology for estimating state level costs for reducing CO2 emissions from existing coal-fired power plants by cofiring switchgrass, a biomass energy crop, and coal. This paper presents national level results of applying the methodology to the entire portion of the United States in which switchgrass could be grown without irrigation. We present incremental switchgrass and coal cofiring carbon cost of mitigation curves along with a presentation of regionally specific cofiring economics and policy issues. The results show that cofiring 189 million dry short tons of switchgrass with coal in the existing U.S. coal-fired electricity generation fleet can mitigate approximately 256 million short tons of carbon-dioxide (CO2) per year, representing a 9% reduction of 2005 electricity sector CO2 emissions. Total marginal costs, including capital, labor, feedstock, and transportation, range from $20 to $86/ton CO2 mitigated,with average costs ranging from $20 to $45/ton. If some existing power plants upgrade to boilers designed for combusting switchgrass, an additional 54 million tons of switchgrass can be cofired. In this case, total marginal costs range from $26 to $100/ton CO2 mitigated, with average costs ranging from $20 to $60/ton. Costs for states east of the Mississippi River are largely unaffected by boiler replacement; Atlantic seaboard states represent the lowest cofiring cost of carbon mitigation. The central plains states west of the Mississippi River are most affected by the boiler replacement option and, in general, go from one of the lowest cofiring cost of carbon mitigation regions to the highest. We explain the variation in transportation expenses and highlight regional cost of mitigation variations as transportation overwhelms other cofiring costs.

State-level infrastructure and economic effects of switchgrass cofiring with coal in existing power plants for carbon mitigation.

This paper presents a linear programming (LP) methodology for estimating the cost of reducing a state's coal-fired power plant carbon dioxide emissions by cofiring switchgrass and coal. LP modeling allows interplay between regionally specific switchgrass production forecasts, coal plant locations, and individual coal plant historic performance data to determine an allocation of switchgrass minimizing cost or maximizing carbon reduction. The LP methodology is applied to two states, Pennsylvania (PA) and Iowa (IA), and results are presented with a discussion of modeling assumptions, techniques, and carbon mitigation policy implications. The LP methodology estimates that, in PA, 4.9 million tons of CO2/year could be mitigated at an average cost of less than $34/ton of CO2 and that, in IA, 7 million tons of CO2/year could be mitigated at an average Cost of Mitigation of $27/ton of CO2. Because the factors determining the cofiring costs vary so much between the two states, results suggest that cofiring costs will also vary considerably between different U.S. regions. A national level analysis could suggest a lowest-cost cofiring region. This paper presents techniques and assumptions that can simplify biomass energy policy analysis with little effect on analysis conclusions.

Noninvasive cerebral oximeter as a surrogate for mixed venous saturation in children.

We evaluated the relationship between regional cerebral oxygen saturation (rSO(2)) measured by near-infrared spectroscopy (NIRS) cerebral oximeter with superior vena cava (SVC), inferior vena cava (IVC), right atrium (RA), and pulmonary artery (PA) saturation measured on room air and 100% inspired oxygen administered via a non-rebreather mask (NRB) in children. Twenty nine pediatric post-orthotopic heart transplant patients undergoing an annual myocardial biopsy were studied. We found a statistically significant correlation between rSO(2) and SVC saturations at room air and 100% inspired oxygen concentration via NRB (r = 0.67, p = 0.0002 on room air; r = 0.44, p = 0.02 on NRB), RA saturation (r = 0.56, p = 0.002; r = 0.56, p = 0.002), and PA saturation (r = 0.67, p < 0.001; r = 0.4, p = 0.03). A significant correlation also existed between rSO(2) and measured cardiac index (r = 0.45, p = 0.01) and hemoglobin levels (r = 0.41, p = 0.02). The concordance correlations were fair to moderate. Bias and precision of rSO(2) compared to PA saturations on room air were -0.8 and 13.9%, and they were 2.1 and 15.6% on NRB. A stepwise linear regression analysis showed that rSO(2) saturations were the best predictor of PA saturations on both room air (p = 0.0001) and NRB (p = 0.012). In children with biventricular anatomy, rSO(2) readings do correlate with mixed venous saturation.

Ruptured tricuspid valve papillary muscle: a treatable cause of neonatal cyanosis.

Severe tricuspid regurgitation resulting from a flail leaflet is a rare cause of neonatal cyanosis. We report two neonates with profound cyanosis and severe tricuspid regurgitation caused by rupture of the papillary muscle supporting the anterior leaflet, without other structural heart defects. Ductal patency could not be established. Repair of the tricuspid valve was performed by reimplantation of the ruptured papillary muscle head, after initial stabilization using extracorporeal membrane oxygenation. Early recognition and treatment of this otherwise fatal condition can be lifesaving.

Determinants of renal function in pediatric heart transplant recipients: long-term follow-up study.

BACKGROUND: Renal insufficiency (RI) is a known complication in heart transplant recipients. We sought to determine the prevalence and risk factors for RI in pediatric heart transplant recipients over a long-term follow-up period. METHODS: The study cohort included 77 pediatric heart transplant recipients (35 girls, 18 African Americans) who had a minimum follow-up of 1 year. Data were obtained from pre-transplant evaluations and at 1, 6 and 12 months post-transplant and annually thereafter. Factors evaluated for their influence on renal function included duration of listing, age at transplant, gender, race, cardiac diagnosis, use of assist devices, inotropic support, rejection episodes and use of calcineurin inhibitors. RESULTS: The median age at transplant was 2 years, with a median follow-up duration of 5.1 years. RI was prevalent in 33% pre-transplant, and in 17%, 21% and 25.9% at 1, 3 and 5 years post-transplant, respectively. Two patients developed end-stage renal disease requiring long-term dialysis, with 1 eventually receiving a renal transplant. Significant risk factors for RI were African-American race (p = 0.04), younger age at transplant (p = 0.007), duration of listing (p < 0.0001) and calcineurin inhibitor level (p = 0.003). RI at 6 months post-transplant predicted chronic kidney disease at 5 years (odds ratio = 9). CONCLUSIONS: The prevalence of RI increased during a median follow-up of 5 years in this pediatric heart transplant cohort. African-American race, younger age at transplant, longer duration of listing, high level of calcineurin inhibitors and RI at 6 months were important determinants of RI. These patients should be followed-up carefully with early referral to a pediatric nephrologist if they develop chronic kidney disease.

Report of the Tennessee Task Force on Screening Newborn Infants for Critical Congenital Heart Disease.

A member of the Tennessee state legislature recently proposed a bill that would mandate all newborn infants to undergo pulse oximetry screening for the purpose of identifying those with critical structural heart disease before discharge home. The Tennessee Task Force on Screening Newborn Infants for Critical Congenital Heart Defects was convened on September 29, 2005. This group reviewed the current medical literature on this topic, as well as data obtained from the Tennessee Department of Health, and debated the merits and potential detriments of a statewide screening program. The estimated incidence of critical congenital heart disease is 170 in 100,000 live births, and of those, 60 in 100,000 infants have ductal-dependent left-sided obstructive lesions with the potential of presentation by shock or death if the diagnosis is missed. Of the latter group, the diagnosis is missed in approximately 9 in 100,000 by fetal ultrasound assessment and discharge examination and might be identified by a screening program. Identification of the missed diagnosis in these infants before discharge could spare many of them death or neurologic sequelae. Four major studies using pulse oximetry screening were analyzed, and when data were restricted to critical left-sided obstructive lesions, sensitivity values of 0% to 50% and false-positive rates of between 0.01% and 12% were found in asymptomatic populations. Because of this variability and other considerations, a meaningful cost/benefit analysis could not be performed. It was the consensus of the task force to provide a recommendation to the legislature that mandatory screening not be implemented at this time. In addition, we determined that a very large, prospective, perhaps multistate study is needed to define the sensitivity and false-positive rates of lower-limb pulse oximetry screening in the asymptomatic newborn population and that there needs to be continued partnering between the medical community, parents, and local, state, and national governments in decisions regarding mandated medical care.

Modeling switchgrass derived cellulosic ethanol distribution in the United States.

Discussions of alternative fuel and propulsion technologies for transportation often overlook the infrastructure required to make these options practical and cost-effective. We estimate ethanol production facility locations and use a linear optimization model to consider the economic costs of distributing various ethanol fuel blends to all metropolitan areas in the United States. Fuel options include corn-based E5 (5% ethanol, 95% gasoline) to E16 from corn and switchgrass, as short-term substitutes for petroleum-based fuel. Our estimates of 1-2 cents per L of ethanol blend for downstream rail or truck transportation remain a relatively small fraction of total fuel cost. However, for even the relatively small blends of ethanol modeled, the transportation infrastructure demands would be comparably larger than the current demands of petroleum. Thus if ethanol is to be competitive in the long run, then in addition to process efficiency improvements, more efficient transportation infrastructure will need to be developed, such as pipelines. In addition to these results, national and regional policy challenges on how to pay for and optimize a new fuel and distribution infrastructure in the United States are discussed.

Lessons learned from the pediatric heart transplant study.

The Pediatric Heart Transplant Study (PHTS) group was founded in 1991 as a voluntary, collaborative effort dedicated to the advancement of the science and treatment of children following listing for heart transplantation. Since 1993, the PHTS has collected data in an international, prospective, event-driven database that examines risk factors for outcome events following listing for transplantation. The events include transplantation, death, rejection, infection, malignancy, graft vasculopathy, and retransplantation. Over its 12 years of existence, the PHTS has made major contributions to the field of pediatric heart transplantation, especially in the areas of outcome analysis and risk factor assessment for death and other major morbidities after listing and after transplantation. The new challenges facing the PHTS include how to implement the practice of evidence-based medicine in the field of pediatric heart transplantation and how to support ongoing data collection and analysis to provide long-term outcomes as the PHTS subjects enter their second decade after transplantation.

The first successful DeBakey VAD child implantation as a bridge to transplant.

A 14-year-old boy with repaired transposition of the great arteries and ventricular septal defect presented with atrial flutter and severe congestive heart failure. Despite successful cardioversion and optimal medical therapy, the patient deteriorated and was supported with extracorporeal membrane oxygenation (ECMO). Two days after initiating ECMO support, we implanted the DeBakey VAD Child ventricular assist device (MicroMed Technology, Inc., Houston, TX) under the Humanitarian Device Exemption program. Later, he was able to pursue normal daily activities including physical rehabilitation and ambulation in the hospital. After 56 days, he underwent a successful cardiac transplantation. After 3 months, he had good cardiac function and no evidence of rejection. The DeBakey VAD Child device is a valuable option for cardiac support as a bridge to transplantation.

The impact and outcome of transplant coronary artery disease in a pediatric population: a 9-year multi-institutional study.

BACKGROUND: Transplant coronary artery disease (TCAD) limits survival in heart transplant recipients; however, its incidence in children is unknown. The purpose of this study was to determine the angiographic incidence of TCAD, potential risk factors, and outcomes in a large pediatric cohort. METHODS: From January 1993 to December 1, a total of 1,222 children, aged newborn to 17 years, underwent primary cardiac transplantation at 20 institutions. A total of 2,049 coronary angiograms were performed in 751 patients. All angiograms were graded for coronary disease and results were submitted to the Pediatric Heart Transplant Study database. We analyzed time-related freedom from graded severity and events from coronary disease, and we examined risk factors. RESULTS: The incidence of angiographic abnormalities at 1, 3, and 5 years was 2%, 9%, and 17%, respectively; however, moderate-to-severe disease occurred in only 6% at 5 years, compared with 15% in the adult transplant database (p <0.0001). The major risk factors were older recipient and donor age. Two or more episodes of rejection in the 1st year correlated with coronary disease (p = 0.05). Overall freedom from graft loss caused by primary TCAD was 99%, 96%, and 91% at 1, 5, and 9 years after heart transplantation, respectively. Death or graft loss occurred within 2 years of diagnosis in patients with severe disease; 24% of patients with any coronary disease died within 2 years. CONCLUSIONS: The incidence of TCAD in children is smaller than the incidence in adults, but increases with age. Graft loss is infrequent in children; however, severe coronary disease correlates with poor prognosis.

Angiographic and hemodynamic predictors for successful outcome of transcatheter occlusion of patent ductus arteriosus in infants less than 8 kilograms.

Transcatheter occlusion of patent ductus arteriosus (PDA) using Gianturco coils (GCs) has been performed for the past decade. However, little has been written regarding anatomical and hemodynamic predictors for successful occlusion of the PDA in infants. This report is to evaluate the outcome of transcatheter occlusion of PDA in symptomatic infants less than 8 kg and to assess predictors of successful occlusion. Retrospective review of catheterization charts and cineangiograms of 42 symptomatic infants who underwent cardiac catheterization for attempted transcatheter occlusion of their PDA was conducted. The hemodynamic and angiographic data evaluated included the length/diameter (L/D) ratio, defined as the length divided by the narrowest diameter of the ductus arteriosus, and preocclusion pulmonary artery pressures. Thirty-one out of 42 patients (74%) had successful occlusion. Twenty-nine out of 42 infants had an L/D ratio > 3. Of these, 26 (90%) had successful occlusion of their PDA. Thirteen out of 42 patients had an L/D ratio < or = 3. Of these, 8 (62%) had unsuccessful occlusion. Complications encountered were transient loss of femoral arterial pulse (n = 6), coil embolization (n = 5), hemolysis (n = 2), and mild left pulmonary artery obstruction (n = 2). No permanent loss of femoral arterial pulse was noted. These complications resulted in no mortality and minimal morbidity. The L/D ratio was the strongest predictor of successful outcome, with an L/D ratio greater than 3.0 being more amenable to transcatheter occlusion (odds ratio of 4.6). Other predictors for success included lower preocclusion systolic, diastolic, and mean pulmonary artery pressure and smaller ductal diameter. Our conclusion was that infants less than 8 kg with an L/D ratio > 3.0 can safely and successfully undergo transcatheter occlusion of their PDA using transcatheter coils.