The coagulation system is activated in idiopathic cardiomyopathy

Whole-Exome Sequencing Revealed New Candidate Genes for Human Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is a complex disease affecting young adults. It is a pathological condition impairing myocardium activity that leads to heart failure and, in the most severe cases, transplantation, which is currently the only possible therapy for the disease. DCM can be attributed to many genetic determinants interacting with environmental factors, resulting in a highly variable phenotype. Due to this complexity, the early identification of causative gene mutations is an important goal to provide a genetic diagnosis, implement pre-symptomatic interventions, and predict prognosis. The advent of next-generation sequencing (NGS) has opened a new path for mutation screening, and exome sequencing provides a promising approach for identifying causal variants in known genes and novel disease-associated candidates. We analyzed the whole-exome sequencing (WES) of 15 patients affected by DCM without overloading (hypertension, valvular, or congenital heart disease) or chronic ischemic conditions. We identified 70 pathogenic or likely pathogenic variants and 1240 variants of uncertain clinical significance. Gene ontology enrichment analysis was performed to assess the potential connections between affected genes and biological or molecular function, identifying genes directly related to extracellular matrix organization, transcellular movement through the solute carrier and ATP-binding cassette transporter, and vitamin B12 metabolism. We found variants in genes implicated to a different extent in cardiac function that may represent new players in the complex genetic scenario of DCM.

Fibrinolysis in Dogs with Intracavitary Effusion: A Review

Simple Summary

In blood vessels there is a balance between clot formation and its dissolution. Fibrinolysis normally allows the breakdown of blood clots during the healing of injured blood vessels. This process is mediated by the activation of a blood enzyme (plasmin) which breaks down a meshed protein (fibrin) which holds blood clots at the site of the vessel injury. In some diseases, the activation of plasmin becomes excessive, leading to bleeding tendencies (hyperfibrinolysis). Under normal conditions, abdominal and thoracic cavities are filled with a small amount of fluid deriving from the blood. The results of recent studies have shown that, in dogs, all types of pathologic intracavitary fluids have an increased fibrinolytic activity. This increased fibrinolytic activity is also present in their blood, in some cases reaching a hyperfibrinolytic state. Hyperfibrinolysis and bleeding tendencies have also been documented in cardiopathic dogs with ascites. The latter result is surprising considering that thrombotic events are commonly documented in humans and cats with some cardiac diseases.

Abstract

Physiologic fibrinolysis is a localized process in which stable fibrin strands are broken down by plasmin in response to thrombosis. Plasmin activation can also take place separately from the coagulation process, resulting in pathologic fibrinolysis. When plasmin activation exceeds the neutralizing capacity of plasmin inhibitors, severe bleeding can potentially take place. Although the processes which regulate coagulation and fibrinolysis in the blood are well known, it is less clear as to what extent the same processes take place in the body cavities and whether they influence systemic hemostasis. The results of the studies herein cited demonstrate that coagulation followed by fibrinogenolytic/fibrinolytic activity takes place in all kinds of canine ascitic and pleural fluids. Moreover, systemic clotting abnormalities suggesting primary fibrinolysis/primary hyperfibrinolysis (i.e., elevated plasma fibrin/fibrinogen degradation products [FDPs] and normal D-dimer concentrations with fibrinogen concentrations ≤ 100 mg/dL or above this cut-off, respectively) occur in dogs with intracavitary effusion. Enhanced fibrinolytic activity in dogs with intracavitary effusion can also be detected using rotational thromboelastometry (ROTEM), although the degree of agreement between ROTEM and FDPs, D-dimer and fibrinogen concentrations is poor. Finally, contrary to the thrombotic events commonly documented in some humans and cats with cardiac diseases, bleeding tendencies due to primary fibrinolysis/primary hyperfibrinolysis have been documented in dogs with cardiogenic ascites.

Left ventricular thrombus in ischaemic heart disease: diagnosis, treatment, and gaps of knowledge

Although the management of ischaemic heart disease has markedly improved over the last decades, left ventricular thrombus remains a serious finding in patients with myocardial infarction. Routine diagnostic detection of left ventricular thrombus relies mainly on echocardiography; however, cardiac magnetic resonance has emerged as a method with higher diagnostic accuracy, while cardiac computed tomography angiography represents a valuable alternative modality. To reduce the left ventricular thrombus-associated morbidity and mortality, optimal selection of anticoagulation is warranted after balancing the risk of bleeding. In this review, we will discuss contemporary diagnostic modalities to detect left ventricular thrombus in ischaemic heart disease and summarize evidence on risk stratification and therapy. In addition, we propose a novel diagnosis, follow-up imaging, and treatment algorithm. Further, we identify knowledge gaps at different levels to address emerging research questions and to refine the design of future studies aiming to improve the management of patients in this clinical setting.

The rationale for using low-molecular weight heparin in the therapy of symptomatic COVID-19 patients

Accumulated evidence suggest that the adverse outcome of severe coronavirus disease 2019 (COVID-19) is closely related to prothrombotic microvascular pathology with a high risk of venous thromboembolism. Furthermore, the first observational studies indicated that adjunct therapy with low-molecular weight heparin (LMWH) was associated with lower mortality in this cohort of patients. However, the timing of starting LMWH and the dose remain controversial in COVID-19 patients. Considering the above, the aim of this study was to reveal the rationale for using LMWH in the therapy of symptomatic COVID-19 patients based on experimental and clinical studies on LMWH in inflammatory settings with special consideration given to randomized trials.

Anticoagulation in cardiomyopathy: unravelling the hidden threat and challenging the threat individually

Cardiomyopathy comprises a heterogeneous group of myocardial abnormalities, structural or functional in nature, in the absence of coronary artery disease and other abnormal loading conditions. These myocardial pathologies can result in premature death or disability from progressive heart failure, arrhythmia, stroke, or other embolic events. The European Cardiomyopathy Registry reports a high stroke risk in cardiomyopathy patients ranging from 2.1% to 4.5%, as well as high prevalence of atrial fibrillation ranging from 14.0% to 48.5%. There is a growing interest in evaluating the risk of thromboembolism depending on the type of cardiomyopathy, as well as if anticoagulation is indicated in patients with cardiomyopathy without atrial fibrillation. Data available do not unequivocally support anticoagulation therapy in all of these patients; the management of these patients remains challenging. Many published reports pertaining to the risk of thromboembolism and consecutive treatment strategies mainly focus on single cardiomyopathy subtype. We summarize essential pathophysiological knowledge and review current literature associated with thromboembolism in various cardiomyopathy subtypes, providing recommendations for the diagnostic evaluation as well as clinical management strategies in this field. Certain cardiomyopathy subtypes require anticoagulation independent of atrial fibrillation or CHA2 DS2 -VASc score. Despite the scarcity of evidence regarding the choice of anticoagulation regimen (vitamin K antagonist vs. non-vitamin K oral anticoagulants) in cardiomyopathy, it is discussed and reviewed in this article. Each patient should receive a tailored strategy based on thorough clinical evaluation, published evidence, and clinical experience, due to the current recommendations mostly developed on small-sample studies or empirical evidence. The future research priorities in this area are also addressed in this article.

Impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after catheter ablation of atrial fibrillation: insights from AF frontier ablation registry

The impact of catheter ablation for atrial fibrillation (AF) on cardiovascular events and mortality is controversial. We investigated the impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after AF ablation from a Japanese multicenter cohort of AF ablation. We investigated 3326 consecutive patients (25.8% female, mean age 63.3 ± 10.3 years) who underwent catheter ablation for AF from the atrial fibrillation registry to follow the long-term outcomes and use of anti coagulants after ablation (AF frontier ablation registry). The primary endpoint was a composite of stroke, transient ischemic attack, cardiovascular events, and all-cause death. During a mean follow-up of 24.0 months, 2339 (70.3%) patients were free from AF after catheter ablation, and the primary composite endpoint occurred in 144 (4.3%) patients. The AF nonrecurrence group had a significantly lower incidence of the primary endpoint (1.8 per 100 person-years) compared with the AF recurrence group (3.0 per 100 person-years, p = 0.003). The multivariate analysis revealed that freedom from AF (hazard ratio 0.61, 95% confidence interval 0.44-0.86, p = 0.005) was independently associated with the incidence of the composite event. In the multicenter cohort of AF ablation, sinus rhythm maintenance after catheter ablation was independently associated with lower rates of major adverse cardiac and cerebrovascular events.

Prevalence, Mechanisms, and Management of Ischemic Stroke in Heart Failure Patients

Heart failure (HF) and stroke, two of the major causes of death worldwide, are closely associated. Although atrial fibrillation (AF), which occurs in more than half of patients with HF, is a major risk factor for stroke, there is a great deal of evidence that HF itself increases the risk of stroke independent of AF. The main mechanism of stroke appears to be thromboembolism. However, previous studies have failed to demonstrate the benefit of warfarin in patients with HF without AF, as the benefit of stroke prevention was counteracted by the increased incidence of major bleeding. Recently, researchers have identified patients with HF at a particularly high risk for stroke who may benefit from anticoagulation therapy. Based on stroke-risk prediction models, it may be possible to make better stroke prevention decisions for patients with HF. Moreover, non-vitamin K oral anticoagulants have emerged as anticoagulants with a more favorable risk-benefit profile than warfarin. Future studies on selecting high-risk patients and using more appropriate antithrombotics will lead to improved management of patients with HF.

Thromboembolism in Heart Failure Patients in Sinus Rhythm: Epidemiology, Pathophysiology, Clinical Trials, and Future Direction

Despite advances in medical and device therapy, patients with heart failure remain at high risk for morbidity and mortality. Experimental and clinical studies have shown an association between heart failure and a hypercoagulable state, and that patients with heart failure experience an increased incidence of stroke and other thromboembolic events, regardless of whether they are in atrial fibrillation. Although oral anticoagulation is recommended when atrial fibrillation is present, the benefits of this therapy in patients with heart failure in sinus rhythm are uncertain. Older randomized controlled trials comparing warfarin with antiplatelet therapy were, for the most part, underpowered and failed to show convincing benefits of warfarin therapy in this population. Several recent studies that assessed the effects of low-dose direct-acting oral anticoagulant therapy in patients with coronary artery disease in sinus rhythm either included or specifically targeted patients with heart failure. Post hoc analysis of their results showed that this treatment strategy was associated with improved outcomes in patients with acute coronary syndrome or stable coronary artery disease and also a significant reduction in thromboembolic events, including ischemic stroke. This review presents the rationale for anticoagulant therapy in patients with heart failure in sinus rhythm, discusses gaps in our knowledge base, offers suggestions for when anticoagulation might be considered, and identifies potential directions for future research.

Soluble fibrin monomer complex is associated with cardio- and cerebrovascular events in patients with heart failure

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The soluble fibrin monomer complex (SFMC), is a marker of fibrin formation.

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SFMC is abnormally elevated in a variety of clinical situations of hypercoagulability.

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SFMC is an independent predictor of adverse prognosis in patients with heart failure.

Background

A biomarker of fibrin formation, the soluble fibrin monomer complex (SFMC), is abnormally elevated in a variety of clinical situations of hypercoagulability. The aim of the present study was to examine the prognostic impact of SFMC, with regard to increased risk of major cardio- and cerebrovascular events (MACCE) and all-cause mortality, on patients with heart failure (HF).

Methods and Results

We conducted a prospective observational study where we analyzed data of 723 hospitalized patients with decompensated HF who were discharged alive and whose SFMC had been measured in a stable condition prior to discharge. The patients were divided into tertiles based on SFMC levels: the first (SFMC < 1.7 μg/ml, n = 250), second (≤1.8 SFMC < 2.9 μg/ml, n = 233), and third (3.0 μg/ml ≤ SFMC, n = 240) tertiles. The prevalence of chronic kidney disease and anemia was significantly higher in the third tertile than in the first and second tertiles. In contrast, age, sex, CHADS₂-Vasc score, left ventricular ejection fraction, and prevalence of hypertension, diabetes and atrial fibrillation did not differ among the tertiles. In the Kaplan-Meier analysis, accumulated event rates of both MACCE and all-cause mortality progressively increased from the first to third tertiles (log-rank P < 0.05, respectively). In the multivariate Cox proportional hazard analysis, the third tertile was found to be an independent predictor of MACCE (HR 2.014, P = 0.046) and all-cause mortality (HR 1.792, P = 0.036).

Conclusion

SFMC is an independent predictor of adverse prognosis in patients with HF.

Atrial fibrillation and stroke prevention: state of the art-epidemiology and pathophysiology: new risk factors, concepts and controversies

Atrial fibrillation (AF) increases the risk of thromboembolism, and risk assessment for thromboembolism is necessary for the management of AF patients. CHADS2 and CHA2DS2-VASc scores have been adopted in international guidelines for AF management, but the significance of each risk factor included in these risk scores are sometimes controversial, and the performance of these scores is only modest. There are several other risk factors not included in the scores such as renal dysfunction, low body weight, type of AF (paroxysmal or non-paroxysmal) as well as echocardiographic parameters and blood biomarkers, and physicians should assess patients risk in an integrated manner.

Antithrombotic Treatment in Cardiomyopathies

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Cardiomyopathies are a heterogeneous group of heart muscle diseases and important cause of heart failure with reduced or preserved ejection fraction. Although there is an increasing body of evidence on the incidence, pathophysiology, and natural history of heart failure (HF) in cardiomyopathies, certain aspects of the therapeutic strategies remain unclear. More particularly, there is no consensus if to whether antithrombotic therapy has a favorable risk: benefit ratio in reducing thromboembolic event rate in patients with cardiomyopathies without suffering from primary valvular disease or atrial fibrillation. Although the observational data on increased venous thromboembolic risk are supported by multiple pathophysiological mechanisms, the role of antithrombotic therapy in these patients remains unclear. This review article provides an overview of epidemiologic, pathophysiologic, clinical, and therapeutic data for the prevention of thromboembolism in heart failure due to cardiomyopathies.

Novel biomarkers in cats with congestive heart failure due to primary cardiomyopathy

The pathogenesis of feline cardiomyopathy and congestive heart failure (CHF) requires further understanding. In this study, we assessed serum proteome change in feline CHF, aiming to identify novel biomarker for both research and clinical use. The study comprised 15 cats in CHF, 5 cats in preclinical cardiomyopathy and 15 cats as healthy controls. Serum proteome profiles were obtained by tandem mass tag labelling followed by mass spectrometry. Protein concentrations in CHF cats were compared with healthy controls. Western blot was performed for proteomic validation. Correlations were assessed between the altered proteins in CHF and clinical variables in cats with cardiomyopathy to evaluate protein-cardiac association. Bioinformatic analysis was employed to identify pathophysiological pathways involved in feline CHF. Sixteen serum proteins were significantly different between CHF and healthy control cats (P < .05). These included serine protease inhibitors, apolipoproteins and other proteins associated with inflammation and coagulation. Clinical parameters from cats with cardiomyopathy significantly correlated with the altered proteins (P < .05). Bioinformatic analysis identified 13 most relevant functional profiles in feline CHF, which mostly associated with extracellular matrix organization and metabolism. Data are available via ProteomeXchange with identifier PXD017761. SIGNIFICANCE: Cardiomyopathies affect both cats and humans, and they can cause serious consequence such as congestive heart failure (CHF). To date, the pathophysiological mechanism of CHF is not fully understood. In this study, for the first time, we used a proteomic approach combined with bioinformatic analysis to evaluate serum protein change in cats with CHF. Results indicate systemic inflammation, coagulation protein changes, innate immunity and extracellular matrix remodeling are involved in feline CHF, which are largely comparable with findings in previous human studies. Our study provides new insights into CHF and cardiomyopathy in cats, and the identified novel biomarkers and pathophysiological pathways provide valuable information for future studies.

The Role of Antithrombotic Therapy in Heart Failure

Heart failure is a major contributor to global morbidity and mortality burden affecting approximately 1-2% of adults in developed countries, mounting to over 10% in individuals aged >70 years old. Heart failure is characterized by a prothrombotic state and increased rates of stroke and thromboembolism have been reported in heart failure patients compared with the general population. However, the impact of antithrombotic therapy on heart failure remains controversial. Administration of antiplatelet or anticoagulant therapy is the obvious (and well-established) choice in heart failure patients with cardiovascular comorbidity that necessitates their use, such as coronary artery disease or atrial fibrillation. In contrast, antithrombotic therapy has not demonstrated any clear benefit when administered for heart failure per se, i.e. with heart failure being the sole indication. Randomized studies have reported decreased stroke rates with warfarin use in patients with heart failure with reduced left ventricular ejection fraction, but at the expense of excessive bleeding. Non-vitamin K oral anticoagulants have shown a better safety profile in heart failure patients with atrial fibrillation compared with warfarin, however, current evidence about their role in heart failure with sinus rhythm is inconclusive and further research is needed. In the present review, we discuss the role of antithrombotic therapy in heart failure (beyond coronary artery disease), aiming to summarize evidence regarding the thrombotic risk and the role of antiplatelet and anticoagulant agents in patients with heart failure.

Prevalence and determinants of elevated D-dimer in patients with hypertrophic cardiomyopathy

Aim: To evaluate D-dimer levels in patients with hypertrophic cardiomyopathy (HCM). Patients & methods: A total of 346 patients with HCM were recruited. Plasma D-dimer was determined by clinical laboratory of our hospital. Left ventricular mass, stroke volume, cardiac output and cardiac index were assessed with cardiovascular magnetic resonance. Results: A total of 36 (10.4%) patients had elevated D-dimer levels. Age, female patients and statin therapy were independently associated with increasing D-dimer levels, and predictors of elevated D-dimer. Conclusion: Patients with HCM may have higher plasma D-dimer levels than subjects without HCM. D-dimer levels in patients with HCM are influenced by age, sex, atrial fibrillation, statin therapy and diastolic blood pressure.

Effect of hypertrophic cardiomyopathy on the prediction of thromboembolism in patients with nonvalvular atrial fibrillation

BACKGROUND

Anticoagulation is recommended for hypertrophic cardiomyopathy (HCM) with nonvalvular atrial fibrillation (NVAF) according to European and American guidelines. However, it is unclear whether HCM is a risk factor for thromboembolism in NVAF in Japan, and the management for NVAF with HCM is not established.

OBJECTIVE

We studied the impact of concomitant HCM on predicting thromboembolism in NVAF.

METHODS

We retrospectively studied consecutive 2374 Japanese patients with NVAF (1682 men, 70.9%; mean age 71±10 years). Clinical factors were evaluated using the Cox proportional hazards model. We also investigated whether adding HCM to CHADS₂ or CHA₂DS₂-VASc score improved the prediction of thromboembolism.

RESULTS

Thromboembolism was observed in 122 patients (5.1%) during the median follow-up of 2.4 years (interquartile range 2.0-3.2 years). The Cox proportional hazards model showed that HCM was significantly associated with thromboembolism after adjustment for CHADS₂ or CHA₂DS₂-VASc score (hazard ratio 3.41; 95% confidence interval [CI] 1.98-5.73; P<.0001 and hazard ratio 3.38; 95% CI 1.97-5.64; P<.0001, respectively). NVAF with HCM had significantly higher thromboembolism rates, even in those with a CHADS₂ or CHA₂DS₂-VASc score of 1 or 0-1, respectively. Based on the comparison of C-statistics, the addition of HCM to CHADS₂ or CHA₂DS₂-VASc score significantly improved the prediction of thromboembolism (C-statistics 0.75 vs 0.71; P=.003 and C-statistics 0.77 vs 0.71; P=.0001, respectively).

CONCLUSION

HCM is an independent risk factor for thromboembolism in patients with NVAF. A markedly high incidence of thromboembolism is observed in NVAF patients with HCM with CHA₂DS₂-VASc score of both ≥2 and 0-1, and anticoagulation therapy is recommended for them.

Identification of Novel Hemostatic Biomarkers of Adverse Clinical Events in Patients Implanted With a Continuous-Flow Left Ventricular Assist Device

Heart failure affects over 5 million people in the United States. Its rising prevalence and the limited supply of donor hearts is increasing the use of mechanical cardiac support with the implantation of continuous-flow ventricular assist devices (CF-VAD). Patients with CF-VAD implants are at risk of complications, specifically adverse hemostatic events such as nonsurgical bleeding and thrombosis. Development of a pump thrombus requires clinical intervention and/or surgical replacement significantly increasing the risk of patient morbidity and mortality. Identification of biomarkers for these events could improve current risk assessment models, subsequent treatment, and quality of life prognoses for VAD-implanted patients. The standard means for identifying thrombus in VAD patients is currently limited to monitoring levels of lactate dehydrogenase (>2× upper limit of normal), which is incapable of predicting a future event, but describes the risk of a present thrombus. Surface-enhanced laser desorption ionization time-of-flight mass spectrometry is a technique used to identify biomarkers. In this study, 3 groups of unique peaks were identified in plasma from patients with left ventricular assist devices: 8.1-kDa, 11.7-kDa, and a 15.2-/16.1-kDa pair. Unique correlations were found for each peak, respectively, with microparticles (MPs) and MP procoagulant activity, C-reactive protein, and MP-tissue factor. Furthermore, the use of 8.1-kDa peaks may be able to differentiate thrombotic events from other hemostatic events.

Serum proteome profiling in canine idiopathic dilated cardiomyopathy using TMT-based quantitative proteomics approach

Idiopathic dilated cardiomyopathy (iDCM) is a primary myocardial disorder with an unknown aetiology, characterized by reduced contractility and ventricular dilation of the left or both ventricles. Naturally occurring canine iDCM was used herein to identify serum proteomic signature of the disease compared to the healthy state, providing an insight into underlying mechanisms and revealing proteins with biomarker potential. To achieve this, we used high-throughput label-based quantitative LC-MS/MS proteomics approach and bioinformatics analysis of the in silico inferred interactome protein network created from the initial list of differential proteins. To complement the proteomic analysis, serum biochemical parameters and levels of know biomarkers of cardiac function were measured. Several proteins with biomarker potential were identified, such as inter-alpha-trypsin inhibitor heavy chain H4, microfibril-associated glycoprotein 4 and apolipoprotein A-IV, which were validated using an independent method (Western blotting) and showed high specificity and sensitivity according to the receiver operating characteristic curve analysis. Bioinformatics analysis revealed involvement of different pathways in iDCM, such as complement cascade activation, lipoprotein particles dynamics, elastic fibre formation, GPCR signalling and respiratory electron transport chain.

SIGNIFICANCE

Idiopathic dilated cardiomyopathy is a severe primary myocardial disease of unknown cause, affecting both humans and dogs. This study is a contribution to the canine heart disease research by means of proteomic and bioinformatic state of the art analyses, following similar approach in human iDCM research. Importantly, we used serum as non-invasive and easily accessible biological source of information and contributed to the scarce data on biofluid proteome research on this topic. Bioinformatics analysis revealed biological pathways modulated in canine iDCM with potential of further targeted research. Also, several proteins with biomarker potential have been identified and successfully validated.

Spontaneous ventricular thrombosis in patients with inflammatory bowel disease

Inflammatory bowel disease is closely associated with an increased risk for thrombotic events. Thrombosis mostly occurs in the extremities, lungs, and liver; but it can also occur in the ventricles of the heart. The primary goal of this article is to increase awareness of the risk for ventricular thrombosis in this patient population among healthcare professionals and, thus, appropriate prompt use of thromboprophylaxis therapy for these patients during acute flare-ups. Early diagnosis and intervention are critical for ventricular thrombosis to prevent systemic embolisation of the thrombus. Concisely, inflammatory bowel disease predisposes to the development of thrombi. A low threshold for the use of imaging studies to detect such thrombi is warranted.

Reduced cardiac function and risk of venous thromboembolism in Asian countries

Patients with reduced cardiac function are thought to have a higher risk of venous thromboembolism (VTE). Additionally, they are vulnerable to complications of pulmonary embolism (PE) as well as right heart failure (HF), which in return is supposed to increase the rate of mortality. Studies focusing on VTE in heart failure patients were rare in Asian countries before the 21st century. Nowadays, more and more data are becoming available in this field in Asia. It is already known that heart failure can increase the risk of VTE, but so far a consensus on this issue has not been reached for many years, not only in Asian countries but all over the world. This condition may be due to the detailed pathological advancement in Virchow’s triad and some other theories. In clinical practice, VTE, especially PE is difficult to diagnose in patients with heart failure because of overlapping symptoms (e.g. cough and chest pain) and the elevation of laboratory markers (e.g. probrain natriuretic peptide (NT-proBNP) and D-dimer in both heart failure and VTE patients). Management of VTE in heart failure patients is also controversial because heart failure patients always have complications, such as renal failure and hepatic failure, which increase the risk of bleeding. In this study, we analyzed data from China, Japan, Korea, Singapore and India mainly to get a better understanding of the research progress in VTE in patients with heart failure. The aim of this review is to discuss the risk, incidence, advancement of diagnosis, management and prevention of VTE in patients with heart failure in Asian countries.

Role of Antiplatelet Therapy and Anticoagulation in Nonischemic Cardiomyopathy

Heart failure continues to be a leading cause of morbidity and mortality throughout the United States. The pathophysiology of heart failure involves the activation of complex neurohormonal pathways, many of which mediate not only hypertrophy and fibrosis within ventricular myocardium and interstitium, but also activation of platelets and alteration of vascular endothelium. Platelet activation and vascular endothelial dysfunction may contribute to the observed increased risk of thromboembolic events in patients with chronic heart failure. However, current data from clinical trials do not support the routine use of chronic antiplatelet or oral anticoagulation therapy for ambulatory heart failure patients without other indications (atrial fibrillation and/or coronary artery disease) as the risk of bleeding seems to outweigh the potential benefit related to reduction in thromboembolic events. In this review, we consider the potential clinical utility of targeting specific pathophysiological mechanisms of platelet and vascular endothelial activation to guide clinical decision making in heart failure patients.

Tissue thrombin is associated with the pathogenesis of dilated cardiomyopathy

BACKGROUND

Thrombin is a serine protease known to be the final product of the coagulation cascade. However, thrombin plays other physiological roles in processes such as gastric contractions and vessel wound healing, and a state of coagulability is increased in patients with dilated cardiomyopathy (DCM). In this study, we investigate the role of thrombin in the pathogenesis of DCM. The purpose of this study is to clarify the role of thrombin in the pathogenesis of DCM and investigate the possibility of treatment against DCM by thrombin inhibition.

METHODS

We investigated the expression of thrombin in the left ventricles of five patients with DCM who underwent the Batista operation and four patients without heart disease. Furthermore, we investigated the involvement of thrombin in the development of DCM using knock-in mice with a deletion mutation of cardiac troponin T that causes human DCM (∆K210 knock-in mouse) (B6;129-Tnnt2^tm2Mmto) and assessed the effects of a direct thrombin inhibitor, dabigatran on ∆K210 knock-in mice using echocardiographic examinations, the Kaplan-Meier method and Western blotting.

RESULTS

The immunohistochemical analysis showed a strong thrombin expression in the DCM patients compared to the patients without heart disease. In immunohistochemical analysis, a strong thrombin expression was observed in the heart tissues analysis in the ∆K210 knock-in mice. Dabigatran administration significantly improved fractional shortening according to the echocardiographic examination and the survival outcomes in ∆K210 knock-in mice.

CONCLUSION

Tissue thrombin is involved in the pathogenesis of DCM and thrombin inhibition can be beneficial for the treatment of DCM.

Blood cell microparticles as biomarkers of hemostatic abnormalities in patients with implanted cardiac assist devices

For heart failure patients unable to undergo cardiac transplantation, mechanical circulatory support with left ventricular assist devices can be utilized. These devices improve quality of life and prolong life expectancy, but they are associated with bleeding and thrombotic complications impacting patient survival. Little is known of the relevant mechanisms of these hemostatic issues, hindering identification of a clinically useful biomarker. However, there is suggestive evidence that blood cell-derived microparticles may fulfill this unmet clinical need. Recent publications have shown an association of up regulated microparticle production with implanted left ventricular assist devices and the potential to use this as a biomarker to predict thrombosis (and perhaps other adverse events) with an onset time earlier than currently used clinical indicators.

Proteomic identification of putative biomarkers for early detection of sudden cardiac death in a family with a LMNA gene mutation causing dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a severe heart disease characterized by progressive ventricular dilation and impaired systolic function of the left ventricle. We recently identified a novel pathogenic mutation in the LMNA gene in a family affected by DCM showing sudden death background. We now aimed to identify potential biomarkers of disease status, as well as sudden death predictors, in members of this family. We analysed plasma samples from 14 family members carrying the mutation, four of which (with relevant clinical symptoms) were chosen for the proteomic analysis. Plasma samples from these four patients and from four sex- and age-matched healthy controls were processed for their enrichment in low- and medium-abundance proteins (ProteoMiner™) prior to proteomic analysis by 2D-DIGE and MS. 111 spots were found to be differentially regulated between mutation carriers and control groups, 83 of which were successfully identified by MS, corresponding to 41 different ORFs. Some proteins of interest were validated either by turbidimetry or western blot in family members and healthy controls. Actin, alpha-1-antytripsin, clusterin, vitamin-D binding protein and antithrombin-III showed increased levels in plasma from the diseased group. We suggest following these proteins as putative biomarkers for the evaluation of DCM status in LMNA mutation carriers.

BIOLOGICAL SIGNIFICANCE

We developed a proteomic analysis of plasma samples from a family showing history of dilated cardiomyopathy caused by a LMNA mutation, which may lead to premature death or cardiac transplant. We identified a number of proteins augmented in mutation carriers that could be followed as potential biomarkers for dilated cardiomyopathy on these patients.

Embolic Stroke in Cardiomyopathy: Should Patients be Anticoagulated?

Despite advances in the treatment of patients with heart failure, mortality is still substantial. Part of this mortality is explained by cardioembolic stroke. Patients with heart failure are predisposed to developing cardioembolic strokes owing to abnormalities in Virchow's triad (endothelial function, relative hypercoagulable state, and static blood flow). Several randomized controlled trials have addressed whether patients with heart failure benefit from anticoagulation. Overall, the results suggest the risk of bleeding with anticoagulation outweighs any small benefit conferred by anticoagulation.

Thrombocytopaenia as a Prognostic Indicator in Heart Failure with Reduced Ejection Fraction

BACKGROUND

Studies suggest that thrombocytopaenia is associated with a higher mortality in several diseases. Little is known about the effect of low platelet count on mortality in patients with heart failure with reduced ejection fraction (HFrEF). The aim of this study was to determine the prognostic value of thrombocytopaenia in these patients by assessing all-cause mortality.

METHODS

A total of 1,907 patients with HFrEF, defined by left ventricular ejection fraction <40% on echocardiography, were analysed in this multi-centre retrospective study. All patients were on medical therapy with a beta-blocker and an angiotensin-converting enzyme inhibitor. Patients were categorised into two groups based on platelet count measured within one month of the diagnosis of HFrEF: normal to mild thrombocytopaenia (platelet count 100,000-450,000 per uL); and moderate to severe thrombocytopaenia (platelet count <100,000 per uL). One-year all-cause mortality was compared between the two groups.

RESULTS

Mean age was 65±15 years and 62% of patients were male. Overall one-year mortality was 17.2% with higher mortality among patients with HFrEF and moderate/severe thrombocytopaenia compared to those with normal/mild thrombocytopaenia (33.0% vs. 15.4%, p <0.001). After adjusting for baseline characteristics, patients with HFrEF and moderate/severe thrombocytopaenia had a higher mortality compared to patients with normal/mild thrombocytopaenia (HR 1.84, 95% CI 1.33-2.56, p <0.001).

CONCLUSION

In patients with HFrEF, higher degree of thrombocytopaenia is associated with higher all-cause mortality. These findings may support the use of platelet counts as a prognostic marker in the assessment of the patient with HFrEF.

Anticoagulation Therapy and NOACs in Heart Failure

Current evidence indicates that heart failure (HF) confers a hyper-coagulable state that is associated with adverse events including stroke, systemic embolism, and mortality. This may be due to the elevated levels of pro-thrombotic and pro-inflammatory cytokines that are seen in patients with acute and chronic HF. Left ventricular wall motion abnormalities in patients with systolic dysfunction predispose to local thrombosis due to blood stasis as does atrial fibrillation (AF) which leads to blood stasis in regions of the atria. The high risk of thromboemboli in HF patients with AF has resulted in the use anticoagulation therapy to prevent the occurrence of catastrophic events. There is evidence, however, that the pro-inflammatory, pro-thrombotic state that exists in HF puts patients who are in sinus rhythm at risk. The novel oral anticoagulants (NOACs) have been shown in RCT to have at least equivalent efficacy in reducing stroke as warfarin while exposing patients to a lower risk of bleeding. The fact that the NOACs don't require routine monitoring to assure that patients remain within the therapeutic range and have relatively simple dosing requirements and a safer risk profile makes them attractive substitutes to warfarin in HF patients with atrial fibrillation and other conditions (e.g. deep venous thrombosis). Post hoc analyses from a subset of HF patients from the RCTs in AF patients have demonstrated similar findings as were reported in the entire populations that were included in the trials. As a result, NOACS are commonly used now in HF patients with AF. For HF patients with reduced ejection fraction in sinus rhythm, the use of warfarin in randomized clinical trials (RCT) to reduce stroke has been disappointing and associated with increase bleeding risk when compared to aspirin. The advantages of the NOACs over warfarin, however, raise the question of whether they might improve outcomes in HF patients who are in sinus rhythm. The currently ongoing COMMANDER-HF trial has been designed to address this issue. In this chapter we review evidence of existence of a prothombotic state in HF, the pharmacodynamics and clinical trials of the NOACs and the outcomes from NOAC substudies in the HF subgroup. We also discuss the rationale for using anticoagulation in HF independent of arrhythmia burden.

Stroke Risk Factors Beyond the CHA₂DS₂-VASc Score: Can We Improve Our Identification of "High Stroke Risk" Patients With Atrial Fibrillation?

The prevention of stroke and other thromboembolic events plays a crucial role in the management of patients with atrial fibrillation. Not all patients with atrial fibrillation are equal in terms of thromboembolic risk; therefore, not all will benefit from oral anticoagulation treatment. The general principle is that the expected benefit of anticoagulation in reduction of thromboembolic risk must exceed the expected harm caused by possible bleeding. Some guidelines have focused on a categorical approach to stroke prevention, with a focus on identifying patients at high risk for oral anticoagulation. Various current guidelines recommend assessment of stroke risk using the CHADS2 or CHA2DS2-VASc scores to initially detect patients at low risk who require no antithrombotic therapy. However, the scores do not incorporate all possible risk factors causing a high thromboembolic risk. Factors such as impaired renal function, obstructive sleep apnea, and echocardiographic and biochemical or coagulation parameters can also predict adverse thromboembolic events. The present review aims to describe biomarkers whether blood, urine, imaging (cardiac or cerebral), or clinical that go beyond the CHA2DS2-VASc score and potentially aid stroke risk assessment. Although useful in some cases, the presented parameters should be perhaps used to further refine initial identification of patients at low risk, after which effective stroke prevention can be offered to those with ≥1 additional stroke risk factors.

Monitoring of Serial Presurgical and Postsurgical Changes in the Serum Proteome in a Series of Patients with Calcific Aortic Stenosis

Background. Comprehensive analysis of proteome differentially expressed in response to surgery or drug treatment is useful to understand biological responses to dispensed interventions. Here we investigated expression changes in sera of patients who suffered from calcific aortic stenosis (CAS), before and after surgery for aortic valve replacement. Materials and Methods. Sera obtained before and after surgery with depletion of highly abundant proteins were analyzed with iTRAQ labeling followed by nanoLC-MALDI-TOF/TOF-MS/MS. Results. Fifty-one proteins shared in five patients were identified with differential levels in postsurgical and presurgical sera. Finally, 16 proteins that show statistically significant levels in patients' sera compared with those in control sera (P < 0.05) were identified. Most of the identified proteins were positive acute-phase proteins. Among three proteins other than acute-phase proteins, we confirmed increased levels of antithrombin-III and zinc-α-2-glycoprotein in postsurgical sera by Western blot analysis using other CAS patients' sera. Furthermore, antithrombin-III and zinc-α-2-glycoprotein were not found among proteins with differential levels in postsurgical and presurgical sera of patients with aortic aneurysms that we identified in a previous study. Conclusions. The results indicated that antithrombin-III and zinc-α-2-glycoprotein would become unique monitoring proteins for evaluating pathophysiological and biochemical processes occurring before and after surgery for CAS.

Time-related changes in determinants of antiplatelet effect of clopidogrel in patients after myocardial infarction

Substantial variability of antiplatelet action is an important limitation of clopidogrel. The aim of this study was to evaluate time-related changes in determinants of clopidogrel responsiveness in patients after myocardial infarction. The study population comprised 191 consecutive patients treated with primary percutaneous coronary intervention for acute myocardial infarction. Follow-up visits were scheduled at 3, 6 and 9 months after discharge. ADP-induced platelet aggregation was tested with Multiplate Analyzer. Patients with ADP-PA>46.8U were defined as clopidogrel non-responders. The prevalence of clopidogrel non-responsiveness was highest during hospitalization and at 9 month follow-up visit, while it was lowest at 3 and 6 months after myocardial infarction (P=0.004). According to multivariate analysis, platelet count, mean platelet volume, concentration of hsCRP and leukocyte count influenced ADP-induced platelet aggregation in multiple assessment points. BMI, concentrations of hemoglobin, glycated hemoglobin, and BNP, hematocrit, adherence to medication, and patient׳s age were found to be independent predictors of high on-treatment ADP-induced platelet aggregation only at a single follow-up visit. Determinants of clopidogrel responsiveness in patients after myocardial infarction change within the long-term therapy. During hospitalization and early after discharge only biological factors affect ADP-induced platelet aggregation, while non-adherence to antiplatelet therapy may be a significant factor in determining clopidogrel non-responsiveness during late follow-up visits.

Thrombocytopenia is an independent predictor of mortality in pulmonary hypertension

BACKGROUND

Established prognostic factors for pulmonary hypertension (PH) include brain natriuretic peptide, troponins and hemodynamic measures such as central venous pressure and cardiac output. The prognostic role of thrombocytopenia, however, has yet to be determined in patients with PH. The aim of this study was to evaluate effect of thrombocytopenia on mortality in patients with PH.

METHODS

521 patients with severe PH, defined by a pulmonary artery systolic pressure >60 mm Hg on transthoracic echocardiography and a platelet count measured within one month after diagnosis were enrolled from three hospitals of Montefiore Medical Center. The cohort was divided into two groups: mild thrombocytopenia to a normal platelet count (platelet count 100,000-450,000 per uL); and moderate to severe thrombocytopenia (platelet count <100,000 per uL). Inpatient and social security death records were used to determine 1-year all-cause mortality.

RESULTS

Mean age was 70.3 ± 15.6 with 40% of patients being male. Overall mortality at 1 year was 30.7%, with increased mortality in PH patients with mild thrombocytopenia compared to those with moderate to severe thrombocytopenia (46.5% vs. 27.0%, p < 0.001). In multivariate analysis, moderate to severe thrombocytopenia remained an independent predictor of mortality (HR 1.798, 95% CI 1.240-2.607, p = 0.002).

CONCLUSIONS

Moderate to severe thrombocytopenia is an independent predictor of higher mortality in patients with severe PH. These findings may support the use of thrombocytopenia as a useful prognostic indicator in patients with severe PH.

Concurrent diseases and conditions in cats with renal infarcts

Background

Renal infarcts identified without definitive association with any specific disease process.

Objective

Determine diseases associated with diagnosis of renal infarcts in cats diagnosed by sonography or necropsy.

Animals

600 cats underwent abdominal ultrasonography, necropsy, or both at a veterinary medical teaching hospital.

Methods

Information obtained from electronic medical records. Cats classified as having renal infarct present based on results of sonographic evaluation or necropsy. Time‐matched case‐controls selected from cats that underwent the next scheduled diagnostic procedure.

Results

309 of 600 cats having diagnosis of renal infarct and 291 time‐matched controls. Cats 7–14 years old were 1.6 times (odds ratio, 95% CI: 1.03–2.05, P = .03) more likely to have renal infarct than younger cats but no more likely to have renal infarct than older cats (1.4, 0.89–2.25, P = .14). All P = .14 are statistically significant. Cats with renal infarcts were 4.5 times (odds ratio, 95% CI: 2.63–7.68, P < .001) more likely to have HCM compared to cats without renal infarcts. Cats with renal infarcts were 0.7 times (odds ratio, 95% CI: 0.51–0.99, P = .046) less likely to have diagnosis of neoplasia compared to cats without renal infarcts. Cats with diagnosis of hyperthyroidism did not have significant association with having renal infarct. Cats with renal infarcts were 8 times (odds ratio, 95% CI: 2.55–25.40, P ≤ .001) more likely to have diagnosis of distal aortic thromboembolism than cats without renal infarcts.

Conclusions and Clinical Importance

Cats with renal infarcts identified on antemortem examination should be screened for occult cardiomyopathy.

[Anticoagulant therapy with dabigatran in elderly patients ≥80 years of age with atrial fibrillation]

AIM

Atrial fibrillation is a potent risk factor for stroke, and the administration of anticoagulant therapy is important for preventing thromboembolism. Dabigatran is the first new oral anticoagulant developed as an alternative to warfarin. However, serious major gastrointestinal bleeding events have been observed in elderly patients in post-market case reports. We therefore retrospectively investigated elderly cases of the use of anticoagulant therapy with dabigatran.

METHODS

Twenty-eight patients over 80 years of age were treated with anticoagulant therapy at our satellite hospital. Nine of the patients received dabigatran, and all others received warfarin. We evaluated the CHADS2 score, HAS-BLED score, renal function and incidence of adverse effects in nine patients treated with dabigatran.

RESULTS

All of the nine patients received 220 mg/day of dabigatran, with no antiplatelet agents. Seven patients continued to receive dabigatran. One patient had an impaired renal function (Cr 1.55 mg/dl, Ccr 30 ml/min). However, the activated partial thromboplastin time (APTT) was not prolonged and neither major bleeding nor stroke were noted in seven patients. Although two patients were unable to continue dabigatran treatment due to APTT prolongation, no serious complications were observed during the administration of dabigatran.

CONCLUSIONS

No serious adverse effects of dabigatran anticoagulant therapy were detected in our elderly patients. Although it is necessary to monitor the risk of bleeding, renal dysfunction, effects of drug combination and so on, some elderly patients with atrial fibrillation are good candidates for dabigatran treatment.

Both carvedilol and nebivolol may improve platelet function and prothrombotic state in patients with nonischemic heart failure

It is unclear whether carvedilol and nebivolol will produce different effects on platelet function and prothrombotic state in heart failure (HF). Thus, we compared their effects on these functions in patients with nonischemic HF. We included 61 patients with symptomatic nonischemic HF having ejection fraction ≤40%. The patients were randomized to carvedilol (n = 31) or nebivolol (n = 30). Analyses were made at baseline, 3, and 6 months. At 6 months, mean platelet volume (MPV) was significantly lowered by both carvedilol and nebivolol therapy. However, MPV tended to be lower in the carvedilol group (7.7 ± 1.0 vs 8.0 ± 0.7 fL, P = .05). Fibrinogen and d-dimer levels were significantly decreased in but comparable in both the groups. Carvedilol and nebivolol have similar beneficial effects on platelet function and prothrombotic state in patients with nonischemic HF.

Increased mean platelet volume in hypertrophic cardiomyopathy

Thromboembolic events may be seen in patients with hypertrophic cardiomyopathy (HCM). We investigated the mean platelet volume (MPV), an indicator of platelet activation in patients with HCM. This study included 112 patients with HCM, in which 40 were patients with hypertrophic obstructive cardiomyopathy (HOCM), and 106 were control participants. The MPV was significantly higher in patients with HCM than in controls (9.1 ± 0.3 vs 7.9 ± 0.3 fL, P = .01). In the subgroup analyses, MPV was also higher in patients with HOCM compared to those with hypertrophic nonobstructive cardiomyopathy (HNCM; 9.3 ± 0.3 vs 9.0 ± 0.2 fL, P = .01). Similarly, patients with HNCM had higher MPV values than controls (9.0 ± 0.2 vs 7.9 ± 0.3 fL, P = .01). The MPV was significantly and positively correlated with left ventricular outflow tract (LVOT) obstruction (r = .42, P = .001) and septal thickness (r =.62, P = .001). In linear regression analysis, MPV was independently associated only with septal thickness (β = .07, 95% confidence interval: 0.04-0.09, P = .001). The MPV can be elevated in patients with HCM regardless of the obstruction of LVOT and may be associated with the severity of septal thickness.