I'll just give her some Aspirin...

Betty is a healthy 74-year-old. She has osteoarthritis, which she controls with acetaminophen as she experienced a GI bleed while taking an NSAID several years ago. You have just diagnosed Betty with persistent non-valvular atrial fibrillation and prescribed a beta-blocker for rate control. What will you use for stroke prevention?

You know she should be on an anticoagulant to prevent stroke, but you are nervous about her bleeding risk, so you treat her with low-dose ASA rather than warfarin. You know it’s less effective — but isn’t it safer?

CADTH research recently confirmed that warfarin was more effective than ASA for preventing strokes; it also showed that warfarin did not cause more bleeding than ASA. In fact, bleeding with ASA (with or without clopidogrel) was similar or worse than with all oral anticoagulants used in atrial fibrillation. See the report for full details.

Even though ASA is inexpensive, the costs associated with the extra strokes and bleeds that can be experienced must be factored in. This means that ASA is less cost-effective than warfarin.

For Betty, warfarin is the drug of choice.

Bottom line

• For people who are able to use an anticoagulant, anticoagulant drugs should be used in preference to antiplatelet drugs such as ASA.

ASA - acetylsalicylic acid (Aspirin)
GI - gastrointestinal
NSAID - non-steroidal anti-inflammatory drug