A 1-Day-Old Girl With Infantile Hemangioma and Sternal Cleft.

CASE PRESENTATION: A newborn girl presented to the hospital on the first day of life because of respiratory failure. She was born at home at 37 weeks' gestation with minimal prenatal care and was found to be small for gestational age. The patient was found to have partial sternal agenesis and sternal cleft, cutis aplasia, left facial hemangioma, micrognathia, wide-spaced nipples, and low-set ears. The mother's and baby's urine toxicology screening were positive for amphetamines. Chest radiographs on admission showed bilateral hazy opacities. CT scan of the chest showed an absent sternum with midline chest wall concavity. The patient was monitored preoperatively in the cardiac ICU for risks of arrythmia, respiratory failure, altered cardiac output, and acute cardiopulmonary decompensation.

A prospective multicenter feasibility study of a miniaturized implantable continuous flow ventricular assist device in smaller children with heart failure.

BACKGROUND: There is no FDA-approved left ventricular assist device (LVAD) for smaller children permitting routine hospital discharge. Smaller children supported with LVADs typically remain hospitalized for months awaiting heart transplant-a major burden for families and a challenge for hospitals. We describe the initial outcomes of the Jarvik 2015, a miniaturized implantable continuous flow LVAD, in the NHLBI-funded Pumps for Kids, Infants, and Neonates (PumpKIN) study, for bridge-to-heart transplant. METHODS: Children weighing 8 to 30 kg with severe systolic heart failure and failing optimal medical therapy were recruited at 7 centers in the United States. Patients with severe right heart failure and single-ventricle congenital heart disease were excluded. The primary feasibility endpoint was survival to 30 days without severe stroke or non-operational device failure. RESULTS: Of 7 children implanted, the median age was 2.2 (range 0.7, 7.1) years, median weight 10 (8.2 to 20.7) kilograms; 86% had dilated cardiomyopathy; 29% were INTERMACS profile 1. The median duration of Jarvik 2015 support was 149 (range 5 to 188) days where all 7 children survived including 5 to heart transplant, 1 to recovery, and 1 to conversion to a paracorporeal device. One patient experienced an ischemic stroke on day 53 of device support in the setting of myocardial recovery. One patient required ECMO support for intractable ventricular arrhythmias and was eventually transplanted from paracorporeal biventricular VAD support. The median pump speed was 1600 RPM with power ranging from 1-4 Watts. The median plasma free hemoglobin was 19, 30, 19 and 30 mg/dL at 7, 30, 90 and 180 days or time of explant, respectively. All patients reached the primary feasibility endpoint. Patient-reported outcomes with the device were favorable with respect to participation in a full range of activities. Due to financial issues with the manufacturer, the study was suspended after consent of the eighth patient. CONCLUSION: The Jarvik 2015 LVAD appears to hold important promise as an implantable continuous flow device for smaller children that may support hospital discharge. The FDA has approved the device to proceed to a 22-subject pivotal trial. Whether this device will survive to commercialization remains unclear because of the financial challenges faced by industry seeking to develop pediatric medical devices. (Supported by NIH/NHLBI HHS Contract N268201200001I, clinicaltrials.gov 02954497).

Educating Surgeons to Construct Valved Conduits: What Does It Take to Achieve Reproducible Results?

BACKGROUND: Despite the demonstrated utility of surgeon-fashioned polytetrafluoroethylene (PTFE) valved conduits, methods for educating surgeons to reproducibly construct these conduits are lacking. We present a surgeon education process and early outcomes for children receiving surgeon-fashioned PTFE valved conduits during the initial learning curve. METHODS: The educational curriculum included 4 hours of proctored instruction/supervised valve construction, followed by 2 hours of individual practice. A surgeon with prior mastery of the technique provided templated designs, videos, and follow-up consultation. A retrospective medical record review (2017-2022) described early outcomes and valve function for patients receiving surgeon-fashioned PTFE right ventricle-to-pulmonary artery conduits. RESULTS: Two surgeons were educated using the method described. Fifteen valved conduits were implanted in 14 patients (median patient age, 38 months; conduit size range, 10-24 mm). At discharge, no patient had more than mild stenosis or regurgitation, and 12 of 15 valves (80%) had none or trivial regurgitation. Median follow-up was 14 months (range, 1-52 months). At the last follow-up, median peak conduit gradient of the 15 valves was low (18 mm Hg), 1 (7%) had moderate stenosis, and 1 (7%) had mild-moderate regurgitation. Two conduits were replaced concomitantly during repair of associated lesions at 14 and 38 months (sizes 10 and 12 mm, respectively). There were no deaths and no infectious complications. CONCLUSIONS: Four hours of proctored surgeon education plus deliberate practice is an effective method for teaching valved PTFE conduit construction and is associated with excellent early valve function. This study provides educational methods and initial evidence of safety for congenital surgeons wishing to learn and adopt this technique.

Capturing Adult Congenital Heart Disease: Framework for Development of an Adult Congenital Heart Disease Mortality Risk Model.

BACKGROUND: As a formative step toward development of adult congenital heart disease (ACHD) risk-adjusted metrics, we describe The Society of Thoracic Surgeons (STS) ACHD population, procedural frequency, and early mortality. METHODS: Adults (≥18 years) with CHD (2014-2019) were identified in the STS Adult Cardiac Surgery (ASCD) and the Congenital Heart Surgery (CHSD) Databases. After deduplication, variable mapping, data concatenation, and harmonization of preprocedure factors, procedures were grouped, and unadjusted mortality was catalogued for the overall cohort and the cohort excluding patients with an isolated bicuspid aortic valve (BAV). RESULTS: Among 171 186 ACSD and 18 281 CHSD records, 152 731 unique records met inclusion criteria. Twenty-eight congenital diagnoses accounted for 86% of the overall cohort, and prevalence of ACHD increased over the study time frame. ACHD patients underwent operations to treat both acquired and CHD. Most common procedures overall and after excluding isolated BAV were aortic valve replacement (AVR), ascending aortic surgery, and coronary artery bypass grafting (CABG). After excluding isolated BAV, major procedure combinations occurred in 46% (31% had 2 major procedures and 3% had ≥4), and the most prevalent combinations included AVR + CABG (n = 2352), AVR + subaortic stenosis repair (n = 1481), and AVR + ascending aortic surgery (n = 1239). Unadjusted 30-day mortality was procedure dependent, 2.8% overall and 3.6% with isolated BAV excluded. CONCLUSIONS: The ACHD surgical population is heterogenous, and patients undergo surgery for CHD-related and adult/acquired procedure combinations. Early mortality is variable and influenced by surgical complexity. Excluding isolated BAV patients and developing procedure-based ACHD mortality risk models may be ideal but will require empirically derived grouping and collaboration.

A Minimal Opioid Postoperative Management Protocol in Congenital Cardiac Surgery: Safe and Effective.

There is evidence that reducing opioid exposure in children undergoing cardiac surgery may enhance postoperative recovery. We aimed to describe a minimal opioid postoperative management protocol in children undergoing cardiac surgery and our early outcomes with this strategy. We reviewed the medical records of children (6 months-18 years) who underwent elective cardiac surgery through a median sternotomy with cardiopulmonary bypass at our institution between 2016 and 2018. All patients were managed postoperatively using a standardized protocol. 101 children (median age 5 years) were included and 85% were extubated in the operating room. Although most patients (96%) received opioids postoperatively, opioid requirements decreased steadily over time, with 88%, 58%, and 18% of children receiving opioids on postoperative day 1, 2, and 3, respectively; 41% received no opioids after postoperative day 1. The median cumulative opioid exposure was 0.25 morphine milligram equivalents per kg (interquartile range, 0.10-0.75). Greater than mild pain was rare (<10%) at each time point. The rates of operative mortality and major complication were 0% and 3%, respectively. The median postoperative length of stay was 3 days, and 13% required readmission within 30 days. Age, cardiopulmonary bypass time, and number of benzodiazepine doses were independently associated with cumulative opioid exposure. Any complication, chest tube time, and higher STAT Category were independently associated with prolonged postoperative length of stay. A minimal opioid postoperative management protocol can be safe and effective in children undergoing cardiac surgery. Future prospective studies are needed to determine optimal practice and patient selection.

A shifting landscape: Practice patterns and outcomes of cystic fibrosis and non-cystic fibrosis pediatric lung transplantation.

BACKGROUND: New drugs may further decrease the need for lung transplant (LTx) in pediatric patients with cystic fibrosis (CF), but few studies highlight pediatric non-CF LTx characteristics and outcomes. METHODS: The ISHLT registry was used to report morbidity, graft failure, and survival for primary pediatric (<18 years) LTx performed 1990-2017. Recipient/donor characteristics and long-term outcomes were analyzed for CF and non-CF recipients. Survival was assessed using Kaplan-Meier curves. RESULTS: Of 2232 primary LTx, (43% in males), 918 (41%) were performed for non-CF indications; most commonly pulmonary hypertension (43%). Non-CF patients were younger (median age 11 vs. 15, p < .001), and more frequently on inotropes and/or extracorporeal membrane oxygenation (15% vs. 2.4%, p < .001) at transplant, compared to CF recipients. In-hospital major complications more commonly affected CF LTx recipients (57% vs. 48%, p = .003), but 30-day mortality was higher in the non-CF group (9% non-CF vs. 5% CF, p < .001). One-, five-, and ten-year mortality was 18%, 50%, and 65% for CF recipients, respectively, and 21%, 45%, and 58% for non-CF recipients (p = .01 at 10 years). Five-year survival was significantly better for non-CF females versus CF females (56% vs. 48%, p = .013), but was similar between groups for males (55% vs. 54%, p = .305). While age was a late outcomes risk factor, pulmonary hypertension and later transplants eras were protective. CONCLUSIONS: Early mortality is higher and late mortality is lower in non-CF LTx. Current non-CF LTx outcomes leave room for improvement. Further study is needed to evaluate the effects of center volume and pediatric-specific experience on outcomes.

Aortic Valve Replacement in Young and Middle-Aged Adults: Current and Potential Roles of TAVR.

BACKGROUND: Contemporary practice patterns and outcomes for aortic valve replacement (AVR) among young and middle-aged adults are unknown given guideline modifications for surgical AVR (SAVR) and increasing transcatheter AVR (TAVR) acceptance. This study describes SAVR and TAVR use and outcomes using The Society of Thoracic Surgeons (STS) National Databases. METHODS: Adults 18 to 55 years of age in the Congenital Heart Surgery Database (CHSD) and the Adult Cardiac Surgery Database (ACSD) who underwent SAVR or TAVR from 2013 to 2018 were included. Perioperative characteristics and early outcomes were described by valve type. Multivariable regression identified determinants of death, length of hospital stay, and a composite end point of renal failure, persistent neurologic deficit, readmission, and reoperation. RESULTS: The study analyzed 1580 unique CHSD and 44,173 ACSD operations, 16% of which were performed in patients with congenital heart disease. Valve use included the following: TAVR, 1%; mechanical, 42%; bioprosthetic, 55%; autograft, 0.6%; homograft, 1.2%; and Ozaki, 0.4%. Over time, TAVR volumes increased by 167%. The 30-day mortality was as follows: TAVR, 3.8%; mechanical, 3.2%; bioprosthetic, 3.7%; autograft, 0.6%; homograft, 9%; and Ozaki, 3.4%. Stroke rate was lower for isolated SAVR vs isolated TAVR (0.9% vs 2.4%; P = .002). In multivariable analyses, mortality risk was lower with mechanical valves, congenital morbidity risk was higher with TAVR, and length of stay was shorter with TAVR. CONCLUSIONS: TAVR is increasingly used for adults younger than 55 years of age. Given the uniformly excellent results with SAVR, including both mortality and morbidity-particularly regarding stroke, our data favor SAVR in this population, but a prospective trial is needed. Ongoing efforts to harmonize variables and outcomes definitions between the ACSD and CHSD are valuable.

A 22-Month-Old Girl With 3 Weeks of Dyspnea.

CASE PRESENTATION: A previously healthy 22-month-old girl presented to the ED with a 3-week history of dyspnea on exertion. A chest radiograph showed a right upper-lobe opacity suspicious for pneumonia (Fig 1A). The patient was prescribed amoxicillin but returned to the ED 7 days later with cough and persistent dyspnea and tachypnea. At that time, a repeat chest radiograph was concerning for worsening pneumonia (Fig 1B). Treatment with azithromycin and albuterol was initiated, and amoxicillin was discontinued. Her symptoms briefly improved; however, she returned to the ED 10 days later because of worsening cough and tachypnea, and a 2-day history of increased irritability, decreased oral intake, decreased urine output, and intermittent perioral cyanosis. She was afebrile throughout this period per parent report and vital sign documentation at each ED visit.

Impact of Circuit Size on Coagulation and Hemolysis Complications in Pediatric Extracorporeal Membrane Oxygenation.

Extracorporeal membrane oxygenation (ECMO) circuit volume, patient size, and blood flow may influence coagulation and hemolysis complications. We performed a single-center retrospective analysis of ECMO patients over a 6.5 year period. In 299 ECMO runs, 13% required coagulation-associated circuit changes. Respiratory ECMO was associated with coagulation-associated circuit changes [odds ratio (O/R) 2.8, p < 0.05] and developed severe (plasma-free hemoglobin [pfHb] > 100 mg/dl) hemolysis (O/R 2.3, p < 0.05). Severe hemolysis and component changes were associated with hospital mortality (O/R 2.3 and 2.5, respectively, p < 0.05). The activated partial thromboplastin time (aPTT) to residence time (RT) ratio (aPTT/RT) was used as a surrogate for coagulation risk. We found that aPTT/RT > 2.5 more than doubled time to circuit change (3-8 days, p < 0.05), but aPTT/RT > 3 increased bleeding risks and hospital mortality (O/R 1.8; p < 0.1). Hemolysis was associated with patient weight and circuit to patient volume ratio (CPVR) (p < 0.05), but not pump type. Hemolysis slightly increased with transfusion (p = 0.08), and transfusion requirements increased for CPVR >50% (p < 0.1).Our data suggest that pediatric respiratory ECMO patients are more likely to develop coagulation and hemolysis complications, which are associated with increased mortality. This may result from higher inflammatory processes, which affect coagulation and red cell fragility. Minimizing circuit volume, inflammation, and red cell stress may help to reduce these two complications and their associated mortality.

Surgery for Dysphagia Lusoria in Children.

Aberrant right subclavian artery, or arteria lusoria, is a common congenital anomaly of the aortic arch and may be associated with dysphagia. Surgical treatment, particularly in children, remains controversial. Current surgical interventions include supraclavicular and thoracotomy approaches, as well as hybrid endovascular techniques. However, these techniques have significant limitations and varying degrees of success. This case report describes a 2-site operation whereby the arteria lusoria is transected via a left thoracotomy and subsequently re-implanted into the right common carotid artery via a median sternotomy. This approach has provided complete symptom resolution for dysphagia lusoria in 2 children.

Cardiac venous malformation in a teenager.

We present the case of a 17-year-old boy with a cardiac venous malformation. This case highlights the diagnostic challenges of such tumours and demonstrates the potential efficacy of a watch-and-wait management approach.

National Practice Patterns and Early Outcomes of Aortic Valve Replacement in Children and Teens.

BACKGROUND: Several options exist for aortic valve replacement (AVR) in children and teens, but contemporary practice patterns and outcome data are lacking. We describe national AVR practice patterns and early outcomes. METHODS: Children (aged 1 to 18 years) in The Society of Thoracic Surgeons Congenital Heart Surgery Database undergoing AVR from 2000 to 2016 were included. Preoperative characteristics, operative data, and outcomes were described. To evaluate practice patterns, centers were assigned tertiles by aortic valve surgical volume. Statistical comparisons included Mann-Whitney U statistic, Kruskal-Wallis, χ2 test, and gamma testing. RESULTS: In total, 3446 operations (46% children aged 1 to 12 years; 54% teens aged 12 to 18 years) were included. Preoperative risk factors were present in 23%, and 46% had a prior sternotomy. Valve utilization included autograft (64% child, 37% teen), mechanical (19% child, 35% teen), bioprosthetic (8% child, 20% teen), and homograft (9% child, 7% teen). Autografts were utilized more often for teenage girls than for teenage boys (odds ratio 1.3, 95% confidence interval: 1.05 to 1.66, P < .05). Overall, inpatient mortality and major complications affected 1% and 10%, respectively, and these rates were highest for homografts (5%, P < .001, and 13%, P < .05). Autograft utilization varied widely across centers (10th to 90th percentile: 21% to 71% of total AVR volume). More autografts were utilized at high-volume centers vs low- or medium-volume centers (53% ± 2.3% vs 46% ± 2.6%, P < .001). CONCLUSIONS: Practice patterns for AVR in children and teens vary across centers, age groups, and sexes. Although early outcomes were similar across valve types, homografts had higher morbidity and mortality. Valve choice was related to aortic valve surgical volume. Further efforts are needed to understand and optimize AVR practice patterns and long-term outcomes.

Acute In Vivo Evaluation of the Pittsburgh Pediatric Ambulatory Lung.

Respiratory failure is a significant problem within the pediatric population. A means of respiratory support that readily allows ambulation could improve treatment. The Pittsburgh Pediatric Ambulatory Lung (P-PAL) is being developed as a wearable pediatric pump-lung for long-term respiratory support and has previously demonstrated positive benchtop results. This study aimed to evaluate acute (4-6 hours) in vivo P-PAL performance, as well as develop an optimal implant strategy for future long-term studies. The P-PAL was connected to healthy sheep (n = 6, 23-32 kg) via cannulation of the right atrium and pulmonary artery. Plasma-free hemoglobin (PfHb) and animal hemodynamics were measured throughout the study. Oxygen transfer rates were measured at blood flows of 1-2.5 L/min. All animals survived the complete study duration with no device exchanges. Flow limitation because of venous cannula occlusion occurred in trial 2 and was remedied via an altered cannulation approach. Blood exiting the P-PAL had 100% oxygen saturation with the exception of trial 4 during which inadequate device priming led to intrabundle clot formation. Plasma-free hemoglobin remained low (<20 mg/dl) for all trials. In conclusion, this study demonstrated successful performance of the P-PAL in an acute setting and established the necessary methods for future long-term evaluation.

Paracorporeal Lung Devices: Thinking Outside the Box.

Extracorporeal Membrane Oxygenation (ECMO) is a resource intensive, life-preserving support system that has seen ever-expanding clinical indications as technology and collective experience has matured. Clinicians caring for patients who develop pulmonary failure secondary to cardiac failure can find themselves in unique situations where traditional ECMO may not be the ideal clinical solution. Existing paracorporeal ventricular assist device (VAD) technology or unique patient physiologies offer the opportunity for thinking "outside the box." Hybrid ECMO approaches include splicing oxygenators into paracorporeal VAD systems and alternative cannulation strategies to provide a staged approach to transition a patient from ECMO to a VAD. Alternative technologies include the adaptation of ECMO and extracorporeal CO2 removal systems for specific physiologies and pediatric aged patients. This chapter will focus on: (1) hybrid and alternative approaches to extracorporeal support for pulmonary failure, (2) patient selection and, (3) technical considerations of these therapies. By examining the successes and challenges of the relatively select patients treated with these approaches, we hope to spur appropriate research and development to expand the clinical armamentarium of extracorporeal technology.

Cost-Effectiveness of Ventricular Assist Device Destination Therapy for Advanced Heart Failure in Duchenne Muscular Dystrophy.

Destination ventricular assist device therapy (DT-VAD) is well accepted in select adults with medically refractory heart failure (HF) who are not transplant candidates; however, its use in younger patients with progressive diseases is unclear. We sought to evaluate the cost-effectiveness of DT-VAD in Duchenne muscular dystrophy (DMD) patients with advanced HF. We created a Markov-state transition model (5-year horizon) to compare survival, costs, and quality of life (QOL) between medical management and DT-VAD in DMD with advanced HF. Model input parameters were derived from the literature. We used sensitivity analyses to explore uncertainty around model assumptions. DT-VAD had higher costs ($435,602 vs. $125,696), survival (3.13 vs. 0.60 years), and quality-adjusted survival (1.99 vs. 0.26 years) than medical management. The incremental cost-effectiveness ratio (ICER) for DT-VAD was $179,086 per quality-adjusted life year (QALY). In sensitivity analyses that were widely varied to account for uncertainty in model assumptions, the DT-VAD strategy generally remained more costly and effective than medical management. Only when VAD implantation costs were <$113,142 did the DT-VAD strategy fall below the $100,000/QALY willingness-to-pay threshold commonly considered to be "cost-effective." In this exploratory analysis, DT-VAD for patients with DMD and advanced HF exceeded societal expectations for cost-effectiveness but had an ICER similar to the accepted practice of DT-VAD in adult HF patients. While more experience and research in this population is needed, our analysis suggests that DT-VAD for advanced HF in DMD should not be dismissed solely based on cost.

Preclinical performance of a pediatric mechanical circulatory support device: The PediaFlow ventricular assist device.

OBJECTIVES: The PediaFlow (HeartWare International, Inc, Framingham, Mass) is a miniature, implantable, rotodynamic, fully magnetically levitated, continuous-flow pediatric ventricular assist device. The fourth-generation PediaFlow was evaluated in vitro and in vivo to characterize performance and biocompatibility. METHODS: Supported by 2 National Heart, Lung, and Blood Institute contract initiatives to address the limited options available for pediatric patients with congenital or acquired cardiac disease, the PediaFlow was developed with the intent to provide chronic cardiac support for infants as small as 3 kg. The University of Pittsburgh-led Consortium evaluated fourth-generation PediaFlow prototypes both in vitro and within a preclinical ovine model (n = 11). The latter experiments led to multiple redesigns of the inflow cannula and outflow graft, resulting in the implantable design represented in the most recent implants (n = 2). RESULTS: With more than a decade of extensive computational and experimental efforts spanning 4 device iterations, the AA battery-sized fourth-generation PediaFlow has an operating range of 0.5 to 1.5 L/min with minimal hemolysis in vitro and excellent hemocompatibility (eg, minimal hemolysis and platelet activation) in vivo. The pump and finalized accompanying implantable components demonstrated preclinical hemodynamics suitable for the intended pediatric application for up to 60 days. CONCLUSIONS: Designated a Humanitarian Use Device for "mechanical circulatory support in neonates, infants, and toddlers weighing up to 20 kg as a bridge to transplant, a bridge to other therapeutic intervention such as surgery, or as a bridge to recovery" by the Food and Drug Administration, these initial results document the biocompatibility and potential of the fourth-generation PediaFlow design to provide chronic pediatric cardiac support.

In Vitro Characterization of the Pittsburgh Pediatric Ambulatory Lung.

Acute and chronic respiratory failure are a significant source of pediatric morbidity and mortality. Current respiratory support options used to bridge children to lung recovery or transplantation typically render them bedridden and can worsen long-term patient outcomes. The Pittsburgh Pediatric Ambulatory Lung (P-PAL) is a wearable pediatric blood pump and oxygenator (0.3 m surface area) integrated into a single compact unit that enables patient ambulation. The P-PAL is intended for long-term use and designed to provide up to 90% of respiratory support in children weighing 5-25 kg. Computational fluid dynamics and numerical gas exchange modeling were used to design the P-PAL and predict its performance. A P-PAL prototype was then used to obtain pressure versus flow curves at various impeller rotation rates using a blood analog fluid. In vitro oxygen exchange rates were obtained in blood in accordance with ISO standard 7199. The normalized index of hemolysis (NIH) was measured over a 6 hour period at blood flow rates of 1 and 2.5 L/min. The P-PAL provided blood flows of 1-2.5 L/min against the pressure drop associated with its intended-use pediatric cannulas. The oxygen exchange rate reached a maximum of 108 ml/min at a blood flow rate of 2.5 L/min and met our respiratory support design target. Device-induced hemolysis was low with NIH values of 0.022-0.027 g/100 L in the intended blood flow rate range. In conclusion, the current P-PAL design met our pumping, oxygenation, and hemolysis specifications and has the potential to improve treatment for pediatric respiratory failure.

Development of Risk Indices for Neonatal Respiratory Extracorporeal Membrane Oxygenation.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has saved thousands of newborns. Population comparisons for research and quality initiatives require risk-matching, but no indices exist for this population. We sought to create a pre-ECMO risk index using the registry data from the Extracorporeal Life Support Organization. We analyzed 5,455 neonatal (<30 days old) respiratory VA-ECMO patients for the period 2000-2010. Multivariate regression examining the impact of pre-ECMO variables on survival to hospital discharge was performed to create the Pittsburgh Index for Pre-ECMO Risk (PIPER), which was ultimately was based on seven pre-ECMO variables. Each PIPER quartile demonstrated increasing mortality by 15% (R = 0.98) and was associated with increased complications on ECMO. Further modeling to include on-ECMO complications (PIPER), including complications and length of time on ECMO, increased the predictive power of the model, with 21% increases in mortality per PIPER quartile (R = 0.97). Our developed indices provide the first steps towards risk-adjusting patients for meaningful comparisons amongst patient populations. There may be additional clinically relevant measures, both pre- and on-ECMO, which could provide better predictive capability. Future work will focus on finding these additional measures and expansion of our techniques to include other patient populations.