Evaluation and management of patients with chronic thromboembolic pulmonary hypertension - consensus statement from the ISHLT.

ISHLT members have recognized the importance of a consensus statement on the evaluation and management of patients with chronic thromboembolic pulmonary hypertension. The creation of this document required multiple steps, including the engagement of the ISHLT councils, approval by the Standards and Guidelines Committee, identification and selection of experts in the field, and the development of 6 working groups. Each working group provided a separate section based on an extensive literature search. These sections were then coalesced into a single document that was circulated to all members of the working groups. Key points were summarized at the end of each section. Due to the limited number of comparative trials in this field, the document was written as a literature review with expert opinion rather than based on level of evidence.

Multicenter Evaluation of Octreotide as Secondary Prophylaxis in Patients With Left Ventricular Assist Devices and Gastrointestinal Bleeding.

BACKGROUND: Gastrointestinal (GI) bleeding is one of the most common complications after continuous-flow left ventricular assist device implantation. More than one third of patients with incident bleed go on to develop recurrent GI bleeding. Octreotide, a somatostatin analog, is proposed to reduce the risk of recurrent GI bleeding in this population. METHODS AND RESULTS: This multicenter, retrospective analysis evaluated 51 continuous-flow left ventricular assist device patients who received secondary prophylaxis with octreotide after their index GI bleed from 2009 to 2015. All patients had a hospitalization for GI bleed and received octreotide after discharge. Patient demographics, medical and medication history, and clinical characteristics of patients who rebled after receiving octreotide were compared with non-rebleeders. These data were also compared with matched historical control patients previously enrolled in the HMII (HeartMate II) clinical trials, none of whom received octreotide, to provide a context for the bleeding rates. Twelve patients (24%) who received secondary octreotide prophylaxis developed another GI bleed, whereas 39 (76%) did not. There were similar intergroup demographics; however, significantly more bleeders had a previous GI bleeding history before left ventricular assist device placement (33% versus 5%; P=0.02) and greater frequency of angiodysplasia confirmed during endoscopy (58% versus 23%; P=0.03). Fewer patients in this study experienced a recurrent GI bleed compared with a matched historical control group that did not receive octreotide (24% versus 43%; P=0.04). CONCLUSIONS: Patients with continuous-flow left ventricular assist device receiving secondary prophylaxis with octreotide had a significantly lower GI bleed recurrence compared with historical controls not treated with octreotide. Additional prospective studies are needed to confirm these data.

The vexing problem of thrombosis in long-term mechanical circulatory support.

Durable left ventricular assist devices (LVADs) have not only enhanced longevity but also conferred sustained improvements in quality of life, symptom control, and functional capacity in patients with medically refractory advanced heart failure. Problems with device-related infection, bleeding, neurologic events, right-sided heart failure, and device malfunction have dominated the clinical care of patients living on mechanical support. Even as adoption of durable LVADs accelerated globally, we began to encounter a growing dilemma of pump malfunction caused by thrombosis. In early 2011, clinicians began to notice a spike in the incidence of pump thrombosis with the HeartMate II (Thoratec Corp, Pleasanton, CA) LVAD. By 2012, the problem of thrombosis in LVADs began to consume most of the scientific direction as centers and collaborative groups began to dissect this nascent phenomenon. In this perspective, we describe the magnitude and implications of pump thrombosis, discuss secular and management trends in this unique population, attempt to dissect the problem at its root, offer guidance on surveillance and therapeutic principles, and outline issues that deserve our immediate and collaborative attention.

Current and future challenges in therapy for antibody-mediated rejection.

Antibody-mediated rejection (AMR) continues to present a challenge for the survival of the cardiac allograft. AMR appears to be on the rise, likely secondary to changing trends in clinical practice, including selection of patients for transplantation on mechanical circulatory support and development of more effective combinations of immunosuppressive drugs against acute cellular rejection. Most current strategies are aimed at treating acute AMR, but the treatment of chronic AMR is still not well defined. Clinically, AMR can often be more severe than cellular rejection and more difficult to treat, often not responding to typical protocols of increased immunosuppression. Complex steps involved in the antibody response allows for several potential targets for therapeutic intervention, including suppression of T and B cells, elimination of circulating antibodies, and inhibition of residual antibodies. Existing evidence suggests a multiregimen approach is the best option. Sustenance of accommodation and induction of tolerance could be viewed as viable options if adequate immune surveillance can be achieved in this setting. This review discusses the challenges in treating AMR and provides a critical analysis of current and possible future therapies.

International Society for Heart and Lung Transplantation working formulation of a standardized nomenclature for cardiac allograft vasculopathy-2010.

The development of cardiac allograft vasculopathy remains the Achilles heel of cardiac transplantation. Unfortunately, the definitions of cardiac allograft vasculopathy are diverse, and there are no uniform international standards for the nomenclature of this entity. This consensus document, commissioned by the International Society of Heart and Lung Transplantation Board, is based on best evidence and clinical consensus derived from critical analysis of available information pertaining to angiography, intravascular ultrasound imaging, microvascular function, cardiac allograft histology, circulating immune markers, non-invasive imaging tests, and gene-based and protein-based biomarkers. This document represents a working formulation for an international nomenclature of cardiac allograft vasculopathy, similar to the development of the system for adjudication of cardiac allograft rejection by histology.

Veno-venous extracorporeal membrane oxygenation bridging to pharmacotherapy in pulmonary arterial hypertensive crisis.

We report the case of a treatment-naive patient with pulmonary arterial hypertension who presented with decompensated right ventricular failure and cardiogenic shock. Unstable hemodynamics, hypoxia and end-organ hypoperfusion limited up-titration of pharmacotherapy. Mechanical circulatory support with veno-venous extracorporeal membrane oxygenation (VV-ECMO) was initiated to permit dose titration of pulmonary vasodilator therapy. VV-ECMO was weaned after 10 days of support, with successful transition to intravenous epoprostenol and oral sildenafil.

Chronic heart failure: contemporary diagnosis and management.

Chronic heart failure (CHF) remains the only cardiovascular disease with an increasing hospitalization burden and an ongoing drain on health care expenditures. The prevalence of CHF increases with advancing life span, with diastolic heart failure predominating in the elderly population. Primary prevention of coronary artery disease and risk factor management via aggressive blood pressure control are central in preventing new occurrences of left ventricular dysfunction. Optimal therapy for CHF involves identification and correction of potentially reversible precipitants, target-dose titration of medical therapy, and management of hospitalizations for decompensation. The etiological phenotype, absolute decrease in left ventricular ejection fraction and a widening of QRS duration on electrocardiography, is commonly used to identify patients at increased risk of progression of heart failure and sudden death who may benefit from prophylactic implantable cardioverter-defibrillator placement with or without cardiac resynchronization therapy. Patients who transition to advanced stages of disease despite optimal traditional medical and device therapy may be candidates for hemodynamically directed approaches such as a left ventricular assist device; in selected cases, listing for cardiac transplant may be warranted.

Gene-based bio-signature patterns and cardiac allograft rejection.

Clinicians have long awaited an alternative to invasive endomyocardial biopsy for surveillance of cardiac transplant rejection. Transcriptional signals in peripheral blood mononuclear cells allow for the development of multigene-based panels that can inform on the presence or absence of immunologic quiescence. The informative genes represent several biologic pathways, including T-cell activation (PDCD1), T-cell migration (ITGA4), and mobilization of hematopoietic precursors (WDR40A and microRNA gene family cMIR), and steroid-responsive genes such as IL1R2, the decoy receptor for interleukin 2. The greatest value may include the ability to inform on the potential of future proclivity for rejection, allowing patients to be stratified into low, intermediate, or high risk subsets for future rejection. In these individuals, this knowledge may allow clinicians to use tailored approaches to immunosuppression, thereby avoiding adverse pharmacologic effects in low-risk patients while improving rejection outcomes in those at high risk for future allograft compromise. Despite these advances, clinical entrenchment of gene-based pharmacotherapy in cardiac transplantation will require independent replication and validation of investigational findings.

Tobacco smoke exposure in either the donor or recipient before transplantation accelerates cardiac allograft rejection, vascular inflammation, and graft loss.

BACKGROUND: Tobacco exposure in cardiac transplant recipients, before and after transplantation, may increase the risk of cardiac allograft vasculopathy and allograft loss, but no direct evidence for this phenomenon is forthcoming. In this experimental study, we investigated early consequences of tobacco smoke exposure in cardiac transplant donors and recipients with an emphasis on alloinflammatory mediators of graft outcome. METHODS AND RESULTS: Using heterotopic rat cardiac transplantation, we tested the effects of donor or recipient tobacco smoke exposure in 6 groups of animals (rat heterotopic cardiac transplantation) as follows: tobacco-naïve allogeneic rejecting controls (n=6), tobacco-naïve nonrejecting controls (n=3; killed on day 5 to simulate survival times of tobacco-treated animals), isografts (n=3), both donor and recipient rats exposed to tobacco smoke (n=4), only donor rats exposed to tobacco smoke (n=7), and only recipient rats exposed to tobacco smoke (n=6). Polymerase chain reaction studies of tissue and peripheral (systemic) protein expression were performed to evaluate inflammatory (tumor necrosis factor-alpha, interferon-gamma, interleukin-6) and alloimmune (interleukin-1 receptor 2, programmed cell death-1, and stromal cell-derived factor-1) pathways, as was histological analysis of the cardiac allografts. Our experiments reveal that pretransplantation tobacco exposure in donors and/or recipients results in heightened systemic inflammation and increased oxidative stress, reduces posttransplantation cardiac allograft survival by 33% to 57%, and increases intragraft inflammation (tumor necrosis factor-alpha, interferon-gamma, interleukin-6) and alloimmune activation (CD3, interleukin-1 receptor 2, programmed cell death-1, and stromal cell-derived factor-1) with consequent myocardial and vascular destruction. CONCLUSIONS: These sentinel findings confirm that tobacco smoke exposure in either donors or recipients leads to accelerated allograft rejection, vascular inflammation, and graft loss. Molecular pathways that intersect as arbiters in this phenomenon include instigation of alloimmune activation associated with tobacco smoke-induced inflammation.

High-density lipoprotein cholesterol levels and prognosis in advanced heart failure.

BACKGROUND: High-density lipoproteins (HDLs) influence the generation of prostacyclin via cyclooxygenase stimulation. Prostaglandins represent an important compensatory pathway in advanced heart failure (HF). Whether HDL levels discriminate prognosis in HF remains unknown. METHODS: We prospectively evaluated the prognostic relationship of HDL levels in severe HF by examining 132 consecutive patients listed for heart transplantation (52 +/- 11 years of age, 80% men, 79% white, mean follow-up 18 months). Using population mean HDL levels (HDL <33 mg/dl [n = 47] vs > or =33 mg/dl [n = 85]), patients were grouped and followed for the primary composite end-points of HF hospitalizations or death, stratified by underlying etiology (non-ischemic, n = 52; ischemic, n = 80). RESULTS: Patients with HDL <33 mg/dl had lower serum sodium (135 vs 137 mEq/liter, p = 0.008), higher total bilirubin (1.3 vs 0.7 mg/dl, p < 0.001) and higher uric acid (7.6 vs 6.7 mg/dl, p = 0.048) levels, but similar serum creatinine compared with the > or =33 mg/dl HDL group. Survival analysis, using a Cox proportional hazards model, revealed reduced HDL (<33 mg/dl) as the most significant independent predictor of HF hospitalizations or death, independent of underlying etiology. Low-cholesterol and low-density lipoprotein (LDL)-cholesterol alone were not found to be independently predictive of outcome. CONCLUSIONS: Lower HDL levels correlate with adverse prognosis independent of etiology and predict clinical worsening or death in advanced HF. Further study is warranted as to whether these findings represent a clinical marker or suggest a potential therapeutic target.

Cardiomyopathy and the dilemma of geometric mitral regurgitation.

PURPOSE OF REVIEW: Geometric mitral regurgitation is a phenomenon encountered by an otherwise anatomically normal mitral valve in the setting of advanced adverse left ventricular remodeling that alters the alignment characteristics of the mitral valve apparatus leading to functional production of a leaking valve. In this review, we discuss contemporary directions in the knowledge base for managing geometric mitral regurgitation. RECENT FINDINGS: Much progress has been encountered in describing the types of geometric mitral regurgitation (nonischemic and ischemic origins), standardization of echocardiographic techniques to allow for a common language in ascertaining the severity of mitral regurgitation, knowledge on dynamic mitral regurgitation during exercise, effectiveness of therapy and appropriate use and timing of surgical repair. SUMMARY: Geometric mitral regurgitation develops in tandem with progressive ischemic or nonischemic cardiomyopathy and can improve with antiremodeling pharmacological and device-based therapy. Surgical therapy can be accomplished at experienced centers with low morbidity and mortality, and may improve symptoms and enhance pump function. Whether such therapy saves lives remains uncertain. New percutaneous approaches to tackle geometric mitral regurgitation are developing, and early data is encouraging but remains experimental.

The progressive cardiorenal syndrome in heart failure: mechanisms and therapeutic insights.

The cardiorenal syndrome refers to the interdependence of cardiocirculatory aberrations and renal dysfunction that signify a worsening in heart failure outcome. Biochemically, it appears covertly as an abnormality in renal function and when progressive, is manifested by symptom exacerbation and worsening renal impairment during application of therapy to ameliorate such symptoms. The pathways leading to these distinct impairments involve not only hemodynamic deterioration but also neurohormonal, inflammatory, and intrinsic renal mechanisms that produce this syndrome. Traditional therapy with diuretics typically worsens the cardiorenal syndrome, and vasodilator or inotropic therapy has not been shown to help either. New therapeutic avenues involving vasopressin antagonists, adenosine antagonists, and ultrafiltration are being investigated. In the absence of underlying primary renal parenchymal disease, mechanical ventricular assist devices or cardiac transplantation achieve reversal of the progressive cardiorenal syndrome, indicating the sentinel role of interrupting the cardiocirculatory aberrations that accompany this clinical manifestation.

Clinical implications and longitudinal alteration of peripheral blood transcriptional signals indicative of future cardiac allograft rejection.

BACKGROUND: We have previously demonstrated that a peripheral blood transcriptional profile using 11 distinct genes predicts onset of cardiac allograft rejection weeks to months prior to the actual event. METHODS: In this analysis, we ascertained the performance of this transcriptional algorithm in a Bayesian representative population: 28 cardiac transplant recipients who progressed to moderate to severe rejection; 53 who progressed to mild rejection; and 46 who remained rejection-free. Furthermore, we characterized longitudinal alterations in the transcriptional gene expression profile before, during and after recovery from rejection. RESULTS: In this patient cohort, we found that a gene expression score (range 0 to 40) of or =3A) rejection; 16 of 53 (30%) from the intermediate group (those who progressed to ISHLT Grade 1B or 2) and 13 of 46 (28%) controls (who remained Grade 0 or 1A) had scores < or =20. A gene score of > or =30 was associated with progression to moderate to severe rejection in 58% of cases. These two extreme scores (< or =20 or > or =30) represented 44% of the cardiac transplant population within 6 months post-transplant. In addition, longitudinal gene expression analysis demonstrated that baseline scores were significantly higher for those who went on to reject, remained high during an episode of rejection, and dropped post-treatment for rejection (p < 0.01). CONCLUSIONS: The use of gene expression profiling early after transplantation allows for separation into low-, intermediate- or high-risk categories for future rejection, permitting development of discrete surveillance strategies.

Transcriptional signals of T-cell and corticosteroid-sensitive genes are associated with future acute cellular rejection in cardiac allografts.

BACKGROUND: Profiling mRNA levels of 11 informative genes expressed by circulating immune effector cells identifies cardiac allograft recipients at low risk for current moderate-severe acute cellular rejection (ACR). METHODS: We conducted a nested case-control study of 104 cardiac allograft recipients to investigate the association of transcriptional profiles of blood samples with either a future rejection episode within 12 weeks of a baseline clinical sample or persistent histologic quiescence for the same time period. RESULTS: The transcription profile yielded a score (0 to 40 scale) of 27.4 +/- 6.3 for future rejectors (n = 39) and 23.9 +/- 7.1 for controls (n = 65) (p = 0.01). In patients who were