Switch Language
Alt tag

Never miss out on the latest news!

Sign up to the Thrombosis Adviser newsletter.

 

Subscribe

See Also

Peripheral Artery Disease: causes and consequences

Coronary Artery Disease: causes and consequences

Anticoagulant Therapy

This section introduces oral anticoagulation and stroke prevention in patients with AF, looking at the options available, the regimens used and the potential benefits and risks involved

Oral anticoagulation – with either VKAs or NOACs – is the mainstay of stroke prevention strategies in patients with NVAF. Supported by guidelines on the management of NVAF, the use of NOACs has increased markedly over the past 5 years since they were first licenced in this indication.1-3

VKAs such as warfarin, phenprocoumon and acenocoumarol have been used for stroke prevention in AF for many years. Although highly effective, the management of VKAs can be challenging and underpinned the need for alternatives. The NOACs – apixaban, dabigatran, edoxaban and rivaroxaban – are increasingly prescribed in preference to VKAs because of their potential to improve the quality of care. All NOACs:4,5

  • Offer effective stroke prevention with a good safety profile
  • Lack the requirement for routine coagulation monitoring or frequent dose adjustments
  • Have fixed-dose regimens, with rivaroxaban showing consistent, dose-dependent plasma levels across a range of patent populations, and pharmacodynamic parameters correlating with rivaroxaban plasma concentrations
  • Have a low risk of drug–drug or drug–food interactions

The following anticoagulants are approved in Europe for the prevention of stroke and systemic embolism in patients with NVAF and at least one additional risk factor for stroke:

  • VKAs, e.g. warfarin, phenprocoumon and acenocoumarol6-8
  • NOACs
    • Direct Factor Xa inhibitors:
      • Apixaban (ARISTOTLE study)9 – brand name: Eliquis® (BMS/Pfizer)
      • Edoxaban (ENGAGE AF study)10 – brand name: Lixiana®/Savaysa® (Daiichi Sankyo)
      • Rivaroxaban (ROCKET AF study) – brand name: Xarelto® (Bayer AG)
    • Direct thrombin inhibitor:
      • Dabigatran (RE-LY study)11,12 – brand name: Pradaxa® (Boehringer Ingelheim)

 

For detailed dosing information, see our interactive ‘Which anticoagulant?’ table

 

For more information on these drugs and their targets in the coagulation cascade, click here

Video title

YYMMDD Author/Uploaded by

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

When to use a reduced NOAC dose
Patients receiving anticoagulation with a NOAC should receive a reduced dose in certain clinical situations
© 2017, Bayer AG. All rights reserved. Approval number: PP-XAR-ALL-1742-1

VKAs do not have fixed-dose regimens; although taken once daily, the dose taken may vary and is adjusted based on the results of coagulation monitoring to maintain an INR of between 2.0 and 3.0 (target 2.5). A typical initial dose of warfarin is 10 mg once daily for 2 days, followed by 3–9 mg once daily, depending on the INR.6-8

All NOACs offer fixed-dose regimens and do not require routine coagulation monitoring, but in certain key patient populations, these doses can be reduced. Dosing decision trees for each NOAC (according to European summaries of product characteristics) are shown below.

apixaban-dosing

Dosing and adjustments for the NOACs in patients with NVAF, according to European summaries of product characteristics: apixaban13

Alt tag

Dosing and adjustments for the NOACs in patients with NVAF, according to European summaries of product characteristics: dabigatran14

Alt tag

Dosing and adjustments for the NOACs in patients with NVAF, according to European summaries of product characteristics: edoxaban15

Alt tag

Dosing and adjustments for the NOACs in patients with NVAF, according to European summaries of product characteristics: rivaroxaban16

Video title

YYMMDD Author/Uploaded by

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

From ROCKET AF to real-world evidence
The ROCKET AF study assessed the safety and efficacy of rivaroxaban compared with warfarin in patients with NVAF for the prevention of stroke. These results were consistent with real-world evidence seen in prospective non-interventional studies
© 2017, Bayer AG. All rights reserved. Approval number: PP-XAR-ALL-0097-2

Anticoagulants significantly reduce the risk of stroke,5 but this must be balanced against bleeding safety, persistence and – in the case of VKAs – routine coagulation monitoring issues. Clinical decision making must always balance the benefits and risks of anticoagulant use.

 

A ‘user-friendly’ score to assess the 1-year risk of major bleeding in a patient with AF has been proposed. The HAS-BLED score predicts the risk of bleeding based on a combination of risk factors.17 Bleeding risk scores should be considered in patients with AF to identify modifiable risk factors for major bleeding.18 Several studies have shown HAS-BLED to have better predictive value than other published risk scores.

Bleeding risk according to HAS-BLED score
  Risk factor Description Points
H Hypertension Uncontrolled, >160 mmHg systolic pressure 1
A Abnormal renal or liver function (1 point each) Abnormal renal function: chronic dialysis or renal transplantation or serum creatinine ≥200 µmol/l

Abnormal liver function: chronic hepatic disease or biochemical evidence of significant hepatic derangement
1 or 2
S Stroke Previous history, particularly lacunar stroke 1
B Bleeding history or predisposition Predisposition could include bleeding diathesis or anaemia 1
L Labile INR Therapeutic time in range <60% 1
E Elderly Age >65 years 1
D Drugs/alcohol concomitantly (1 point for drugs plus 1 point for alcohol excess) Drugs, including antiplatelet agents and NSAIDs 1 or 2
      Maximum:
9 points

Adapted from Pisters et al. 201017

Link to online HAS-BLED risk calculator: http://www.mdcalc.com/has-bled-score-for-major-bleeding-risk/

 

Studies of the HAS-BLED score indicate that the annual risk of bleeding increases with the addition of each risk factor, up to five risk factors. HAS-BLED has demonstrated good predictive accuracy.17 Nevertheless, the score should not be used alone to exclude patients from oral anticoagulant therapy but rather allows clinicians to make an informed judgement as to the risk of bleeding and to identify modifiable bleeding risks that need to be addressed. Patient preferences should also be taken into account when making therapy choices.1

 

Next section: Antiplatelet Therapy

References

Never miss out on the latest news!

Over 4,000 healthcare professionals have already signed up.