Discovery of non-HLA antibodies associated with cardiac allograft rejection and development and validation of a non-HLA antigen multiplex panel: From bench to bedside.

We analyzed humoral immune responses to nonhuman leukocyte antigen (HLA) after cardiac transplantation to identify antibodies associated with allograft rejection. Protein microarray identified 366 non-HLA antibodies (>1.5 fold, P < .5) from a discovery cohort of HLA antibody-negative, endothelial cell crossmatch-positive sera obtained from 12 cardiac allograft recipients at the time of biopsy-proven rejection. From these, 19 plasma membrane proteins and 10 autoantigens identified from gene ontology analysis were combined with 48 proteins identified through literature search to generate a multiplex bead array. Longitudinal sera from a multicenter cohort of adult cardiac allograft recipients (samples: n = 477 no rejection; n = 69 rejection) identified 18 non-HLA antibodies associated with rejection (P < .1) including 4 newly identified non-HLA antigenic targets (DEXI, EMCN, LPHN1, and SSB). CART analysis showed 5/18 non-HLA antibodies distinguished rejection vs nonrejection. Antibodies to 4/18 non-HLA antigens synergize with HLA donor-specific antibodies and significantly increase the odds of rejection (P < .1). The non-HLA panel was validated using an independent adult cardiac transplant cohort (n = 21 no rejection; n = 42 rejection, >1R) with an area under the curve of 0.87 (P < .05) with 92.86% sensitivity and 66.67% specificity. We conclude that multiplex bead array assessment of non-HLA antibodies identifies cardiac transplant recipients at risk of rejection.

Heart and heart-liver transplantation in adults with failing Fontan physiology.

BACKGROUND: As the population of patients with a Fontan palliation grows so does, the number of patients with cardiac failure necessitating orthotopic heart transplant (OHT) and combined heart-liver transplant (CHLT). There is recent evidence that current era cardiac transplant in Fontan patients has improved outcomes, but most studies have a preponderance of pediatrics patients in their cohorts. We examine our institutional experience with adult OHT and CHLT transplantation for failed Fontan physiology. METHODS AND RESULTS: Retrospective analysis of patients at the Ahmanson/UCLA Adult Congenital Heart Disease Center who underwent OHT or CHLT for failing Fontan physiology from January 1, 2002 to May 31, 2017. We identified 20 patients with single-ventricle physiology and Fontan palliation who underwent OHT or CHLT. The median age was 29.5 years (range 19-44). Five patients underwent CHLT because of biopsy proven hepatic cirrhosis. The median length of hospital stay was 23 days (range 8-76) post-OHT and 51 days (range 26-77) post-CHLT. During a median follow-up of 56 months (range 2-178), there was one mortality occurring at 34 months post-OHT due to coronary vasculopathy. Most frequent early postoperative complications included bleeding and infection (55% and 20%, respectively) and surgical reintervention for bleeding complications (n = 8, 40%). One CHLT patient experienced clinically significant hepatic rejection requiring admission and steroid treatment. CONCLUSIONS: Despite inherent risks and complexities of OHT or CHLT in patients with a failed Fontan, transplant is a reasonable therapy. Peri- and postoperative complications are common and may require surgical reintervention. Continued observation of practices and unifying themes may help improve patient selection, pre- and postoperative treatment and ultimately outcomes.

Survival After Heart Transplantation in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Outcomes of arrhythmogenic right ventricular cardiomyopathy (ARVC) patients after heart transplantation have not been well studied. Diagnostic criteria were established in 1994 and subsequently revised in 2010. We sought to better characterize this population in a national cohort. METHODS: A total of 35,138 heart transplant-only recipients were identified from the United Network for Organ Sharing (UNOS) Thoracic Registry (1994-2011); 73 had ARVC. The non-ARVC group included ischemic cardiomyopathy, restrictive cardiomyopathy, dilated cardiomyopathy, hypertrophic cardiomyopathy, and other. Survival was censored at 12 years. Multivariate Cox proportional hazard regression analysis was adjusted for age, sex, DM, race, ischemia time, dialysis, life support, wait time, and HLA mismatch. RESULTS: There were 73 ARVC and 35,065 non-ARVC patients. The ARVC cohort was associated with less ventricular assist device use (P = .001) and significantly decreased pulmonary arterial and capillary wedge pressures (P < .001). Survivals at 1, 5, and 10 years were, respectively, ARVC 87%, 81%, and 77%, and non-ARVC 87%, 72%, and 53% (log rank P = .07). The ARVC unadjusted hazard ratio for all-cause mortality was 0.59 (95% confidence interval [CI] 0.34-1.04; P = .073). Multivariate analysis yielded a hazard ratio of 0.68 (95% CI 0.35-1.30; P = .25). ARVC survival was similar to restrictive, hypertrophic, and dilated cardiomyopathies and significantly better than ischemic cardiomyopathy. CONCLUSIONS: This is the largest reported series of ARVC after heart transplantation, of which 11% were pediatric. Survival was similar to the non-ARVC cohort, with improved survival over ischemic and restrictive etiologies.

The AlloMap™ genomic biomarker story: 10 years after.

Over the last >20 years, we have co-developed the rationale for the first diagnostic and prognostic leukocyte gene expression profiling (GEP) biomarker test in transplantation medicine that gained US-FDA-regulatory clearance and international evidence-based medicine guideline acceptance to rule out moderate/severe acute cellular cardiac allograft rejection without invasive endomyocardial biopsies (EMB). Based on this test, a non-invasive clinical algorithm was implemented since 2005. After clinical implementation, this GEP-based monitoring in direct comparison with an EMB-based strategy was non-inferior with respect to detection of clinical rejection, defined as new onset allograft dysfunction with/without histology of ACR, re-transplantation or death, and at the same time improved patient satisfaction. Subsequently, we demonstrated the test's capacity when used as serial monitoring tool to predict these clinical rejection events. In this Personal Viewpoint article, I will discuss the various decision-making branching points that were made in the AlloMap biomarker test development to inform future genomic biomarker test development projects.

Cardiac Amyloidosis: Diagnosis and Treatment Strategies.

Cardiac amyloidosis in the United States is most often due to myocardial infiltration by immunoglobulin protein, such as in AL amyloidosis, or by the protein transthyretin, such as in hereditary and senile amyloidosis. Cardiac amyloidosis often portends a poor prognosis especially in patients with systemic AL amyloidosis. Despite better understanding of the pathophysiology of amyloid, many patients are still diagnosed late in the disease course. This review investigates the current understanding and new research on the diagnosis and treatment strategies in patients with cardiac amyloidosis. Myocardial amyloid infiltration distribution occurs in a variety of patterns. Structural and functional changes on echocardiography can suggest presence of amyloid, but CMR and nuclear imaging provide important complementary information on amyloid burden and the amyloid subtype, respectively. While for AL amyloid, treatment success largely depends on early diagnosis, for ATTR amyloid, new investigational agents that reduce production of transthyretin protein may have significant impact on clinical outcomes. Advancements in the non-invasive diagnostic detection and improvements in early disease recognition will undoubtedly facilitate a larger proportion of patients to receive early therapy when it is most effective.

Clinical usefulness of gene-expression profile to rule out acute rejection after heart transplantation: CARGO II.

AIMS: A non-invasive gene-expression profiling (GEP) test for rejection surveillance of heart transplant recipients originated in the USA. A European-based study, Cardiac Allograft Rejection Gene Expression Observational II Study (CARGO II), was conducted to further clinically validate the GEP test performance. METHODS AND RESULTS: Blood samples for GEP testing (AlloMap(®), CareDx, Brisbane, CA, USA) were collected during post-transplant surveillance. The reference standard for rejection status was based on histopathology grading of tissue from endomyocardial biopsy. The area under the receiver operating characteristic curve (AUC-ROC), negative (NPVs), and positive predictive values (PPVs) for the GEP scores (range 0-39) were computed. Considering the GEP score of 34 as a cut-off (>6 months post-transplantation), 95.5% (381/399) of GEP tests were true negatives, 4.5% (18/399) were false negatives, 10.2% (6/59) were true positives, and 89.8% (53/59) were false positives. Based on 938 paired biopsies, the GEP test score AUC-ROC for distinguishing ≥3A rejection was 0.70 and 0.69 for ≥2-6 and >6 months post-transplantation, respectively. Depending on the chosen threshold score, the NPV and PPV range from 98.1 to 100% and 2.0 to 4.7%, respectively. CONCLUSION: For ≥2-6 and >6 months post-transplantation, CARGO II GEP score performance (AUC-ROC = 0.70 and 0.69) is similar to the CARGO study results (AUC-ROC = 0.71 and 0.67). The low prevalence of ACR contributes to the high NPV and limited PPV of GEP testing. The choice of threshold score for practical use of GEP testing should consider overall clinical assessment of the patient's baseline risk for rejection.

Heart Failure Therapies for End-Stage Chemotherapy-Induced Cardiomyopathy.

With ongoing advancements in cancer-related treatments, the number of cancer survivors continues to grow globally, with numbers in the United States predicted to reach 18 million by 2020. As a result, it is expected that a greater number of patients will present with chemotherapy-related side effects. One entity in particular, chemotherapy-related cardiomyopathy (CCMP), is a known cardiotoxic manifestation associated with agents such as anthracyclines, trastuzumab, and tyrosine kinase inhibitors. Although such effects have been described in the medical literature for decades, concrete strategies for screening, prevention, and management of CCMP continue to be elusive owing to limited studies. Late recognition of CCMP is associated with a poorer prognosis, including a lack of clinical response to pharmacologic therapy, and end-stage heart failure. A number of advanced cardiac therapies, including cardiac resynchronization therapy, ventricular assist devices, and orthotopic cardiac transplantation, are available to for end-stage heart failure; however, the role of these therapies in CCMP is unclear. In this review, management of end-stage CCMP with the use of advanced therapies and their respective effectiveness are discussed, as well as clinical characteristics of patients undergoing these treatments. The relative paucity of data in this field highlights the importance and need for larger-scale longitudinal studies and long-term registries tracking the outcomes of cancer survivors who have received cardiotoxic cancer therapy to determine the overall incidence of end-stage CCMP, as well as prognostic factors that will ultimately guide such patients toward receiving appropriate end-stage care.

Molecular basis of recovering on mechanical circulatory support.

Our insights into different system levels of mechanisms by left ventricular assist device support are increasing and suggest a complex regulatory system of overlapping biological processes. To develop novel decision-making strategies and patient selection criteria, heart failure and reverse cardiac remodeling should be conceptualized and explored by a multifaceted research strategy of transcriptomics, metabolomics, proteomics, molecular biology, and bioinformatics. Knowledge of the molecular mechanisms of reverse cardiac remodeling is in its early stages, and comprehensive reconstruction of the underlying networks is necessary.

An Exercise Immune Fitness Test to Unravel Disease Mechanisms-A Proof-of-Concept Heart Failure Study.

Background: Cardiorespiratory fitness positively correlates with longevity and immune health. Regular exercise may provide health benefits by reducing systemic inflammation. In chronic disease conditions, such as chronic heart failure and chronic fatigue syndrome, mechanistic links have been postulated between inflammation, muscle weakness, frailty, catabolic/anabolic imbalance, and aberrant chronic activation of immunity with monocyte upregulation. We hypothesize that (1) temporal changes in transcriptome profiles of peripheral blood mononuclear cells during strenuous acute bouts of exercise using cardiopulmonary exercise testing are present in adult subjects, (2) these temporal dynamic changes are different between healthy persons and heart failure patients and correlate with clinical exercise-parameters and (3) they portend prognostic information. Methods: In total, 16 Heart Failure (HF) patients and 4 healthy volunteers (HV) were included in our proof-of-concept study. All participants underwent upright bicycle cardiopulmonary exercise testing. Blood samples were collected at three time points (TP) (TP1: 30 min before, TP2: peak exercise, TP3: 1 h after peak exercise). We divided 20 participants into 3 clinically relevant groups of cardiorespiratory fitness, defined by peak VO2: HV (n = 4, VO2 ≥ 22 mL/kg/min), mild HF (HF1) (n = 7, 14 < VO2 < 22 mL/kg/min), and severe HF (HF2) (n = 9, VO2 ≤ 14 mL/kg/min). Results: Based on the statistical analysis with 20-100% restriction, FDR correction (p-value 0.05) and 2.0-fold change across the three time points (TP1, TP2, TP3) criteria, we obtained 11 differentially expressed genes (DEG). Out of these 11 genes, the median Gene Expression Profile value decreased from TP1 to TP2 in 10 genes. The only gene that did not follow this pattern was CCDC181. By performing 1-way ANOVA, we identified 8/11 genes in each of the two groups (HV versus HF) while 5 of the genes (TTC34, TMEM119, C19orf33, ID1, TKTL2) overlapped between the two groups. We found 265 genes which are differentially expressed between those who survived and those who died. Conclusions: From our proof-of-concept heart failure study, we conclude that gene expression correlates with VO2 peak in both healthy individuals and HF patients, potentially by regulating various physiological processes involved in oxygen uptake and utilization during exercise. Multi-omics profiling may help identify novel biomarkers for assessing exercise capacity and prognosis in HF patients, as well as potential targets for therapeutic intervention to improve VO2 peak and quality of life. We anticipate that our results will provide a novel metric for classifying immune health.

Gene-expression profiling for rejection surveillance after cardiac transplantation.

BACKGROUND: Endomyocardial biopsy is the standard method of monitoring for rejection in recipients of a cardiac transplant. However, this procedure is uncomfortable, and there are risks associated with it. Gene-expression profiling of peripheral-blood specimens has been shown to correlate with the results of an endomyocardial biopsy. METHODS: We randomly assigned 602 patients who had undergone cardiac transplantation 6 months to 5 years previously to be monitored for rejection with the use of gene-expression profiling or with the use of routine endomyocardial biopsies, in addition to clinical and echocardiographic assessment of graft function. We performed a noninferiority comparison of the two approaches with respect to the composite primary outcome of rejection with hemodynamic compromise, graft dysfunction due to other causes, death, or retransplantation. RESULTS: During a median follow-up period of 19 months, patients who were monitored with gene-expression profiling and those who underwent routine biopsies had similar 2-year cumulative rates of the composite primary outcome (14.5% and 15.3%, respectively; hazard ratio with gene-expression profiling, 1.04; 95% confidence interval, 0.67 to 1.68). The 2-year rates of death from any cause were also similar in the two groups (6.3% and 5.5%, respectively; P=0.82). Patients who were monitored with the use of gene-expression profiling underwent fewer biopsies per person-year of follow-up than did patients who were monitored with the use of endomyocardial biopsies (0.5 vs. 3.0, P<0.001). CONCLUSIONS: Among selected patients who had received a cardiac transplant more than 6 months previously and who were at a low risk for rejection, a strategy of monitoring for rejection that involved gene-expression profiling, as compared with routine biopsies, was not associated with an increased risk of serious adverse outcomes and resulted in the performance of significantly fewer biopsies. (ClinicalTrials.gov number, NCT00351559.)

Variability in Donor-Derived Cell-Free DNA Scores to Predict Mortality in Heart Transplant Recipients - A Proof-of-Concept Study.

BACKGROUND: Over the last decade, expanding use of molecular diagnostics in heart transplantation has allowed implementation of non-invasive surveillance strategies for monitoring allograft health. The commercially available HeartCare platform combines the AlloMap gene expression profiling assay and the AlloSure donor-derived cell-free DNA test (dd-cfDNA). Beyond their established use for assessment of rejection, evidence is building for predictive utility, with the longitudinal AlloMap Variability score previously shown to correlate with the risk of future rejection, graft dysfunction, re-transplantation, or death. In this single-center, retrospective pilot study, we evaluated the performance of a novel AlloSure Variability metric in predicting mortality in a cohort of heart transplant recipients. METHODS: Seventy-two adult heart transplant recipients with at least 3 concurrent AlloMap/AlloSure results were included. Demographic, clinical, imaging, and laboratory parameters were captured. Variability was defined as the standard deviation of longitudinal AlloMap/AlloSure results. A Cox multivariable adjusted proportional hazards model was used to evaluate the variability metrics as predictors of mortality. Associations between AlloMap/AlloSure variability and donor specific antibody (DSA) status were also assessed. RESULTS: A total of 5 patients (6.9%) died during a median follow-up of 480 days. In a univariate Cox proportional hazards model, higher AlloSure variability (HR 1.66, 95%CI 1.14 - 2.41), but not AlloMap variability or the cross-sectional AlloSure/AlloMap results was associated with increased mortality risk. Longitudinal AlloSure variability was also higher among patients with both preformed DSA and those developing de novo DSA. CONCLUSION: Our results suggest that increased variability of dd-cfDNA in heart transplant patients is associated with both mortality risk and the presence of donor specific antibodies. These findings highlight the added value of longitudinal data in the interpretation of AlloMap/AlloSure scores in this population and open the door to larger studies investigating the utility of these metrics in shaping post-transplant clinical care paradigms.

Drawing networks of rejection - a systems biological approach to the identification of candidate genes in heart transplantation.

Technological development led to an increased interest in systems biological approaches to characterize disease mechanisms and candidate genes relevant to specific diseases. We suggested that the human peripheral blood mononuclear cells (PBMC) network can be delineated by cellular reconstruction to guide identification of candidate genes. Based on 285 microarrays (7370 genes) from 98 heart transplant patients enrolled in the Cardiac Allograft Rejection Gene Expression Observational study, we used an information-theoretic, reverse-engineering algorithm called ARACNe (algorithm for the reconstruction of accurate cellular networks) and chromatin immunoprecipitation assay to reconstruct and validate a putative gene PBMC interaction network. We focused our analysis on transcription factor (TF) genes and developed a priority score to incorporate aspects of network dynamics and information from published literature to supervise gene discovery. ARACNe generated a cellular network and predicted interactions for each TF during rejection and quiescence. Genes ranked highest by priority score included those related to apoptosis, humoural and cellular immune response such as GA binding protein transcription factor (GABP), nuclear factor of κ light polypeptide gene enhancer in B-cells (NFκB), Fas (TNFRSF6)-associated via death domain (FADD) and c-AMP response element binding protein. We used the TF CREB to validate our network. ARACNe predicted 29 putative first-neighbour genes of CREB. Eleven of these (37%) were previously reported. Out of the 18 unknown predicted interactions, 14 primers were identified and 11 could be immunoprecipitated (78.6%). Overall, 75% (n= 22) inferred CREB targets were validated, a significantly higher fraction than randomly expected (P < 0.001, Fisher's exact test). Our results confirm the accuracy of ARACNe to reconstruct the PBMC transcriptional network and show the utility of systems biological approaches to identify possible molecular targets and biomarkers.

SdrF, a Staphylococcus epidermidis surface protein, contributes to the initiation of ventricular assist device driveline-related infections.

Staphylococcus epidermidis remains the predominant pathogen in prosthetic-device infections. Ventricular assist devices, a recently developed form of therapy for end-stage congestive heart failure, have had considerable success. However, infections, most often caused by Staphylococcus epidermidis, have limited their long-term use. The transcutaneous driveline entry site acts as a potential portal of entry for bacteria, allowing development of either localized or systemic infections. A novel in vitro binding assay using explanted drivelines obtained from patients undergoing transplantation and a heterologous lactococcal system of surface protein expression were used to identify S. epidermidis surface components involved in the pathogenesis of driveline infections. Of the four components tested, SdrF, SdrG, PIA, and GehD, SdrF was identified as the primary ligand. SdrF adherence was mediated via its B domain attaching to host collagen deposited on the surface of the driveline. Antibodies directed against SdrF reduced adherence of S. epidermidis to the drivelines. SdrF was also found to adhere with high affinity to Dacron, the hydrophobic polymeric outer surface of drivelines. Solid phase binding assays showed that SdrF was also able to adhere to other hydrophobic artificial materials such as polystyrene. A murine model of infection was developed and used to test the role of SdrF during in vivo driveline infection. SdrF alone was able to mediate bacterial adherence to implanted drivelines. Anti-SdrF antibodies reduced S. epidermidis colonization of implanted drivelines. SdrF appears to play a key role in the initiation of ventricular assist device driveline infections caused by S. epidermidis. This pluripotential adherence capacity provides a potential pathway to infection with SdrF-positive commensal staphylococci first adhering to the external Dacron-coated driveline at the transcutaneous entry site, then spreading along the collagen-coated internal portion of the driveline to establish a localized infection. This capacity may also have relevance for other prosthetic device-related infections.

Patients' sex and emotional support as predictors of death and clinical deterioration in the waiting for a new heart study: results from the 1-year follow-up.

CONTEXT: Little is known about the role of patient's sex and emotional support in the prognosis of heart transplant candidates. OBJECTIVE: To examine patient's sex and emotional support as predictors of outcomes in the Waiting for a New Heart Study. DESIGN, SETTING, AND PARTICIPANTS: The Waiting for a New Heart Study is a prospective observational study of 318 patients (18% female) newly added to the waiting list for a heart transplant. Demographic, medical, psychosocial characteristics (including social support [ENRICHD Social Support Index; high vs. low support]) were assessed at the time of wait-listing. Main Outcomes-Time until death/delisting due to deteriorated tealth, considering competing outcomes (e.g., transplantation) during the first 12 months after wait-listing were analyzed via cause-specific Cox proportional hazard models. RESULTS: By 12 months, 32 men (12%) and 10 women (17%) had died/deteriorated. Medical risk was comparable across sexes. More men than women reported low emotional support (20.4% vs. 8.6%) and being a past or current smoker (80.4% vs. 56.9%). More women than men had low vocational level (93.1% vs. 69.6%; all P values < .05). With medical risk and other confounding variables controlled for, female sex significantly increased risk of death/deterioration (hazard ratio, 2.30; 95% confidence interval, 1.04-5.12; P = .04); low emotional support further tended to increase the risk for this outcome (P = .07). As none of the 5 women with low emotional support had reached this end point, analyses were performed in the male sample and revealed that men with low emotional support were more than twice as likely to die/deteriorate than were men with high support (hazard ratio, 2.23; 95% confidence interval, 1.04-4.82; P = .04). CONCLUSION: Women had worse survival while awaiting a heart transplant than men had, independent of confounding variables. Even though emotional support may be an important buffer for men, protective factors for women warrant further investigation with larger samples and/or longer follow-ups.

The evolution of patient-specific precision biomarkers to guide personalized heart-transplant care.

INTRODUCTION: In parallel to the clinical maturation of heart transplantation over the last 50 years, rejection testing has been revolutionized within the systems biology paradigm triggered by the Human Genome Project. AREAS COVERED: We have co-developed the first FDA-cleared diagnostic and prognostic leukocyte gene expression profiling biomarker test in transplantation medicine that gained international evidence-based medicine guideline acceptance to rule out moderate/severe acute cellular cardiac allograft rejection without invasive endomyocardial biopsies. This work prompted molecular re-classification of intragraft biology, culminating in the identification of a pattern of intragraft myocyte injury, in addition to acute cellular rejection and antibody-mediated rejection. This insight stimulated research into non-invasive detection of myocardial allograft injury. The addition of a donor-organ specific myocardial injury marker based on donor-derived cell-free DNA further strengthens the non-invasive monitoring concept, combining the clinical use of two complementary non-invasive blood-based measures, host immune activity-related risk of acute rejection as well as cardiac allograft injury. EXPERT OPINION: This novel complementary non-invasive heart transplant monitoring strategy based on leukocyte gene expression profiling and donor-derived cell-free DNA that incorporates longitudinal variability measures provides an exciting novel algorithm of heart transplant allograft monitoring. This algorithm's clinical utility will need to be tested in an appropriately designed randomized clinical trial which is in preparation.

Keeping immune checkpoint inhibitor myocarditis in check: advanced circulatory mechanical support as a bridge to recovery.

Immune checkpoint inhibitor (ICI)-associated myocarditis is a rare, potentially life-threatening complication of immunotherapy. We report a case of a 60-year-old female with a history of colorectal cancer treated with nivolumab immunotherapy who presented with new cardiomyopathy complicated by cardiogenic shock and ventricular arrhythmias. Treatment of ICI-associated myocarditis requires aggressive immunosuppression and supportive therapy. In this case, the patient required advanced mechanical circulatory support as a bridge to recovery. This case highlights the complexity of diagnosis, haemodynamic management, and treatment of fulminant ICI myocarditis.

Orthotopic Heart and Combined Heart Liver Transplantation: the Ultimate Treatment Option for Failing Fontan Physiology.

Purpose of the Review: This is a comprehensive update on failing Fontan physiology and the role of heart and combined heart and liver transplantation in the current era. Recent Findings: Single ventricle physiology encompasses a series of rare congenital cardiac abnormalities that are characterized by absence of or hypoplasia of one ventricle. This effectively results in a single ventricular pumping chamber. These abnormalities are rarely compatible with long-term survival if left without surgical palliation in the first few years of life. Surgical treatment of single ventricle physiology has evolved over the past 60 years and is characterized by numerous creative innovations. These include the development of arteriopulmonary shunts, the evolution of partial cavopulmonary connections, and the eventual development of the "Fontan" operation. Regardless of the type of Fontan modification, the long-term consequences of the Fontan operation are predominantly related to chronic central venous hypertension and the multi-organ consequences thereof. Atrial arrhythmias can further compromise this circulation.Patients with single ventricle physiology represent a special sub-segment of congenital cardiac transplants and are arguably the most challenging patients considered for transplantation. Summary: This review describes in detail the challenges and opportunities of heart and liver transplantation in Fontan patients, as viewed and managed by the experienced team at the Ahmanson/UCLA Adult Congenital Heart Center.

Relationship between a validated molecular cardiac transplant rejection classifier and routine organ function parameters.

BACKGROUND: As acute cellular cardiac allograft rejection is a systemic process affecting the entire organism, we hypothesized that scores of a peripheral blood mononuclear cell gene expression profiling (GEP) test developed and validated to rule out International Society of Heart and Lung Transplantation (ISHLT) grade > or = 3A/2R acute cellular cardiac allograft rejection also reflects biologically plausible changes of the routinely assessed clinical parameters. METHODS: We retrospectively analyzed 76 patients who underwent GEP testing, at the time of their routine clinical follow-up in our Institution between February 1, 2006 and January 31, 2007. Data were analyzed with t-test, nonparametric tests, bivariate Spearman's correlation, and multivariate linear regression modeling. RESULTS: More activated GEP-score correlated with longer corrected QT (QTc)-interval (r = 0.377, p = 0.001, n = 63), longer QRS duration (r = 0.231, p = 0.03, n = 66), higher heart rate (r = 0.221, p = 0.037, n = 66), higher serum creatinine (r = 0.26, p = 0.01, n = 75), higher gamma-glutamyl transferase (GGT) GGT (r = 0.266, p = 0.037, n = 46), lower pulmonary artery oxygen saturation (r = -0.313, p = 0.003, n = 76), lower platelet count (r = -0.372, p = 0.001, n = 74), lower monocyte count (r = -0.208, p = 0.040, n = 72), and lower high-density lipoprotein (HDL) HDL level (r = -0.242, p = 0.041, n = 53). Multivariate analysis showed a significant amount of variance in the GEP score independently explained by the variability of QTc-interval (beta = 1.998, p = 0.001) and platelet count (beta = -1.540, p = 0.017). Post hoc analysis of the 11 individual GEP-classifier genes showed WDRA40 (p = 0.02) and ras homolog gene family, member U (RHOU) RHOU (p = 0.01) independently related to mixed venous O(2)Sat%. CONCLUSION: A GEP test developed and validated to detect the absence of cardiac rejection correlates with electrocardiographic and hemodynamic cardiac parameters as well as renal, hepatic, bone marrow, and lipid metabolism parameters suggesting a complex relationship between rejection, leukocytes, and organ function within the continuum between alloimmunological quiescence and rejection.

Composite risk scores and depression as predictors of competing waiting-list outcomes: the Waiting for a New Heart Study.

We evaluated two composite risk scores, (Heart Failure Survival Score, HFSS; German Transplant Society Score, GTSS), and depression as predictors of mortality and competing waiting-list outcomes [high-urgency transplantation (HU-HTx), elective transplantation, delisting because of clinical improvement] in 318 heart transplant (HTx) candidates (18% women; aged 53 ± 11 years) from 17 hospitals and newly registered with Eurotransplant. Demographic variables and depression (Hospital Anxiety and Depression Scale, HADS) were assessed using questionnaires. Variables to compute HFSS and GTSS, age, medications, and outcomes were provided by Eurotransplant. At 12 months, 33 patients died, 83 received urgent HTx, 30 elective HTx, and 17 were delisted because of improvement. Applying cause-specific Cox regressions, only the HFSS was significantly associated with 1-year mortality [HR = 0.64 (95% CI = 0.43-0.95), P = 0.029]. The GTSS was the strongest predictor of HU-HTx [HR= 1.02 (95% CI = 1.01-1.02), P < 0.001]. Low depression scores contributed significantly to clinical improvement, even after adjusting for age and risk scores [HADS: HR = 0.12 (95% CI = 0.02-0.89), P = 0.039]. These findings confirm the usefulness of composite risk scores for the prediction of mortality and HU-HTx, validating both scores for their intended use. The finding that depression was an independent predictor of the waiting-list outcome clinical improvement suggests that considering patients' psychological attributes in addition to their medical characteristics is advisable.

Comparing NGS and NanoString platforms in peripheral blood mononuclear cell transcriptome profiling for advanced heart failure biomarker development.

In preparation to create a clinical assay that predicts 1-year survival status of advanced heart failure (AdHF) patients before surgical/interventional therapies and to select the appropriate clinical assay platform for the future assay, we compared the properties of next generation sequencing (NGS) used in the gene discovery phase to the NanoString platform used in the clinical assay development phase. In 25 AdHF patients in a tertiary academic medical center from 2015 to 2016, PBMC samples were collected and aliquoted for NGS RNA whole transcriptome sequencing and compared to 770 genes represented on NanoString's PanCancer IO 360 Gene Expression research panel. Prior to statistical analysis, NanoString and NGS expression values were log transformed. We computed Pearson correlation coefficients for each sample, comparing gene expression values between NanoString and NGS across the set of matched genes and for each of the matched genes across the set of samples. Genes were grouped by average NGS expression, and the NanoString-NGS correlation for each group was computed. Out of 770 genes from the NanoString panel, 734 overlapped between both platforms and showed high intrasample correlation. Within an individual sample, there was an expression-level dependent correlation between both platforms. The low- vs. intermediate/high-expression groups showed NGS average correlation 0.21 vs. 0.58-0.68, respectively, and NanoString average correlation 0.07-0.34 vs. 0.59-0.70, respectively. NanoString demonstrated high reproducibility (R 2 > 0.99 for 100 ng input), sensitivity (probe counts between 100 and 500 detected and quantified), and robustness (similar gene signature scores across different RNA input concentrations, cartridges, and outcomes). Data from NGS and NanoString were highly correlated. These platforms play a meaningful, complementary role in the biomarker development process.