Antiplatelet therapy in primary care - secondary prevention of cardiovascular disease (CVD)

Antiplatelet therapy in primary care with respect to secondary prevention of cardiovascular disease

• aspirin:
  • low-dose aspirin (75mg daily) is recommended indefinitely for long-term secondary prevention following a myocardial infarction (MI), and in people with symptomatic peripheral arterial disease
  • NICE state that (2):
    • aspirin should be offered to all people after an MI and continue it indefinitely, unless they are aspirin intolerant or have an indication for anticoagulation
    • aspirin should be offered to people who have had an MI more than 12 months ago and continue it indefinitely
    • if aspirin hypersensitivity, clopidogrel monotherapy should be considered as an alternative treatment
      
      
• dipyridamole:
  • MR-dipyridamole 200mg twice daily plus low-dose aspirin (50mg or 75mg daily) is recommended for secondary prevention following an ischaemic stroke or a transient ischaemic attack (TIA) for a period of two years from the most recent event
  • following two years of combination treatment, or if dipyridamole is not tolerated, preventative therapy should revert to long-term treatment with low-dose aspirin alone
  • NICE however state that clopidogrel is the antiplatelet treatment of choice in the long term secondary prevention of ischaemic stroke (3)
    
    
• clopidogrel:
  • clopidogrel 75mg daily is a suitable alternative to aspirin (or aspirin plus MR-dipyridamole post-stroke) where aspirin is contraindicated or genuinely not tolerated (i.e. proven hypersensitivity to aspirin-containing medicines or history of severe dyspepsia induced by low-dose aspirin)
  • in patients with non-ST-segment-elevation acute coronary syndrome (ACS) who are at moderate to high risk of MI or death, clopidogrel 75mg daily should be considered in combination with low-dose aspirin (75mg daily) for up to 12 months following the most recent acute event. Following this period, reatment should revert to low-dose aspirin alone
  • NICE with respect to secondary prevention of MI state that (2):
    • clopidogrel should be offered as a treatment option for up to 12 months to:
      • people who have had an NSTEMI, regardless of treatment
      • people who have had a STEMI and received a bare-metal or drug-eluting stent
      • offer clopidogrel as a treatment option for at least 1 month and consider continuing for up to 12 months to:
        • people who have had a STEMI and medical management with or without reperfusion treatment with a fibrinolytic agent
    • continue the second antiplatelet agent for up to 12 months in people who have had a STEMI and who received coronary artery bypass graft (CABG) surgery
    • offer clopidogrel instead of aspirin to people who also have other clinical vascular disease who have
      • had an MI and stopped dual antiplatelet therapy or
      • had an MI more than 12 months ago
      • i.e. if a patient who has an MI has evidence of other clinical vascular disease (e.g. PVD, cerebrovascular disease) then after twelve months the patient should be taking clopidogrel and not aspirin

Notes:

• for patients with dyspepsia on low-dose aspirin, or who are at risk from gastrointestinal bleeding, co-prescription of a proton pump inhibitor should be considered initially before switching to clopidogrel

Reference:

1. MeReC Bulletin 2005; 15(6):21-4.
2. NICE (2013).MI - secondary prevention Secondary prevention in primary and secondary care for patients following a myocardial infarction
3. NICE (December 2010).Clopidogrel and modified-release dipyridamole for the prevention of occlusive vascular events