Deep Learning for Automated Measurement of Total Cardiac Volume for Heart Transplantation Size Matching.

Total Cardiac Volume (TCV)-based size matching using Computed Tomography (CT) is a novel technique to compare donor and recipient heart size in pediatric heart transplant that may increase overall utilization of available grafts. TCV requires manual segmentation, which limits its widespread use due to time and specialized software and training needed for segmentation. This study aims to determine the accuracy of a Deep Learning (DL) approach using 3-dimensional Convolutional Neural Networks (3D-CNN) to calculate TCV, with the clinical aim of enabling fast and accurate TCV use at all transplant centers. Ground truth TCV was segmented on CT scans of subjects aged 0-30 years, identified retrospectively. Ground truth segmentation masks were used to train and test a custom 3D-CNN model consisting of a DenseNet architecture in combination with residual blocks of ResNet architecture. The model was trained on a cohort of 270 subjects and a validation cohort of 44 subjects (36 normal, 8 heart disease retained for model testing). The average Dice similarity coefficient of the validation cohort was 0.94 ± 0.03 (range 0.84-0.97). The mean absolute percent error of TCV estimation was 5.5%. There is no significant association between model accuracy and subject age, weight, or height. DL-TCV was on average more accurate for normal hearts than those listed for transplant (mean absolute percent error 4.5 ± 3.9 vs. 10.5 ± 8.5, p = 0.08). A deep learning-based 3D-CNN model can provide accurate automatic measurement of TCV from CT images. This initial study is limited as a single-center study, though future multicenter studies may enable generalizable and more accurate TCV measurement by inclusion of more diverse cardiac pathology and increasing the training data.

Socioeconomic Influences on Outcomes Following Congenital Heart Disease Surgery.

Associations between social determinants of health (SDOH) and adverse outcomes for children with congenital heart disease (CHD) are starting to be recognized; however, such links remain understudied. We examined the relationship between community-level material deprivation on mortality, readmission, and length of stay (LOS) for children undergoing surgery for CHD. We performed a retrospective cohort study of patients who underwent cardiac surgery at our institution from 2015 to 2018. A community-level deprivation index (DI), a marker of community material deprivation, was generated to contextualize the lived experience of children with CHD. Generalized mixed-effects models were used to assess links between the DI and outcomes of mortality, readmission, and LOS following cardiac surgery. The DI and components were scaled to provide mean differences for a one standard deviation (SD) increase in deprivation. We identified 1,187 unique patients with surgical admissions. The median LOS was 11 days, with an overall mortality rate of 4.6% and readmission rate of 7.6%. The DI ranged from 0.08 to 0.85 with a mean of 0.37 (SD 0.12). The DI was associated with increased LOS for patients with more complex heart disease (STAT 3, 4, and 5), which persisted after adjusting for factors that could prolong LOS (all p < 0.05). The DI approached but did not meet a significant association with mortality (p = 0.0528); it was not associated with readmission (p = 0.36). Community-level deprivation is associated with increased LOS for patients undergoing cardiac surgery. Future work to identify the specific health-related social needs contributing to LOS and identify targets for intervention is needed.

Epidemiology of Postoperative Junctional Ectopic Tachycardia in Infants Undergoing Cardiac Surgery.

BACKGROUND: Junctional ectopic tachycardia (JET) complicates congenital heart surgery in 2% to 8.3% of cases. JET is associated with postoperative morbidity in single-center studies. We used the Pediatric Cardiac Critical Care Consortium data registry to provide a multicenter epidemiologic description of treated JET. METHODS: This is a retrospective study (February 2019-August 2022) of patients with treated JET. Inclusion criteria were (1) <12 months old at the index operation, and (2) treated for JET <72 hours after surgery. Diagnosis was defined by receiving treatment (pacing, cooling, and medications). A multilevel logistic regression analysis with hospital random effect identified JET risk factors. Impact of JET on outcomes was estimated by margins/attributable risk analysis using previous risk-adjustment models. RESULTS: Among 24,073 patients from 63 centers, 1436 (6.0%) were treated for JET with significant center variability (0% to 17.9%). Median time to onset was 3.4 hours, with 34% present on admission. Median duration was 2 days (interquartile range, 1-4 days). Tetralogy of Fallot, atrioventricular canal, and ventricular septal defect repair represented >50% of JET. Patient characteristics independently associated with JET included neonatal age, Asian race, cardiopulmonary bypass time, open sternum, and early postoperative inotropic agents. JET was associated with increased risk-adjusted durations of mechanical ventilation (incidence rate ratio, 1.6; 95% CI, 1.5-1.7) and intensive care unit length of stay (incidence rate ratio, 1.3; 95% CI, 1.2-1.3), but not mortality. CONCLUSIONS: JET is treated in 6% of patients with substantial center variability. JET contributes to increased use of postoperative resources. High center variability warrants further study to identify potential modifiable factors that could serve as targets for improvement efforts to ameliorate deleterious outcomes.

Unmasking the Impact of Oxygenator Induced Hypocapnia on Blood Lactate in Veno-Arterial Extracorporeal Membrane Oxygenation.

Extracorporeal membrane oxygenation (ECMO) is often associated with disturbances in acid/base status that can be triggered by the underlying pathology or the ECMO circuit itself. Extracorporeal membrane oxygenation is known to cause hypocapnia, but the impact of reduced partial pressure of carbon dioxide (pCO2) on biomarkers of tissue perfusion during veno-arterial (VA)-ECMO has not been evaluated. To study the impact of low pCO2 on perfusion indices in VA-ECMO, we placed Sprague-Dawley rats on an established VA-ECMO circuit using either an oxygen/carbon dioxide mixture (O2 95%, CO2 5%) or 100% O2 delivered through the oxygenator (n = 5 per cohort). Animals receiving 100% O2 developed a significant VA CO2 difference (pCO2 gap) and rising blood lactate levels that were inversely proportional to the decrease in pCO2 values. In contrast, pCO2 gap and lactate levels remained similar to pre-ECMO baseline levels in animals receiving the O2/CO2 mixture. More importantly, there was no significant difference in venous oxygen saturation (SvO2) between the two groups, suggesting that elevated blood lactate levels observed in the rats receiving 100% O2 were a response to oxygenator induced hypocapnia and alkaline pH rather than reduced perfusion or underlying tissue hypoxia. These findings have implications in clinical and experimental extracorporeal support contexts.

Contemporary Trends in Cardiac Surgical Care for Trisomy 13 and 18 Patients Admitted to Hospitals in the United States.

OBJECTIVE: To assess rates of cardiac surgery and the clinical and demographic features that influence surgical vs nonsurgical treatment of congenital heart disease (CHD) in patients with trisomy 13 (T13) and trisomy 18 (T18) in the United States. STUDY DESIGN: A retrospective study was performed using the Pediatric Health Information System. All hospital admissions of children (<18 years of age) with T13 and T18 in the United States were identified from 2003 through 2022. International Classifications of Disease (ICD) codes were used to identify presence of CHD, extracardiac comorbidities/malformations, and performance of cardiac surgery. RESULTS: Seven thousand one hundred thirteen patients were identified. CHD was present in 62% (1625/2610) of patients with T13 and 73% (3288/4503) of patients with T18. The most common CHD morphologies were isolated atrial/ventricular septal defects (T13 40%, T18 42%) and aortic hypoplasia/coarctation (T13 21%, T18 23%). Single-ventricle morphologies comprised 6% (100/1625) of the T13 and 5% (167/3288) of the T18 CHD cohorts. Surgery was performed in 12% of patients with T13 plus CHD and 17% of patients with T18 plus CHD. For all cardiac diagnoses, <50% of patients received surgery. Nonsurgical patients were more likely to be born prematurely (P < .05 for T13 and T18). The number of extracardiac comorbidities was similar between surgical/nonsurgical patients with T13 (median 2 vs 2, P = .215) and greater in surgical vs nonsurgical patients with T18 (median 3 vs 2, P < .001). Hospital mortality was <10% for both surgical cohorts. CONCLUSIONS: Patients with T13 or T18 and CHD receive surgical palliation, but at a low prevalence (≤17%) nationally. Given operative mortality <10%, opportunity exists perhaps for quality improvement in the performance of cardiac surgery for these vulnerable patient populations.

Later Brain Death Declaration Correlates to Favorable Donor Characteristics but Decreased Heart Acceptance.

BACKGROUND: With rates of potential donor heart discard as high as 66% nationally, quality improvement efforts must seek to optimize donor utilization. Whether the timing of donor brain death declaration (BDD) influences organ acceptance is understudied. The authors sought to characterize the impacts of time between donor hospital admission and BDD on heart utilization and posttransplant outcomes. METHODS: All potential heart donors and recipients in the United Network for Organ Sharing database were identified (2006-2021). Admission-to-BDD cohorts were: 1 to 2 d (n = 52 469), 3 to 4 d (n = 44 033), 5 to 7 d (n = 24 509), and 8 to 10 d (n = 8576). Donor clinical characteristics were compared between cohorts, and donor acceptance was assessed using multivariable binary logistic regression. Recipient posttransplant survival was assessed with the Kaplan-Meier method. RESULTS: Donor demographics and comorbidity profiles (diabetes and hypertension) were comparable across cohorts. Anoxia/overdose deaths were more common (10% > 21% > 24% > 18%, respectively) and cardiopulmonary resuscitation requirements were higher (37% > 52% > 58% > 47%) when BDD occurred longer after admission. Renal dysfunction (44% > 44% > 35% > 29%) and inotrope requirements (52% > 25% > 36% > 29%) were lower in the later BDD cohorts. Proportions of hepatic dysfunction (18%-21%) and left ventricular ejection fraction <50% (13%-16%) were clinically equivalent. Donor acceptance differed by admission-to-BDD cohort (36% [1-2 d], 34% [3-4 d], 30% [5-7 d], and 28% [8-10 d]). Admission-to-BDD >4 d was independently associated with lower odds of acceptance on multivariable analysis (odds ratio 0.79, P < 0.001). Recipients experienced equivalent posttransplant survival for all donor admission-to-BDD cohorts ( P = 0.999 adults and P = 0.260 pediatrics). CONCLUSIONS: Heart donors with later BDD were disproportionately discarded despite similar-to-favorable overall clinical profiles, resulting in nearly 3000 fewer transplants during the study. Increased utilization of donors with later BDD and "high-risk" characteristics (eg, anoxia/overdose, cardiopulmonary resuscitation requirement) can improve rates of transplantation without compromising outcomes.

Donation after circulatory death significantly reduces waitlist times while not changing post-heart transplant outcomes: A United Network for Organ Sharing Analysis.

BACKGROUND: Recently, several centers in the United States have begun performing donation after circulatory death (DCD) heart transplants (HTs) in adults. We sought to characterize the recent use of DCD HT, waitlist time, and outcomes compared to donation after brain death (DBD). METHODS: Using the United Network for Organ Sharing database, 10,402 adult (aged >18 years) HT recipients from January 2019 to June 2022 were identified: 425 (4%) were DCD and 9,977 (96%) were DBD recipients. Posttransplant outcomes in matched and unmatched cohorts and waitlist times were compared between groups. RESULTS: DCD and DBD recipients had similar age (57 years for both, p = 0.791). DCD recipients were more likely White (67% vs 60%, p = 0.002), on left ventricular assist device (LVAD; 40% vs 32%, p < 0.001), and listed as status 4 to 6 (60% vs 24%, p < 0.001); however, less likely to require inotropes (22% vs 40%, p < 0.001) and preoperative extracorporeal membrane oxygenation (0.9% vs 6%, p < 0.001). DCD donors were younger (29 vs 32 years, p < 0.001) and had less renal dysfunction (15% vs 39%, p < 0.001), diabetes (1.9% vs 3.8%, p = 0.050), or hypertension (9.9% vs 16%, p = 0.001). In matched and unmatched cohorts, early survival was similar (p = 0.22). Adjusted waitlist time was shorter in DCD group (21 vs 31 days, p < 0.001) compared to DBD cohort and 5-fold shorter (DCD: 22 days vs DBD: 115 days, p < 0.001) for candidates in status 4 to 6, which was 60% of DCD cohort. CONCLUSIONS: The community is using DCD mostly for those recipients who are expected to have extended waitlist times (e.g., durable LVADs, status >4). DCD recipients had similar posttransplant early survival and shorter adjusted waitlist time compared to DBD group. Given this early success, efforts should be made to expand the donor pool using DCD, especially for traditionally disadvantaged recipients on the waitlist.

National experience with pediatric surgical aortic valve repair: A Pediatric Health Information System analysis.

OBJECTIVE: To characterize national experience with surgical aortic valve repair in pediatric patients. METHODS: Patients in the Pediatric Health Information System database aged 17 years or younger with International Statistical Classification of Diseases and Related Health Problems codes for open aortic valve repair from 2003 to 2022 were included (n = 5582). Outcomes of reintervention during index admission (repeat repair, n = 54; replacement, n = 48; and endovascular intervention, n = 1), readmission (n = 2176), and in-hospital mortality (n = 178) were compared. A logistic regression was performed for in-hospital mortality. RESULTS: One-quarter (26%) of patients were infants. The majority (61%) were boys. Heart failure was present in 16% of patients, congenital heart disease in 73%, and rheumatic disease in 4%. Valve disease was insufficiency in 22% of patients, stenosis in 29%, and mixed in 15%. The highest quartile of centers by volume (median, 101 cases; interquartile range, 55-155 cases) performed half (n = 2768) of cases. Infants had the highest prevalence of reintervention (3%; P < .001), readmission (53%; P < .001), and in-hospital mortality (10%; P < .001). Previously hospitalized patients (median, 6 days; interquartile range, 4-13 days) were at higher risk for reintervention (4%; P < .001), readmission (55%; P < .001), and in-hospital mortality (11%; P < .001), as were patients with heart failure (reintervention [6%; P < .001], readmission [42%; P = .050], and in-hospital mortality [10%; P < .001]). Stenosis was associated with reduced reintervention (1%; P < .001) and readmission (35%; P = .002). The median number of readmissions was 1 (range, 0-6) and time to readmission was 28 days (interquartile range, 7-125 days). A regression of in-hospital mortality identified heart failure (odds ratio, 3.05; 95% CI, 1.59-5.49), inpatient status (odds ratio, 2.40; 95% CI, 1.19-4.82), and infancy (odds ratio, 5.70; 95% CI, 2.60-12.46) as significant. CONCLUSIONS: The Pediatric Health Information System cohort demonstrated success with aortic valve repair; however, early mortality remains high in infants, hospitalized patients, and patients with heart failure.

Reality of DCD donor use in pediatric thoracic transplantation in the United States.

In the US, the first pediatric donation after circulatory death (DCD) thoracic transplant was done in 2004; however, ethical controversy led to minimal utilization of these donors. The present study was performed to characterize the current state of pediatric DCD heart and lung transplantation (HTx, LTx). Children (<18 year old) who underwent HTx or LTx using DCD donors from June 2004 to June 2022 were identified in the United Network for Organ Sharing registry. A total of 14 DCD recipients were identified: 7 (50%) HTx and 7 (50%) LTx. Donor and recipient demographics are described in Table 1. One and 5-year post-transplant survival were as follows: HTx recipients (64% for each) and LTx recipients (86%, 55%). Although often discussed, the national experience with DCD donors for pediatric HTx and LTx remains limited and not being practiced consistently by any pediatric program. Given the critical organ shortage, DCD use in the field of pediatric thoracic transplantation should be strongly considered.

Up to an Hour of Donor Resuscitation Does Not Affect Pediatric Heart Transplantation Survival.

BACKGROUND: In pediatric heart transplantation, surgeons historically avoided donors requiring cardiopulmonary resuscitation (CPR), despite evidence that donor CPR does not change posttransplant survival (PTS). This study sought to determine whether CPR duration affects PTS. METHODS: All potential brain-dead donors aged <40 years from 2001 to 2021 consented for heart procurement were identified in the United Network for Organ Sharing database (n = 54,671). Organ acceptance was compared by CPR administration and duration. All recipients aged <18 years with donor CPR data were then identified (n = 5680). Survival analyses were conducted using increasing CPR duration as a cut point to identify the shortest duration beyond which PTS worsened. Additional analyses were performed with multivariable and cubic spline regression. RESULTS: Fifty-one percent of donors (28,012 of 54,671) received CPR. Donor acceptance was lower after CPR (54% vs 66%; P < .001) and across successive quartiles of CPR duration (P < .001). Of the transplant recipients, 48% (2753 of 5680) belonged to the no-CPR group, and 52% (2927 of 5680) belonged to the CPR group. Kaplan-Meier analyses of CPR duration attained significance at 55 minutes, after which PTS worsened (11.1 years vs 9.2 years; P = .025). There was no survival difference between the CPR ≤55 minutes group and the no-CPR group (11.1 years vs 11.2 years; P = .571). A cubic spline regression model confirmed that PTS worsened at more than 55 minutes of CPR. A Cox regression demonstrated that CPR >55 minutes predicted worsened PTS relative to no CPR (HR, 1.51; P = .007) but CPR ≤55 minutes did not (HR, 1.01; P = .864). CONCLUSIONS: Donor CPR decreases organ acceptance for transplantation; however, shorter durations (≤55 minutes) had equivalent PTS when controlling for other risk factors.

Seventh Annual Society of Thoracic Surgeons Pedimacs Report.

BACKGROUND: The Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs), supported by The Society of Thoracic Surgeons, provides detailed information on pediatric patients supported with ventricular assist devices (VADs). METHODS: From September 19, 2012, to December 31, 2022, 1463 devices in 1219 patients aged <19 years were reported to the registry from 40 North American hospitals. RESULTS: Cardiomyopathy remains the most common underlying etiology (59%), followed by congenital heart disease (26%) and myocarditis (8%). Implantable continuous devices were most common (39%) type, followed by paracorporeal pulsatile (28%) and paracorporeal continuous (27%) devices. At 6 months after VAD implantation, a favorable outcome (transplant, recovery, or alive on device) was achieved in 85% of patients, which was greatest among those on implantable continuous VADs (92%) and least for paracorporeal continuous VADs (68%), although the patient population supported on these devices is different. CONCLUSIONS: This Seventh Pedimacs Report demonstrates the continued importance of VADs in the treatment of children. With the complexity of cardiac physiologies and sizes of patients, multiple types of devices are used, including paracorporeal continuous, paracorporeal pulsatile, and implantable continuous devices. The preoperative risk factors and differences in patient populations may account for some of the differences in survival observed among these devices. This report, along with other collaborative work, continues to advance the care of this challenging and vulnerable population.

Lung Transplantation for Pulmonary Vascular Disease in Children: A United Network for Organ Sharing Analysis.

Pulmonary vascular disease (PVD) represents an important clinical indication for lung transplant (LTx) in infants, children, and adolescents. There is limited information on LTx outcomes in these patients. We explored LTx volumes and post-LTx survival in children with PVD compared to other diagnoses. The UNOS Registry was queried from 1989 to 2020 to identify first-time pediatric LTx recipients (< 18 yo). PVD was categorized as idiopathic pulmonary arterial hypertension (IPAH) and non-idiopathic arterial hypertension (non-IPAH) and compared to all other patients as other diagnoses. Univariate and multivariate regression models were performed. 984 pediatric LTx patients (593 before 2010 and 391 during/after 2010) were identified, of which 145 (14.7%) had PVD. There has been no significant change in annual rate of all LTxs over comparative eras. However, there has been a decrease in rate of LTxs for PVD patients. Children with PVD had similar survival to other LTx groups in the early era (p = 0.2) and the latter era (p = 0.9). Univariate Cox models, showed that LTx in patients with PVD was associated with a significantly less risk of mortality for children aged 6-11 years compared to younger and older cohorts (HR = 0.4 [0.17-0.98]; p = 0.045), whereas multivariate analysis showed a trend toward higher mortality in 11-17-year-olds (HR = 1.54 [0.97-2.45]; p = 0.06). For PVD patients, oxygen supplementation and ventilator support at LTx were associated with worse post-transplant survival (p = 0.029 and p = 0.01). There has been a decrease in LTx volume for pediatric patients with PVD in the modern era. Post-LTx outcomes for children with PVD are similar to those of other diagnoses in both eras, with children aged 6-11 years having the best survival. Given these findings, LTx should be considered for this patient population.

Hand-Constructed CorMatrix Tubular Valve Used for Tricuspid Valve Replacement in Neonate With Congenital Tricuspid Dysplasia: Five-Year Follow-Up.

Tricuspid valve (TV) dysplasia is a rare congenital defect that, in severe cases, can cause heart failure necessitating surgical correction. TV replacement options are limited in neonates since few commercial valves are available and the rates of failure and postoperative mortality are high. The authors report a neonate with TV dysplasia who underwent replacement with a hand-constructed tube valve using small intestinal submucosal extracellular matrix, which functioned well for >5 years.

Improved donor lung size matching by estimation of lung volumes based on chest X-ray measurements.

RATIONALE: Organ size matching is an important determinant of successful allocation and outcomes in lung transplantation. While computed tomography (CT) is the gold standard, it is rarely used in an organ-donor context, and chest X-ray (CXR) may offer a practical and accurate solution in estimating lung volumes for donor and recipient size matching. We compared CXR lung measurements to CT-measured lung volumes and traditional estimates of lung volume in the same subjects. METHODS: Our retrospective study analyzed clinically obtained CXR and CT lung images of 250 subjects without evidence of lung disease (mean age 9.9 ± 7.8 years; 129 M/121F). From CT, each lung was semi-automatically segmented and total lung volumes were quantified. From anterior-posterior CXR view, each lung was manually segmented and areas were measured. Lung lengths from the apices to the mid-basal regions of each lung were measured from CXR. Quantified CT lung volumes were compared to the corresponding CXR lung lengths, CXR lung areas, height, weight, and predicted total lung capacity (pTLC). RESULTS: There are strong and significant correlations between CT volumes and CXR lung areas in the right lung (R2 = .89, p < .0001), left lung (R2 = .87, p < .0001), and combined lungs (R2 = .89, p < .0001). Similar correlations were seen between CT volumes and CXR measured lung lengths in the right lung (R2 = .79, p < .0001) and left lung (R2 = .81, p < .0001). This correlation between anatomical lung volume (CT) and CXR was stronger than lung-volume correlation to height (R2 = .66, p < .0001), weight (R2 = .43, p < .0001), or pTLC (R2 = .66, p < .0001). CONCLUSION: CXR measures correlate much more strongly with true lung volumes than height, weight, or pTLC. The ability to obtain efficient and more accurate lung volume via CXR has the potential to change our current listing practices of using height as a surrogate for lung size, with a case example provided.

The majority of pediatric Fontan patients have excellent post-transplant survival.

OBJECTIVE: Many pediatric Fontan patients require heart transplant, but this cohort is understudied given the difficulty in identifying these patients in national registries. We sought to characterize survival post-transplant in a large cohort of pediatric patients undergoing the Fontan. METHODS: The United Network for Organ Sharing and Pediatric Health Information System were used to identify Fontan heart transplant recipients aged less than 18 years (n = 241) between 2005 and 2022. Decompensation was defined as the presence of extracorporeal membrane oxygenation, ventilation, hepatic/renal dysfunction, paralytics, or total parenteral nutrition at transplant. RESULTS: Median age at transplant was 9 (interquartile range, 5-12) years. Median waitlist time was 107 (37-229) days. Median volume across 32 center was 8 (3-11) cases. Approximately half (n = 107, 45%) of recipients had 1A/1 initial listing status. Sixty-four patients (28%) were functionally impaired at transplant, 10 patients (4%) were ventilated, and 18 patients (8%) had ventricular assist device support. Fifty-nine patients (25%) had hepatic dysfunction, and 15 patients (6%) had renal dysfunction. Twenty-one patients (9%) were dependent on total parenteral nutrition. Median postoperative stay was 24 (14-46) days, and in-hospital mortality was 7%. Kaplan-Meier analysis showed 1- and 5-year survivals of 89% (95% CI, 85-94) and 74% (95% CI, 81-86), respectively. Kaplan-Meier of Fontan patients without decompensation (n = 154) at transplant demonstrated 1- and 5-year survivals of 93% (95% CI, 88-97) and 88% (95% CI, 82-94), respectively. In-hospital mortality was higher in decompensated patients (11% vs 4%, P = .023). Multivariable analysis showed that decompensation predicted worse post-transplant survival (hazard ratio, 2.47; 95% CI, 1.16-5.22; P = .018), whereas older age at transplant predicted superior post-transplant survival (hazard ratio, 0.89/year; 95% CI, 0.80-0.98; P = .019). CONCLUSIONS: Pediatric Fontan post-transplant outcomes are promising, although early mortality remains high. For nondecompensated pediatric patients at transplant without end-organ disease (>63% of cohort), early mortality is circumvented and post-transplant survival is excellent and similar to all pediatric transplantation.

Survival in Pediatric Patients With Ventricular Assist Devices: A Special Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) Report.

BACKGROUND: The Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) provides detailed understanding on pediatric patients supported with ventricular assist devices (VADs). We sought to identify important variables affecting mortality in pediatric VADs. METHODS: Patients aged <19 years, from 2012 to 2021, were included. Survival analyses were performed using Kaplan-Meier. Parametric hazard modeling was used to identify risk factors for death. RESULTS: Of the 1109 patients, the most common devices were implantable continuous (IC, 448 [40%]), followed by paracorporeal pulsatile (PP, 306 [28%]), paracorporeal continuous (PC, 293 [26%]), and percutaneous (58 [5%]). Patients with percutaneous device, infants, congenital heart disease, biventricular support, and Interagency Registry for Mechanically Assisted Circulatory Support profile 1 had worse overall survival at 6 months. Positive outcome was 83% at 6 months. Consistent with their cohort composition, device type positive outcomes at 6 months were IC, 92%; PP, 84%; and PC, 69%. Parametric hazard modeling for overall survival showed an early hazard for death with biventricular support, congenital heart disease (CHD), intubation before implantation, PC device, and renal impairment, whereas a constant hazard was associated with ascites. For patients <10 kg, parametric modeling showed an early hazard for CHD, intubation, and renal impairment. Modeling in CHD patients showed an early hazard for biventricular support, renal impairment, and use of PC/PP devices. CONCLUSIONS: This multivariable analysis of the complete Pedimacs database demonstrates that illness at VAD implantation, diagnosis, and strategy of support affect survival and differ by device type. We hope this is the first step in creating a predictive tool to help providers and families have informed expectations.

Widening care gap in VAD therapy.

BACKGROUND: The removal of the HeartWare ventricular assist device (HVAD) due to pump malfunctions and inferior outcomes compared to HeartMate 3 (HM3) in adults has created a care gap for younger patients. It is unclear if the reported HVAD survival differs by age and if the initial experience with HM3 can bridge the gap. METHODS: Using the Society of Thoracic Surgeons (STS) Intermacs and Pedimacs registries, durable ventricular assist device (VAD) implants between September 2012 and December 2021 were identified. Young adults (YA) were defined as <40 years old in Intermacs. Patients were excluded if they had an isolated right VAD (RVAD) or were implanted as destination therapy (DT). Survival analysis by Kaplan-Meier (KM) and competing outcomes curves was performed, and 1-year survival is reported. RESULTS: The Intermacs cohort consisted of YA (n = 1226; HVAD 818; HM3 408) with a median age of YA of 32.07 (26.66-36.27) years and weight (wt) of 83.2 (68-104.2) kg. Most had cardiomyopathy (CM) (92.2%). The Pedimacs cohort was 668 patients (median age 9.47 [1.82-14.23] years, wt 27.2 [10-57.05] kg), and most also had CM (70.5%). Device breakdown included HVAD (n = 326), Berlin EXCOR (n = 277), and HM3 (n = 65). HVAD survival differed by age in adults, with YA fairing better than adults >40 years old (88.8% vs 79.4% at 1 year, p < 0.0001). YA survival was also better compared to Pedimacs patient (88.9% vs 83.7%, p = 0.0002), but when competing events were analyzed, mortality was similar to YA (9.2% vs 9.6%, p = 0.1) with a higher proportion of patient undergoing transplant at 1 year in Pedimacs (74% vs 31.3%, p < 0.0001). Survival by device differed between HVAD and HM3 in YA (88.8% vs 94.4%, p = 0.0025). This difference in device survival was not seen in all children (83.7% vs 87.3%, p = 0.21), including those ≥25 kg. Adverse event profiles also differed across the groups with adults seeing less adverse events with the HM3, but the same was not found (including stroke) in the pediatric cohort. Survival outcomes for patients between 10 and 25 kg were similar with the HVAD compared to the Berlin Heart EXCOR (p = 0.4290), with similarities in stroke risk. CONCLUSION: The removal of the HVAD device may result in a care gap in younger patient whose survival outcomes do not mirror that of older adults. The HM3 can fill a portion of this gap with good survival, but there remains a subset of pediatric patients that, based on initial HM3 use, will no longer have access to intracorporeal support and therefore, despite reasonable outcomes with the Berlin Heart EXCOR, will not be able to be discharged home. Lastly, it is essential that future changes to the availability of devices take into account the various patient populations that utilize the device to avoid unintended consequences of access inequality.