Cardiac Transplant Patients Research Articles

Empagliflozin use in cardiac transplant patients

Objectives: Sodium-glucose transport protein 2 inhibitor |(SGLT2) drugs are used to treat patients with type 2 diabetes. In additions to their beneficial metabolic effects in lowering the glaciated hemoglobin, body weight and blood pressure, these agents have shown favorable and protective effects on the heart and the kidneys. These cardio renal benefits are seen even in people without diabetes. There is little evidence on the safety and efficacy of SGLT2 inhibitors use in cardiac transplant recipients. We wanted to study the cardiac transplant recipients who used Empagliflozin for the treatment of diabetes to evaluate its safety and efficacy in this niche sub group of patients. Method: We retrospectively identified 20 patients on the cardiac transplant recipient register taking Empagliflozin (Jardiance) or Empagliflozin combined with Metformin (Synjardy). We studied the safety and efficacy parameters. Results: Our results show improvement in HBA1c, body weight and stability in serum creatinine. There was no increased risk of genitourinary infection, hypoglycemia or diabetic ketoacidosis. Conclusion: While we need larger studies in cardiac transplant patients taking Empagliflozin, our small study provides assurance that Empagliflozin is safe to use in cardiac transplant recipients.

Risk prediction models of primary graft dysfunction in cardiac transplant patients: a need to improve?

Risk prediction models of primary graft dysfunction in cardiac transplant patients: a need to improve?

Post-operative medication considerations in cardiac transplant patients

The first successful heart transplant was carried out in 1979, and there are now approximately 200 transplants undertaken in the UK each year. Many medications are used to prevent rejection of the transplanted organ, but this needs to be balanced with the risk of complications of immunosuppression, such as infection, organ dysfunction, graft dysfunction and vasculopathy. Patients must be able to adhere to the complex and vast regimen of medications started post-transplant, and extensive monitoring is required to ensure the correct balance of rejection risk and adverse effects, depending on where the patient is in their postoperative journey. Immediately after the transplant is when the patient is at highest risk of rejecting their new heart. Guidance is available to recommend regimens to prevent rejection, but needs to be adapted to each patient, taking into consideration their clinical picture, together with comorbidities, drug interactions and organ dysfunction.

Postoperative cognitive dysfunction in heart transplantation recipients.

This study aimed to investigate the occurrence and risk factors of postoperative neurocognitive disorder (NCD) in patients who underwent heart transplantation. Seventy-six heart transplant patients were analyzed for clinical data including gender, age, height, weight, education level, left ventricular ejection fraction (LVEF), stroke volume (SV), transplantation duration, and pretransplant medical history. Cognitive function was assessed using the mini-mental status examination (MMSE) and Montreal cognitive assessment (MoCA) scales. Patients were categorized into cognitively normal and impaired groups based on the presence or absence of cognitive dysfunction, and their cognitive function scores were compared. Multivariate logistic regression was used to identify independent risk factors for cognitive impairment in postoperative cardiac transplant patients. Cognitive dysfunction was observed in 48 out of 76 heart transplant patients, representing an incidence of 63.2%. Cognitive impairment in heart transplant recipients predominantly affected multiple cognitive domains. Logistic regression analysis identified age (OR=1.057, 95% CI 1.002-1.115), gender (OR=.200, 95% CI.044-.919), education level (OR=.728, 95% CI.600-.883), LVEF (OR=.891, 95% CI.820-.969), and history of diabetes (OR=7.674, 95% CI 1.317-44.733) as independent risk factors for postoperative NCD in heart transplant recipients (P<.05). The study found a high incidence of postoperative NCD in heart transplant patients, with gender, age, education level, LVEF, and diabetes history being significant risk factors. Early identification and intervention targeting these risk factors may help prevent NCD in postheart transplant patients and improve long-term outcomes.

A machine learning algorithm improves the diagnostic accuracy of the histologic component of antibody mediated rejection (AMR-H) in cardiac transplant endomyocardial biopsies

BackgroundPathologic antibody mediated rejection (pAMR) remains a major driver of graft failure in cardiac transplant patients. The endomyocardial biopsy remains the primary diagnostic tool but presents with challenges, particularly in distinguishing the histologic component (pAMR-H) defined by 1) intravascular macrophage accumulation in capillaries and 2) activated endothelial cells that expand the cytoplasm to narrow or occlude the vascular lumen. Frequently, pAMR-H is difficult to distinguish from acute cellular rejection (ACR) and healing injury. With the advent of digital slide scanning and advances in machine deep learning, artificial intelligence technology is widely under investigation in the areas of oncologic pathology, but in its infancy in transplant pathology. For the first time, we determined if a machine learning algorithm could distinguish pAMR-H from normal myocardium, healing injury and ACR. Materials and MethodsA total of 4,212 annotations (1,053 regions of normal, 1,053 pAMR-H, 1,053 healing injury and 1,053 ACR) were completed from 300 hematoxylin and eosin slides scanned using a Leica Aperio GT450 digital whole slide scanner at 40X magnification. All regions of pAMR-H were annotated from patients confirmed with a previous diagnosis of pAMR2 (>50% positive C4d immunofluorescence and/or >10% CD68 positive intravascular macrophages). Annotations were imported into a Python 3.7 development environment using the OpenSlide™ package and a convolutional neural network approach utilizing transfer learning was performed. ResultsThe machine learning algorithm showed 98% overall validation accuracy and pAMR-H was correctly distinguished from specific categories with the following accuracies: normal myocardium (99.2%), healing injury (99.5%) and ACR (99.5%). ConclusionOur novel deep learning algorithm can reach acceptable, and possibly surpass, performance of current diagnostic standards of identifying pAMR-H. Such a tool may serve as an adjunct diagnostic aid for improving the pathologist's accuracy and reproducibility, especially in difficult cases with high inter-observer variability. This is one of the first studies that provides evidence that an artificial intelligence machine learning algorithm can be trained and validated to diagnose pAMR-H in cardiac transplant patients. Ongoing studies include multi-institutional verification testing to ensure generalizability.

Dental care for cardiac transplant patients in the UK

Dental care for cardiac transplant patients in the UK

The Effect of Neurodevelopmental Disorders on the Prognosis of Children Undergoing Heart Transplantation: A Retrospective Analysis of the National Inpatient Sample 2011–2019

Background: Many international governing bodies recommend against heart transplantation in patients with severe cognitive-behavioral disabilities, however no clear criteria are offered to define severity. Patients with neurodevelopmental disorders may face systematic discrimination when being evaluated for transplant. We set out to investigate whether children with neurodevelopmental disorders that undergo heart transplantation have poorer in-hospital outcomes compared to neurotypical children. Methods: A retrospective analysis of the National Inpatient Sample database was conducted to identify pediatric patients with neurodevelopmental disorders who underwent heart transplantation from 2011–2019. Baseline characteristics and in-hospital outcomes between patients were compared. Binary logistic regression was used to investigate the association between the documented presence of a neurodevelopmental disorder and in-hospital outcomes in children undergoing heart transplantation. Results: We identified a weighted sample of 3770 pediatric cardiac transplant patients, of whom 245 (6.5%) had a documented diagnosis of neurodevelopmental disorder. There was no significant difference in the odds of major adverse cardiovascular events (all-cause mortality, stroke complications or myocardial infarction), surgical complications, infection, venous thromboembolic events, delirium/restraint use, or cardiac dysrhythmia. Patients with neurodevelopmental disorders had lower overall length of stay (44.0 days interquartile range (IQR): 16.0–90.0 vs. 57.08 days IQR: 22.0–112.0, p &lt; 0.050), and cost of stay ($956,031 IQR: 548,559.0–1,801,412.0 vs. $1,074,793 IQR: 599,089.8–2,129,086.0, p &lt; 0.050). Patients with neurodevelopmental disorders had significantly lower odds of acute transplant complications (adjusted odds ratio (aOR): 0.39, 95% confidence interval (CI): 0.21–0.74, p &lt; 0.050) vascular complications (aOR: 0.36, 95% CI: 0.19–0.66, p &lt; 0.050) and acute kidney injury (AKI) (aOR: 0.52, 95% CI: 0.33–0.83, p &lt; 0.050). Conclusions: These data suggest that patients with neurodevelopmental disorders have overall similar if not potentially improved post-transplant outcomes in the acute setting compared to neurotypical patients, possibly secondary to selection bias in the patient selection process.

(164) - In-Hospital Outcomes After Cardiac Transplantation in Patients with Neurodevelopmental Disorders: Insights from The National Inpatient Sample 2011-2019

(164) - In-Hospital Outcomes After Cardiac Transplantation in Patients with Neurodevelopmental Disorders: Insights from The National Inpatient Sample 2011-2019

Panniculitis in reactivation of Chagas disease in a cardiac transplant patient

Panniculitis in reactivation of Chagas disease in a cardiac transplant patient

Ten-year outcomes post percutaneous coronary intervention in cardiac transplant recipients

BackgroundCardiac allograft vasculopathy (CAV) is one of the major late causes of mortality in cardiac transplant recipients beyond the first year. Given the lack of longer term data for PCI in cardiac transplant recipients, we report ten year follow up of such cardiac transplant recipients who underwent PCI at Mayo Clinic. MethodsA retrospective observational study was conducted that included cardiac transplant recipients who underwent PCI at the Mayo Clinic. Continuous variables were presented as mean (SD) or median (IQR) and discrete variables were presented as frequency (percentage). ResultsThirty-eight consecutive cardiac transplant recipients underwent PCI from January 1, 1995, to June 30, 2023, at the Mayo Clinic. The median age of the cohort was 61.00 years (IQR:51.00–70.00) comprised predominantly of men (65.80%), and 47.40% of the cohort presented with an acute coronary syndrome. The antirejection therapy prior to the PCI included steroids (47.30%), cyclosporine (26.30%), tacrolimus (15.80%), mycophenolate (42.10%), azathioprine (13.10%), & sirolimus (31.57%). Intravascular ultrasound during PCI was utilized in 10.50% of the cases. The median time duration between heart transplant and PCI was 9.00 years (IQR:6.00–13.00 years). Two individuals needed repeat heart transplant for severe CAV. In hospital mortality was 5.20% and the long-term median survival was 7.20 years with a 10-year mortality rate of 65.70%. ConclusionsThis is the first publication reporting ten-year outcomes for PCI in cardiac transplant patients. The salient features for our cohort were a 65.70% mortality rate at 10 years and a median survival of 7.20 years.

Dental care for cardiac transplant patients in the UK.

Cardiac transplantation replaces a severely damaged non-functioning heart with a healthy heart from a donor. Within the UK, the number of cardiac transplants being performed each year is increasing, with significant improvements in longer-term survival. Dental professionals are therefore more likely to see and manage these patients in the pre- and post-transplant periods. This paper proposes a protocol for the dental management of these patients, reinforced by a case series from Scotland and London.

Peak insulin drip rate associated with decreased infections post-solid organ transplant.

Infection and rejection outcomes were retrospectively analyzed in patients following liver transplant and separately following heart transplant with patients being stratified by their severity of immediate postoperative insulin resistance as measured by the peak insulin drip rate that was required to reduce glucose levels. For each group, these peak insulin drip rates were divided into quartiles (Q). In liver transplant patients (n=207), those in Q4 (highest infusion rate) had significantly fewer infections up to 6 months post-transplant (42.3%vs. 60.0%, p=.036) and borderline fewer rejection episodes (25.0%vs. 40.0%, p=.066) compared to Q1-Q3 patients. To confirm these unexpected results, a subsequent similar analysis in heart transplant (n=188) patients again showed that Q4 patients had significantly fewer infections up to 6 months (19.1%vs. 53.9%, p<.0001) compared to Q1-Q3 patients. Logistic regression in a subset of 103 cardiac transplant patients showed that the maximum glucose during surgery, prior MI, and hypertension were associated with severe insulin resistance (SIR) status, while the presence of pre-existing diabetes and BMI were not. We hypothesize that patients are who are able to mount a more robust counter-regulatory response that causes the insulin resistance may be healthier and thus able to mount a better response to infections.

Reactivation of Tumor-like Chagas Disease in the Central Nervous System in Cardiac Transplant Patients: A Case Series and Literature Review

Abstract Introduction Chagas disease is an important public health problem in Latin American countries, affecting ∼ 6 million people within the region. In patients with chronic Chagas disease who undergo some type of immunosuppression reactivation of the acute form may occur, and manifestations involve many organs, including the central nervous system. Tumor-like brain reactivations are well described in patients with acquired immunodeficiency syndrome; however, this is a very rare event among Chagasic patients immunosuppressed after a heart transplantation. Case Report We describe three cases of cardiac transplant patients who had a tumor-like intracranial lesion, whose biopsies were compatible with Chagas disease. All 3 patients were treated with benznidazole, and 2 of them presented parameters of cure after 60 days of treatment, while 1 required a 2nd cycle of treatment. Discussion A tumor-like Chagas disease reactivation in the central nervous system may happen in heart-transplant patients and, due to the multiple differential diagnoses, we believe that brain biopsies should be considered when feasible.

Comparison of milrinone versus dobutamine on invasive haemodynamics in patients with advanced heart failure on home inotropes

Abstract Background Home inotropic support is an established bridge to cardiac transplantation in patients with advanced heart failure. Milrinone, a phosphodiesterase 3 inhibitor, preferentially vasodilates pulmonary vasculature, thus is often chosen over dobutamine in patients with concomitant pulmonary hypertension. However, there is a paucity of data on the haemodynamic effects of milrinone in the pre-cardiac transplant population. Purpose We sought to examine the haemodynamic effects of milrinone vs. dobutamine out to 3 months in patients with advanced heart failure awaiting cardiac transplantation. Methods Patients in the home inotrope program at a quaternary referral centre from January 2000 to May 2022 were included. Retrospective analysis of echocardiographic and invasive haemodynamic studies via right heart catheterisation were performed at baseline (prior to commencement of inotrope), at 30 days (30D) and 3 months (3m). Results From a total of 119 patients, 57 were on milrinone and 62 on dobutamine. Non-ischaemic cardiomyopathies of various aetiologies accounted for 67%, while ischaemic cardiomyopathies accounted for 33%. Majority of patients were male (79%) with a mean age of 52±13 years. There was a significant increase in LVEF from 21±7% at baseline to 27±14% at 3m in those on dobutamine, p = 0.02. Similar increase in LVEF from 22±8% to 26±13% in the milrinone group did not reach significance, p = 0.43. Comparably, CI increased from 2.0±0.6L/min/m2 at baseline to 2.5±0.9L/min/m2 at 3m in the dobutamine cohort, p = 0.05, and from 2.0±0.7L/min/m2 at baseline to 2.3±0.6L/min/m2 at 3m in the milrinone cohort, p = 0.27. In the dobutamine cohort LVEDD was static from 68±14mm at baseline to 66±21mm at 3m, p = 0.78. LVEDD reduced from 67±11mm to 60± 9mm at 3m in the milrinone group, p = 0.09. Classification of mild right ventricular dysfunction increased from 7% to 18% after 30 days on milrinone, p= 0.2, compared to an increase from 10% to 16% in the dobutamine group, p = 0.47. Mean pulmonary artery pressure (mPAP) reduced from 34±11mmHg to 29±11mmHg at 3m in the milrinone group, p = 0.15. mPAP was static in the dobutamine group from 34±9mmHg at baseline to 34±10mmHg at 3m, p = 0.96. TPG in the milrinone group was 11.9±6.0mmHg to 12.9±6.3mmHg at 30D, with reduction at 3m to 9.6±6.3mmHg, p = 0.26. In the dobutamine group TPG remained static from 10.9±5.7mmHg at baseline to 11.4±5.1mmHg at 30D and 10.9±5.2 at 3m, p = 0.97. Wedge pressure (PCWP) reduced from 22±7mmHg at baseline to 21±7mmHg at 30D to 18±8mmHg at 3m in the milrinone group, p = 0.11. PCWP in the dobutamine group was static at 23±8mmHg at baseline to 24±5mmHg at 30D and 23±6mmHg at 3m, p = 0.92. Conclusion(s) Dobutamine demonstrated a significant increase in LVEF and CI out to 3 months, however milrinone demonstrated a larger improvement in RV function and greater reduction in cardiac and pulmonary pressures as compared to dobutamine. Larger studies are required to confirm these trends.Figure 1

Abstract 15677: Heart Transplant in Older Adults: Before and After the 2018 United Network for Organ Sharing Allocation Change

Introduction: There is an increasing trend towards transplanting older adults, and the proportion of those over 70 who have been transplanted has increased in recent years. In 2018, the United Network for Organ Sharing (UNOS) implemented a 6-tier allocation policy to replace the prior 3-tier system. There have been significant shifts in cardiac transplantation practices and patient outcomes following the implementation of the new policy. Hypothesis: This study aims to evaluate the impact of the new allocation policy on older adults. Methods: Adult patients who received heart transplant between January 1, 2010 and December 31, 2021 were identified in the UNOS registry and stratified by whether they were transplanted pre-2018 or post-2018. Outcome of interest was mortality at 1 after heart transplant. Multivariable Cox proportional hazard modeling was used to estimate hazard ratios associated with outcomes of interest. Results: 661 patients over the age of 70 were transplanted pre-2018 and 413 patients over 70 were transplanted post-2018. Those who were transplanted after the 2018 UNOS allocation change were less likely to have had an ischemic cardiomyopathy, more likely to have had an IABP or be on ECMO prior to transplant, and more likely to have had cancer prior to transplant. There was no difference in rates of diabetes, prior CVA, and dialysis for those transplanted pre- vs post-2018. 1 Year mortality for those pre- and post-2018 were similar (10.4% pre-2018, 11.4% post-2018, HR 1.11, CI 0.77-1.61, p=0.6). Conclusions: There has not been a change in mortality in older adults with the 2018 UNOS allocation change. The increase in usage of IABP and ECMO prior to transplant post-2018 mirror changes in the overall population. Notably, post-2018, more older adults with prior malignancies are being transplanted.

Induction immunosuppression and post-transplant diabetes mellitus: a propensity-matched cohort study.

Post-transplant diabetes mellitus (PTDM) is a common complication among cardiac transplant recipients, causing diabetes-related complications and death. While certain maintenance immunosuppressive drugs increase PTDM risk, it is unclear whether induction immunosuppression can do the same. Therefore, we evaluated whether induction immunosuppression with IL-2 receptor antagonists, polyclonal anti-lymphocyte antibodies, or Alemtuzumab given in the peri-transplant period is associated with PTDM. We used the Scientific Registry of Transplant Recipients database to conduct a cohort study of US adults who received cardiac transplants between January 2008-December 2018. We excluded patients with prior or multiple organ transplants and those with a history of diabetes, resulting in 17,142 recipients. We created propensity-matched cohorts (n=7,412) using predictors of induction immunosuppression and examined the association between post-transplant diabetes and induction immunosuppression by estimating hazard ratios using Cox proportional-hazards models. In the propensity-matched cohort, the average age was 52.5 (SD=13.2) years, 28.7% were female and 3,706 received induction immunosuppression. There were 867 incident cases of PTDM during 26,710 person-years of follow-up (32.5 cases/1,000 person-years). There was no association between induction immunosuppression and post-transplant diabetes (Hazard Ratio= 1.04, 95% confidence interval 0.91 - 1.19). Similarly, no associations were observed for each class of induction immunosuppression agents and post-transplant diabetes. The use of contemporary induction immunosuppression in cardiac transplant patients was not associated with post-transplant diabetes.

Electroconvulsive Therapy in Heart Transplant Patients: To Avoid or Embrace?

Patients with heart disease are at an increased risk of depression. Electroconvulsive therapy (ECT) is a highly effective treatment for severe depressive episodes. However, ECT may increase the risk for adverse outcomes in certain patients because of changes in blood pressure and heart rate secondary to an initial parasympathetic surge followed by a sympathetic surge and peripheral catecholamine release. In post-cardiac transplant patients, these acute hemodynamic changes on a denervated heart may bring clinical challenges. The available data on ECT in heart transplant patients are limited. The authors of this article present a summary of the available literature relating to ECT in heart transplant patients.The authors performed a literature search of 6 online databases yielding 6 English-language case reports of ECT in cardiac transplant patients. All patients experienced changes in hemodynamic variables during and immediately after ECT, ranging from moderate decrease in blood pressure to extreme hypertension. The cases did not report any serious cardiac complications during the course of ECT. In the 5 patients whose psychiatric responses to treatment were detailed, all had improvement in their depressive symptoms. Electroconvulsive therapy may be considered for severe cases of depression in patients with a history of cardiac transplant, but the potential benefit of ECT needs to be weighed against risks. In the limited number of cases reported in the literature, ECT seems to have been relatively safe and effective.

The Role of Cardiopulmonary Exercise Testing in Hypertrophic Cardiomyopathy.

This review emphasizes the importance of cardiopulmonary exercise testing (CPET) in patients diagnosed with hypertrophic cardiomyopathy (HCM). In contrast to standard exercise testing and stress echoes, which are limited due to the ECG changes and wall motion abnormalities that characterize this condition, CPET allows for the assessment of the complex pathophysiology and severity of the disease, its mechanisms of functional limitation, and its risk stratification. It is useful tool to evaluate the risk for sudden cardiac death and select patients for cardiac resynchronization therapy (CRT), cardiac transplantation, or mechanical circulatory support, especially when symptomatology and functional status are uncertain. It may help in differentiating HCM from other forms of cardiac hypertrophy, such as athletes' heart. Finally, it is used to guide and monitor therapy as well as for exercise prescription. It may be considered every 2 years in clinically stable patients or every year in patients with worsening symptoms. Although performed only in specialized centers, CPET combined with echocardiography (i.e., CPET imaging) and invasive CPET are more informative and provide a better assessment of cardiac functional status, left ventricular outflow tract obstruction, and diastolic dysfunction during exercise in patients with HCM.

The role of peak VO2 in prognosis in patients undergoing a Cardiac Rehabilitation program

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Peak oxygen uptake (peak VO2) is a strong predictor of mortality and is commonly used in the evaluation of patients for cardiac transplantation. Although guidelines suggest a peak VO2&amp;lt;14mL/(kg.min) as a cut-off for transplant and a peak VO2&amp;lt;12mL/(kg.min) in patients under beta-blockade (BB), recent data emerged, questioning the suitability of such cut-offs. Purpose To correlate CPET and echo data with outcomes after CR programs and to determine the best cut off for peak VO2 in a population with a high percentage of BB therapeutics. Methods Single center prospective study which included consecutive pts who were participating in a centre-based CR program lasting 8-12 weeks from 2019 to 2021. The CR program included initial evaluation by cardiologist and rehabilitation specialist with collection of clinical characteristics, three times weekly supervised exercise sessions, appointment with rehabilitation nurse, nutritionist and psychologist and educational sessions. Lab tests, echocardiogram and CPET were done before and after completion of the program. Multivariate analysis with Cox regression was used to correlate with events and survival was analyzed with Kaplan Meier curves. Results We analyzed 349 patients who underwent CR (82% male, mean age 60 ±11,4 years). The majority was referred for ischemic heart disease (83%) followed by valvular heart disease (7%). Mean follow-up was 36,7± 19,2 months. During FUP, 7,2% pts had CV related admissions (n=25), 4 of which were myocardial infarction. Sixteen pts died (4,6%) of which 2,3% were from cardiovascular causes. On multivariate analysis peak VO2 (HR 0.827 CI 95% 0.72-0.949, p=0.07), ejection fraction (HR 0.962 CI 95% 0.933-0.991, p=0.01) and test duration (HR 0.756 CI 95% 0.712-0.778, p=0.01) correlated with hospital admissions. Regarding mortality only peak VO2 showed statistical significance (HR 0.8 CI 95% 0.69-0.93, p=0.04). On this matter we further analyzed the best cut-off in predicting events: a peak VO2 &amp;gt; 14 mL/(kg.min) was a better predictor of event free-survival in these patients when comparing with a peak VO2 of 12 mL/(kg.min). Conclusions Cardiac rehabilitation has an established impact in prognosis. Echo and CPET data obtained at the beginning of the CR program can be used to identify patients who might benefit from a more closed surveillance in order to reduce risks of hospitalization. Moreover, in our population, a peak VO2 cut-off of 14mL/(kg.min) seemed to better correlate with event-free survival.

Differences in Baseline Immunophenotype in Pediatric Cardiac Transplant Evaluation: How Informed Reductions in Immunosuppression can Improve Patient Outcomes

Lifelong multi-drug immunosuppression is essential in pediatric cardiac transplant with regimens varying between pediatric centers. Current data suggests pre-transplant immunologic phenotype differences may predispose patients to over-immunosuppression. At our tertiary care center, targeted reduction of immunosuppression has recently become common practice despite limited published data. We hypothesize that individualized reduction of immunosuppression in pediatric cardiac transplant patients based on baseline immunophenotype will lead to improved outcomes post-transplant.From January 2020 through July 2022, 52 pediatric patients were referred to our tertiary care center for cardiac transplant evaluation, which includes Immunology evaluation. Patient demographics, cardiac history, and pre-transplant immune evaluation (T/B/NK cell quantitation, quantitative immunoglobulins, vaccine responses and T cell functional testing, as available) were collected. Genetic testing was reviewed. 28 patients who completed cardiac transplant were followed up to 12 months for information on reduced immunosuppression (decreased/bypassed induction with antithymocyte globulin and/or decreased long-term immunosuppression goals), infections, and rejection post-transplant.Of patients referred for evaluation, 63% had congenital heart disease (CHD). Nearly 100% of CHD patients required cardiac surgery in the first year of life with thymectomy. Of all referred patients and of those with available total T cell count (CD3+ T cells), 54% were lymphopenic (CD3+ T cells < 1000/mm3), and 11% of the lymphopenic children were severely lymphopenic (CD3+ T cells < 300/mm3). Patient IgG levels outside of protein losing enteropathy (PLE) and vaccine responses were within normal limits. Available microarray results showed 5 children with abnormal chromosomal syndromes (including 22q11.2 deletion syndrome). Of those referred, 28 patients underwent cardiac transplant and review of outcomes for up to 12 months post-transplant is on-going.Immunologic abnormalities are inconsistent in cardiac patients and may be secondary to early thymectomy, PLE or chromosomal deletion syndromes. Our data demonstrates significant differences in pre-transplant immunologic phenotypes and will add to the limited literature on decreasing immunosuppression in severely lymphopenic cardiac patients. This retrospective study provides encouragement for partnership between immunology and cardiology teams to conduct larger, prospective multicenter studies to further understand individualization of immunosuppression regimens, the role of baseline immunophenotyping to inform these decisions and the resulting improvement in transplant outcomes.