Plasma From Patients Undergoing Liver Transplantation Is Resistant to Anticoagulant Activity of Soluble Thrombomodulin.

Recombinant human soluble thrombomodulin (ART-123) is an anticoagulant and anti-inflammatory agent clinically used for treatment of disseminated intravascular coagulation. Preclinical studies have shown that ART-123 reduces hepatic ischemia/reperfusion. Although ART-123 may therefore have clinical benefit in orthotopic liver transplantation, the substantial alterations in the hemostatic system may complicate its use in this setting. Here, we studied the in vitro effect of ART-123 on coagulation of patients with end-stage liver disease undergoing liver transplantation. Ten patients with end-stage liver disease undergoing liver transplantation were included in this study. Plasma samples of 10 healthy individuals were included to establish reference values. Different concentrations of ART-123 were added to plasma samples, and peak thrombin generation and clot lysis times (CLTs) were determined. In patient samples, plasma was profoundly resistant to the anticoagulant action of ART-123, as reflected by significantly higher median inhibitory concentration (IC50 ) values of peak thrombin generation compared with controls. This might be partially explained by low levels of protein C, protein S, and elevated levels of factor VIII during transplantation. Intraoperative levels of thrombin activatable fibrinolysis inhibitor were significantly lower when compared with controls. However, ART-123-dependent prolongation of CLTs was not significantly different from healthy controls. In conclusion, this study suggests that ART-123 is unlikely to provoke bleeding in patients undergoing liver transplantation because proposed clinical dosages have a virtually absent anticoagulant effect in these patients. Clinical studies are required to confirm the safety of ART-123 and efficacy on alleviating ischemia/reperfusion injury during liver transplantation.

Elevated Plasma Levels of Cell-Free DNA During Liver Transplantation Are Associated With Activation of Coagulation.

Patients undergoing liver transplantation have complex changes in their hemostatic system, and the net effect of these changes appears to be a "rebalanced" hemostatic profile. Recently, a process called NETosis in which a neutrophil expels DNA and proteins that form a weblike structure, has been described as a mechanism of pathogen entrapment. Increasing evidence suggests a pivotal role for neutrophil extracellular traps (NETs) and their main component, cell-free DNA (cfDNA), in activation of coagulation. Because liver transplantation is associated with substantial (hepatocyte) cell death and intrahepatic neutrophil accumulation, NETs might play an important role in the hemostatic balance during liver transplantation. Here, we determined markers for NETs in the plasma of patients undergoing a liver transplantation and examined their association with activation of coagulation. Markers for NETs and markers for activation of coagulation were determined in serial plasma samples taken from patients undergoing a liver transplantation (n = 21) and compared with plasma levels in healthy controls. We found perioperative increases of markers for NETs with levels of cfDNA and nucleosomes that peaked after reperfusion and myeloperoxidase (MPO)-DNA complexes that peaked during the anhepatic phase. CfDNA and nucleosome levels, but not MPO-DNA levels, correlated with prothrombin fragment 1+2 and thrombin-antithrombin complex levels, which are established markers for activation of coagulation. Neutrophils undergoing NETosis were observed by immunostainings in postreperfusion biopsies. In conclusion, although NETosis occurs during liver transplantation, the majority of circulating DNA appears to be derived from cell death within the graft. The perioperative increases in cfDNA and nucleosomes might contribute to the complex hemostatic rebalance during liver transplantation.

In vitro efficacy of pro- and anticoagulant strategies in compensated and acutely ill patients with cirrhosis.

BACKGROUND & AIMS: A simultaneous decline in pro- and anticoagulant drivers in patients with liver diseases results in a "rebalanced" haemostatic system, even in acutely ill patients. Nevertheless, both bleeding and thrombotic events are common. Here, we explored efficacy of pro- and antihaemostatic strategies in compensated and acutely ill cirrhotics which may be unpredictable given the profound haemostatic changes. METHODS: We tested the effects in vitro of the addition of clinically relevant doses of commonly used pro- and antihaemostatic strategies in plasma from healthy individuals (n = 30) and patients with compensated (n = 18) and acutely decompensated cirrhosis (n = 18), and acute-on-chronic liver failure (n = 10). We used thrombin generation tests and fibrin clot permeability assays to assess potency of various approaches. RESULTS: Fresh frozen plasma and recombinant factor VIIa modestly increased thrombin generation (10%-20%). Prothrombin complex concentrate increased thrombin generation two-fold in controls and 2-4-fold in patients. Clot permeability decreased after addition of fibrinogen concentrate by 51% in controls and by 50%-60% in patients. Low molecular weight heparin decreased thrombin generation by 18% in controls and by 23%-54% in patients. Similarly, dabigatran decreased thrombin generation by 33% in controls and by 47%-100% in patients. In contrast, rivaroxaban decreased thrombin generation by 55% in controls, but only by 11%-38% in patients. CONCLUSIONS: These in vitro data suggest little prohaemostatic effect of fresh frozen plasma and recombinant factor VIIa in acutely ill cirrhotics, whereas prothrombin complex concentrate and fibrinogen concentrate clearly improved haemostasis. Furthermore, our data suggest the requirement for dose adjustments of commonly used anticoagulants in these patients.

Clinically relevant increases in the international normalized ratio and model of end-stage liver disease score by therapeutic doses of direct oral anticoagulants in patients with cirrhosis.

Background: Patients with cirrhosis are increasingly using direct oral anticoagulants (DOACs) in therapeutic doses for the treatment of portal vein thrombosis or for concomitant atrial fibrillation. DOACs may affect routine diagnostic tests of coagulation including the international normalized ratio (INR). The INR is a part of the model of end-stage liver disease (MELD) score, a validated score that predicts the mortality risk in patients with cirrhosis and is used to prioritize patients for liver transplantation. DOAC-induced increases in the INR may thus lead to artificial inflation of the MELD score. Objective: We studied the effect of DOACs on INR prolongation in patients with cirrhosis. Methods: We spiked plasma from 20 healthy individuals and 20 patients at the start of liver transplantation with DOACs in concentrations representing peak therapeutic levels. In addition, we studied INR increases in healthy controls and patients with mild cirrhosis who received the DOAC edoxaban for 1 week for study purposes. Results: In controls and patients, the INR increased by an ex vivo addition of a DOAC, and the INR increase in patients was proportional to the baseline INR values. The increase in INR translated to a median increase of between 3 and 10 MELD points, depending on the DOAC used. In controls and patients alike, the INR increased on the ingestion of edoxaban, which translated to an increase in 5 MELD points. Conclusions: Taken together, DOACs result in an INR increase that translates to clinically meaningful increases in MELD points in patients with cirrhosis, and precautions to avoid artificial inflation of the MELD score in these patients are warranted.

Congruent identification of imbalanced fibrinolysis by 2 distinct clot lysis time assays.

Background: A plasma-based clot lysis time (CLT) assay is an established research test to assess plasma fibrinolytic potential, with application in hyperfibrinolytic or hypofibrinolytic conditions. Interprotocol variations make comparisons between laboratories challenging. The aim of this study was to compare the results of 2 different CLT assays performed by 2 distinct research laboratories by using their own protocol. Methods: We evaluated fibrinolysis in the plasma of 60 patients undergoing hepatobiliary surgery and in plasma from a healthy donor that was spiked with commonly used anticoagulant drugs (enoxaparin, dabigatran, and rivaroxaban) in 2 distinct laboratories (Aarhus and Groningen) by using 2 different assays that differ, among others, in tissue plasminogen activator (tPA) concentration. Results: Overall conclusions on fibrinolytic potential in patients undergoing hepatobiliary surgery were similar between the 2 CLT assays, with hyperfibrinolytic and hypofibrinolytic profiles identified at the same time points during and after surgery. Severe hypofibrinolysis was less commonly reported in the Aarhus assay (36/319 samples; 11%) than in the Groningen assay (55/319 samples; 17%). No clot formation was observed in 31 of 319 samples in the Aarhus assay vs 0 of 319 samples in the Groningen assay. Clotting times increased much more profoundly on the addition of all 3 anticoagulants in the Aarhus assay. Conclusions: Despite the differences in laboratory, protocol, reagents, operator, data processing, and analysis, overall conclusions on fibrinolytic capacity are similar between the 2 laboratories. With a higher concentration of tPA in the Aarhus assay, the test becomes less sensitive for the detection of hypofibrinolysis and is more sensitive to the addition of anticoagulants.

Long-term renal outcome in patients with malignant hypertension: a retrospective cohort study.

BACKGROUND: Malignant hypertension is frequently complicated by renal insufficiency. Although the survival of this hypertensive emergency has improved, recent data on renal outcome and its predictors are lacking. We assessed renal outcome and its predictors in patients with malignant hypertension. METHODS: Retrospective analysis of patients admitted with malignant hypertension in Amsterdam, the Netherlands between August 1992-January 2010. Follow-up data on vital status, renal function and blood pressure (BP) were obtained from the outpatient department and from general practitioners. The primary composite endpoint was end-stage renal disease (ESRD) defined as the start of kidney replacement therapy (KRT) or ≥ 50% decline of estimated glomerular filtration rate (eGFR). The secondary endpoint was all cause mortality. RESULTS: A total of 120 patients admitted with malignant hypertension were included. After a median follow-up period of 67 months (IQR 28 to 108 months) the primary endpoint was reached by 37 (31%) patients, whereas 18 patients (15%) reached the secondary endpoint. Twenty-nine (24%) patients started KRT and 8 patients (7%) had an eGFR decline ≥ 50%. After the acute phase (> 3 months after admission), initial serum creatinine and follow-up BP were the main predictors of future ESRD with hazard ratios of 6.1 (95% CI, 2.2-17) for patients with initial serum creatinine ≥ 175 µmol /L and 4.3 (95% CI, 1.4-14) for patients with uncontrolled hypertension. CONCLUSIONS: Progressive renal function decline leading to ESRD remains a major threat to patients with malignant hypertension. BP control during follow-up was an important modifiable predictor of renal outcome.

Alcohol consumption and risk of cardiovascular disease among hypertensive women.

AIM: This study investigated the relation between alcohol consumption and the risk of cardiovascular disease (CVD) among 10 530-hypertensive women from the EPIC-NL cohort. METHODS AND RESULTS: Alcohol consumption was assessed using a validated food-frequency questionnaire and participants were followed for occurrence of CVD. During 9.4 years follow-up, we documented 580 coronary heart disease (CHD) events and 254 strokes, 165 of which were ischemic. An inverse association (Ptrend=0.009) between alcohol consumption and risk of CHD was observed with a multivariate-adjusted hazard ratio of 0.72 (95% confidence interval: 0.52-1.01) for those consuming 70-139.9 g alcohol/week compared to lifetime abstainers. Of different beverages, only red wine consumption was associated with a reduced risk of CHD. A U-shaped relation (P=0.08) was observed for total stroke with a hazard ratio of 0.65 (0.44-0.95) for consuming 5-69.9 g alcohol/week compared with lifetime abstainers. Similar results were observed for ischemic stroke with a hazard ratio of 0.56 (0.35-0.89) for consuming of 5-69.9 g alcohol/week. CONCLUSION: We conclude that moderate alcohol consumption is associated with a reduced risk of CHD among hypertensive women. Light alcohol consumption tended to be related to a lower risk of stroke. Current guidelines for alcohol consumption in the general population also apply to hypertensive women.

Efficacy of pro- and anticoagulant strategies in plasma of patients undergoing hepatobiliary surgery.

BACKGROUND: In vitro efficacy of pro- and antihemostatic drugs is profoundly different in patients with compensated cirrhosis and in those who have cirrhosis and are critically ill. OBJECTIVES: Here we assessed the efficacy of pro- and anticoagulant drugs in plasma of patients undergoing hepato-pancreato-biliary (HPB) surgery, which is associated with unique hemostatic changes. METHODS: We performed in vitro analyses on blood samples of 60 patients undergoing HPB surgery and liver transplantation: 20 orthotopic liver transplantations, 20 partial hepatectomies, and 20 pylorus-preserving pancreaticoduodenectomies. We performed thrombin generation experiments before and after in vitro addition of fresh frozen plasma (FFP), prothrombin complex concentrate (PCC), recombinant factor VIIa (rFVIIa), low molecular weight heparin (LMWH), unfractionated heparin, dabigatran, and rivaroxaban. RESULTS: We showed that patients undergoing HPB surgery are in a hypercoagulable state by thrombin generation testing. FFP and rFVIIa had minimal effects on thrombin generation, whereas PCC had a more pronounced procoagulant effect in patients compared with controls. Dabigatran showed a more pronounced anticoagulant effect in patients compared with controls, whereas rivaroxaban and LMWH had a decreased anticoagulant effect in patients. CONCLUSION: We demonstrate profoundly altered in vitro efficacy of commonly used anticoagulants, in patients undergoing HPB surgery compared with healthy controls, which may have implications for anticoagulant dosing in the early postoperative period. In the correction of perioperative bleeding complications, PCCs appear much more potent than FFP or rFVIIa, and PCCs may require conservative dosing and caution in use in patients undergoing HPB surgery.

Haemostatic Profiles are Similar across All Aetiologies of Cirrhosis.

BACKGROUND AND AIM: Patients with cirrhosis may acquire profound changes in haemostasis. Although haemostatic changes in cirrhosis have been extensively studied, most studies were performed in groups of patients with mixed aetiology. As thrombotic events appear more common in some aetiologies of disease, notably non-alcoholic steatohepatitis (NASH) and cholestatic disease, we hypothesized that haemostatic changes might be different across aetiologies. PATIENTS AND METHODS: We studied 109 patients with cirrhosis (31 cholestatic liver disease, 23 NASH, 37 alcoholic liver disease [ALD], 18 viral hepatitis) and 44 healthy controls. Patients with malignancy were excluded. Routine diagnostic tests of haemostasis, thrombin generation assays, fibrin permeability assays and a plasma-based fibrinolytic assay were performed. RESULTS: All patients had comparable severity of disease according to their Model for End-Stage Liver Disease score (9 [7-11]). Plasma levels of von Willebrand factor were substantially elevated across all aetiologies, with a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 levels comparable to controls. Thrombin generation capacity was elevated in all aetiologies, most profoundly in ALD. Fibrin permeability was decreased in all aetiologies, which was accompanied by elevated fibrinogen levels. Clot lysis times were prolonged in NASH and cholestatic disease. Plasma levels of individual proteins were similarly altered in all aetiologies. CONCLUSION: Our in-depth haemostatic profiling of primary, secondary and tertiary haemostasis in a group of patients with Childs-Turcotte-Pugh A/B cirrhosis showed no large differences between aetiologies, and was consistent with a general hypercoagulable profile in patients with mild cirrhosis. These results suggest that patients with cirrhosis have an increased risk of thrombosis, irrespective of their aetiology.

Clinical usefulness of the SAMe-TT2R2 score: A systematic review and simulation meta-analysis.

BACKGROUND: Vitamin K antagonist (VKA) therapy is safer and more effective when patients have a high time within the therapeutic range and low international normalised ratio variability. The SAMe-TT2R2 score aims to identify those at risk for poor VKA control. OBJECTIVES: To evaluate the predictive value and clinical usefulness of the SAMe-TT2R2 score to identify those at risk for poor VKA control. METHODS: We performed a systematic review in MEDLINE and Embase for original research papers assessing the SAMe-TT2R2's relation to poor TTR. We performed a meta-analysis where scores ≥ 2 and ≥ 3 predicting TTR < 70%. When studies evaluated other cutoffs for TTR or SAMe-TT2R2, they were harmonised by multiple simulations with patient characteristics from the individual studies, if the data were available. RESULTS: 16 studies were identified and used in the meta-analysis: 4 and 2 times directly, 8 and 8 times harmonised for scores ≥ 2 and ≥ 3, respectively (not all studies provided information about both cutoffs). The sensitivities and specificities were too heterogeneous to pool. The positive likelihood ratios were 1.25 (1.14-1.38) for a score ≥ 2, and 1.24 (1.09-1.40) for a score ≥ 3; the negative ones were 0.87 (0.82-0.93) and 0.96 (0.91-1.02), respectively. This shows that the post-test probabilities hardly differ from the prior probability (prevalence). CONCLUSION: The SAMe-TT2R2 score does predict low TTR, but the effect is small. Its effect on individual patients is too limited to be clinically useful.