The Spectrum of Disease Severity in Cirrhosis and Its Implications for Hemostasis

Prothrombin conversion and thrombin decay in patients with cirrhosis-role of prothrombin and antithrombin deficiencies

BACKGROUND

Thrombin generation (TG) in the presence of thrombomodulin (TG-TM) in the plasma of patients with cirrhosis (PWC) is tilted toward a hypercoagulable phenotype. Low protein C and elevated factor VIII levels play a role, but other determinants, such as the prothrombin/antithrombin pair, must also be studied.

OBJECTIVES

The objectives were (i) to quantitatively assess the subprocesses (prothrombin conversion and thrombin decay) and (ii) to understand the underlying mechanism by studying TG dynamics after prothrombin and antithrombin plasma level correction in PWC.

METHODS

We studied TG-TM in plasma samples of 36 healthy controls (HCs) and 41 PWC with prothrombin and antithrombin levels of <70% and after their correction. We initiated coagulation with an intermediate picomolar concentration of tissue factor. We determined the overall thrombin potential, prothrombin conversion, and thrombin decay.

RESULTS

TG-TM was increased in PWC compared with HC due to impaired thrombin inhibition. Indeed, thrombin decay capacity (min-1) decreased from 0.37 (0.35-0.40) in HC to 0.33 (0.30-0.37) in the Child-Turcotte-Pugh A (CTP-A; P = .09), 0.27 (0.26-0.30) in the CTP-B (P < .001), and 0.20 (0.19-0.20) in the CTP-C (P < .001) group. Concomitant correction of prothrombin and antithrombin increased endogenous thrombin potential with prothrombin conversion surpassing thrombin decay. By contrast, when we corrected only antithrombin, TG-TM was normalized and even consistent with a hypocoagulable phenotype in the CTP-C group.

CONCLUSION

Our results highlight that in PWC, hypercoagulability (evidenced in the presence of TM) is due to impaired thrombin decay, whereas low prothrombin levels do not translate into decreased prothrombin conversion, likely due to altered TM-activated protein C negative feedback.

Procedural-Related Bleeding in Hospitalized Patients With Liver Disease (PROC-BLeeD): An International, Prospective, Multicenter Observational Study

BACKGROUND & AIMS

Hospitalized patients with cirrhosis frequently undergo multiple procedures. The risk of procedural-related bleeding remains unclear, and management is not standardized. We conducted an international, prospective, multicenter study of hospitalized patients with cirrhosis undergoing nonsurgical procedures to establish the incidence of procedural-related bleeding and to identify bleeding risk factors.

METHODS

Hospitalized patients were prospectively enrolled and monitored until surgery, transplantation, death, or 28 days from admission. The study enrolled 1187 patients undergoing 3006 nonsurgical procedures from 20 centers.

RESULTS

A total of 93 procedural-related bleeding events were identified. Bleeding was reported in 6.9% of patient admissions and in 3.0% of the procedures. Major bleeding was reported in 2.3% of patient admissions and in 0.9% of the procedures. Patients with bleeding were more likely to have nonalcoholic steatohepatitis (43.9% vs 30%) and higher body mass index (BMI; 31.2 vs 29.5). Patients with bleeding had a higher Model for End-Stage Liver Disease score at admission (24.5 vs 18.5). A multivariable analysis controlling for center variation found that high-risk procedures (odds ratio [OR], 4.64; 95% confidence interval [CI], 2.44-8.84), Model for End-Stage Liver Disease score (OR, 2.37; 95% CI, 1.46-3.86), and higher BMI (OR, 1.40; 95% CI, 1.10-1.80) independently predicted bleeding. Preprocedure international normalized ratio, platelet level, and antithrombotic use were not predictive of bleeding. Bleeding prophylaxis was used more routinely in patients with bleeding (19.4% vs 7.4%). Patients with bleeding had a significantly higher 28-day risk of death (hazard ratio, 6.91; 95% CI, 4.22-11.31).

CONCLUSIONS

Procedural-related bleeding occurs rarely in hospitalized patients with cirrhosis. Patients with elevated BMI and decompensated liver disease who undergo high-risk procedures may be at risk to bleed. Bleeding is not associated with conventional hemostasis tests, preprocedure prophylaxis, or recent antithrombotic therapy.

Blood products and liver transplantation: A strategy to balance optimal preparation with effective blood stewardship

BACKGROUND

Unanticipated transfusion requirements during liver transplantation can delay lifesaving intraoperative resuscitation and strain blood bank resources. Risk-stratified preoperative blood preparation can mitigate these deleterious outcomes.

STUDY DESIGN AND METHODS

A two-tiered blood preparation protocol for liver transplantation was retrospectively evaluated. Eleven binary variables served as criteria for high-risk (HR) allocation. Primary outcomes included red blood cell (RBC), plasma (FFP), and platelet (Plt) utilization. Secondary outcomes included product under- and overpreparation. Contingency tables for transfusion requirements above the population means were generated using 15 clinical variables. Modified protocols were developed and retrospectively optimized using the study population.

RESULTS

Of 225 recipients, 102 received HR preoperative orders, which correlated to higher intraoperative transfusion requirements. However, univariate analysis identified only two statistical risk factors per product: Hgb ≤7.8 g/dl (p < .001) and MELD ≥38 (p = .035) for RBCs, Hgb ≤7.8 g/dl (p = .002) and acute alcoholic hepatitis (p = 0.015) for FFP, and Hgb ≤7.8 g/dl (p = .001) and normothermic liver preservation (p = .037) for Plts. Based on these findings, we developed modified protocols for individual products, which were evaluated retrospectively for their effectiveness at reducing under-preparatory events while limiting product overpreparation. Cohort statistics were used to define the preparation strategy for each protocol. Retrospective comparative analysis demonstrated the superiority of the modified protocols by improving the under-preparation rate from 24% to <10% for each product, which required a 1.56-fold and 1.44-fold increase in RBC and FFP overpreparation, respectively. Importantly, there was no difference in Plt overpreparation.

DISCUSSION

We report translatable data-driven blood bank preparation protocols for liver transplantation.

Coagulopathy and hemostasis management in patients undergoing liver transplantation: Defining a dynamic spectrum across phases of care

Patients with acute and chronic liver disease present with a wide range of disease states and severity that may require liver transplantation (LT). Physiologic alterations occur that are dynamic throughout all phases of perioperative care, creating complex management scenarios that necessitate multidisciplinary clinical care. Specifically, alterations in hemostasis in liver disease can be pronounced and evolve with disease progression over time. Recent studies and society guidance address this emerging paradigm and offer recommendations to assist with hemostatic management in patients with liver disease. However, patients undergoing LT are unique and diverse, often with unstable disease that requires specialized approaches. Our aim is to provide a focused review of hemostatic management of the LT patient, distinguish unique aspects of the three main phases of care (before LT, perioperative, and after LT), and identify knowledge gaps and critical areas of future research.

Liver status and outcomes in patients without previous known liver disease receiving anticoagulant therapy for venous thromboembolism

The association between elevated liver enzymes or FIB-4 (fibrosis index 4) and outcome in patients with venous thromboembolism (VTE) has not been evaluated. Data from patients in RIETE (Registro Informatizado Enfermedad TromboEmbólica) were used to assess the association between elevated liver enzymes or FIB-4 levels and the rates of major bleeding or death in apparent liver disease-free patients with acute VTE under anticoagulation therapy. A total of 6206 patients with acute VTE and without liver disease were included. Of them, 92 patients had major bleeding and 168 died under anticoagulation therapy. On multivariable analysis, patients with elevated liver enzymes were at increased mortality risk (HR: 1.58; 95% CI: 1.10-2.28), while those with FIB-4 levels > 2.67 points were at increased risk for major bleeding (HR: 1.69; 95% CI: 1.04-2.74). Evaluation of liver enzymes and FIB-4 index at baseline in liver disease-free patients with VTE may provide additional information on the risk for major bleeding or death during anticoagulation.

Fibrin clot quality in acutely ill cirrhosis patients: Relation with outcome and improvement with coagulation factor concentrates

BACKGROUND & AIMS

Patients with liver disease may acquire substantial changes in their hemostatic system, which are most pronounced in patients who are critically ill. Changes in the quality of the fibrin clot in critically ill patients have not been studied in detail. Here we assessed markers of fibrin clot quality and effects of coagulation factor concentrates in patients with acutely decompensated (AD) cirrhosis and acute on chronic liver failure (ACLF).

METHODS

We measured plasma levels of fibrinogen, factor XIII, prothrombin and performed thrombin generation assays in 52 AD patients, 58 ACLF patients and 40 controls. In addition, we examined the effects of coagulation factor concentrates on functional assays of fibrin quality.

RESULTS

We found increased thrombin generating capacity in both AD and ACLF in comparison with healthy controls. Plasma levels of prothrombin, fibrinogen, and factor XIII were lower in patients compared to controls, appeared lower in ACLF compared to AD patients, and were related to clinical outcomes. Fibrinogen concentrate, but not factor XIII or prothrombin complex concentrate, improved clot quality in vitro. Prothrombin complex concentrate increased the resistance of the clot to break down.

CONCLUSIONS

We have demonstrated elevated thrombin generation but decreased plasma levels of prothrombin, fibrinogen and FXIII in acutely ill patients with cirrhosis. In addition, we showed that fibrinogen concentrate and PCCs, but not factor XIII concentrate, improve clot properties in patient plasma. Whether there is true clinical benefit from coagulation factor concentrates in prevention or treatment of bleeding requires further study.

LAY SUMMARY

Patients with liver diseases are at risk of bleeding, but mechanisms involved in this bleeding risk are incompletely understood. We studied components that determine the stability of the blood clot and found that concentrations of certain proteins involved in clot stability are present in low levels in acutely ill patients with liver disease. We furthermore demonstrated that some clinically available drugs improve the stability of blood clots from these patients in a test tube.