Combining antiplatelet and anticoagulant therapy in cardiovascular disease

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Oral anticoagulant therapy in patients with peripheral artery disease

Patients with peripheral artery disease suffer from a high incidence of ischemic vascular complications in coronary, cerebral, and peripheral vascular beds. Reduction of atherothrombotic complications with aspirin or clopidogrel has proven to be successful. The role of oral anticoagulants in patients with symptomatic peripheral artery is limited. Randomized controlled trials comparing the effects of aspirin with oral anticoagulants are scarce. Oral anticoagulants (International Normalized Ratio = 2.5 to 4.5) are more effective than aspirin in preventing infrainguinal bypass occlusion only when venous graft material is used and the bypass is considered to be at high risk for occlusion. Whether the use of oral anticoagulants reduces all-cause morbidity and mortality is not unequivocally clear. The risk of ischemic events is reduced at the expense of an increased number of bleeding complications, which is one of the main reasons that therapy has not been widely adopted.     

Oral anticoagulant therapy in patients with coronary artery disease

Oral anticoagulation (OA) has been used to treat patients with coronary artery disease (CAD) for more than 40 years and has been a subject of intense controversy since that time. Seven to 10% of patients with acute myocardial infarction (MI) develop recurrent MI, stroke, or death in the 6 weeks following the index event and approximately 20% after 4 years, despite optimal background therapy with aspirin. Recent large studies and systematic reviews have greatly clarified the role of OA in the modern era. On the weight of the evidence, which is reviewed in detail in this article, long-term, moderate-intensity OA (International Normalized Ratio 2.0 to 3.0) should be considered an option for the prevention of recurrent CAD, particularly in high-risk patients.     

Long-term anticoagulant therapy in patients with coronary artery disease.

Secondary prevention of coronary events in coronary artery disease (CAD) patients with aspirin is generally accepted because of ease of administration, predictable safety, and proven efficacy. The use of long-term anticoagulant therapy with heparins, vitamin-K antagonists (VKAs), or thrombin inhibitors is, however, more controversial. During the last 40 years, several trials have been conducted in order to evaluate the role of anticoagulant therapy in patients with CAD as a protection against subsequent death and thrombo-embolic complications. The conducted trials are heterogeneous in many ways, concerning comparative medications, patient populations, endpoints and follow-up, which makes a standardized recommendation on the basis of these studies difficult. This review is an overview of the largest and best studies on this topic and discusses the scientific background for a possible use of VKA or an alternative anticoagulant treatment in CAD patients, looking at both the beneficial effects and the risk of bleeding.     

Role of liver biopsy in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), defined as abnormal accumulation (> 5%) of hepatic triglyceride without excess alcohol intake, is the most common form of chronic liver disease in adults and children in the United States. NAFLD encompasses a spectrum of histologic findings including uncomplicated steatosis, steatosis with inflammation and steatohepatitis [nonalcoholic steatohepatitis (NASH)]; the latter can advance to cirrhosis and hepatocellular carcinoma. NASH is currently accepted as the hepatic manifestation of the set of cardiovascular risk factors collectively known as metabolic syndrome. In 1999 a system for histologic grading and staging for NASH was proposed; this was revised by the NASH Clinical Research Network in 2005 for the entire spectrum of lesions in NAFLD, including the lesions and patterns of pediatric NAFLD, and for application in clinical research trials. Diagnosis remains distinct from grade and stage. A recent European proposal separates steatosis from activity to derive a numeric diagnosis of NASH. Even though there have been promising advancements in non-invasive testing, these tests are not yet detailed enough to replace the full range of findings provided by liver biopsy evaluation. Limitations of biopsy are acknowledged, but liver biopsy remains the “gold standard” for diagnosis and determination of amounts of necroinflammatory activity, and location of fibrosis, as well as remodeling of the parenchyma in NASH. This review focuses on the specific histologic lesions of NAFLD and NASH, grading and staging, differential diagnoses to be considered, and the continuing role of the liver biopsy in this important liver disease.     

Development in anticoagulant therapy

Venous thromboembolism is an important clinical problem. Cancer patients have higher risk to develop venous thrombosis and vice versa. The treatment consists of heparin followed by vitamin K antagonists. Both agents have several limitations. Especially in cancer patients, vitamin K antagonists cause bleeding or recurrence of VTE because of a small therapeutic window. Monotherapy with low-molecular weight heparin seems to cause less of these complications in cancer patients compared to vitamin K antagonists. Besides, the drug is thought to have anti-cancer properties. Several novel anticoagulants are being developed and are undergoing clinical evaluation. New anticoagulants should also be evaluated on the effect on progression of cancer and cancer-related survival.     

Role of CD98 in liver disease

CD98 is a multifunctional glycoprotein that is involved in various biological processes such as amino acid transport, cell adhesion, diffusion, adhesion, and proliferation. The role of CD98 in liver disease has not thoroughly been examined and is limited reports in the literature. Among these reports, direct association for CD98 in nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) have been reported. Our lab has reported that targeting CD98 in high fat diet mice reduced steatosis and inflammation in NAFLD. Other reports associate CD98 in HCC due in part to the role of CD98 in activating integrin signaling. Herein, we present CD98 staining on liver biopsies from NAFLD, chronic active hepatitis, cirrhosis, and 3 stages of HCC to demonstrate the upregulation of CD98 expression throughout liver disease progression. In addition, we analyze current literature to elucidate roles and potential roles of CD98 with each stage of liver disease.     

Role of mitochondria in alcoholic liver disease

Alcohol abuse is the leading cause of liver related morbidity and mortality. Chronic or binge alcohol drinking causes hepatic steatosis which can develop to steatohepatitis, cirrhosis and ultimately hepatocellular carcinoma. The pathogenesis of alcoholic liver disease (ALD) is poorly characterized, however several recent studies point to a major role of mitochondria in this process. Mitochondria play a crucial role in cellular energy metabolism and in reactive species formation. Alcohol treatment causes mitochondrial DNA damage, lipid accumulation and oxidative stress. Studies in both animal models and in humans showed that alcohol administration causes changes in the mitochondrial morphology and function suggesting a role of these changes in the pathogenesis of ALD. We review recent findings on mechanisms by which alcohol negatively impacts mitochondrial biogenesis and function and we will discuss the specific intracellular pathways affected by alcohol consumption. Interestingly, recent findings indicate that a large number of mitochondrial proteins are acetylated and that mitochondrial proteins acetylation and sirtuins are modulated by alcohol. Understanding the mechanisms behind alcohol mediated impaired mitochondrial biogenesis and function may help identify potential therapeutic targets for treating ALD in humans.     

Role of antiviral therapy in the natural history of hepatitis B virus-related chronic liver disease

Hepatitis B virus(HBV) infection is a dynamic state ofinteractions among HBV, hepatocytes, and the host immune system. Natural history studies of chronic hepatitis B(CHB) infection have shown an association between active viral replication and adverse clinical outcomes such as cirrhosis and hepatocellular carcinoma. The goal of therapy for CHB is to improve quality of life and survival by preventing progression of the disease to cirrhosis, decompensation, end-stage liver disease, hepatocellular carcinoma(HCC) and death. This goal can be achieved if HBV replication is suppressed in a sustained manner. The accompanying reduction in histological activity of CHB lessens the risk of cirrhosis and of HCC, particularly in non-cirrhotic patients. However, CHB infection cannot be completely eradicated, due to the persistence of covalently closed circular DNA in the nucleus of infected hepatocytes, which may explain HBV reactivation. Moreover, the integration of the HBV genome into the host genome may favour oncogenesis, development of HCC and may also contribute to HBV reactivation.     

Hepatocyte cell therapy in liver disease

Liver disease is a leading cause of morbidity and mortality. Liver transplantation remains the only proven treatment for end-stage liver failure but is limited by the availability of donor organs. Hepatocyte cell therapy, either with bioartificial liver devices or hepatocyte transplantation, may help address this by delaying or preventing liver transplantation. Early clinical studies have shown promising results, however in most cases, the benefit has been short lived and so further research into these therapies is required. Alternative sources of hepatocytes, including stem cell-derived hepatocytes, are being investigated as the isolation of primary human hepatocytes is limited by the same shortage of donor organs. This review summarises the current clinical experience of hepatocyte cell therapy together with an overview of possible alternative sources of hepatocytes. Current and future areas for research that might lead towards the realisation of the full potential of hepatocyte cell therapy are discussed.     

Role of ezetimibe in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) encompasses a histological spectrum ranging from simple steatosis to steatohepatitis,advanced fibrosis and inflammatory changes.Ezetimibe inhibits cholesterol absorption from the intestinal lumen into enterocytes.The molecular target of ezetimibe is the sterol transporter Niemann-Pick C1-like 1 protein (NPC1L1).Human NPC1L1 is abundantly expressed in the liver and may facilitate the hepatic accumulation of cholesterol.Ezetimibe ex-erts beneficial effects on several metabolic variables.Ezetimibe treatment attenuates hepatic steatosis and is beneficial in terms of NAFLD biochemical markers.The combination of ezetimibe with other interventions may also be beneficial in NAFLD patients.Our group inves-tigated the ezetimibe-orlistat combination treatment in overweight and obese patients with hypercholeste-rolemia,with beneficial effects on NAFLD biochemical markers.These results are promising for patients with NAFLD,who usually have increased cardiovascular disease risk and need a multifactorial treatment.How-ever,it should be mentioned that most results are from animal studies and,although modest elevation of liver function tests may raise the suspicion of NAFLD,none of these tests are sensitive to establish the diagnosis of NAFLD with great accuracy.     

脂联素与非酒精性脂肪肝病

脂联素(adiponectin,ADP)作为一种新发现的脂肪激素,主要是由脂肪细胞分泌的,在肥胖者、糖尿病及非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)患者中血清ADP水平低于正常.ADP有胰岛素增敏作用,与胰岛素抵抗相关;能够使肝脏肿瘤坏死因子(tumor necrosis factor-alpha,TNF-α)分泌下降,减少肝中脂肪堆积和炎症介质作用,对ADP的研究将为探讨NAFLD的发病机制及治疗方案提供新的线索.