Thrombosis and anticoagulation in liver disease

The incidence of venous thromboembolism and practice of deep venous thrombosis prophylaxis in hospitalized cirrhotic patients

Background

Cirrhotic patients are characterized by a decreased synthesis of coagulation and anticoagulation factors. The coagulopathy of cirrhotic patients is considered to be auto-anticoagulation. Our aim was to determine the incidence and predictors of venous thromboembolism (VTE) and examine the practice of deep venous thrombosis (DVT) prophylaxis among hospitalized cirrhotic patients.

Methods

A retrospective cohort study was performed in a tertiary teaching hospital. We included all adult patients admitted to the hospital with a diagnosis of liver cirrhosis from January 1, 2009 to December 31, 2009. We grouped our cohort patients in two groups, cirrhotic patients without VTE and cirrhotic with VTE.

Results

Over one year, we included 226 cirrhotic patients, and the characteristics of both groups were similar regarding their clinical and laboratory parameters and their outcomes. Six patients (2.7%) developed VTE, and all of the VTEs were DVT. Hepatitis C was the most common (51%) underlying cause of liver cirrhosis, followed by hepatitis B (22%); 76% of the cirrhotic patients received neither pharmacological nor mechanical DVT prophylaxis.

Conclusion

Cirrhotic patients are at risk for developing VTE. The utilization of DVT prophylaxis was suboptimal.

Feasibility and long-term evolution of TIPS in cirrhotic patients with portal thrombosis

AIM

Many researchers consider portal thrombosis (PT) as a contraindication to transjugular intrahepatic portosystemic shunt (TIPS). The aim of this retrospective study was to compare the feasibility and long-term prognosis of TIPS in cirrhotic patients, with and without, complete PT.

PATIENTS AND METHODS

Four hundred and thirty-six consecutive cirrhotic patients with portal hypertension were referred for TIPS, between 1990 and 2004. These patients were divided into two groups according to their portal patency. PT+: 34 patients with complete PT with cavernoma (19) or without (15) cavernoma versus PT-: 402 patients with normal portal patency (308) and partial PT (94). Epidemiological data were compared using the chi and Student's t-tests, and comparative evolution was made from actuarial data using the log-rank test.

RESULTS

PT+ patients were more frequently women with viral hepatitis, and TIPS was performed more often for bleeding indications. The TIPS success rate was significantly lower in the PT+ group (79%) than in the PT- group (99.5%) (P<10). Presence of a cavernoma decreased the success rate to 63%. TIPS was always feasible in cases of recent PT and portal cavernoma with an accessible intrahepatic patent portal branch. Early and late outcome and complications were not significantly different between the two groups.

CONCLUSION

Complete PT does not modify TIPS' long-term outcome. Rather than a contraindication, PT should be considered as an indication for TIPS in cirrhotic patients with accessible intrahepatic portal vein. Further randomized studies should be planned in cirrhotic patients with recent PT to better qualify TIPS and anticoagulation indications, respectively.

Hemostasis and thrombosis in patients with liver disease: the ups and downs

Patients with chronic or acute liver failure frequently show profound abnormalities in their hemostatic system. Whereas routine laboratory tests of hemostasis suggest these hemostatic alterations result in a bleeding diathesis, accumulating evidence from both clinical and laboratory studies suggest that the situation is more complex. The average patient with liver failure may be in hemostatic balance despite prolonged routine coagulation tests, since both pro- and antihemostatic factors are affected, the latter of which are not well reflected in routine coagulation testing. However, this balance may easily tip towards a hypo- or hypercoagulable situation. Indeed, patients with liver disease may encounter both hemostasis-related bleeding episodes as well as thrombotic events. During the 3rd International Symposium on Coagulopathy and Liver disease, held in Groningen, The Netherlands (18-19 September 2009), a multidisciplinary panel of experts critically reviewed the current data concerning pathophysiology and clinical consequences of hemostatic disorders in patients with liver disease. Highlights of this symposium are summarized in this review.

Detection of the imbalance of procoagulant versus anticoagulant factors in cirrhosis by a simple laboratory method

Patients with cirrhosis possess an imbalance in procoagulant versus anticoagulant activity due to increased factor VIII and decreased protein C. This imbalance can be detected by thrombin-generation assays performed in the presence/absence of thrombomodulin (predicate assay) that are not readily available in clinical laboratories. We sought to assess this hypercoagulability with a simpler thrombin-generation assay performed in the presence/absence of Protac, a snake venom that activates protein C in a manner similar to thrombomodulin (new assay). We analyzed blood from 105 patients with cirrhosis and 105 healthy subjects (controls). Results for the predicate-assay or the new-assay were expressed as ratio (with:without thrombomodulin) or as Protac-induced coagulation inhibition (PICI%). By definition, high ratios or low PICI% translate into hypercoagulability. The median(range) PICI% was lower in patients (74% [31%-97%]) than controls (93% [72%-99%]; P < 0.001), indicating that patients with cirrhosis are resistant to the action of Protac. This resistance resulted in greater plasma hypercoagulability in patients who were Child class C than those who were A or B. The hypercoagulability of Child C cirrhosis (63% [31%-92%]) was similar to that observed for patients with factor V Leiden (69% [15%-80%]; P = 0.59). The PICI% values were correlated with the levels of protein C (rho = 0.728, P < 0.001) or factor VIII (rho = -0.517, P < 0.001). Finally, the PICI% values were correlated with the predicate assay (rho = -0.580, P < 0.001).

CONCLUSION

The hypercoagulability of plasma from patients with cirrhosis can be detected with the new assay, which compares favorably with the other markers of hypercoagulability (i.e., high factor VIII and low protein C) and with the predicate-assay based on thrombin-generation with/without thrombomodulin. Advantages of the new assay over the predicate assay are easy performance and standardized results. Prospective trials are needed to ascertain whether it is useful to predict thrombosis in patients with cirrhosis.

Safety and efficacy of anticoagulation therapy with low molecular weight heparin for portal vein thrombosis in patients with liver cirrhosis

BACKGROUND

Treatment of portal vein thrombosis (PVT) in patients with liver cirrhosis is not well established.

AIM

We intended to assess the safety and efficacy of low molecular weight heparin (LMWH) to treat PVT in cirrhotic patients.

STUDY

All 39 patients diagnosed with non-neoplastic PVT and cirrhosis from June 2005 to December 2006 were evaluated for anticoagulation therapy (AT). PVT was occludent in 15.4%, partial in 64.1%, and portal cavernoma presented in 20.5%. Twenty-eight patients received 200 U/kg/d of enoxaparin for at least 6 months. In 39.3% of patients PVT was an occasional finding, in 10.7% presented with acute abdominal pain, in 50% with bleeding from gastroesophageal varices. In this last group LMWH was started after endoscopic eradication of varices by band ligation.

RESULTS

Complete recanalization of portal vein occurred in 33.3%, partial recanalization in 50% and no response in 16.7% of patients. Further 12 patients who continued AT obtained complete recanalization at a median time of 11 months (range 7 to 17 mo). Overall, a complete response was obtained in 75% of patients. No significant side effects, particularly bleeding complications, were observed during the treatment.

CONCLUSIONS

LMWH demonstrated safe and effective in the treatment of PVT in patients with liver cirrhosis.

Systemic thrombolysis of portal vein thrombosis in cirrhotic patients: a pilot study

BACKGROUND

Portal vein thrombosis is a frequent complication in liver cirrhosis. Encouraging reports of systemic thrombolysis in non-cirrhotic patients suffering from acute portal vein thrombosis led us to start a pilot study on the efficacy and safety of systemic low dose recombinant tissue plasminogen activator (Actilyse, Boheringer Ingelheim, Florence, Italy).

PATIENTS

Nine cirrhotic patients (6 males and 3 females) with recent portal vein thrombosis were enrolled. Exclusion criteria were portal cavernomatosis, recent (30 days) surgery, active bleeding, hepatocellular carcinoma and cancer in other sites.

METHODS

All cases were treated for a maximum of 7 days by continuous i.v. infusion of 0.25mg/kg/die of r-tPA plus subcutaneous low molecular weight heparin. Efficacy was evaluated by colour doppler sonography monitoring and confirmed by contrast enhanced computerized tomography.

RESULTS

The combined r-tPA/LMWH treatment was well tolerated without clinically significant side effects. Complete resolution of thrombosis occurred in 4 cases, partial regression in 4 and none in 1. Retreatment of a complete recurrence in 1 patient was successful. Variceal pressure dropped from 30.7+/-4.5 mmHg to 21.2+/-6.6 mmHg (p=0.012).

CONCLUSIONS

Our preliminary data demonstrate that thrombolytic treatment of recent portal vein thrombosis with i.v. r-tPA and LMWH in patients with cirrhosis appears to be safe and effective and can significantly reduce pressure in oesophageal varices.

Abnormalities of hemostasis and bleeding in chronic liver disease: the paradigm is challenged

Chronic liver disease is characterized by a global hemostatic defect including platelet-vessel wall interaction (primary hemostasis), coagulation and fibrinolysis that may cause abnormalities of the relevant laboratory tests. The causal relationship between abnormal tests and bleeding has been widely accepted, despite the fact that abnormal tests are poorly associated with the timing and incidence of actual bleeding. In this article, we review recent evidence from the literature that disputes the above paradigm, and opens new venues for laboratory/clinical research and patient management in this field.

Deep vein thrombosis in patients with advanced liver cirrhosis: a rare condition?

PURPOSE

Patients with liver cirrhosis are generally considered to be "auto-anticoagulated" because of coagulopathy and thrombocytopenia. However, deep vein thrombosis (DVT) has been reported in patients with liver cirrhosis. The objectives of this study were to know the prevalence of DVT among cirrhotic patients and to compare clinical pictures between cirrhotic patients with and without DVT.

METHODS

A case-control study was performed on the basis of medical record data of patients with liver cirrhosis admitted between August 2004 and July 2007 in Medistra hospital in Jakarta. Diagnosis of DVT was established by duplex Doppler ultrasonography of the lower extremities. Patients with splanchnic thrombosis were excluded from this study. Diagnosis of liver cirrhosis was based on history and clinical manifestation, consistent with liver cirrhosis and confirmed by ultrasonography or computed tomography.

RESULTS

A total of 256 patients with liver cirrhosis were included in this study; 164 (64.1%) among them were men. Patients' mean age was 60.5 +/- 12.5 years, ranging from 16 to 88 years. Viral hepatitis accounted for 74.6% of patients with liver cirrhosis. DVT was found in 12 (4.7%) patients. There was no significant laboratory difference between cirrhotic patients with and without DVT (serum albumin, platelet count, aminotransferases, gamma-glutamyl transpeptidase, alkaline phosphatase, total bilirubin levels, and prothrombin time). Diabetes mellitus was significantly higher in the DVT group than that in the control group (66.6 vs. 34.0%, P = 0.025). Multivariate analysis confirmed diabetes mellitus as an independent risk factor for the occurrence of DVT (odds ratio = 4.26; 95% confidence interval = 1.206-15.034; P = 0.024).

CONCLUSIONS

The prevalence of DVT in patients with liver cirrhosis was 4.7%, and Deep vein thrombosis is not a rare condition in cirrhotic patients with coagulopathy and warrants further studies on the mechanisms and prevention.

An imbalance of pro- vs anti-coagulation factors in plasma from patients with cirrhosis

BACKGROUND & AIMS

Patients with cirrhosis have an increased tendency to develop thromboses despite the longer coagulation times of their plasma, compared with that of healthy individuals. We investigated whether plasma from cirrhotic patients has an imbalance of pro- vs anti-coagulation factors.

METHODS

We analyzed blood samples from 134 cirrhotic patients and 131 healthy subjects (controls) for levels of pro- and anti-coagulants and for thrombin generation in the presence or absence of thrombomodulin (the main physiologic activator of the protein C anticoagulant pathway).

RESULTS

The median ratio of thrombin generation (with/without thrombomodulin) was higher in patients (0.80; range, 0.51-1.06) than controls (0.66; range, 0.17-0.95), indicating that cirrhotic patients are resistant to the action of thrombomodulin. This resistance resulted in greater hypercoagulability of plasma from patients of Child-Pugh class C than of class A or B. The hypercoagulability of plasma from patients of Child-Pugh class C (0.86; range, 0.70-1.06) was slightly greater than that observed under the same conditions in patients with congenital protein C deficiency (0.76; range, 0.60-0.93). Levels of factor VIII, a potent pro-coagulant involved in thrombin generation, increased progressively with Child-Pugh score (from Child-Pugh class A to C). Levels of protein C, one of the most potent naturally occurring anti-coagulants, showed the opposite trend.

CONCLUSIONS

The hypercoagulability of plasma from patients with cirrhosis appears to result from increased levels of factor VIII and decreased levels of protein C-typical features of patients with cirrhosis. These findings might explain the risk for venous thromboembolism in patients with chronic liver disease.

Management of portal vein thrombosis in cirrhotic patients

Portal vein thrombosis (PVT) not associated with hepatocellular carcinoma is considered a frequent complication of liver cirrhosis but, unlike PVT occurring in non-cirrhotic patients, very few data are available on its natural history and management. The reduced portal blood flow velocity is the main determinant of PVT but, as in other venous thromboses, multiple factors local and systemic, inherited or acquired often can concur with. PVT has a variety of clinical presentations ranging from asymptomatic to life-threatening diseases like gastroesophageal bleeding or acute intestinal ischemia. It is usually diagnosed by Doppler ultrasound but computed tomography and magnetic resonance imaging are useful to study the extent of thrombosis and the involvement of the abdominal organs. The risk of bleeding mainly determined by the presence of gastroesophageal varices and clotting alterations causes concern for the treatment of PVT in cirrhotic patients. To date, anticoagulant therapy seems to be indicated only in patients awaiting liver transplantation. This review focuses on the definition of the subgroups of patients with cirrhosis that might benefit from treatment of PVT and examines the pros and cons of the available treatments in terms of efficacy, monitoring and safety, providing also perspectives for future studies.

Primary Budd-Chiari syndrome

Primary Budd-Chiari syndrome is characterized by a blocked hepatic venous outflow tract at various levels from small hepatic veins to inferior vena cava, resulting from thrombosis or its fibrous sequellae. This rare disease affects mainly young adults. Multiple risk factors have been identified and are often combined in the same patient. Myeloproliferative diseases of atypical presentation account for nearly 50% of patients; their diagnosis can be made by showing the V617F mutation in Janus tyrosine kinase-2 gene of peripheral blood granulocytes and, should this mutation be absent, by showing clusters of dystrophic megacaryocytes at bone marrow biopsy. Presentation and manifestations are extremely varied, so that the diagnosis must be considered in any patient with acute or chronic liver disease. Doppler-ultrasound, computed tomography or magnetic resonance imaging of hepatic veins and inferior vena cava are usually successful in demonstrating non-invasively the obstacle or its consequences, the collaterals to hepatic veins or inferior vena cava. The disease is considered to be spontaneously lethal within 3 years of first symptoms. A therapeutic strategy has been proposed where anticoagulation, correction of risk factors, diuretics and prophylaxis for portal hypertension are used first; then angioplasty for short-length venous stenoses; then TIPS; and ultimately liver transplantation. Treatment progression is dictated by the response to previous therapy. This strategy has achieved 5-year survival rates approaching 90%. Medium-term prognosis depends on the severity of liver disease. Long-term outcome might be jeopardized by transformation of underlying conditions and hepatocellular carcinoma.