Prophylactic anticoagulation in cirrhotics: a paradox for prime time?

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.

Thrombosis and anticoagulation in the setting of renal or liver disease

Thrombosis and bleeding are among the most common causes of morbidity and mortality in patients with renal disease or liver disease. The pathophysiology underlying the increased risk for venous thromboembolism and bleeding in these 2 populations is distinct, as are considerations for anticoagulation. Anticoagulation in patients with kidney or liver disease increases the risk of bleeding; this risk is correlated with the degree of impairment of anticoagulant elimination by the kidneys and/or liver. Despite being in the same pharmacologic category, anticoagulant agents may have varied degrees of renal and liver metabolism. Therefore, specific anticoagulants may require dose reductions or be contraindicated in renal impairment and liver disease, whereas other drugs in the same class may not be subject to such restrictions. To minimize the risk of bleeding, while ensuring an adequate therapeutic effect, both appropriate anticoagulant drug choices and dose reductions are necessary. Renal and hepatic function may fluctuate, further complicating anticoagulation in these high-risk patient groups.

Resistance to thrombomodulin is associated with de novo portal vein thrombosis and low survival in patients with cirrhosis

BACKGROUND & AIMS

Portal vein thrombosis (PVT) is frequently observed in cirrhosis and may be a clinically important complication. In vitro assays for endogenous thrombin potential (ETP) demonstrated that in cirrhosis plasma has intrinsic resistance to the anticoagulant action of thrombomodulin (TM-R). This study retrospectively explores the association of TM-R with de novo PVT and its clinical impact on cirrhosis.

METHODS

Fifty-three patients with cirrhosis were tested for ETP-ratio with/without thrombomodulin. Clinical, endoscopic variables, presence/absence of PVT by Doppler-US and/or CT examination were collected at baseline and up to 4 years from baseline. The de novo PVT was the primary clinical end-point. Portal hypertension (PHT)-related complications and transplantation free survival were secondary end-points. ETP-ratio higher than the 95° percentile of the distribution in 173 healthy controls defined TM-R.

RESULTS

During 48 months of follow-up, 11 patients developed de novo PVT, with preference for the 36 patients with TM-R after adjusting for Child-Pugh class (HR: 8.354; 90%CI:1.475 - 47.305; P = 0.009). Seventeen patients experienced PHT-related complications, 23 either died or underwent liver transplantation. PHT complications and transplantation free survival were associated with TM-R, but were independently predicted by Child-Pugh class, only. Same results were obtained by considering the MELD score.

CONCLUSIONS

Owing to PVT results from the pro-coagulant imbalance occurring in patients with advanced cirrhosis, TM-R might serve as a predictor and could possibly be a biological mediator of adverse outcome in patients with advanced cirrhosis.

Anticoagulation in Patients With Cirrhosis: Caught Between a Rock-Liver and a Hard Place

OBJECTIVE

To review current literature for anticoagulation in patients with cirrhosis and provide a summary of the effects of cirrhosis on the coagulation cascade, therapeutic monitoring through interpretation of antifactor Xa (anti-Xa), activated partial thromboplastin time (aPTT), and international normalized ratio (INR) as well as current prophylaxis and treatment recommendations in cirrhotic patients.

METHODS

A systematic electronic literature search was conducted in PubMed using the key termsanticoagulation, warfarin, low-molecular-weight heparin(LMWH),unfractionated heparin(UFH),target-specific oral anticoagulants, deep-vein thrombosis(DVT),pulmonary embolism(PE),portal vein thrombosis(PVT),venous thromboembolism, anti-Xa, activated partial thromboplastin time, anticoagulation therapeutic monitoring, coagulopathy, coagulation cascade, chronic liver disease, cirrhosis, anddecompensated liver disease

STUDY SELECTION

Studies written in the English language from January 2000 to December 2015 were considered for this review article. All search results were reviewed, and the relevance of each article was determined by authors independently.

CONCLUSIONS

Patients with cirrhosis are at higher risk for both bleeding and thrombosis-related complications. Cirrhosis affects production of both procoagulant and anticoagulant factors, thus resulting in increased INR and aPTT levels and decreased anti-Xa levels. LMWH is the treatment of choice for the prevention and treatment of DVT/PE/PVT in patients with cirrhosis, and monitoring with anti-Xa levels for dose adjustment is not recommended. UFH is an alternative in cirrhotic patients for shorter-term use and in cases of severe renal dysfunction and/or hemodynamic instability. Cirrhotic patients on anticoagulation therapy should be monitored closely for signs and symptoms of bleeding and thrombosis.

Management of portal vein thrombosis in liver cirrhosis

Portal vein thrombosis (PVT) is a fairly common complication of liver cirrhosis. Importantly, occlusive PVT might influence the prognosis of patients with cirrhosis. Evidence from a randomized controlled trial has shown that anticoagulation can prevent the occurrence of PVT in patients with cirrhosis without prior PVT. Evidence from several case series has also demonstrated that anticoagulation can achieve portal vein recanalization in patients with cirrhosis and PVT. Early initiation of anticoagulation therapy and absence of previous portal hypertensive bleeding might be positively associated with a high rate of portal vein recanalization after anticoagulation. However, the possibility of spontaneous resolution of partial PVT questions the necessity of anticoagulation for the treatment of partial PVT. In addition, a relatively low recanalization rate of complete PVT after anticoagulation therapy suggests its limited usefulness in patients with complete PVT. Successful insertion of a transjugular intrahepatic portosystemic shunt (TIPS) not only recanalizes the thrombosed portal vein, but also relieves the symptomatic portal hypertension. However, the technical difficulty of TIPS potentially limits its widespread application, and the risk and benefits should be fully balanced. Notably, current recommendations regarding the management of PVT in liver cirrhosis are insufficient owing to low-quality evidence.