antithrombin therapy in unstable angina / NSTEMI

Last reviewed 01/2018

Antithrombin therapy

• fondaparinux should be offered to patients who do not have a high bleeding risk, unless coronary angiography is planned within 24 hours of admission
• unfractionated heparin should be offered as an alternative to fondaparinux to patients who are likely to undergo coronary angiography within 24 hours of admission
• clinician should carefully consider the choice and dose of antithrombin in patients who have a high risk of bleeding associated with any of the following:
  • advancing age
  • known bleeding complications
  • renal impairment
  • low body weight
    
    
• unfractionated heparin should be considered, with dose adjustment guided by monitoring of clotting function, as an alternative to fondaparinux for patients with significant renal impairment (creatinine above 265 micromoles per litre)
  
  
• systemic unfractionated heparin (50-100 units/kg) should be offered in the cardiac catheter laboratory to patients receiving fondaparinux who are undergoing PCI
  
  
• consider bivalirudin as an alternative to the combination of a heparin plus a glycoprotein inhibitor (GPI),or patients who:
  • are at intermediate or higher risk of adverse cardiovascular events (predicted 6-month mortality above 3%), and
  • are not already receiving a GPI or fondaparinux, and
  • are scheduled to undergo angiography (with follow-on PCI if indicated) within 24 hours of admission
    
    
• consider bivalirudin as an alternative to the combination of a heparin plus a GPI, for patients undergoing PCI who:
  • are at intermediate or higher risk of adverse cardiovascular events, and
  • are not already receiving a GPI or fondaparinux

Notes:

• as soon as the diagnosis of unstable angina or NSTEMI is made, and aspirin and antithrombin therapy have been offered, formally assess individual risk of future adverse cardiovascular events using an established risk scoring system that predicts 6-month mortality (for example, Global Registry of Acute Cardiac Events [GRACE])
  • include in the formal risk assessment:
    • a full clinical history (including age, previous myocardial infarction [MI] and previous percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG])
    • a physical examination (including measurement of blood pressure and heart rate)
    • resting 12-lead electrocardiography (ECG) (looking particularly for dynamic or unstable patterns that indicate myocardial ischaemia)
    • blood tests (such as troponin I or T, creatinine, glucose and haemoglobin)

• Predicted 6-month mortality	Risk of future adverse cardiovascular events
  1.5% or below	lowest
  > 1.5 to 3.0%	low
  > 3.0 to 6.0%	intermediate
  > 6.0 to 9.0% over 9.0%	high
  over 9.0%	highest

Reference:

• 1) NICE (March 2010). Unstable angina and NSTEMI The early management of unstable angina and non-ST-segment-elevation myocardial infarction