Two analyses from the GLORIA-AF Registry Program examining the use of anticoagulant treatments for stroke prevention in patients with atrial fibrillation ( AF ) were presented at 64th Annual Meeting of American College of Cardiology ( ACC ).
These new analyses found that although oral anticoagulant use is increasing in the US, approximately a fifth of North American AF patients in the GLORIA-AF Registry Program were either inadequately treated with the antiplatelet Acetylsalicylic acid ( ASA, Aspirin ) or did not receive any treatment at all.
This is despite current US guidelines stating that AF patients with a CHA2DS2-VASc score of 2 or above are considered at high risk for stroke and require anticoagulant treatment.

The new data are the first reported prescribing patterns from phase II of the GLORIA-AF Registry Program, which began in November 2011 after the first novel oral anticoagulant ( NOAC ), Pradaxa ( Dabigatran etexilate ), was approved in the US.
The data is based on treatment trends in 3,415 AF patients who entered the GLORIA-AF registry from November 2011 to February 2014.
All patients had a recent diagnosis of atrial fibrillation and 86% had a CHA2DS2-VASc score of 2 or higher, placing them at high risk of stroke.
The data have shown that Dabigatran etexilate was the most widely prescribed NOAC for stroke prevention among the patients included in the study.

Patterns of newly detected atrial fibrillation and antithrombotic treatment in North America

Results have demonstrated that 21.9% of patients with occasional atrial fibrillation and a CHA2DS2-VASc score of 2 or higher were either undertreated with Acetylsalicylic acid or given no anticoagulant treatment at all, compared to 12.4% and 11.2% of those diagnosed with persistent or permanent atrial fibrillation, respectively.
Current atrial fibrillation guidelines call for patients to receive oral anticoagulant therapy based on their risk of stroke, rather than their type of atrial fibrillation.
Furthermore, given the availability of NOACs, guidelines state that the use of antiplatelet therapies ( such as ASA ) for stroke prevention in atrial fibrillation should be limited to the few patients who refuse any form of oral anticoagulant as the evidence for effective stroke prevention from ASA is weak, with a potential for harm.

Antithrombotic treatment in relation to age in patients with newly diagnosed atrial fibrillation in North America

The second study, which grouped patients by their age and CHA2DS2-VASc score, found that about 20% of new-onset atrial fibrillation patients below 75 years with a CHA2DS2-VASc score of 2 or higher received ASA alone or went untreated ( 20.6% of patients aged below 65 years and 19.7% of patients aged 65-74 years ).
Over half of patients were prescribed NOACs for stroke prevention, ( 25% Dabigatran, 20.5% Rivaroxaban, and 6.6% Apixaban ).
Vitamin K antagonists ( VKAs e.g. Warfarin [ Coumadin ] ) remain widely used, particularly in high-risk, elderly patients ( 31.7% of patients aged 80 and older with a CHA2DS2-VASc score of 2 or higher ).

CHA2DS2-VASc is a scoring system used by physicians to assess the risk of stroke in people diagnosed with atrial fibrillation. The system scores 1 point for: age 65-74, congestive heart failure, high blood pressure, diabetes, vascular disease, and being female, and 2 points for: age 75 and over and previous stroke/ mini-stroke or thromboembolism.

European guidelines recommend that anyone with a score of 1 or over should be considered for oral anticoagulant treatment with the exception of women aged less than 65 and who have lone atrial fibrillation because their score of 1 is due to their gender.

European and US guidelines state that anticoagulant treatment is recommended for all atrial fibrillation patients with a score of 2 or higher except where this is contraindicated. ( Xagena )

Source: Boehringer Ingelheim, 2015

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