Point-of-care Measurement of the Antifibrinolytic Activity of Tranexamic Acid in Cardiac Surgery

NCT ID: NCT06128330

Last Updated: 2025-06-06

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE4
• Total Enrollment: 322 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-12-15
• Study Completion Date: 2026-12-31

Brief Summary

Tranexamic acid (TXA) is a widely used antifibrinolytic agent that can reduce postoperative blood loss and packed red blood cell transfusions during cardiac surgery. Previous (in-vivo) studies have measured TXA plasma concentration and associated clinical effect (e.g. blood loss). Patient blood management guidelines recommend the routine use of TXA in cardiac surgery, especially for procedures with a high risk of bleeding.

A new point-of-care viscoelastic diagnostic assay (tissue plasminogen activator assay, TPA assay) allows for a rapid determination of antifibrinolytic activity in a patient in the operating room making TXA dose adjustment easily possible intraoperatively. Currently, there is no consensus on the dosing of TXA and different protocols are used. Recommendations for high doses (e.g. 30 mg/kg followed by 16 mg/kg per hour during cardiac surgery with 2 mg/kg added to extracorporeal circulation) alternate with recommendations for low doses (e.g., 10 mg/kg followed by 1 mg/kg per hour for 12 hours).

Tranexamic acid administration increases the risk of postoperative seizure, a risk that appears to be dose dependant. A recent meta-analysis suggests that a single TXA bolus of 20 mg/kg is sufficient to reduce postoperative blood loss and packed red blood cell transfusion in patients undergoing aortocoronary bypass surgery. The calculations in the meta-analysis were, however, based on a simulation of blood concentrations of TXA by a pharmacokinetic model, so the results are subject to many uncertainties. The optimal TXA regimen for cardiac surgery, both in terms of efficacy and safety therefore remains uncertain and requires further investigation.

This study was invented to determine the actual levels of tranexamic acid in vivo to observe antifibrinolytic activity during cardiac surgery up to 48 hours after termination of surgery. The risk category is evaluated as risk category A as the study is a clinical trial examining the effect of drugs that are already authorized for the clinical use.

Conditions

Antifibrinolytic Agents

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Standard dose group

The standard dose group will receive a bolus of 20 mg/kg tranexamic acid after anaesthesia induction.

Group Type: ACTIVE_COMPARATOR

Tranexamic acid bolus 20 mg/kg

Intervention Type: DRUG

Bolus of tranexamic acid in the standard dose group

Low dose group

The low dose group will receive a bolus of 10 mg/kg tranexamic acid. In addition 1 mg/kg tranexamic acid will be added to the priming of the extracorporeal circuit (ECC) and a continuous infusion of 1mg/kg/h tranexamic acid will be started after the bolus infusion until the end of surgery.

Group Type: EXPERIMENTAL

Tranexamic acid bolus 10 mg/kg

Intervention Type: DRUG

Bolus of tranexamic acid in the low dose group

Tranexamic acid bolus 1 mg/kg

Intervention Type: DRUG

Bolus of tranexamic acid in the low dose group (to add into the CPB prime)

Tranexamic acid continuous infusion of 1 mg/kg/h in the low dose group

Intervention Type: DRUG

Tranexamic acid continuous infusion during the procedure

Interventions

Tranexamic acid bolus 20 mg/kg

Bolus of tranexamic acid in the standard dose group

Intervention Type: DRUG

Tranexamic acid bolus 10 mg/kg

Bolus of tranexamic acid in the low dose group

Intervention Type: DRUG

Tranexamic acid bolus 1 mg/kg

Bolus of tranexamic acid in the low dose group (to add into the CPB prime)

Intervention Type: DRUG

Tranexamic acid continuous infusion of 1 mg/kg/h in the low dose group

Tranexamic acid continuous infusion during the procedure

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

Eligible patients:

• Over 18 years old
• Elective surgery
• Written informed consent
• Patient planned for aortocoronary artery bypass graft surgery, aortic valve replacement or mitral valve surgery (or a combination of these procedures)
• Normal renal function
• No previous intake of anticoagulants except acetylsalicylic acid in the preoperative period

Exclusion Criteria

• Impaired renal function (eGFR < 30 ml/min.)
• History of seizure
• Pregnancy
• Inability to understand and sign the informed consent (e.g., language problems, dementia, psychological disorders)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Insel Gruppe AG, University Hospital Bern

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Annegret Kauert-Willms, MD

Role: PRINCIPAL_INVESTIGATOR

University Hospital Berne

Locations

Dpt. Anesthesiology and pain Medicine

Bern, , Switzerland

Site Status: RECRUITING

Countries

Switzerland

Central Contacts

Gabor Erdoes, MD

Role: CONTACT

Gabor.erdoes@insel.ch

++41 31 632 2726

Facility Contacts

Gabor Erdoes, MD

Role: primary

gabor.erdoes@insel.ch

+41316322726

Annegret Kauert-Willms, MD

Role: backup

annegret.kauert@insel.ch

+41316322111

Other Identifiers

2022-02070

Identifier Type: -

Identifier Source: org_study_id