Congenital Pulmonic Valve Dysfunction Treated With SAPIEN 3 Transcatheter Heart Valve (from the COMPASSION S3 Trial).

Significant pulmonary regurgitation (PR) and pulmonary stenosis are common after surgical repair of some congenital heart defects. This prospective, single-arm, multicenter trial enrolled patients who underwent transcatheter heart valve (THV) implantation with a SAPIEN 3 valve to treat dysfunctional right ventricular outflow tract (RVOT) conduits or pulmonic surgical valves (≥ moderate PR and/or mean RVOT gradient ≥35 mm Hg). The primary end point was a nonhierarchical composite of THV dysfunction at 1 year comprising RVOT reintervention, ≥ moderate total PR, and mean RVOT gradient >40 mm Hg. A performance goal of <25% of upper confidence interval (CI) was prespecified for the primary end point, using a 95% exact binomial CI. Patients (n = 58) were enrolled between July 5, 2016 and July 17, 2018, with mean age of 32 years. Prestenting was performed in 53.4%. At discharge, the device success was 98.1% (single valve without explant, < moderate PR, gradient <35 mm Hg). At 30 days, there were no major adjudicated adverse clinical events. At 1 year, the primary end point composite was 4.3% (95% CI 0.5 to 14.5). The composite components were 0% (0 of 56) RVOT reintervention, 2.1% (1 of 47) ≥ moderate PR, and 2.1% (1 of 48) mean RVOT gradient >40 mm Hg. No mortality, endocarditis, thrombosis, or stent fracture were reported at 1 year. In conclusion, the SAPIEN 3 THV was safe and effective in patients with dysfunctional RVOT conduits or previously implanted valves in the pulmonic position to 1 year. Clinical trial registration: NCT02744677; https://clinicaltrials.gov/ct2/show/NCT02744677.

Transcatheter Occlusion of Left-To-Right Shunts in Premature Infants with Bronchopulmonary Dysplasia.

INTRODUCTION: Patent ductus arteriosus (PDA) and atrial septal defects (ASDs) cause pulmonary overcirculation, potentially worsening bronchopulmonary dysplasia (BPD) in premature infants. Transcatheter device occlusion of these defects is feasible and safe, though no case-controlled studies have assessed respiratory outcomes in infants with BPD. We hypothesized infants with BPD and ASDs or PDAs would experience improved respiratory outcomes following device occlusion of these lesions as compared to those who did not. METHODS: We conducted a single-center, retrospective case-control study of premature infants diagnosed with BPD and either a small to large ASD or a small to moderate PDA from 2015 to 2021. The intervention group underwent transcatheter device occlusion of their defects and the control group did not. We compared changes in BPD severity over time between these two groups. RESULTS: The control and intervention groups demonstrated comparable baseline demographics. Of the 15 patients in the intervention group, 9 underwent PDA device occlusion and 6 underwent ASD device occlusion at median postmenstrual age of 42 weeks (IQR 41-45 weeks). Despite having higher severity BPD at baseline, there was a more pronounced improvement in BPD severity in the intervention group as compared to the control group. DISCUSSION: Premature infants with BPD and an ASD or PDA who underwent transcatheter occlusion of their lesion demonstrated a faster rate of improvement of their BPD severity as compared to a control cohort with similar lesions who did not undergo device occlusion of their lesion.

Early Postoperative Congenital Cardiac Catheterization Outcomes: A Multicenter Study.

BACKGROUND: Early postoperative catheterizations (EPOCs) within 6 weeks after a congenital heart surgical procedure can treat residual lesions and provide important clinical information. However, EPOCs are often assumed to impose additional risk on a vulnerable patient population. This study aimed to describe the EPOC population, evaluate procedural safety, compare EPOC patients with procedure-matched non-EPOC patients, and determine risk factors for poor outcomes using data from the Congenital Cardiac Catheterization Project on Outcomes registry. METHODS: In a retrospective cohort, demographic, clinical, and procedural characteristics were analyzed for diagnostic and interventional catheterizations performed in 13 participating institutions from January 2014 to December 2017, excluding patients after heart transplant. The primary outcome was a high-severity adverse event (AE). Three distinct analyses included (1) describing the full cohort and EPOC patients, (2) comparing EPOC patients with and without a high-severity AE, and (3) comparing EPOC patients with controls matched on case type. RESULTS: This study included 17,776 catheterizations, with 1399 EPOCs. The high-severity AE rate was 6.4% overall, 8.9% in the EPOC cohort, and 8.4% in matched controls (P = .74). The association between EPOC status and high-severity AE was not significant in a multivariable model (P = .17). In EPOCs with a high-severity AE, median procedure duration was 30 minutes longer (P < .001), and median time from surgical procedure to catheterization was 3 days longer (P = .05). CONCLUSIONS: EPOC was not associated with additional risk. Individual patient characteristics of size and hemodynamic vulnerability may serve as informative predictors. Timely catheterization may preempt further clinical deterioration, and intraprocedure duration optimization may correlate with improved outcomes.

Changes in Practice/Outcomes of Pediatric/Congenital Catheterization in Response to the First Wave of COVID.

Background: The COVID-19 pandemic has posed tremendous stress on the health care system. Its effects on pediatric/congenital catheterization program practice and performance have not been described. Objectives: The purpose of this study was to evaluate how case volumes, risk-profile, and outcomes of pediatric/congenital catheterization procedures changed in response to the first wave of COVID-19 and after that wave. Methods: A multicenter retrospective observational study was performed using Congenital Cardiac Catheterization Project on Outcomes Registry (C3PO) data to study changes in volume, case mix, and outcomes (high-severity adverse events [HSAEs]) during the first wave of COVID (March 1, 2020, to May 31, 2020) in comparison to the period prior to (January 1, 2019, to February 28, 2020) and after (June 1, 2020, to December 31, 2020) the first wave. Multivariable analyses adjusting for case type, hemodynamic vulnerability, and age group were performed. Hospital responses to the first wave were captured with an electronic study instrument. Results: During the study period, 12,557 cases were performed at 14 C3PO hospitals (with 8% performed during the first wave of COVID and 32% in the postperiod). Center case volumes decreased from a median 32.1 cases/month (IQR: 20.7-49.0 cases/month) before COVID to 22 cases/month (IQR: 13-31 cases/month) during the first wave (P = 0.001). The proportion of cases with risk factors for HSAE increased during the first wave, specifically proportions of infants and neonates (P < 0.001) and subjects with renal insufficiency (P = 0.02), recent cardiac surgery (P < 0.001), and a higher hemodynamic vulnerability score (P = 0.02). The observed HSAE risk did not change significantly (P = 0.13). In multivariable analyses, odds of HSAE during the first wave of COVID (odds ratio: 0.75) appeared to be lower than that before COVID, but the difference was not significant (P = 0.09). Conclusions: Despite increased case-mix complexity, C3PO programs maintained, if not improved, their performance in terms of HSAE. Exploratory analyses of practice changes may inform future harm-reduction efforts.

Standard volume infusion unmasked diastolic dysfunction in pediatric heart transplant recipients during surveillance cardiac catheterization, but without echocardiographic correlates.

BACKGROUND: Adult experience evaluating left ventricular diastolic function (LVDFx) includes volume administration during catheterization while obtaining pulmonary capillary wedge pressures (PCWP) or left ventricular end diastolic pressures (LVEDP). Catheterization is inherently challenging in pediatric patients, making echocardiographic assessment ideal. Pediatric echocardiographic studies predicting LVDFx have variable hemodynamic and hydration conditions and have produced inconsistent results. We evaluated the association between simultaneous echocardiographic and catheterization assessment of LVDFx, using a fluid bolus for optimal loading conditions. METHODS: Prospective cohort study of pediatric heart transplant recipients receiving echocardiogram simultaneous with routine cardiac catheterization. Mitral valve inflow velocities, septal and lateral wall tissue Doppler indices, and PCWP and/or LVEDP were obtained and repeated following a 10 ml/kg bolus. Echocardiographic parameters were evaluated for an association with changes in PCWP or LVEDP following the bolus. Abnormal LVDFx was defined as PCWP or LVEDP ≥12 mm Hg. RESULTS: Twenty-nine patients underwent catheterization. Median pre-bolus PCWP and LVEDP were 11.0 mm Hg and 10.0 mm Hg, respectively. After bolus, median PCWP and LVEDP increased to 14.0 mm Hg (p < .001) and 13 mm Hg (p < .001), respectively. Of 21 patients with normal pre-bolus catheterization hemodynamics, 14 (66.7%) increased to abnormal following fluid bolus. Using area under an ROC, no echocardiographic parameter of LVDFx, or their ratios, were associated with predetermined abnormal LVEDP and/or PCWP. CONCLUSION: After bolus, our cohort demonstrated significant increases in LVEDP and/or PCWP, unmasking diastolic dysfunction. Fluid challenges should be considered in pediatric patients undergoing cardiac catheterization with suspected diastolic dysfunction. Echocardiographic measurements were unable to discriminate between normal and abnormal LVEDP and/or PCWP.

Interpreting Quality Improvement When Introducing New Technology: A Collaborative Experience in ASD Device Closures.

The objective of this study was to evaluate the impact of the regular introduction of new technologies into interventional cardiac catheterization procedures, in this case new atrial septal defect (ASD) closure devices, while conducting a multi-center collaborative initiative to reduce radiation usage during all procedures. Data were collected prospectively by 8 C3PO institutions between January 1, 2014 and December 31, 2017 for ASD device closure procedures in the cardiac catheterization lab during a quality improvement (QI) initiative aimed at reducing patient radiation exposure. Radiation exposure was measured in dose area product per body weight (µGy*m2/kg). Use of proposed practice change strategies at the beginning and end of the QI intervention period was assessed. Radiation exposure was summarized by institution and by initial type of device used for closure. This study included 602 ASD device closures. Without changes in patient characteristics, total fluoroscopy duration, or number of digital acquisitions, median radiation exposure decreased from 37 DAP/kg to 14 DAP/kg from 2014 to 2017. While all individual centers decreased overall median DAP/kg, the use of novel devices for ASD closure correlated with a temporary period of worsening institutional radiation exposure and increased fluoroscopy time. The introduction of new ASD closure devices resulted in increased radiation exposure during a QI project designed to reduce radiation exposure. Therefore, outcome assessment must be contextualized in QI projects, hospital evaluation, and public reporting, to acknowledge the expected variation during innovation and introduction of novel therapies.

Procedural Risk in Congenital Cardiac Catheterization (PREDIC3T).

Background Advancements in the field, including novel procedures and multiple interventions, require an updated approach to accurately assess patient risk. This study aims to modernize patient hemodynamic and procedural risk classification through the creation of risk assessment tools to be used in congenital cardiac catheterization. Methods and Results Data were collected for all cases performed at sites participating in the C3PO (Congenital Cardiac Catheterization Project on Outcomes) multicenter registry. Between January 2014 and December 2017, 23 119 cases were recorded in 13 participating institutions, of which 88% of patients were <18 years of age and 25% <1 year of age; a high-severity adverse event occurred in 1193 (5.2%). Case types were defined by procedure(s) performed and grouped on the basis of association with the outcome, high-severity adverse event. Thirty-four unique case types were determined and stratified into 6 risk categories. Six hemodynamic indicator variables were empirically assessed, and a novel hemodynamic vulnerability score was determined by the frequency of high-severity adverse events. In a multivariable model, case-type risk category (odds ratios for category: 0=0.46, 1=1.00, 2=1.40, 3=2.68, 4=3.64, and 5=5.25; all P≤0.005) and hemodynamic vulnerability score (odds ratio for score: 0=1.00, 1=1.27, 2=1.89, and ≥3=2.03; all P≤0.006) remained independent predictors of patient risk. Conclusions These case-type risk categories and the weighted hemodynamic vulnerability score both serve as independent predictors of patient risk for high-severity adverse events. This contemporary procedure-type risk metric and weighted hemodynamic vulnerability score will improve our understanding of patient and procedural outcomes.

Longitudinal Improvements in Radiation Exposure in Cardiac Catheterization for Congenital Heart Disease: A Prospective Multicenter C3PO-QI Study.

BACKGROUND: The C3PO-QI (Congenital Cardiac Catheterization Project on Outcomes - Quality Improvement), a multicenter registry launched in 2015, instituted quality improvement (QI) initiatives to reduce patient radiation exposure. Through regular collaboration, this initiative would allow for harmony among active participants, maximizing efforts and efficiency at achieving radiation best practices. This study sought to report these efforts with a detailed methodology for which institutions can target initiatives, reducing radiation exposure, and increasing patient safety. METHODS: Data were collected prospectively by 8 C3PO-QI institutions between January 1, 2015 and December 31, 2017. Radiation exposure was measured in dose area product per body weight (dose area product/kg; µGy*m2/kg) and reported by expected radiation exposure categories (REC) and institution for 40 published unique procedure types. Targeted interventions addressing selected strategic domains for radiation reduction were implemented in the pediatric catheterization labs of the C3PO-QI institutions. RESULTS: The study consisted of 15 257 unique cases. Median exposure (dose area product/kg) was decreased by 30% for all procedures. Dose area product/kg was reduced in all 3 REC, with the greatest improvement observed in REC I (REC I, -37%; REC II, -23%; REC III, -27%). Although the baseline radiation exposures and exact percent decrease varied across all C3PO-QI sites, each institution demonstrated improvements in radiation dose over time. These improvements occurred with the implementation of institution-specific QI interventions accelerated by participation in the C3PO-QI multicenter collaborative. CONCLUSIONS: Substantial radiation dose reductions can be achieved using targeted QI methodology and interventions. Participation in a multicenter QI collaborative may accelerate improvement across all centers due to enhanced engagement and shared learning between sites.

Adverse Events, Radiation Exposure, and Reinterventions Following Transcatheter Pulmonary Valve Replacement.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) is associated with a risk of procedural serious adverse events (SAE) and exposure to ionizing radiation. OBJECTIVES: The purpose of this study was to define the risk of, and associations with, SAE and high-dose radiation exposure using large-scale registry data. METHODS: The analysis of the multicenter C3PO-QI registry was limited to patients who underwent TPVR from January 1, 2014, to December 31, 2016. SAE were defined as the occurrence of ≥1 moderate, major, or catastrophic events. Radiation dose was reported as dose area product adjusted for weight. Associations with outcome measures were explored in univariate and multivariable analyses. RESULTS: A total of 530 patients (59% male) underwent TPVR at a median age of 18.3 years (interquartile range [IQR]: 12.9 to 27.3 years) and weight of 58 kg (IQR: 43 to 77 kg) at 14 centers. Implant substrate included homograft (41%), bioprosthesis (30%), native right ventricular outflow tract (RVOT) (27%) and other (2%). TPVR indications were pulmonary insufficiency (28%), stenosis (23%), and mixed (49%). AE and SAE occurred in 26% and 13% of cases, respectively, including 1 mortality. SAE were more frequent in homograft conduit than other RVOT substrates, although SAE type and severity differed between implant substrates. Median radiation dose was 198 µGy·m2/kg (IQR: 94 to 350 µGy·m2/kg). Higher radiation dose was associated with older age, greater RVOT obstruction, and concomitant interventions (p < 0.001). During a median follow-up duration of 1 year, 13.3% underwent catheterization, surgery, or both, unrelated to infection. Younger age, smaller size, and hemodynamic and anatomic factors indicative of greater RVOT obstruction were associated with TPV reintervention. CONCLUSIONS: The incidence of SAE during TPVR in the C3PO-QI registry is high, but mortality is uncommon. Radiation dose is greater than for other congenital interventions and is associated with patient and procedural factors. Reintervention is common during early follow-up.

Respiratory failure secondary to congenital pulmonary arterial thrombus with lung dysplasia.

Respiratory failure requiring extracorporeal membranous oxygenation in the newborn is commonly seen secondary to severe pathology such as congenital diaphragmatic hernia, meconium aspiration syndrome, pulmonary hypertension and pulmonary hypoplasia. However, atypical causes of respiratory failure, such as pulmonary arterial thrombi, are often refractory to traditional management and require careful multidisciplinary evaluation. We report a case of respiratory failure secondary to congenital pulmonary arterial thrombosis of unknown aetiology in an otherwise healthy neonate. We discuss the abnormal anatomy and pathophysiology that presented in our patient secondary to this condition and discuss our diagnostic process, management and outcomes. Additionally, we review the literature for reported cases and discuss current hypotheses on the development of congenital pulmonary arterial thrombi. Given the rare occurrence of this event, we hope to contribute to the understanding of future similar cases and emphasise the importance of keeping pulmonary arterial thrombi in the clinical differential.

Economic implications of outpatient cardiac catheterisation in infants with single ventricle congenital heart disease.

BACKGROUND: Resource utilisation for infants with single ventricle CHD remains high without well-studied ways to decrease economic burden. Same-day discharge following cardiac catheterisation has been shown to be safe and effective in children with CHD, but those with single ventricle physiology are commonly excluded. The purpose of this study was to investigate the economic implications of planned same-day discharge following cardiac catheterisation versus universal overnight hospital admission in infants with single ventricle CHD. METHODS AND RESULTS: A probabilistic decision-tree analysis with sensitivity analyses was performed. All included patients were categorised into four possible outcomes; discharge, readmission following discharge (within 48 hours), observation and prolonged hospitalisation. Baseline probabilities of each node of the tree were then combined with the cost data to evaluate the comparative dominance of one decision (immediately discharge) versus the other decision (routinely admit). Patients discharged on the same day as the procedure accrued the lowest attributed hospital cost ($5469), while patients readmitted to the hospital had the highest attributed cost ($11,851). Currently, no other studies have assessed the cost of hospitalisation following cardiac catheterisation in this population. Thus, we allowed for a wide range of cost variation, but same-day discharge dominated the decision outcome with a lower economic burden. CONCLUSION: Same-day discharge following routine cardiac catheterisation in patients with single ventricle physiology is less costly compared to universal overnight admission. This demonstrates an important cost-limiting step in a complex population of patients who have high resource utilisation.

Mid-Term Valve-Related Outcomes After Transcatheter Tricuspid Valve-in-Valve or Valve-in-Ring Replacement.

BACKGROUND: Transcatheter aortic and pulmonary valves have been used to treat stenosis or regurgitation after prior surgical tricuspid valve (TV) replacement or repair. Little is known about intermediate-term valve-related outcomes after transcatheter tricuspid valve replacement (TTVR), including valve function, thrombus, and endocarditis. OBJECTIVES: The authors sought to evaluate mid-term outcomes in a large cohort of patients who underwent TTVR after surgical TV repair or replacement, with a focus on valve-related outcomes. METHODS: Patients who underwent TTVR after prior surgical TV replacement or repair were collected through an international registry. Time-related outcomes were modeled and risk factors assessed. RESULTS: Data were collected for 306 patients who underwent TTVR from 2008 through 2017 at 80 centers; 52 patients (17%) had a prior history of endocarditis. Patients were followed for a median of 15.9 months after implantation (0.1 to 90 months), with 64% of patients estimated to be alive without TV reintervention or a valve-related event at 3 years. The cumulative 3-year incidence of death, reintervention, and valve-related adverse outcomes (endocarditis, thrombosis, or significant dysfunction) were 17%, 12%, and 8%, respectively. Endocarditis was diagnosed in 8 patients 2 to 29 months after TTVR, for an annualized incidence rate of 1.5% per patient-year (95% confidence interval: 0.45% to 2.5%). An additional 8 patients were diagnosed with clinically relevant valve thrombosis, 3 in the short term, 2 within 2 months, and 3 beyond 6 months. Only 2 of these 8 patients received anticoagulant therapy before thrombus detection (p = 0.13 vs. patients without thrombus). Prior endocarditis was not a risk factor for reintervention, endocarditis, or valve thrombosis, and there was no difference in valve-related outcomes according to TTVR valve type. CONCLUSIONS: TV dysfunction, endocarditis, and leaflet thrombosis were uncommon after TTVR. Patients with prior endocarditis were not at higher risk for endocarditis or other adverse outcomes after TTVR, and endocarditis occurred with similar frequency in different valve types. Though rare, leaflet thrombosis is an important adverse outcome, and further study is necessary to determine the appropriate level of prophylactic therapy after TTVR.

Safety of outpatient cardiac catheterisation in infants with single-ventricle or shunt-dependent biventricular congenital heart disease.

OBJECTIVE: We aimed to investigate the incidence and causes of readmission of infants with single-ventricle and shunt-dependent biventricular CHD following routine, outpatient cardiac catheterisation. BACKGROUND: Cardiac catheterisation is commonly performed in patients with single-ventricle and shunt-dependent biventricular CHD for haemodynamic assessment and surgical planning. Best practices for post-procedural care in this population are unknown, and substantial variation exists between centres. Outpatient catheterisation reduces parental anxiety and decreases cost. Our institutional strategy is to discharge patients following a 4- to 6-hour post-procedure observation period. METHODS: Retrospective cohort study using the Society of Thoracic Surgeons Database identified patients 23 hours. There were no differences in baseline characteristics between discharged and admitted patients. Patients who underwent intervention were more likely to be admitted. Patients with hypoplastic left heart syndrome did not have major adverse events or readmissions. No intra- or peri-procedural deaths occurred. CONCLUSIONS: Outpatient cardiac catheterisation may be a safe option for infants with single-ventricle and shunt-dependent biventricular CHD, with low readmission rates and minimal morbidity.

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

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

Transcatheter Tricuspid Valve-in-Valve Implantation for the Treatment of Dysfunctional Surgical Bioprosthetic Valves: An International, Multicenter Registry Study.

BACKGROUND: Off-label use of transcatheter aortic and pulmonary valve prostheses for tricuspid valve-in-valve implantation (TVIV) within dysfunctional surgical tricuspid valve (TV) bioprostheses has been described in small reports. METHODS AND RESULTS: An international, multicenter registry was developed to collect data on TVIV cases. Patient-related factors, procedural details and outcomes, and follow-up data were analyzed. Valve-in-ring or heterotopic TV implantation procedures were not included. Data were collected on 156 patients with bioprosthetic TV dysfunction who underwent catheterization with planned TVIV. The median age was 40 years, and 71% of patients were in New York Heart Association class III or IV. Among 152 patients in whom TVIV was attempted with a Melody (n=94) or Sapien (n=58) valve, implantation was successful in 150, with few serious complications. After TVIV, both the TV inflow gradient and tricuspid regurgitation grade improved significantly. During follow-up (median, 13.3 months), 22 patients died, 5 within 30 days; all 22 patients were in New York Heart Association class III or IV, and 9 were hospitalized before TVIV. There were 10 TV reinterventions, and 3 other patients had significant recurrent TV dysfunction. At follow-up, 77% of patients were in New York Heart Association class I or II (P<0.001 versus before TVIV). Outcomes did not differ according to surgical valve size or TVIV valve type. CONCLUSIONS: TVIV with commercially available transcatheter prostheses is technically and clinically successful in patients of various ages across a wide range of valve size. Although preimplantation clinical status was associated with outcome, many patients in New York Heart Association class III or IV at baseline improved. TVIV should be considered a viable option for treatment of failing TV bioprostheses.

Fast measurement of methanol concentration in ionic liquids by potential step method.

The development of direct methanol fuel cells required the attention to the electrolyte. A good electrolyte should not only be ionic conductive but also be crossover resistant. Ionic liquids could be a promising electrolyte for fuel cells. Monitoring methanol was critical in several locations in a direct methanol fuel cell. Conductivity could be used to monitor the methanol content in ionic liquids. The conductivity of 1-butyl-3-methylimidazolium tetrafluoroborate had a linear relationship with the methanol concentration. However, the conductivity was significantly affected by the moisture or water content in the ionic liquid. On the contrary, potential step could be used in sensing methanol in ionic liquids. This method was not affected by the water content. The sampling current at a properly selected sampling time was proportional to the concentration of methanol in 1-butyl-3-methylimidazolium tetrafluoroborate. The linearity still stood even when there was 2.4 M water present in the ionic liquid.

Angioplasty of obstructed homograft conduits in the right ventricular outflow tract with ultra-noncompliant balloons: assessment of therapeutic efficacy and conduit tears.

BACKGROUND: Angioplasty and stent placement in right ventricle-to-pulmonary artery (RV-PA) conduits have been shown to prolong the functional lifespan of a conduit. Safety and efficacy of angioplasty of obstructed RV-PA homografts using ultra-noncompliant (UNC) or ultrahigh-pressure balloons are unknown. METHODS AND RESULTS: From 2004 to 2012, 70 patients underwent 76 procedures for angioplasty of RV-PA homografts with UNC Atlas balloons. The UNC group was compared with a partially contemporaneous control cohort of 81 patients who underwent 84 angioplasty procedures with conventional balloons. Acute hemodynamic changes after angioplasty of homografts with UNC balloons included significantly reduced RV:Ao pressure ratio (P=0.02) and right ventricular outflow tract gradients (P≤0.001). Balloon waist resolution was more frequently achieved with UNC balloons (P=0.04), and balloon rupture occurred less often (P<0.001). Conduit tears of any severity occurred in 22% of patients overall and were more common in the UNC group (P=0.001). Patients with any conduit tear had significantly greater reduction in their RV:Ao pressure ratio (P<0.001) and right ventricular outflow tract gradient (P=0.004) than those with no tear. There were 4 unconfined tears, all in the UNC group, with no acute decompensations or deaths and only 1 patient who required surgical management. CONCLUSIONS: RV-PA conduit tears are common in patients undergoing angioplasty, but clinically important tears, which only occurred during UNC angioplasty in this series, were uncommon. UNC balloons can be used to good effect with significant reduction in right ventricular outflow tract gradient and the RV:Ao ratio when compared with conventional balloons.

Hypoplastic left heart syndrome associated with large omphalocele and hypoplastic left bronchus.

We present a patient with the combination of hypoplastic left heart syndrome (HLHS), large omphalocele, and hypoplastic left bronchus who underwent a modified Norwood procedure and was successfully discharged home. The child required tracheostomy with home ventilation and we elected to delay the primary repair of the omphalocele. To our knowledge, this is the first reported case with this combination of anomalies surviving till hospital discharge. Our experience demonstrates the potential viability of patients with concurrent HLHS, large abdominal wall defects, and airway anomalies and may additionally advocate for delayed repair of large omphaloceles in patients with complex congenital heart disease.