Faculty Bibliography

Recent studies have greatly expanded our understanding of the coagulopathy of cirrhosis. It is clear that cirrhosis patients are at a risk of both bleeding and thrombosis. While prediction of these events remains challenging, cirrhosis patients are not protected from the development of venous and arterial thrombosis. In fact, studies show that hypercoagulability may promote hepatic decompensation and development of fibrosis. Anticoagulation for thrombosis is now becoming a common prospect in many clinical situations. Our understanding of the efficacy and safety of commonly used therapeutics is only beginning to emerge and the risks and benefits remain unclear in this unique population. In this review, we discuss the role of anticoagulation in the treatment and prevention peripheral and splanchnic thrombosis in patients with cirrhosis, as well as examine the potential role of anticoagulants in altering the progression of chronic liver disease.

BACKGROUND:Hyperbilirubinemia is a common side effect of protease inhibitors used to treat chronic hepatitis C (HCV), and most patients do not experience without clinically overt hepatotoxicity. The safety of second-wave protease inhibitors, including simeprevir, has not been well studied in patients with advanced cirrhosis. MATERIALS & METHODS/METHODS:We report two cases of suspected drug-induced liver injury leading to hepatic decompensation in patients with advanced HCV cirrhosis treated with the combination of simeprevir and sofosbuvir on a compassionate basis. Both patients developed marked hyperbilirubinemia out of proportion to their aminotransferases, despite clearance of hepatitis C RNA. RUCAM scoring was probable and possible, respectively. While other factors may have contributed to the liver injury, including infection and concurrent administration of other medications, we believe that the potentially deleterious hepatic effects of simeprevir on transporters or other key functional components were the main reason for their decompensation. CONCLUSIONS:Protease inhibitors should be used with caution, if at all, in patients with cirrhosis, especially in those with the most advanced disease. We await newer, safer, direct-acting antiviral therapies for such patients, especially those on our transplant list.

Recent advances in the understanding of the coagulopathy in chronic liver disease have provided a strong support for anticoagulation as a new therapeutic paradigm for patients with cirrhosis. Laboratory studies indicate that the net effect of changes in hemostasis in many patients with chronic liver disease is a hypercoagulable status. In turn, clinical thrombosis is increasingly recognized as a complication of liver disease. When occurring within the liver, thrombosis may even progress the disease course. Exciting preliminary data regarding the potential of low-molecular-weight heparin to slow down the progression of liver disease indicate that this class of drugs may improve outcome without a major increase in bleeding risk. However, this new era for antithrombotic therapy in chronic liver disease is still hindered by a persistent false notion that patients with cirrhosis are "auto-anticoagulated" by their underlying liver disease. In addition, there is insufficient clinical evidence on safety and efficacy of anticoagulant therapy in cirrhosis and the studies conducted so far are limited by small sample sizes, uncontrolled treatment arms, or by their retrospective nature. Finally, a lack of knowledge on how or when to monitor antithrombotic treatment to optimize the risk-benefit ratio has restricted a widespread application of anticoagulant treatment in clinical management algorithms. Nonetheless, by systematically covering possibilities and pitfalls, this review highlights the potential of antithrombotic therapy to improve the quality of life and the clinical outcome of patients with chronic liver disease.

UNLABELLED:The Model for End-Stage Liver Disease (MELD) allocation system for liver transplantation provides "exceptions" for diseases such as hepatocellular carcinoma (HCC). It was the aim of this study to assess equipoise between exception candidates and nonexception candidates on the waiting list and to assess if the exception system contributes to steadily increasing regional MELD at transplant. In all, 78,595 adult liver transplant candidates between January 2005 and December 2012 were analyzed. Yearly trends in waiting list characteristics and transplantation rates were analyzed for statistical association with MELD exceptions. Regional variations in these associations and the effect of exceptions on regional MELD scores at transplant were also analyzed. 27.29% of the waiting list was occupied by candidates with exceptions. Candidates with exceptions fared much better on the waiting list compared to those without exceptions in mean days waiting (HCC 237 versus non-HCC 426), transplantation rates (HCC 79.05% versus non-HCC 40.60%), and waiting list death rates (HCC 4.49% versus non-HCC 24.63%). Strong regional variation in exception use occurred but exceptions were highly correlated with waiting list death rates, transplantation rates, and MELD score at removal in all regions. In a multivariate model predicting MELD score at transplant within regions, the percentage of HCC MELD exceptions was the strongest independent predictor of regional MELD score at transplant. CONCLUSION/CONCLUSIONS:Liver transplant candidates with MELD exceptions have superior outcomes compared to nonexception candidates and the current MELD exception system is largely responsible for steadily increasing MELD scores at transplant independent of geography.

The complex nature of haemostasis in patients with liver disease can result in bleeding and/or thrombosis. These opposing outcomes, which have multiple contributing factors, can pose diagnostic and therapeutic dilemmas for physicians. With the high rate of haemorrhagic complications in patients with cirrhosis, we examine the various procoagulants available for use in this population. In this Review, we describe the clinical and current rationale for using each of the currently available procoagulants-vitamin K, fresh frozen plasma (FFP), cryoprecipitate, platelets, recombinant factor VIIa (rFVIIa), antifibrinolytics, prothrombin concentrate complexes (PCC), desmopressin and red blood cells. By examining the evidence and use of these agents in liver disease, we provide a framework for targeted, goal-directed therapy with procoagulants.

BACKGROUND:Hospitalized patients with cirrhosis are at risk to develop venous thromboembolism. Although current guidelines support the routine administration of thromboprophylaxis to hospitalized patients, there is limited data regarding the safety or efficacy of this practice in hospitalized cirrhosis patients. AIMS/OBJECTIVE:We aimed to determine if administration of thromboprophylaxis was associated with increased complication rates for hospitalized cirrhosis patients. METHODS:Data were collected on patients admitted to the University of Virginia between 2007 and 2010. Study personnel systematically collected data on complications, including gastrointestinal bleed, venous thromboembolism and death directly from the medical record. RESULTS:A total of 235 patients (accounting for 355 discrete hospitalizations in which thromboprophylaxis was administered) met inclusion criteria accounting for 1660 person-days of thromboprophylaxis administered to patients. The mean age at admission was 58 (95% CI 57.1-59.2) years and 217 (61%) were male patients. The mean admission model for end-stage liver disease (MELD) score was 16.2 (95% CI 15.5-16.9). The mean hospital length of stay was 6.5 (95% CI 5.9-7.4) days. In patients who received thromboprophylaxis, the mean treatment length was 4.7 days (95% CI 4.2-5.2). There were nine gastrointestinal bleeding events (2.5% of admissions), five venous thromboembolisms (1.4% of admissions), two cases of heparin-induced thrombocytopenia (0.5% of admissions) and 14 deaths overall (3.9% of admissions). CONCLUSIONS:The use of thromboprophylaxis in hospitalized cirrhosis patients is not associated with high rates of gastrointestinal bleeding or death.

The human hemostasis system is complex and poorly understood after decades of intense scientific study. Despite multiple defects in routine coagulation laboratory studies in patients with chronic liver disease, there is growing evidence that these patients are effectively "rebalanced" with regard to procoagulant and anticoagulant activity and that most of these patients remain in a tenuous but balanced state of hemostasis. A major difficulty in the assessment of these patients is that there are no established laboratory tests that accurately reflect the changes in both the procoagulant and anticoagulant systems; therefore, routine laboratory testing is misleading to the clinician and may prompt inappropriate or risky therapies with little real benefit to the patient. The international normalized ratio is an example of this type of misleading test. Although the international normalized ratio is inextricably linked to prognosis and severity of protein synthetic dysfunction in acute and chronic liver disease, it is a very poor marker for bleeding risk and should not be used in isolation for this purpose. Coagulation disorders are critical in the management of frequent clinical scenarios such as esophageal variceal bleeding, invasive and percutaneous procedures, portal vein thrombosis, venous thromboembolism, and acute liver failure. This article summarizes the pathophysiology of hemostasis in liver disease, describes the strengths and weaknesses of various laboratory tests in assessment of these patients, and outlines the optimal management of hemostasis for some common clinical scenarios. Further research is needed for proper understanding of hemostasis in liver disease to optimally and safely manage these complex patients.

Until recently, it was widely accepted that patients with cirrhosis have a bleeding tendency related to the changes in the hemostatic system that occur as a consequence of the disease. However, it has now been well established that patients with cirrhosis are at risk for both bleeding and thrombotic complications. These thrombotic complications include portal vein thrombosis, deep vein thrombosis and pulmonary embolism, and coronary or cerebrovascular infarctions. Antithrombotic drugs to prevent or treat thrombotic complications in patients with cirrhosis have been used only minimally in the past due to the perceived bleeding risk. As the thrombotic complications and the necessity of antithrombotic treatment in these patients are increasingly recognized, the use of antithrombotic drugs in this population is likely increasing. Moreover, given the rising incidence of fatty liver disease and generally longer survival times of patients with chronic liver diseases, it would be reasonable to presume that some of these thrombotic complications may be increasing in incidence over time. In this review, we will outline the indications for antithrombotic treatment in patients with cirrhosis. Furthermore, we will discuss the available antithrombotic drugs and indicate possible applications, advantages, and caveats. Since for many of these drugs very little experience in patients with cirrhosis exists, these data are essential in the design of future clinical and laboratory studies on mechanisms, efficacy, and safety of the various antithrombotic strategies in these patients.

Several studies have shown a direct role of liver atrophy in the pathogenesis of thrombocytopenia of cirrhosis via reduced production of thrombopoeitin. About 181 patients listed for liver transplantation at a single transplant center were evaluated at the time of listing with laboratory tests and volumetric liver measurements using computed tomography. Expected normal liver volume was calculated using the Heinemann formula. Liver volume ratio (LVR) was calculated as actual liver volume over expected liver volume. Patients were predominantly male (70.7%), with viral hepatitis (60.2%), had a mean age of 51.8 years (SD 8.7), model for end stage liver disease (MELD) of 14 (SD 6.4), LVR of 0.95 (SD 0.3), and platelet count of 105,000/mcL (SD 66,000). Platelet count (P < 0.0001) correlated more strongly with LVR than MELD, MELD components (P = 0.27) or serum albumin (P = 0.003). Platelet count (HR 0.987, 95% CI 0.979-0.994, P = 0.001) was a strong independent predictor of mortality. Patients with platelet count < 100,000/mcL had a shorter survival (935 vs. 1396 days, P = 0.002) and higher death rate (42.2% vs. 23.6%, P = 0.01), but no different transplantation rate (36.7% vs. 33.3%, P = 0.64) compared to those with platelet count ≥ 100,000/mcL. Low platelet count corresponds to higher waiting list mortality and is a sign of advanced liver atrophy.