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Published on: February 28, 2012
Anticoagulation for the prevention of stroke in non-valvular AF in general practice: room for improvement
Adam Ioannou1, Sofia Metaxa2, George Kassianos3
1Royal Free Hospital, Hampstead, London, UK;
Insights
Many atrial fibrillation (AF) patients at risk of stroke are undertreated with anticoagulants in primary care. A significant number receive suboptimal warfarin or antiplatelet therapy instead of recommended vitamin K antagonists (VKAs) or novel oral anticoagulants (NOACs).
Area of Science:
- Cardiology
- General Practice
- Pharmacology
Background:
- Atrial fibrillation (AF) significantly increases stroke risk, necessitating effective thromboprophylaxis.
- Guidelines recommend oral anticoagulants (OACs) like vitamin K antagonists (VKAs) and novel oral anticoagulants (NOACs) for stroke prevention in AF patients.
- General practice (GP) plays a crucial role in implementing these thromboprophylaxis recommendations.
Purpose of the Study:
- To evaluate the adherence of general practice to established guidelines for thromboprophylaxis in patients diagnosed with atrial fibrillation (AF).
- To assess the quality of anticoagulation management in primary care settings for AF patients.
- To identify potential gaps in the prescription of appropriate oral anticoagulants for stroke risk reduction.
Main Methods:
- Retrospective analysis of a general practice (GP) computer database in Hatfield, UK.
- Inclusion of 9400 patients, with a specific focus on 180 patients diagnosed with AF.
- Assessment of anticoagulation quality, including medication type, time in therapeutic range (TTR) for warfarin, and adherence to risk scores (CHA2DS2VASc, HAS-BLED).
Main Results:
- Only 59.4% of AF patients received warfarin, 10.6% a NOAC, and 17.2% antiplatelet therapy; 12.8% received no antithrombotic treatment.
- 34.6% of warfarin users had a suboptimal time in therapeutic range (TTR) below 65%.
- 27.6% of patients with a CHA2DS2VASc score of two or more were not prescribed a VKA or NOAC, often receiving antiplatelet therapy instead.
Conclusions:
- A significant proportion (one in four) of non-valvular AF patients at stroke risk are inadequately treated with oral anticoagulants in primary care.
- Suboptimal warfarin use (low TTR) and inappropriate prescription of antiplatelet therapy are prevalent issues.
- There is a critical need to review GP practices to ensure appropriate initiation of VKAs or NOACs for stroke prevention in high-risk AF patients.
Objective:
Our aim was to assess whether the recommendations and guidelines for thromboprophylaxis in patients with atrial fibrillation (AF) have been adopted in general practice (GP).
Methods:
We conducted a retrospective study using the GP computer database (Hatfield, UK) on all 9400 patients to assess the quality of anticoagulation in patients with a recorded diagnosis of AF.
Results:
Of the 180 patients with a diagnosis of AF, 107 (59.4%) were treated with warfarin, 19 (10.6%) with a novel oral anticoagulant (NOAC), 31 (17.2%) with aspirin or clopidogrel, and 23 (12.8%) received none. Thirty-seven patients (34.6%) who were taking warfarin had a time in the therapeutic range (TTR) of less than 65%. Forty-five (27.6%) of the 163 patients who had a CHA2DS2VASc score of two or more were not prescribed a vitamin K antagonist (VKA) or a NOAC. None had a HAS-BLED greater than the CHA2DS2VASc score.
Conclusion:
Our study demonstrates that one in four patients with non-valvular AF, at risk of a stroke, is not being adequately treated with an oral anticoagulant in primary care. The majority were treated with warfarin, a third of which had a low TTR. A high proportion of patients are prescribed antiplatelet therapy instead. This is despite overwhelming evidence that VKAs and NOACs, and not aspirin or clopidogrel, improve outcome in patients with non-valvular AF. We suggest that a review of GP practice databases should be considered to identify patients with non-valvular AF, at risk of a disabling or fatal event, and measures taken to initiate anticoagulant therapy.
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