Perioperative management of antithrombotic treatment

Coagulation factor XI in cirrhosis does not predict thrombo-hemorrhagic complications and hepatic decompensation

INTRODUCTION

Factor XI (FXI) is associated with thrombosis in patients without liver disease, but it alterations and prognostic value in cirrhosis are uncertain.

PATIENTS AND METHODS

We studied a prospective cohort of cirrhosis patients determining FXI and its association with portal vein thrombosis (PVT), bleeding, and hepatic decompensation/ACLF during 1-year follow-up. Odds ratios (OR) and 95 % CIs were calculated using logistic regression.

RESULTS

We included 183 patients (Child-Pugh [CP] A/B/C 57/59/57). FXI was reduced in cirrhosis, decreasing with CP stage (78 % [66-94] vs. 58 % [44-78] vs. 41 % [30-52] in CP A, B, and C, respectively; p < 0.001). FXI was correlated with MELD score (rho: -0.6, p < 0.001), INR (rho: -0.6, p < 0.001), and platelet count (rho: 0.4, p < 0.001). Sixteen patients (8.7 %) experienced PVT, which only predictor was baseline platelet count (OR: 0.94; CI95 %: 0.91-0.97, p < 0.001). Bleeding occurred in 7 patients (3.8 %). Cirrhosis severity, platelet count, fibrinogen, and FXI (60% vs. 78 %; p = 0.2) were comparable between bleeding and non-bleeding individuals. Finally, no association was found between FXI and hepatic decompensation/ACLF, which were predicted by lower albumin and platelet count, respectively.

CONCLUSION

FXI seems not to be responsible for thrombosis and cirrhosis progression. The lack of association between low FXI and bleeding events, however, indirectly opens to future studies evaluating FXI inhibitors in cirrhosis.

The evolving knowledge on primary hemostasis in patients with cirrhosis: A comprehensive review

Patients with cirrhosis develop complex alterations in primary hemostasis that include both hypocoagulable and hypercoagulable features. This includes thrombocytopenia, multiple alterations of platelet function, and increased plasma levels of von Willebrand factor. Contrary to the historical view that platelet dysfunction in cirrhosis might be responsible for an increased bleeding tendency, the current theory posits a rebalanced hemostasis in patients with cirrhosis. Severe thrombocytopenia is not indicative of the bleeding risk in patients undergoing invasive procedures and does not dictate per se the need for pre-procedural prophylaxis. A more comprehensive and individualized risk assessment should combine hemostatic impairment, the severity of decompensation and systemic inflammation, and the presence of additional factors that may impair platelet function, such as acute kidney injury and bacterial infections. Although there are multiple, complex alterations of platelet function in cirrhosis, their net effect is not yet fully understood. More investigations evaluating the association between alterations of platelet function and bleeding/thrombosis may improve risk stratification in patients with decompensated cirrhosis. Besides hemostasis, the assessment of von Willebrand factor Ag and ADP-induced, whole-blood platelet aggregation normalized by platelet count (VITRO score and PLT ratio) are promising biomarkers to predict the risk of hepatic decompensation and survival in both compensated and decompensated patients. Further investigations into the in vivo interplay between platelets, circulating blood elements, and endothelial cells may help advance our understanding of cirrhotic coagulopathy. Here, we review the complex changes in platelets and primary hemostasis in cirrhosis and their potential clinical implications.

Quick model-based viscoelastic clot strength predictions from blood protein concentrations for cybermedical coagulation control

Cybermedical systems that regulate patient clotting in real time with personalized blood product delivery will improve treatment outcomes. These systems will harness popular viscoelastic assays of clot strength such as thromboelastography (TEG), which help evaluate coagulation status in numerous conditions: major surgery (e.g., heart, vascular, hip fracture, and trauma); liver cirrhosis and transplants; COVID-19; ICU stays; sepsis; obstetrics; diabetes; and coagulopathies like hemophilia. But these measurements are time-consuming, and thus impractical for urgent care and automated coagulation control. Because protein concentrations in a blood sample can be measured in about five minutes, we develop personalized, phenomenological, quick, control-oriented models that predict TEG curve outputs from input blood protein concentrations, to facilitate treatment decisions based on TEG curves. Here, we accurately predict, experimentally validate, and mechanistically justify curves and parameters for common TEG assays (Functional Fibrinogen, Citrated Native, Platelet Mapping, and Rapid TEG), and verify results with trauma patient clotting data.

Haemostasis in cirrhosis: Understanding destabilising factors during acute decompensation

Hospitalised patients with decompensated cirrhosis are in a rebalanced haemostatic state due to a parallel decline in both pro- and anti-haemostatic pathways. However, this rebalanced haemostatic state is highly susceptible to perturbations and may easily tilt towards hypocoagulability and bleeding. Acute kidney injury, bacterial infections and sepsis, and progression from acute decompensation to acute-on-chronic liver failure are associated with additional alterations of specific haemostatic pathways and a higher risk of bleeding. Unfortunately, there is no single laboratory method that can accurately stratify an individual patient's bleeding risk and guide pre-procedural prophylaxis. A better understanding of haemostatic alterations during acute illness would lead to more rational and individualised management of hospitalised patients with decompensated cirrhosis. This review will outline the latest findings on haemostatic alterations driven by acute kidney injury, bacterial infections/sepsis, and acute-on-chronic liver failure in these difficult-to-treat patients and provide evidence supporting more tailored management of bleeding risk.

Increased platelet aggregation in patients with decompensated cirrhosis indicates higher risk of further decompensation and death

BACKGROUND & AIMS

Studies on platelet aggregation in cirrhosis are controversial because interpretation of platelet function is challenged by thrombocytopenia. We conducted a prospective study to investigate whole blood platelet aggregation in cirrhosis and its association with liver-related outcomes.

METHODS

Platelet aggregation was assessed by whole blood aggregometry (Multiplate®). To overcome the influence of platelet count and compare cirrhosis with thrombocytopenia vs. controls with normal platelet count, we calculated a ratio between platelet aggregation and platelet count (PLT ratio). Then, we prospectively followed patients with cirrhosis and ascertained predictors of decompensation, transplantation, and death.

RESULTS

Two-hundred and three patients with cirrhosis were prospectively recruited (77% decompensated). PLT ratio was significantly higher in cirrhosis than in those with chronic hepatitis and healthy individuals (0.44 vs. 0.25 and 0.26, respectively; p <0.0001). In cirrhosis, the ratio increased with disease severity (Child-Pugh class C>B>A) and was particularly elevated in decompensated patients with severe thrombocytopenia. Among decompensated patients, 65 had further decompensation, underwent transplantation, or died during a 6-month follow-up. On multivariate analysis, PLT ratio (odds ratio 1.87; 95% CI 1.23-2.84; p = 0.003) and MELD score (odds ratio 1.05; 95% CI 1.01-1.08; p = 0.01) were independently associated with outcome. The relative risk of events was 7.5-fold higher in patients with PLT ratio >0.75 vs. patients with PLT ratio <0.25 (95% CI 2.5-21.9; p = 0.003). The increased PLT ratio, its discriminative ability for composite outcome, and the prognostic value of PLT ratio >0.75 were confirmed in an independent cohort of hospitalized patients with decompensated cirrhosis (n = 41).

CONCLUSIONS

Patients with cirrhosis, particularly when decompensated, exhibit significantly increased whole blood platelet aggregation. Decompensated patients with a PLT ratio >0.75 have a >80% probability of further decompensation, transplantation, or liver-related death within 6 months.

LAY SUMMARY

In patients with cirrhosis, previous studies have suggested that platelets (i.e. circulating blood cells that help form clots to stop bleeding) are dysfunctional. In particular, these studies suggested that platelet aggregation (the process by which platelets adhere to each other to form clots) is reduced. Since platelet aggregation is important for clot formation, it has been hypothesized that alterations of platelet aggregation may be responsible for the increased risk of bleeding observed in patients with cirrhosis. Our study demonstrates: i) that platelet aggregation in patients with cirrhosis is higher than in healthy individuals; ii) that platelet aggregation in patients with decompensated cirrhosis (i.e. those who have already experienced some complications of cirrhosis) is particularly elevated and associated with risk of further complications and death.

Management of Acute Coronary Syndrome in Patients with Liver Cirrhosis

Liver cirrhosis (LC) is becoming increasingly common among patients presenting with acute coronary syndromes (ACS) and is associated with significant cardiovascular morbidity and mortality. Management of such patients is complicated by LC related complications. Literature is scarce on the safety of antithrombotic regimens and invasive strategies for ACS in patients with LC, especially those undergoing liver transplant evaluation. Recently there has been evidence that cirrhosis is an independent risk factor for adverse outcomes in ACS. As patients with LC are generally excluded from large randomized trials, definitive guidelines for the management of ACS in this particular cohort are lacking. Many antithrombotic drugs require either hepatic activation or clearance; hence, an accurate assessment of hepatic function is required prior to initiation and dose adjustment. Despite a demonstrated survival benefit of optimal medical therapy and invasive revascularization techniques in LC patients with ACS, both strategies are currently underutilized in this population. This review aims to present currently available data and provide a practical, clinically oriented approach for the management of ACS in LC. Randomized clinical trials in LC patients with ACS are the need of the hour to further refine their management for favorable outcomes.

Recent Advances in the Management of Acute Variceal Hemorrhage

Gastrointestinal bleeding is one of the most relevant causes of death in patients with cirrhosis and clinically significant portal hypertension, with gastroesophageal varices being the most frequent source of hemorrhage. Despite survival has improved thanks to the standardization on medical treatment aiming to decrease portal hypertension and prevent infections, mortality remains significant. In this review, our goal is to discuss the most recent advances in the management of esophageal variceal hemorrhage in cirrhosis with specific attention to the treatment algorithms involving the use of indirect measurement of portal pressure (HVPG) and transjugular intrahepatic portosystemic shunt (TIPS), which aim to further reduce mortality in high-risk patients after acute variceal hemorrhage and in the setting of secondary prophylaxis.

Reduced Clot Stability by Thromboelastography as a Potential Indicator of Procedure-Related Bleeding in Decompensated Cirrhosis

In patients with decompensated cirrhosis, procedure-related bleeding is a potentially lethal complication. Routine coagulation tests such as international normalized ratio and platelet count do not predict bleeding risk. We investigated whether thromboelastography (TEG) can identify patients with cirrhosis who are at risk of procedure-related bleeding. As a part of a prospective study on hemostasis in decompensated cirrhosis, patients had TEG performed on admission and were followed prospectively during hospitalization for the development of procedure-related bleeding. Eighty patients with cirrhosis were included. Among the 72 who had procedures performed, 7 had procedure-related bleeding, which was major in three cases (two following paracentesis and one following thoracentesis). Conventional coagulation tests were comparable between bleeding and nonbleeding patients, whereas TEG parameters of k-time (4.5 minutes vs. 2.2 minutes; P = 0.02), α-angle (34° vs. 59°; P = 0.003), and maximum amplitude (37 mm vs. 50 mm; P = 0.004) were significantly different (all indicative of hypocoagulability). TEG maximum amplitude (MA), a marker of overall clot stability, accurately discriminated between patients who had major, life-threatening bleeding (all with MA < 30 mm) and those who had mild or no bleeding (all with MA > 30 mm), whereas a platelet count < 50 × 109/L could not discriminate between bleeding (minor or major) and nonbleeding patients. Conclusion: In a prospective cohort of hospitalized patients with decompensated cirrhosis, TEG parameters associated with hypocoagulability appeared to predict procedure-related bleeding, particularly a TEG MA < 30 mm. If results are validated in a larger cohort, this could be a threshold to identify patients with decompensated cirrhosis at higher risk for procedure-related bleeding, in whom to consider preprocedural prophylaxis.