Isosorbide DiNitrate Effect on Hemodynamic Profile, Liver Stiffness, and Exercise Tolerance in Fontan Circulation (The NEET Clinical Trial).

After Fontan operation, decreased venous capacitance and venoconstriction are adaptive mechanisms to maintain venous return and cardiac output. The consequent higher venous pressure may adversely impact end-organ function, exercise capacity and result in worse clinical outcomes. This pilot study evaluated the safety and effect of isosorbide dinitrate (ISDN), a venodilator, on exercise capacity, peripheral venous pressure (PVP), and liver stiffness in patients with Fontan circulation. In this prospective single-arm trial, 15 individuals with Fontan circulation were evaluated at baseline and after 4 weeks of therapeutic treatment with ISDN. Primary aims were to assess the safety of ISDN and the effect on maximal exercise. We also aimed to evaluate the effect of ISDN on ultrasound-assessed liver stiffness, markers of submaximal exercise, and PVP at rest and peak exercise. Repeated measures t-tests were used to assess change in variables of interest in response to ISDN. Mean age was 23.5 ± 9.2 years (range 11.2-39.0 years), and 10/15 (67%) were male. There was no statistically significant change in peak VO2 (1401 ± 428 to 1428 ± 436 mL/min, p = 0.128), but VO2 at the anaerobic threshold increased (1087 ± 313 to 1115 ± 302 mL/min, p = 0.03). ISDN was also associated with a lower peak exercise PVP (22.5 ± 4.5 to 20.6 ± 3.0 mmHg, p = 0.015). Liver stiffness was lower with ISDN, though the difference was not statistically significant (2.3 ± 0.4 to 2.1 ± 0.5 m/s, p = 0.079). Of the patients completing the trial, mild headache was common (67%), but there were no major adverse events. Treatment with ISDN for 4 weeks is well-tolerated in patients with a Fontan circulation. ISDN is associated with an increase in VO2 at anaerobic threshold, lower peak PVP, and a trend toward lower liver stiffness. Larger, longer duration studies will be necessary to define the impact of ISDN on clinical outcomes in the Fontan circulation.Clinical Trial Registration: URL: https://clinicaltrials.gov . Unique identifier: NCT04297241.

Targeting the contact system in a rabbit model of extracorporeal membrane oxygenation.

Previous studies suggested that contact pathway factors drive thrombosis in mechanical circulation. We used a rabbit model of veno-arterial extracorporeal circulation (VA-ECMO) to evaluate the role of factors XI and XII in ECMO-associated thrombosis and organ damage. Factors XI and XII (FXI, FXII) were depleted using established antisense oligonucleotides before placement on a blood-primed VA-ECMO circuit. Decreasing FXII or FXI to < 5% of baseline activity significantly prolonged ECMO circuit lifespan, limited the development of coagulopathy, and prevented fibrinogen consumption. Histological analysis suggested that FXII depletion mitigated interstitial pulmonary edema and hemorrhage whereas heparin and FXI depletion did not. Neither FXI nor FXII depletion was associated with significant hemorrhage in other organs. In vitro analysis showed that membrane oxygenator fibers (MOFs) alone are capable of driving significant thrombin generation in a FXII- and FXI-dependent manner. MOFs also augment thrombin generation triggered by low (1 pM) or high (5 pM) tissue factor concentrations. However, only FXI elimination completely prevented the increase in thrombin generation driven by MOFs, suggesting MOFs augment thrombin-mediated FXI activation. Together, these results suggest that therapies targeting FXII or FXI limit thromboembolic complications associated with ECMO. Further studies are needed to determine the contexts wherein targeting FXI and FXII, either alone or in combination, would be most beneficial in ECMO. Moreover, studies are also needed to determine the potential mechanisms coupling FXII to end-organ damage in ECMO.

Overly Selective Offer Acceptance is Associated With High Waitlist Mortality for the Most Ill Lung Transplant Candidates.

The demand for organs for lung transplantation (LTx) continues to outweigh supply. However, nearly 75% of donor lungs are never transplanted. LTx offer acceptance practices and the effects on waitlist/post-transplant outcomes by candidate clinical acuity are understudied. UNOS was used to identify all LTx candidates, donors, and offers from 2005 to 2019. Candidates were grouped by Lung Allocation Score (LAS; applicable post-2005, ages ≥12 years): LAS<40, 40-60, 61-80, and >80. Offer acceptance patterns, waitlist death/decompensation, and post-transplant survival (PTS) were compared. "Acceptable organ offers" were those from donors whose organs were accepted for transplantation. Approximately 3 million offers to 34,531 candidates were reviewed. Median waitlist durations were: 9 days-(LAS>80), 17 days-(LAS 61-80), 42 days-(LAS 40-60), 125 days-(LAS<40) (P < 0.001 between all). Per waitlist-day, offer rates were: total offers - 0.8/day-(LAS>80), 0.7/day-(LAS 61-80), 0.6/day-(LAS 40-60), 0.4/day-(LAS<40); acceptable offers - 0.34/day-(LAS>80), 0.32/day-(LAS 61-80), 0.24/day-(LAS 40-60), 0.15/day-(LAS<40) (both P < 0.001 between all LAS). Among patients who experienced waitlist mortality/decompensation, ≥1 acceptable offer was declined in 92% (3939/4270) of patients - 78% for LAS >80, 88% for LAS 61-80, 93% for LAS 40-60, and 96% for LAS <40. Thirty-day waitlist mortality/decompensation rates were: 46%-(LAS>80), 24%-(LAS 61-80), 5%-(LAS 40-60), <1%-(LAS<40) (P < 0.001 between all). PTS was equivalent between patients for whom the first/second offer vs later offers were accepted (all LAS P > 0.4). The first offers that LTx candidates receive (including acceptable organs) are declined for nearly all candidates. Healthier candidates can afford offer selectivity but more ill patients (LAS>60) cannot, experiencing exceedingly high 30-day waitlist mortality.

Mini right axillary thoracotomy for congenital heart defect repair can become a safe surgical routine.

OBJECTIVE: Owing to its obvious cosmetic appeal, minimal invasive repair of congenital heart defects (CHDs) through the mini right axillary thoracotomy is becoming routine in many centres. Besides cosmesis, and before becoming a new norm, it is important to establish its outcomes as safe compared to repairs through traditional median sternotomy. METHODS: Between 2013 and 2021, 116 consecutive patients underwent defect repairs through mini right axillary thoracotomy. Patient, operative data, and hospital outcomes were compared to contemporary mini right axillary thoracotomy and sternotomy series. RESULTS: There was no mortality or need for approach conversion (mean age 4.3 years, range 0.17-17, mean weight 18.6 kg, range 4.8-74.4) in 118 repairs for atrial septal defect, ventricular septal defect, partial anomalous pulmonary venous return, partial atrioventricular canal with mitral cleft, scimitar syndrome, double-chambered right ventricle, cor triatriatum, and tricuspid valve repair. Protocol included on-table extubation, achieved in 97 children, with 23 outliers leading to 0.7 average hours of mechanical ventilation (range 0-66 hours), indwelling chest drain time of 2.6 days (range 1-9 days), intensive care stay of 1.8 days (range 1-10 days), and hospital stay of 3.9 days (range 2-18 days). Late revisions were required in one patient after scimitar repair for scimitar vein stenosis at 2 weeks, and in another for repair of superior caval vein stenosis after a Warden operation at 2 months; reoperations (5/116 = 4.3%) were successfully performed through the same mini right axillary incision. CONCLUSIONS: While providing obvious cosmetic advantages, the minimally invasive right axillary thoracotomy approach for the surgical repair of common CHDs yields excellent results and is safe compared to the benchmark median sternotomy approach.

Risk of Pediatric Cardiac Surgery Increased in Patients Undergoing Tracheal Surgery During the Same Hospitalization.

BACKGROUND: The impact of complex tracheal surgery (TS) on outcomes of children undergoing cardiac surgery has rarely been investigated in large national databases and could impact anticipated outcomes in those patients. METHODS: The Pediatric Health Information System database was reviewed from January 1, 2005 to December 31, 2014, for pediatric (<18 years) patients undergoing select cardiac surgical procedures using International Classification of Disease-9 procedural coding. Patients were divided based upon having TS (excluding tracheostomy) during the same hospitalization. Patients with tracheal and cardiac surgeries (CHS + TS) were propensity matched in a 1 : 2 fashion to patients undergoing isolated cardiac surgeries without TS (CHS) based upon cardiac procedure(s), age at surgery, gender, and discharge year. Hospital mortality and other outcomes were compared between the 2 matched groups. RESULTS: The 283 CHS + TS patients were similar to the 566 CHS patients in gender, race, age, cardiac procedures, and presence of chromosomal abnormalities, all P > .05. Hospital mortality was 13.8% (n = 39) for CHS + TS and 5.8% (n = 33) for CHS patients with an unadjusted 2.58 hazard ratio of death (95% confidence interval: 1.59-4.20; P < .001). CHS + TS was also associated with a greater length of stay (63 days vs 12 days), a higher cost per hospitalization ($322 402 vs $80 273), and more readmissions (64.3% [n = 182] vs 41.8% [n = 243]), all P < .001. CONCLUSIONS: Patients undergoing cardiac and TS in the same hospitalization are at greater risk of in-hospital mortality than patients undergoing similar cardiac surgeries alone and incur higher resource utilization thereafter. The increased risk of mortality is currently underappreciated, but it is important to recognize when discussing expectations with families and providers.

Transplantation for Congenital Heart Disease: Focus on the Impact of Functionally Univentricular Versus Biventricular Circulation.

BACKGROUND: Varying single center data exist regarding the posttransplant outcomes of patients with single ventricle circulation, particularly following the Fontan operation. We sought to better elucidate these results in patients with congenital heart disease (CHD) through combining two national databases. METHODS: The United Network for Organ Sharing (UNOS) transplantation database was merged with the Pediatric Health Information System (PHIS), an administrative database with 71% of UNOS patients matched. Patients undergoing transplantation at a PHIS hospital from 2006 to 2017 were categorized as single ventricle or biventricular strategy based on their diagnoses and procedures in 90% of patients. When known, single ventricle patients were further analyzed by their palliative stage post-Glenn or post-Fontan (known in 31%). RESULTS: A total of 1,517 CHD transplantations were identified, 67% with single ventricle strategy (1,016). Single ventricle, biventricular, and indeterminate patients had similar survival (log-rank P > .1). Risk factors for mortality in patients with CHD were extracorporeal membrane oxygenation (ECMO) support at transplant (hazard: 2.27), ABO blood type incompatibility (hazard: 1.61), African American recipient (hazard 1.42), and liver dysfunction (hazard 1.29). A total of 130 confirmed Fontan and 185 confirmed bidirectional Glenn patients underwent transplantation, each with survival equivalent to biventricular patients (log-rank P > .500). For Fontan patients, renal dysfunction (hazard: 5.40) and transplant <1 year after Fontan (hazard 2.82) were found to be associated with mortality. CONCLUSIONS: Single ventricle patients, as a group, experience similar outcomes as biventricular patients with CHD undergoing transplantation, and this extends to Fontan patients. Risk factors for mortality correlate with end-organ dysfunction as well as race and ABO blood type incompatibility in the CHD population.

Tracheal surgery for airway anomalies associated with increased mortality in pediatric patients undergoing heart surgery: Society of Thoracic Surgeons Database analysis.

OBJECTIVES: Airway anomalies are common in children with cardiac disease but with an unquantified impact on outcomes. We sought to define the association between airway anomalies and tracheal surgery with cardiac surgery outcomes using the Society of Thoracic Surgery Congenital Heart Surgery Database. METHODS: Index cardiac operations in children aged less than 18 years (January 2010 to September 2018) were identified from the Society of Thoracic Surgery Congenital Heart Surgery Database. Patients were divided on the basis of reported diagnosis of an airway anomaly and subdivided on the basis of tracheal lesion and tracheal surgery. Multivariable analysis evaluated associations between airway disease and outcomes controlling for covariates from the Society of Thoracic Surgery Congenital Heart Surgery Database Mortality Risk Model. RESULTS: Of 198,674 index cardiovascular operations, 6861 (3.4%) were performed in patients with airway anomalies, including 428 patients (0.2%) who also underwent tracheal operations during the same hospitalization. Patients with airway anomalies underwent more complex cardiac operations (45% vs 36% Society of Thoracic Surgeons/European Association for Cardiothoracic Surgery Congenital Heart Surgery Mortality category ≥3 procedures) and had a higher prevalence of preoperative risk factors (73% vs 39%; both P < .001). In multivariable analysis, patients with airway anomalies had increased odds of major morbidity and tracheostomy (P < .001). Operative mortality was also increased in patients with airway anomalies, except those with malacia. Tracheal surgery within the same hospitalization increased the odds of operative mortality (adjusted odds ratio, 3.9; P < .0001), major morbidity (adjusted odds ratio, 3.7; P < .0001), and tracheostomy (adjusted odds ratio, 16.7; P < .0001). CONCLUSIONS: Patients undergoing cardiac surgery and tracheal surgery are at significantly higher risk of morbidity and mortality than patients receiving cardiac surgery alone. Most of those with unoperated airway anomalies have higher morbidity and mortality, which makes it an important preoperative consideration.

Unusual case of isolated major aortopulmonary collateral artery perfusing entire functional left lower lobe of the lung.

Pulmonary sequestrations are nonfunctioning pulmonary parenchyma supplied by a systemic artery. We describe an 18-month-old baby girl with no significant past medical history who was found to have a large isolated collateral from the aorta entirely perfusing the functional left lower lobe. Cardiac catheterization confirmed the major aortopulmonary collateral artery supplying the left lower lobe with normal drainage into the left atrium. At a multidisciplinary meeting, decision was made to preserve the functional lobe. During surgery, the collateral artery was dissected and its course within the pleural space appreciated, the main left pulmonary artery was isolated. Intraoperatively surgeons anastomosed an 8 mm ringed conduit from the left pulmonary artery, anteriorly to the proximal aspect of the collateral. The patient tolerated the surgery well. Postoperative echocardiogram showed pulmonary flow to the lower lobe, and she was discharged home on postoperative day 2 without complications.

Heart-Lung Transplant via an Eighth-Time Sternotomy.

We report a combined heart-lung transplantation following seven prior sternotomies in a patient born with a transitional atrioventricular septal defect. Previous surgeries to repair and replace the mitral valve led to pulmonary vein stenosis and pulmonary vascular disease. Eighth-time sternotomy and significant vascular adhesions led to a prolonged operation and to placing the heart-lung block anterior to the phrenic nerves. Despite this, the patient was ready for discharge after two weeks and continues to do well over nine months later. As more patients survive multiple cardiac palliations with some developing pulmonary vascular disease, heart-lung transplantation may become relevant again.

Cardiomyocyte cell cycling, maturation, and growth by multinucleation in postnatal swine.

BACKGROUND: Rodent cardiomyocytes (CM) undergo mitotic arrest and decline of mononucleated-diploid population post-birth, which are implicated in neonatal loss of heart regenerative potential. However, the dynamics of postnatal CM maturation are largely unknown in swine, despite a similar neonatal cardiac regenerative capacity as rodents. Here, we provide a comprehensive analysis of postnatal cardiac maturation in swine, including CM cell cycling, multinucleation and hypertrophic growth, as well as non-CM cardiac factors such as extracellular matrix (ECM), immune cells, capillaries, and neurons. Our study reveals discordance in postnatal pig heart maturational events compared to rodents. METHODS AND RESULTS: Left-ventricular myocardium from White Yorkshire-Landrace pigs at postnatal day (P)0 to 6 months (6mo) was analyzed. Mature cardiac sarcomeric characteristics, such as fetal TNNI1 repression and Cx43 co-localization to cell junctions, were not evident until P30 in pigs. In CMs, appreciable binucleation is observed by P7, with extensive multinucleation (4-16 nuclei per CM) beyond P15. Individual CM nuclei remain predominantly diploid at all ages. CM mononucleation at ~50% incidence is observed at P7-P15, and CM mitotic activity is measurable up to 2mo. CM cross-sectional area does not increase until 2mo-6mo in pigs, though longitudinal CM growth proportional to multinucleation occurs after P15. RNAseq analysis of neonatal pig left ventricles showed increased expression of ECM maturation, immune signaling, neuronal remodeling, and reactive oxygen species response genes, highlighting significance of the non-CM milieu in postnatal mammalian heart maturation. CONCLUSIONS: CM maturational events such as decline of mononucleation and cell cycle arrest occur over a 2-month postnatal period in pigs, despite reported loss of heart regenerative potential by P3. Moreover, CMs grow primarily by multinucleation and longitudinal hypertrophy in older pig CMs, distinct from mice and humans. These differences are important to consider for preclinical testing of cardiovascular therapies using swine, and may offer opportunities to study aspects of heart regeneration unavailable in other models.

Pediatric heart-lung transplantation: A contemporary analysis of outcomes.

BACKGROUND: Pediatric heart-lung transplantation (HLT) is rare, and no report has analyzed patient outcomes since time of listing. We analyzed pediatric HLTs to understand risk factors for waitlist and post-HLT mortality. METHODS: All pediatric (<18 year old) HLT candidates were identified within the UNOS database (n = 573) and grouped by age, era, and by diagnosis. Logistical regression and Cox proportional hazard modeling identified risk factors for 6-month WL and overall post-transplant mortality. RESULTS: 209/573 (37%) HLT candidates were transplanted, 7% recovered, 42% died waiting, and 15% were removed for another/unknown reason. Diagnoses were primary pulmonary hypertension(n = 130), congenital heart disease(CHD) without Eisenmenger's syndrome (ES) (n = 65), CHD with ES (n = 73), and other (n = 305). Patients with a diagnosis other than CHD with ES (OR: 7.55, P = .001), on IV inotropic support (OR: 2.79, P < .001), and infants (OR: 2.20, P = .004) were associated with waitlist mortality. There has been a 56% reduction in HLTs across eras (Era 1:10.8/yr vs Era 2:4.7/yr). Risk factors for post-transplant mortality were ECMO (HR: 4.1, P = .016), and being infant (HR: 2.2, P = .04) or 1-11 years old (HR: 1.78, P = .015). ECMO patients have an 87% 2-year mortality rate with a median post-transplant survival of 64 days. Overall, post-transplant survival was unchanged (log-rank P = .067) between eras. Excluding ECMO patients, in the recent era 29 non-infant patients with primary pulmonary hypertension had 93% 1-year survival and 67% 5-year survival. CONCLUSIONS: Nearly 600 pediatric patients have been listed for HLT in UNOS, although numbers are decreasing in the current era. HLT for a patient on ECMO appears to be an ineffective strategy; however, in well-selected cohorts, HLT can provide considerable post-transplant survival.

Norwood With Obstructed Total Anomalous Pulmonary Venous Connection and Tracheoesophageal Fistula Repair: Operating Room Delivery.

A baby boy with prenatally diagnosed hypoplastic left heart syndrome variant with obstructed veins was born in the operating room (OR) and underwent emergent Norwood operation and repair of obstructed infra-diaphragmatic total anomalous pulmonary venous connection. Post-operatively, esophageal atresia with tracheoesophageal fistula was identified and repaired on day of life 11. The patient is thriving at 22 months of age. (Level of Difficulty: Advanced.).

Optimizing Postcardiac Transplantation Outcomes in Children with Ventricular Assist Devices: How Long Should the Bridge Be?

Ventricular assist devices (VADs) decrease waitlist mortality and improve end-organ function. Therefore, we sought to determine the duration of VAD support that could allow for optimal posttransplant outcomes. Pediatric transplant recipients were identified from the United Network for Organ Sharing database. Inflection points were determined using hazard of mortality associated with support time fitted by cubic spline method. Of 685 patients, those supported for >2 months had a significant decrease in inotrope use and mechanical ventilation and an increase in functional status compared with those supported for <2 months (all p < 0.001). Those supported for 2-4 months experienced better posttransplant survival than <2 months (p = 0.031). In durable pulsatile devices, similar improvement was seen in mechanical ventilation and functional status for the 2-4 month group with superior survival compared with <2 months (p = 0.008) and >4 months (p = 0.012). In continuous flow devices, used in patients overall less ill, the inflection point was >3 weeks with improvement in most end-organ function (p < 0.001) and posttransplant survival (p = 0.014) compared with <3 weeks. In general, a period of VAD support is associated with improvement in pretransplant risk factors and better posttransplant survival. This suggests that most patients bridged to transplantation by VADs should be supported for some time before listing to optimize posttransplant outcomes.

Adult Congenital Heart Disease: Current Early Expectations After Cardiac Transplantation.

BACKGROUND: Early mortality has plagued the otherwise good outcomes of heart transplantation in patients with adult congenital heart disease (ACHD), but perioperative care is improving. This study sought to identify risk factors for 1-year mortality currently and examine the results of patients without those risk factors compared with patients who did not have ACHD (nACHD). METHODS: The United Network of Organ Sharing database was searched for all adult (>17 years of age) heart transplant recipients from 2000 to 2018. They were divided into an early era and a late era. A multivariate analysis identified risk factors for 1-year mortality in the late era. Patients without these risk factors were compared with the nACHD group by Kaplan-Meier analysis. RESULTS: A total of 495 patients with ACHD were identified from 2000 to 2008, and 666 were identified from 2009 to 2018. The recent era had better 1-year survival (P <.001) and overall survival (P = .003) than did the era from 2000 to 2008. Patients with ACHD were different from the nACHD population in age (37 years vs 57 years), body mass index greater than 25 kg/m2 (45% vs 66%), incidence of renal dysfunction (23% vs 28%) and liver dysfunction (29% vs 23%), sensitization (38% vs 29%), and ischemic times (3.5 hours vs 3.1 hours). Multivariate analysis identified body mass index greater than 25 kg/m2 (hazard ratio [HR], 1.79), renal dysfunction (HR, 1.85), liver dysfunction (HR, 1.69), and longer ischemic time (HR, 1.46) as risk factors for early mortality. Patients with only 1 of the first 3 categorical risk factors had 1-year survival comparable to that reported in patients with nACHD. CONCLUSIONS: Patients with ACHD had better early and long-term outcomes in the recent era. When only 1 of 3 pretransplant risk factors for early mortality was present, patients had survival equal to that of nACHD patients and perhaps better long-term survival.

Mid-term Outcomes of the Supported Ross Procedure in Children, Teenagers, and Young Adults.

The Ross procedure in children, teenagers, and young adults, especially among those with a bicuspid aortic valve with aortic regurgitation, has been associated with neoaortic root dilatation and recurrence of aortic regurgitation. We have shown that at intermediate follow-up, patients who underwent a supported Ross technique were less likely to have neoaortic root dilatation. This study summarizes our most recent outcomes. This was a retrospective review of 40 consecutive pediatric and young adult patients undergoing a supported Ross procedure from 2005 to 2018. Clinical outcomes were reviewed in addition to echocardiographic measures of neoaortic dimension and neoaortic valve function. The median age at surgery was 16.0 years (range 10 - 35 years). Preoperative diagnosis was aortic regurgitation in 15 (37.5%) and mixed regurgitation/stenosis in 20 (50%). Median follow-up was 3.5 years (1.4-5.6) with 3 patients followed for more than 10 years. There were no deaths. Five patients had a reintervention, but only 1 on the aortic valve. One patient returned to the operating room on postoperative day 1 for revision of the right coronary button. Two patients required biventricular pacemakers for reduced ejection fraction. One patient developed aortic regurgitation and underwent mechanical valve replacement and another required a reintervention on the homograft with a percutaneously placed pulmonary valve replacement. At last follow-up, 39 patients had mild or less aortic regurgitation with median sinus z-score of 1.40 (0.48-2.07). Mid-term follow-up of pediatric and young adult patients undergoing a supported Ross operation for various aortic valve pathologies demonstrate excellent results with minimal neoaortic root dilation and reintervention.

The reality of limping to pediatric heart transplantation.

OBJECTIVE: Improvements in surgical technique, critical care, and early repair for congenital heart disease (CHD) have led to improved outcomes with heart transplantation, often used as a salvage procedure after failed palliation, especially in infants. These patients, however, often have several risk factors for poor posttransplant survival. We aimed to identify the reality of survival after heart transplantation in patients "limping to transplant" with common risk factors. METHODS: All heart transplant recipients younger than 18 years were identified from the UNOS data set from 2000 to 2017. Modifiable risk factors (MRFs) of mechanical ventilation, renal dysfunction, and liver dysfunction at transplant and nonmodifiable risk factors of infancy at listing or CHD were examined. One-year posttransplant survival was analyzed with logistic regression. RESULTS: Of 4101 transplants, 1459 patients (36%) had 1 or more MRFs. There was a decrease in 1-year survival with additional MRFs up to a 9.1-times increased risk of death in an infant with CHD. A noninfant without CHD and no MRFs had a 95% 1-year survival, in contrast to an intubated patient with CHD without other end-organ dysfunction, who had 1-year survival of 76%, which decreased to 58% if they were an infant and also had renal dysfunction. CONCLUSIONS: Patients "limping to transplant" with multiple risk factors demonstrates decreasing early survival relative to those without other end-organ dysfunction. It is imperative that we have transparent discussions about expected outcomes with these families and identify ways to optimize patients' conditions through other supportive avenues to improve posttransplant outcomes.

Pondering Higher-Risk Pediatric Heart Donors: Can We Use More?

BACKGROUND: Pediatric heart transplantation is challenged with long waiting list times and high waiting list mortality, mostly due to a continuing organ shortage and high rates of nonuse. This analysis was conducted to determine the outcomes associated with high-risk donors when recipient variability is neutralized. METHODS: The United Network for Organ Sharing (UNOS) thoracic organ transplant database was searched for pediatric heart transplant recipients (≤17 years old at time of listing) between January 2006 and December 2015. High-risk donors were identified using 2 previously published methods based on donor utilization (DUB) and recipient survival (RSB). Within each of the populations, which were not mutually exclusive, low- and high-risk donor cohorts were propensity matched on recipient characteristics, and outcomes (graft survival) were analyzed using Kaplan-Meier methods. RESULTS: When recipient variability was harmonized, the DUB population (n = 3048) did not have different graft survival times between the high-risk graft recipients (n = 1016) and low-risk graft recipients (n = 2032; P = .713). Likewise, the RSB population (n = 1053) also did not have different graft survival times between the high-risk graft recipients (n = 351) and low-risk graft recipients (n = 702; P = .706). CONCLUSIONS: Cardiac allografts deemed high risk by use- and survival-based methods led to equivalent posttransplant survival as matched recipients with low-risk donors. This study demonstrates that traditionally high-risk donors may have been associated with worst posttransplant survival because of the recipients that used them. Therefore, accepting these "high-risk" donor grafts should be considered as a potential approach to reduce waiting list times and mortality while maintaining comparable posttransplant survival.

Expanding the donor pool for congenital heart disease transplant candidates by implementing 3D imaging-derived total cardiac volumes.

BACKGROUND: Heart transplant waitlist mortality remains high in infants <1 year of age and among those with CHD. Currently, the median accepted donor-to-recipient weight percentage is approximately 130% of the recipient's weight. We hypothesized that patients with CHD may accept a larger organ using novel 3D-derived imaging data to estimate donor and recipient TCV. METHODS: A single-center, retrospective study was performed using CT data for 13 patients with CHD and 94 control patients. 3D visualization software was used to create digital 3D heart models that provide an estimate of TCV. In addition, echocardiograms obtained prior to cross-sectional imaging were reviewed for presence of ventricular chamber dilation. RESULTS: Sixty-two percent (8/13) of patients with CHD had 3D-derived TCV resulting in a weight that was >130% larger than their actual weight. This was seen in single-ventricle patients following Blalock-Taussig shunt and Fontan palliation, and patients with biventricular repair. Of those, 75% (6/8) had reported moderate-to-severe ventricular chamber dilation by echocardiogram or cardiac magnetic resonance imaging. CONCLUSIONS: In a large portion of patients with CHD, 3D-derived TCV place the recipient at a higher listing weight than their actual weight. We propose obtaining cross-sectional imaging to better assess TCV in a recipient, which may increase the donor range for CHD recipients and improve organ utilization in pediatrics.