From the Guidelines

No, VTE prophylaxis is not contraindicated in decompensated cirrhosis with elevated INR.

Patients with cirrhosis are at increased risk of venous thromboembolism (VTE) and may benefit from prophylaxis 1.
Low molecular weight heparin (LMWH) such as enoxaparin 40mg subcutaneously daily or unfractionated heparin can be used for VTE prophylaxis in these patients, with close monitoring of their coagulation parameters and platelet count 1.
The dose of LMWH may need to be adjusted based on anti-Xa levels to minimize the risk of bleeding, as the anticoagulant effect of LMWH may be different in patients with cirrhosis compared to patients with adequate liver function 1.
It is essential to weigh the benefits and risks of VTE prophylaxis in each individual patient and to closely monitor for signs of bleeding or thrombosis, as the use of LMWH in patients with cirrhosis is complicated by haemostatic changes and monitoring issues 1.
Close monitoring is required to avoid side effects and to maintain the patient in a therapeutic range, especially when using vitamin K antagonists, which have a narrow therapeutic range and significant drug-drug interactions 1.
Some data suggest that anticoagulation is a relatively safe treatment that may lead to partial or complete recanalisation of the portal vein in patients with cirrhosis and portal vein thrombosis (PVT) 1.
Bleeding complications are a significant concern, with a retrospective study showing that 83% of patients with cirrhosis and non-splanchnic VTE suffered from bleeding complications, and 35% required blood transfusions 1.

From the Research

The use of pharmacological prophylaxis for venous thromboembolism (VTE) in patients with cirrhosis remains controversial 2, 3, 4.
Patients with cirrhosis are at higher risk for both bleeding and thrombosis-related complications, and cirrhosis affects production of both procoagulant and anticoagulant factors, resulting in increased INR and aPTT levels and decreased anti-Xa levels 2.
The available evidence does not support the "autoanticoagulation" theory, which suggests that patients with cirrhosis and elevated INR values may not benefit from VTE risk-reduction therapies 3.
In hospitalized patients with cirrhosis who have elevated INR values, pharmacologic VTE prophylaxis should be strongly considered if there is no active or recent bleeding and if more than one risk factor for VTE is present 3.
Low-molecular-weight heparin (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 2.
The safety and efficacy of VTE prophylaxis in patients with cirrhosis have been evaluated in a systematic review and meta-analysis, which found that prophylaxis was not associated with increased bleeding risk, but current evidence is insufficient to advise for or against its use 4.

Independent predictors of VTE in patients with cirrhosis include malnutrition and significant comorbidities such as chronic kidney disease and congestive heart failure 3.
Serum albumin may serve as a reliable marker of coagulation status and, therefore, VTE risk in patients with cirrhosis 3.
Patients with cirrhosis have a high incidence of portal venous thrombosis, implying that cirrhotic coagulopathy does not fully protect against thrombosis 5, 6.

Except in patients with absolute contraindications to anticoagulant drugs, antithrombotic prophylaxis should always be considered in hospitalized patients with cirrhosis, especially in those with multiple VTE risk factors 3, 5, 6.
The need for VTE prophylaxis in patients on chronic treatment with antiplatelet agents should be evaluated after assessing the individual risk of bleeding complications 5, 6.
The selection of patients who require post-discharge pharmacological prophylaxis remains debated, and new molecules currently under development may contribute to improving the risk/benefit ratio of VTE primary prevention in this setting of patients 5.