Physicians' Academy for Cardiovascular Education

One third of atrial fibrillation patients receive aspirin alone instead of anticoagulation

Hsu JH et al., J Am Coll Cardiol 2016

 

Aspirin Instead of Oral Anticoagulant Prescription in Atrial Fibrillation Patients at Risk for Stroke

 
Hsu JH, Maddox TM, Kennedy K, et al.
J Am Coll Cardiol 2016;67:291323
 

Background

Atrial fibrillation (AF) patients are at risk of stroke, and their individual risk can be quantified based on the CHADS2 and the CHA2DS2-VASc risk scores [1-3]. It has been shown that AF patients at high risk of stroke can benefit from anticoagulation therapy [4,5], and that the use of aspirin in this setting is less effective [6]. In spite of the data, AF patients at risk for stroke are treated with anticoagulation less often than recommended [7], and they receive either aspirin only, or antiplatelet agents with or without anticoagulation.
In this study, the prevalence and the predictors of treatment with aspirin monotherapy compared with oral anticoagulation (OAC) therapy by cardiovascular specialists in every-day clinical practice was investigated, in two cohorts including AF patients at moderate to high risk for stroke.
 

Main results

  • 38.2% Of patients with a CHADS2 score ≥2 (n=210,380) were treated with aspirin alone and 61.8% with warfarin or OAC.
  • 40.2% Of patients with a CHA2DS2-VASc score ≥2 (n=294,642) were treated with aspirin alone and 59.8% with warfarin or OAC.
In patients with a CHADS2 score ≥2 or a CHA2DS2-VASc score ≥2:
  • the concomitant use of any thienopyridine (mainly clopidogrel) was higher in patients prescribed aspirin.
  • the concomitant prescription of aspirin alone as well as aspirin plus thienopyridine was not uncommon in patients who were prescribed an OAC.
  • the combination of dual antiplatelet therapy with aspirin and any thienopyridine was much less common in patients prescribed OAC vs. aspirin (5.7% for CHADS2 score ≥2 and 6.0% for CHA2DS2-VASc score ≥2).
  • in patients receiving anticoagulation, concomitant antiplatelet therapy was more often prescribed in patients prescribed an OAC compared with warfarin.
 
After multivariable adjustment, in patients with a CHADS2 score ≥2 or a CHA2DS2-VASc score ≥2:
  • hypertension, dyslipidaemia, coronary artery disease, prior myocardial infarction, unstable and stable angina, recent bypass surgery, and peripheral arterial disease were associated with more frequent prescription of aspirin only
  • male sex, higher BMI, prior stroke/TIA, prior systemic embolism, and congestive heart failure were associated with more frequent prescription of OAC.

Conclusion

In AF patients at moderate to high risk for stroke treated in every-day clinical practice, approximately one third of patients received aspirin monotherapy, in spite of the lack of data supporting this practice. Predictors of this prescription practice were identified, the most important being atherosclerotic-related comorbidities. These results suggest that there is a need to improve appropriate prescription of OAC in AF.
 
Find this article online at JACC
 

References

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