Can we give tranexamic acid (TXA) to a patient with bleeding and a hypokinetic left ventricle, and are there any alternatives to tranexamic acid (TXA)?

Tranexamic Acid Use in Patients with Bleeding and Hypokinetic Left Ventricle

Tranexamic acid (TXA) can be administered to patients with bleeding and a hypokinetic left ventricle, but should be used with caution due to potential thromboembolic risk, with desmopressin and aprotinin being viable alternatives in specific clinical scenarios. 1, 2, 3

Tranexamic Acid Administration in Cardiac Patients

Tranexamic acid is an antifibrinolytic agent that can be safely administered to patients with bleeding, including those with cardiac conditions. However, the following considerations should be made when administering TXA to patients with a hypokinetic left ventricle:

• Dosing recommendations:

  • Standard dose: 1g IV over 10 minutes, followed by 1g over 8 hours 2
  • For cardiac surgery: 15 mg/kg IV loading dose, followed by 2 mg/kg/hour infusion 2
  • Adjust dosing based on renal function (see table below) 3

• Timing: Administer as early as possible, ideally within 1 hour of bleeding onset, and not after 3 hours as it may increase mortality risk 2

• Monitoring: Closely monitor for signs of thrombosis, especially in patients with pre-existing cardiac conditions 3

Renal Dosage Adjustments

Serum Creatinine	TXA IV Dosage
1.36-2.83 mg/dL	10 mg/kg twice daily
2.83-5.66 mg/dL	10 mg/kg daily
>5.66 mg/dL	10 mg/kg every 48 hours or 5 mg/kg every 24 hours

Thromboembolic Risk Assessment

The FDA label warns that TXA is contraindicated in patients with active intravascular clotting 3. However, clinical studies have shown no increased risk of thrombotic events with TXA use in trauma patients, and there may even be a reduction in myocardial infarction risk 4, 5.

For patients with a hypokinetic left ventricle:

• Assess baseline thromboembolic risk
• Consider the severity and location of bleeding
• Weigh the risk of continued bleeding against potential thrombotic complications
• Monitor cardiac function during and after administration

Alternatives to Tranexamic Acid

1. Desmopressin (DDAVP)

• Mechanism: Stimulates release of von Willebrand factor from the endothelium
• Dosing: 0.3 μg/kg
• Indications:
  • Patients with acquired or inherited von Willebrand factor deficiency
  • Platelet dysfunction secondary to cardiopulmonary bypass
  • Patients on recent antiplatelet therapy prior to cardiac surgery 1
• Efficacy: May lead to small reduction in blood loss and volume of RBCs transfused in cardiac surgery patients, though clinical significance is uncertain 1

2. Aprotinin

• Mechanism: Serine protease inhibitor with antifibrinolytic properties
• Indications:
  • Licensed specifically for isolated coronary artery bypass graft surgery in high-risk patients
  • Used off-label in patients likely to bleed during major cardiac surgery (acute aortic dissection, infective endocarditis) 1
• Evidence: Associated with lower incidence of massive bleeding and reduced mortality in high-risk cardiac surgery 1
• Caution: Was previously withdrawn from European market due to safety concerns before reintroduction with narrow licensing indications 1

Clinical Decision Algorithm

1. Assess bleeding severity and cardiac status:

   • Evaluate the extent and location of bleeding
   • Assess left ventricular function and thrombotic risk

2. For patients with bleeding and hypokinetic left ventricle:

   • If no active intravascular clotting is present, TXA can be administered with caution
   • Use standard dosing (1g IV over 10 minutes, followed by 1g over 8 hours)
   • Adjust dose based on renal function
   • Monitor for signs of thrombosis and cardiac function

3. Consider alternatives if TXA is contraindicated:

   • For patients with platelet dysfunction or on antiplatelet therapy: Consider desmopressin
   • For high-risk cardiac surgery patients: Consider aprotinin (where available)

4. Monitor closely for:

   • Thromboembolic events
   • Seizures (particularly with higher doses)
   • Hypersensitivity reactions
   • Visual disturbances (with prolonged use)

Important Caveats and Pitfalls

• TXA is contraindicated in patients with subarachnoid hemorrhage, active intravascular clotting, or hypersensitivity to TXA 3
• Use with caution in patients with massive hematuria (risk of ureteric obstruction) and in patients on oral contraceptives (increased thrombosis risk) 1
• Avoid rapid IV administration to prevent hypotension 3
• Do not mix TXA with solutions containing penicillin 3
• Higher doses of TXA have been associated with increased risk of seizures, without providing additional hemostatic benefit 6

By carefully weighing the benefits against the risks and selecting the appropriate agent and dosing regimen, bleeding can be effectively managed even in patients with cardiac complications such as a hypokinetic left ventricle.