Anticoagulation in Cirrhosis: Evidence for the Treatment of Portal Vein Thrombosis and Applications for Prophylactic Therapy.

The clinical utility of anticoagulation for patients with cirrhosis and asymptomatic portal vein thrombosis (PVT) is widely debated. Complex hemostatic derangements in cirrhosis that increase risk of both bleeding and thrombosis, as well as a lack of randomized controlled data, limit conclusive assessments regarding optimal management of anticoagulation in this setting. In this review, we summarize the relevant literature pertaining to PVT in cirrhosis, including the effect of untreated PVT on the natural progression of liver disease and the overall impact of anticoagulation on clot burden and other relevant clinical outcomes. Apart from patients who are symptomatic or listed for liver transplantation, data supporting anticoagulation for the treatment of PVT is limited and without clear consensus guidelines. In patients with cirrhosis without PVT, emerging evidence for the role of prophylactic anticoagulation to mitigate the progression of fibrosis suggests an optimal risk-benefit tradeoff with decreased rates of liver decompensation and mortality, without a heightened risk of bleeding. In summation, as our understanding of the role of both prophylactic and therapeutic anticoagulation in cirrhosis continues to evolve, ongoing risk stratification of patients with asymptomatic PVT demands further attention.

Transfusion strategies in patients with cirrhosis.

Bleeding related to portal hypertension and coagulopathy is a common complication in patients with cirrhosis. Complications and management of bleeding is a significant source of healthcare cost and utilization, as well as morbidity and mortality. Due to the scarcity of evidence surrounding transfusion strategies and hemostatic interventions in patients with cirrhosis, there has been significant debate regarding the best practice. Emerging data suggest that evidence supporting transfusion of packed red blood cells to a hemoglobin threshold of 7-8 g/dL is strong. thrombopoietin (TPO) receptor agonists have shown promise in increasing platelet levels and reducing transfusions preprocedurally, although have not specifically been found to reduce bleeding risk. Data for viscoelastic testing (VET)-guided transfusions appear favorable for reducing blood transfusion requirements prior to minor procedures and during orthotopic liver transplantation. Hemostatic agents such as recombinant factor VIIa, prothrombin complex concentrates, and tranexamic acid have been examined but their role in cirrhotic patients is unclear. Other areas of growing interest include balanced ratio and whole blood transfusion. In the following manuscript, we summarize the most up to date evidence for threshold-guided, VET-guided, balanced-ratio, and whole blood transfusions as well as the use of hemostatic agents in cirrhotic patients to provide practice guidance to clinicians.

Thromboelastography Better Reflects Hemostatic Abnormalities in Cirrhotics Compared With the International Normalized Ratio.

GOAL: The goal of this study was to describe potential key differences in thromboelastography (TEG) variables in hospitalized cirrhotics compared with a healthy population, identify patterns of hematologic disturbance with disease progression, and assess the value of traditional tests such as international normalized ratio (INR) and platelet count to determine coagulopathy in cirrhotics. BACKGROUND: TEG, a functional assay of coagulation, has emerged as a useful tool for predicting bleeding risk in cirrhosis. STUDY: Hospitalized cirrhotics who received a TEG before any blood products between January 2017 and February 2018 at a liver transplant center were included. Reaction time (r-time), coagulation time (k-time), angle-rate of clot polymerization (α) and maximum clot strength (maximum amplitude) were measured with kaolin-activated citrated blood TEG assays. RESULTS: A total of 106 cirrhotic patients (Child-Turcotte-Pugh A, B, C; n=25, 25, 56) were identified for comparison against data from 53 healthy controls. TEG parameters in cirrhotics were statistically different from controls. Mean INR and platelet count for all cirrhotics were largely outside the normal reference range, contrary to TEG parameters which demonstrated parameters mostly within the normal reference ranges. The r-time, k-time, and α values in the cirrhotics progressively increased and maximum amplitude values progressively decreased as the liver disease progressed. Regression analysis showed no significant correlations between INR and r-time across any Child-Turcotte-Pugh class (r=0.01, 0.18, 0.23; P=0.95, 0.39, 0.08, respectively). CONCLUSIONS: Although cirrhotics had TEG parameters within normal ranges, there was a propensity for decreased clot formation as liver function worsened. Importantly, the INR did not correlate with TEG parameters in cirrhotic patients, and given the precarious hemostatic balance in these patients, a TEG may be a better predictor of bleeding risk.

Venous thrombosis in unusual sites: A practical review for the hematologist.

Thrombosis of unusual venous sites encompasses a large part of consultative hematology and is encountered routinely by practicing hematologists. Contrary to the more commonly encountered lower extremity venous thrombosis and common cardiovascular disorders, the various thromboses outlined in this review have unique presentations, pathophysiology, workup, and treatments that all hematologists should be aware of. This review attempts to outline the most up to date literature on cerebral, retinal, upper extremity, hepatic, portal, splenic, mesenteric, and renal vein thrombosis, focusing on the incidence, pathophysiology, provoking factors, and current recommended treatments for each type of unusual thrombosis to provide a useful and practical review for the hematologist.

Chronic liver disease, thrombocytopenia and procedural bleeding risk; are novel thrombopoietin mimetics the solution?

Chronic liver disease (CLD) alters normal hemostatic and thrombotic systems via multiple mechanisms including reduced platelet function and number, leading to challenging peri-operative planning. Hepatic thrombopoietin (TPO) synthesis is reduced in CLD, leading to several recent randomized, placebo-controlled trials examining the utility of TPO-mimetics to increase platelet counts prior to surgery. While these trials do suggest that TPO-mimetics are efficacious at increasing platelet counts in patients with CLD and have led to several recent drug approvals in this space by the U.S. Food & Drug Administration, it remains unclear whether these results translate to the relevant clinical endpoint of reduced perioperative bleeding rate and severity. In this article, we review several recently-published, phase 3 trials on the TPO-mimetics eltrombopag, avatrombopag and lusutrombopag, and discuss the clinical significance of their results.

Arterial thrombosis in unusual sites: A practical review.

While cardiovascular disease is common, occasionally hematologists and other practitioners will encounter patients with arterial thrombosis/infarction in unusual sites, without clear cause or obvious diagnostic and treatment paradigms. Contrary to the more commonly encountered cerebrovascular accident and cardiovascular disorders, the various infarctions outlined in this review have unique presentations, pathophysiology, workup, and treatments that all hematologists should be aware of. This review outlines the current literature on arterial thrombosis, with consideration given to anatomic sources and hypercoagulable associations, while focusing on the epidemiology, pathophysiology, provoking factors, and current recommended treatments for intracardiac thrombus, primary aortic mural thrombus, visceral infarctions, and cryptogenic limb ischemia to provide a useful and practical review for the practitioner.

The efficacy and safety of direct oral anticoagulants vs traditional anticoagulants in cirrhosis.

INTRODUCTION: The coagulopathy of cirrhosis is complex, placing patients at risk for both bleeding and thrombosis. Direct oral anticoagulants (DOACs) have equivalent or superior efficacy and safety as compared to vitamin K antagonists (VKAs); however, their efficacy and safety in liver cirrhosis has not been studied. To better define this, we evaluated outcomes of patients with cirrhosis prescribed DOACs compared to other anticoagulants at our center. METHODS: Retrospective cohort study of patients with cirrhosis prescribed therapeutic anticoagulation over a 3-year period for thrombosis or prevention of stroke in patients with atrial fibrillation. The primary outcomes of interest were bleeding events and recurrent thrombosis or stroke. RESULTS: During the study period, 27 patients with cirrhosis were prescribed a DOAC and 18 were prescribed VKA or low molecular weight heparin (LMWH). Both groups had similar total bleeding events (8 DOAC vs 10 other, P=.12). There were significantly less major bleeding episodes in the DOAC group (1 [4%] vs 5 [28%], P=.03). Recurrent thrombosis occurred in one patient receiving a DOAC (4%) and one patient (6%) receiving other anticoagulation (P=1.0). CONCLUSIONS: Direct oral anticoagulant use in patients with cirrhosis may be as safe as traditional anticoagulants. Patients with cirrhosis at our center prescribed DOACs had less major bleeding events, while maintaining efficacy at preventing stroke or thrombosis.

HiTRACE: high-throughput robust analysis for capillary electrophoresis.

MOTIVATION: Capillary electrophoresis (CE) of nucleic acids is a workhorse technology underlying high-throughput genome analysis and large-scale chemical mapping for nucleic acid structural inference. Despite the wide availability of CE-based instruments, there remain challenges in leveraging their full power for quantitative analysis of RNA and DNA structure, thermodynamics and kinetics. In particular, the slow rate and poor automation of available analysis tools have bottlenecked a new generation of studies involving hundreds of CE profiles per experiment. RESULTS: We propose a computational method called high-throughput robust analysis for capillary electrophoresis (HiTRACE) to automate the key tasks in large-scale nucleic acid CE analysis, including the profile alignment that has heretofore been a rate-limiting step in the highest throughput experiments. We illustrate the application of HiTRACE on 13 datasets representing 4 different RNAs, 3 chemical modification strategies and up to 480 single mutant variants; the largest datasets each include 87 360 bands. By applying a series of robust dynamic programming algorithms, HiTRACE outperforms prior tools in terms of alignment and fitting quality, as assessed by measures including the correlation between quantified band intensities between replicate datasets. Furthermore, while the smallest of these datasets required 7-10 h of manual intervention using prior approaches, HiTRACE quantitation of even the largest datasets herein was achieved in 3-12 min. The HiTRACE method, therefore, resolves a critical barrier to the efficient and accurate analysis of nucleic acid structure in experiments involving tens of thousands of electrophoretic bands.

Influence of spontaneous splenorenal shunts on clinical outcomes in decompensated cirrhosis and after liver transplantation.

Cirrhosis and portal hypertension can lead to the formation of a spontaneous splenorenal shunt (SSRS) that may divert portal blood flow to the systemic circulation and reduce hepatic perfusion. Our aims were to evaluate SSRSs as an independent prognostic marker for mortality in patients with decompensated cirrhosis and the influence of SSRSs on liver transplantation (LT) outcomes. We retrospectively analyzed adult patients with decompensated cirrhosis undergoing LT evaluation from January 2001 to February 2016 at a large U.S. center. All patients underwent liver cross-sectional imaging within 6 months of evaluation, and images were reviewed by two radiologists. Clinical variables were obtained by electronic health record review. The cohort was followed until death or receipt of LT, and the subset receiving LT was followed for death after LT or graft failure. Survival data were analyzed using multivariable competing risk and Cox proportional-hazards regression models. An SSRS was identified in 173 (23%) of 741 included patients. Patients with an SSRS more often had portal vein thrombosis and less often had ascites (P < 0.01). An SSRS was independently associated with a nonsignificant trend for reduced mortality (adjusted subhazard ratio, 0.81; Gray's test P = 0.08) but had no association with receipt of LT (adjusted subhazard ratio, 1.02; Gray's test P = 0.99). Post-LT outcomes did not differ according to SSRS for either death (hazard ratio, 0.85; log-rank P = 0.71) or graft failure (hazard ratio, 0.71; log-rank P = 0.43). Conclusion: Presence of an SSRS does not predict mortality in patients with decompensated cirrhosis or in LT recipients. (Hepatology Communications 2018;2:437-444).

Improvement in Glycemic Control of Type 2 Diabetes After Successful Treatment of Hepatitis C Virus.

OBJECTIVE: Hepatitis C virus (HCV) infection is associated with diabetes and may worsen glycemic control in patients with diabetes. We aimed to investigate whether eradication of HCV infection with direct-acting antiviral (DAA) agents is associated with improved glycemic control in patients with diabetes. RESEARCH DESIGN AND METHODS: We identified 2,435 patients with diabetes who underwent interferon-free and ribavirin-free DAA-based antiviral treatment for HCV in the national Veterans Affairs health care system. Changes in average hemoglobin A1c (HbA1c) level and use of antidiabetic medications 1 year before and after antiviral treatment were compared between patients who achieved sustained virologic response (SVR) and those who did not. RESULTS: Among patients with elevated baseline HbA1c, the drop in HbA1c associated with antiviral treatment was greater in those who achieved SVR (0.98%) than in those who sustained treatment failure (0.65%) (adjusted mean difference 0.34, P = 0.02). Use of antidiabetic medications decreased more in patients who achieved SVR than in those who sustained treatment failure, especially for the use of insulin, which dropped significantly from 41.3% to 38% in patients achieving SVR compared with a slight increase from 49.8% to 51% in those who sustained treatment failure. CONCLUSIONS: DAA-based eradication of HCV is associated with improved glycemic control in patients with diabetes as evidenced by decreased mean HbA1c and decreased insulin use. These endocrine benefits of SVR provide additional justification for considering antiviral treatment in all patients with diabetes.

Ultraviolet shadowing of RNA can cause significant chemical damage in seconds.

Chemical purity of RNA samples is important for high-precision studies of RNA folding and catalytic behavior, but photodamage accrued during ultraviolet (UV) shadowing steps of sample preparation can reduce this purity. Here, we report the quantitation of UV-induced damage by using reverse transcription and single-nucleotide-resolution capillary electrophoresis. We found photolesions in a dozen natural and artificial RNAs; across multiple sequence contexts, dominantly at but not limited to pyrimidine doublets; and from multiple lamps recommended for UV shadowing. Irradiation time-courses revealed detectable damage within a few seconds of exposure for 254 nm lamps held at a distance of 5 to 10 cm from 0.5-mm thickness gels. Under these conditions, 200-nucleotide RNAs subjected to 20 seconds of UV shadowing incurred damage to 16-27% of molecules; and, due to a 'skin effect', the molecule-by-molecule distribution of lesions gave 4-fold higher variance than a Poisson distribution. Thicker gels, longer wavelength lamps, and shorter exposure times reduced but did not eliminate damage. These results suggest that RNA biophysical studies should report precautions taken to avoid artifactual heterogeneity from UV shadowing.

Radial construction of an arterial wall.

Some of the most serious diseases involve altered size and structure of the arterial wall. Elucidating how arterial walls are built could aid understanding of these diseases, but little is known about how concentric layers of muscle cells and the outer adventitial layer are assembled and patterned around endothelial tubes. Using histochemical, clonal, and genetic analysis in mice, here we show that the pulmonary artery wall is constructed radially, from the inside out, by two separate but coordinated processes. One is sequential induction of successive cell layers from surrounding mesenchyme. The other is controlled invasion of outer layers by inner layer cells through developmentally regulated cell reorientation and radial migration. We propose that a radial signal gradient controls these processes and provide evidence that PDGF-B and at least one other signal contribute. Modulation of such radial signaling pathways may underlie vessel-specific differences and pathological changes in arterial wall size and structure.