Preoperative Right Heart Dysfunction and Gastrointestinal Bleeding in Patients with Left Ventricular Assist Devices.

Gastrointestinal bleeding (GIB) is a common cause of morbidity among patients supported by left ventricular assist devices (LVADs). The aim of this study was to identify if pre-LVAD right ventricular (RV) dysfunction is associated with risk of GIB after LVAD implantation. Of 398 patients implanted with LVADs between July 2008 and July 2016, 130 (33%) developed GIB at a median of 2.6 months following LVAD implantation. Arteriovenous malformations (AVMs) were found in 42 (34%) GIB patients. Patients with GIB were older and more likely to have hypertension, diabetes, and ischemic cardiomyopathy. On pre-LVAD echocardiography, GIB patients had increased RV diastolic dimension (4.7 ± 0.8 vs. 4.4 ± 0.9 cm, p = 0.02), a higher rate of greater than mild tricuspid valve (TV) regurgitation (73 [60%] vs. 120 [47%], p = 0.006), and underwent TV repair more often (38 [30%] vs. 43 [16%], p = 0.0006) during LVAD implantation. After multivariable adjustment, preoperative greater than mild RV enlargement (hazard ratio [HR] 2.32, 95% CI 1.12-5.03; p = 0.03), TV regurgitation (HR 1.83, CI 1.02-3.44; p = 0.01), and TV repair (HR 3.76, confidence interval [CI] 1.02-4.44; p = 0.01) remained associated with risk of GIB. This finding was driven by the AVM-GIB subgroup. Preoperative RV enlargement and TV regurgitation are associated with post-LVAD AVM-related GIB.

Elevated Heart Rate Following Heart Transplantation Is Associated With Increased Graft Vasculopathy and Mortality.

BACKGROUND: The effect of elevated heart rate (HR) on outcomes after heart transplantation (HT) has not been well established. The aim of this study was to assess predictors of elevated HR following HT and its impact on outcomes. METHODS AND RESULTS: We retrospectively evaluated 394 patients who underwent HT at 2 academic medical centers from 2005 to 2016. Patients were divided into 2 groups based on HR 1 year after HT: HR ≥95 beats/min (n = 162; 41%) and HR <95 beats/min (n = 232; 59%). Median follow-up time was 6.6 (interquartile range [IQR] 2.2-7.5) years. HR ≥95 beats/min 1 year after HT was associated with younger donor age, whereas HR <95 beats/min was associated with heavy donor alcohol use and African-American recipient race. Left ventricular (LV) end-diastolic dimension, mass, and ejection fraction were lower and E/E' higher in the HR ≥95 group at the time of the last follow up. HR ≥95 beats/min at 1 year after HT was independently associated with the development of cardiac allograft vasculopathy and increased mortality. CONCLUSIONS: HR ≥95 beats/min 1 year after HT is associated with a reduction in LV size and function, increased incidence of cardiac allograft vasculopathy, and reduced survival. Studies investigating the effect of medical HR reduction on post-HT outcomes are warranted.

Mitochondrial cardiomyopathy: pathophysiology, diagnosis, and management.

Mitochondrial disease is a heterogeneous group of multisystemic diseases that develop consequent to mutations in nuclear or mitochondrial DNA. The prevalence of inherited mitochondrial disease has been estimated to be greater than 1 in 5,000 births; however, the diagnosis and treatment of this disease are not taught in most adult-cardiology curricula. Because mitochondrial diseases often occur as a syndrome with resultant multiorgan dysfunction, they might not immediately appear to be specific to the cardiovascular system. Mitochondrial cardiomyopathy can be described as a myocardial condition characterized by abnormal heart-muscle structure, function, or both, secondary to genetic defects involving the mitochondrial respiratory chain, in the absence of concomitant coronary artery disease, hypertension, valvular disease, or congenital heart disease. The typical cardiac manifestations of mitochondrial disease--hypertrophic and dilated cardiomyopathy, arrhythmias, left ventricular myocardial noncompaction, and heart failure--can worsen acutely during a metabolic crisis. The optimal management of mitochondrial disease necessitates the involvement of a multidisciplinary team, careful evaluations of patients, and the anticipation of iatrogenic and noniatrogenic complications. In this review, we describe the complex pathophysiology of mitochondrial disease and its clinical features. We focus on current practice in the diagnosis and treatment of patients with mitochondrial cardiomyopathy, including optimal therapeutic management and long-term monitoring. We hope that this information will serve as a guide for practicing cardiologists who treat patients thus affected.

Cardiac amyloidosis masquerading as biventricular hypertrophy in a patient with multiple myeloma.

Cardiac amyloidosis or amyloid cardiomyopathy is a rare disorder characterised by extracellular deposition of insoluble polymers composed of low-molecular-weight subunit proteins within the myocardium. This often results in an infiltrative cardiomyopathy with restrictive pathophysiology, leading to progressive heart failure. In this report, we present an interesting case of cardiac amyloidosis that eventually led to the diagnosis of underlying multiple myeloma in a patient with no previous cardiac history. Cardiac amyloidosis should be suspected in patients with unexplained congestive heart-failure symptoms accompanied by low-voltage complexes on ECG, preserved ejection fraction with asymmetric ventricular hypertrophy and abnormal myocardial texture, described as 'granular sparkling' on echocardiogram. Patients with cardiac amyloidosis should be closely monitored as mortality remains high, despite advances in treatment.

Critical role for IL-17A/F in the immunopathogenesis of obliterative airway disease induced by Anti-MHC I antibodies.

BACKGROUND: The IL-17 axis is implicated in pathogenesis of chronic rejection after human lung transplantation. Using a murine model of obliterative airway disease (OAD), we recently demonstrated that Abs to MHC class I antigens can induce immune responses to self-antigens that contributes to immunopathogenesis of chronic rejection. Using a murine model of OAD, we determined the role of IL-17 family members in induction of autoimmunity leading to OAD after ligation of MHC class I. METHODS: Anti-MHC class I or control antibodies (Abs) were administered intrabronchially to wild-type (WT) and IL-17a knock out (IL-17A-/-) C57BL/6. RESULTS: By day 30, anti-MHC I administered endobronchially in IL-17A-/- mice demonstrated significant reduction in cellular infiltration, a 36.8% reduction in CD4 T cells, 62.7% in CD11b macrophages, 37.5% in degree of fibrosis, 1.94 fold and 2.17 fold decrease in anti-KAT and anti-Col-V, respectively, when compared with wild-type mice. Analysis of lung infiltrating cells in anti-MHC I WT revealed increase in IL-17A (KAT:92+21,Col-V:103+19spm) and IL-17F (KAT:5.03%,Col-V:2.75%) secreting CD4+ T cells. However, administration of anti-MHC I in IL-17A-/- demonstrated increase only in IL-17F for KAT (13.70%) and Col-V (7.08%). Anti-IL-17(A-F) mAb administration after anti-MHC I abrogated OAD in both WT and IL-17A-/-. CONCLUSION: Our findings indicate that IL-17A and IL-17F secreted by CD4+Th17 cells specific to lung self-antigens are critical mediators of autoimmunity leading to the pathogenesis of OAD.

A role for antibodies to human leukocyte antigens, collagen-V, and K-α1-Tubulin in antibody-mediated rejection and cardiac allograft vasculopathy.

BACKGROUND: We determined the role of donor-specific antibodies (DSA) and antibodies (Abs) to self-antigens, collagen-V (Col-V), and K-α1-Tubulin (KAT) in pathogenesis of acute antibody-mediated rejection (AMR) and cardiac allograft vasculopathy (CAV) after human heart transplantation (HTx). METHODS: One hundred thirty-seven HTx recipients, with 60 early period (≤ 12 months) and 77 late period (>12 months), were enrolled in this study. Circulating DSA was determined using LUMINEX. Abs against Col-I, II, IV, V, and KAT were measured using ELISA. Frequency of CD4+T helper cells (CD4+Th) secreting interferon (IFN)-γ, interleukin (IL)-5, -10, or -17 specific to self-antigens were determined using Enzyme Linked Immunosorbent Spot assay. RESULTS: A significant association between AMR and DSA was demonstrated. Development of DSA in AMR patients correlated well with the development of auto-Abs to Col-V (AMR[+]: 383 ± 72 µg/mL, AMR[-]: 172 ± 49 µg/mL, P=0.033) and KAT (AMR[+]: 252 ± 49 µg/mL, AMR[-]: 61 ± 21 µg/mL, P=0.014). Patients who developed AMR demonstrated increased frequencies of CD4+Th secreting IFN-γ and IL-5 with reduction in IL-10 specific for Col-V/KAT. Patients diagnosed with CAV also developed DSA and auto-Abs to Col-V (CAV[+]: 835 ± 142 µg/mL, CAV[-]: 242 ± 68 µg/mL, P=0.025) and KAT (CAV[+]: 768 ± 206 µg/mL, CAV[-]: 196 ± 72 µg/mL, P=0.001) with increased frequencies of CD4+Th secreting IL-17 with reduction in IL-10 specific for Col-V/KAT. CONCLUSIONS.: Development of Abs to human leukocyte antigens and self-antigens are associated with increases in CD4+Th secreting IFN-γ and IL-5 in AMR and IL-17 in CAV, with reduction in CD4+Th secreting IL-10 in both AMR and CAV.

Immune response to extracellular matrix collagen in chronic hepatitis C-induced liver fibrosis.

Hepatitis C virus (HCV) infection and its recurrence after orthotopic liver transplantation (OLT) are associated with the remodeling of extracellular matrix (ECM) components [particularly collagen (Col)], which leads to fibrosis. Our aim was to determine whether the development of antibodies (Abs) to self-antigen Col in HCV-infected patients correlates with the fibrosis stage and the peripheral cytokine response. Patients with chronic HCV infection, patients with HCV recurrence after OLT who had undergone a biopsy procedure, and healthy control subjects were enrolled. The HCV subjects (n = 70) were stratified as follows: (1) a non-OLT group without fibrosis (Scheuer stages 0-2), (2) a non-OLT group with fibrosis (Scheuer stages 3-4), (3) a post-OLT group without fibrosis (Scheuer stages 0-2), and (4) a post-OLT group with fibrosis (Scheuer stages 3-4). Serum samples were analyzed for Abs against Col1, Col2, Col4, Col5, and vimentin with enzyme-linked immunosorbent assays. Serum levels of cytokines were measured with multiplex bead immunoassays. The levels of Abs to Col1 were higher in the fibrosis groups versus the no-fibrosis groups and the controls for both non-OLT patients (P < 0.001) and post-OLT patients (P = 0.01). There were increased levels of Abs to Col2, Col4, Col5, and vimentin in the non-OLT fibrosis group (Col2, P = 0.0001; Col4, P = 0.122; Col5, P < 0.0001; vimentin, P = 0.36) and in the post-OLT fibrosis group (Col2, P = 0.006; Col4, P = 0.19; Col5, P < 0.0001; vimentin, P = 0.24) in comparison with the no-fibrosis groups. The non-OLT and post-OLT fibrosis groups demonstrated significantly higher T helper 2 (T(h) 2) and T helper 17 (T(h) 17) cytokine levels and lower T helper 1 cytokine levels in comparison with the no-fibrosis groups. Our results demonstrate that in HCV-infected patients, the levels of Abs to ECM Col1, Col2, and Col5 positively correlate with liver fibrosis, which is associated with a predominantly T(h) 2 and T(h) 17 cytokine profile.

Donor-specific antibodies to human leukocyte antigens are associated with and precede antibodies to major histocompatibility complex class I-related chain A in antibody-mediated rejection and cardiac allograft vasculopathy after human cardiac transplantation.

Humoral immune responses to mismatched donor human leukocyte antigen (HLA) and major histocompatibility complex (MHC) class I-related chain A (MICA) have been reported to contribute to immunopathogenesis of antibody-mediated rejection (AMR) in the early period and cardiac allograft vasculopathy (CAV) in the late period after cardiac transplantation (HTx). The goal of this study is to define the roles of donor-specific antibodies (DSA) and anti-MICA in AMR and CAV. A total of 95 post-HTx recipients were enrolled; 43 patients in the early period (≤ 12 months post-HTx) and 52 patients in the late period (>12 months post-HTx). Development of DSA and anti-MICA were serially monitored using Luminex. Development of DSA (AMR+: n = 6/8.75%, AMR-: n = 4/35.11%, p = 0.009) and anti-MICA (AMR+: n = 5/8.63%, AMR-: n = 4/35.11%, p = 0.002) was significantly associated with AMR. AMR+DSA+ patients demonstrated increased anti-MICA levels compared with AMR+DSA- patients (p=0.01). Serial monitoring revealed DSA (2.7 ± 1.4 months) preceded development of anti-MICA (6.5 ± 2.1 months) in recipients diagnosed with AMR at 8.3 ± 2.5 months post-HTx. Development of DSA (CAV+: n = 8/12.67%, CAV-: n = 5/40.13%, p = 0.004) and anti-MICA (CAV+: n = 9/12.75%, CAV-: n = 5/40.13%, p = 0.001) was significantly associated with CAV. CAV+DSA+ patients demonstrated increased anti-MICA levels compared with CAV+DSA- patients (p = 0.01). Antibodies to HLA are associated with and precede development of anti-MICA in AMR and CAV. Therefore, DSA and anti-MICA can be used as noninvasive markers for monitoring AMR and CAV.

Increased erythrocyte C4D is associated with known alloantibody and autoantibody markers of antibody-mediated rejection in human lung transplant recipients.

BACKGROUND: Immune responses to mismatched donor human leukocyte antigens (HLA) are important in the pathogenesis of chronic rejection. This study evaluated whether erythrocyte-bound C4d (E-C4d) is associated with known alloimmune and autoimmune markers of antibody-mediated rejection after human lung transplantation (LTx). METHODS: Flow cytometry was used to analyze 22 LTx recipients and 15 healthy individuals for E-C4d. Development of antibodies to donor-mismatched HLA (donor-specific antibody [DSA]) and antibodies to HLA were determined using the solid-phase method by Luminex. Development of antibodies to self-antigens, K-alpha-1-tubulin (KA1T) and collagen V (Col-V), were measured by enzyme-linked immunosorbent assay. C3d deposition in lung biopsy specimens was determined by immunohistochemical staining. RESULTS: Percent E-C4d (%E-C4d) levels were 19.9% in LTx patients vs 3.7% in healthy individuals (p = 0.02). DSA+ patients had higher E-C4d levels than DSA- patients (34.1% vs 16.7%, p = 0.02). In 5 patients with preformed anti-HLA, E-C4d levels were not significantly different vs 13 patients without detectable anti-HLA (p = 0.1). E-C4d levels were higher in patients who developed antibodies to KA1T (p = 0.02) and Col-V (p = 0.03). Recipients with C3d-positive tissue deposition had higher E-C4d levels than patients with C3d-negative biopsy results (p = 0.01). CONCLUSIONS: Increased %E-C4d levels are found in patients with positive DSA, high antibody titers to KA1T and Col-V, and have C3d+ lung biopsy findings. Therefore, %E-C4d can serve as a potential marker for antibody-mediated rejection after LTx.