Antiplatelet therapy is still commonly – but inappropriately – used in atrial fibrillation

Lip GYH, Laroche C, Dan GA, et al.
The American Journal of Medicine. online 28 January 2014 http://dx.doi.org/10.1016/j.amjmed.2013.12.022

Background

Atrial fibrillation (AF) brings about a high risk of stroke and thromboembolism, and when these occur in the context of AF, the outcomes are generally more severe [1]. Hence, stroke prevention is central to management of AF.
The EuroHeart survey report from 2006 concluded that antithrombotic therapy in AF was poorly tailored to the patient’s stroke risk profile [2]. Since then, the European Society of Cardiology (ESC) guideline recommend use of the CHA₂DS₂-VASc and HAS-BLED scores for stroke and bleeding risk stratification [3]. An important change in the focused update of the ESC guidelines is also that the initial decision step is the identification of ‘truly low risk’ patients who do not need antithrombotic therapy. Furthermore, oral anticoagulation should still be used in the presence of stroke risk factors, irrespective of rate or rhythm control [3].
This is an analysis of the baseline dataset of the Euro Observational Research Programme on
Atrial Fibrillation (EORP-AF) Pilot survey [4], to evaluate antithrombotic prescription in light of the risk factors determining oral anticoagulation or antiplatelet therapy use.

Main results

• The majority of AF patients received Vitamin K Antagonist (VKA) therapy (72.2%) whilst novel oral anticoagulants (NOACs) were used in a minority (7.7%).
• Oral anticoagulation was more often prescribed in females, and was less often associated with valvular heart disease, heart failure, coronary or peripheral artery disease, diabetes and AF subtype. NOAC use was more often associated with previous transient ischaemic attack (TIA)/stroke and heart rhythm strategy.
• Antiplatelet drug prescription was mostly associated with female gender, coronary artery disease and AF type. It was less often prescribed after previous stroke/TIA and diabetes.
• Coronary artery disease was the strongest reason for combination therapy with oral anticoagulation plus antiplatelet drugs (OR:8.54, P<0.0001). Combination therapy was less common in females, after previous stroke/TIA and heart rhythm strategy.
• Based on CHA₂DS₂-VASc, 95.6% with a score of >1 received antithrombotic therapy, 80.5% receiving anticoagulation. When considering a score of >2, 83.7% received antithrombotic therapy, 70.9% of whom were on oral anticoagulation. In this group, 64.1% received VKAs and 6.9% received NOACs.

Conclusion

This survey reveals that oral anticoagulation is commonly used for atrial fibrillation, specifically in the context of heart failure or other cardiac disease. Antiplatelet therapy was still also commonly prescribed, alone or in combination with oral anticoagulation, mostly when there was also myocardial infarction or coronary artery disease. Elderly patients more often received antiplatelet therapy alone.
In AF with stable vascular disease, combination therapy does not reduce thromboembolism, but does increase the risk of major bleeding. Guidelines have therefore downgraded the role of aspirin for stroke prevention in AF, due to lack of efficacy and poor safety.
When CHA₂DS₂-VASc was applied, the vast majority with >1 appropriately received oral anticoagulation, which is an improvement since the 2006 EuroHeart survey [2]. Considering the preference for NOACs as described in the ESC guidelines, NOAC use is still rather low.

Find this article online

References

1. Banerjee A, Marin F, Lip GY. The improved but unfinished business of stroke risk stratification in atrial fibrillation. Rev Esp Cardiol. 2011;64:639-641
2. Nieuwlaat R, Capucci A, Lip GY, et al. Antithrombotic treatment in real-life atrial fibrillation patients: A report from the euro heart survey on atrial fibrillation. Eur Heart J. 2006;27:3018-3026
3. Camm AJ, Lip GY, De Caterina R, et al. 2012 focused update of the esc guidelines for the  management of atrial fibrillation: An update of the 2010 esc guidelines for the management of atrial
fibrillation--developed with the special contribution of the european heart rhythm association. Europace. 2012;14:1385-1413
4. Lip G, et al. A prospective survey in european society of cardiology member countries of atrial fibrillation management: Baseline results of euroobservational research programme atrial fibrillation (eorp-af) pilot general registry. Europace. 2014: doi:10.1093/europace/eut1373