Anticoagulation in Atrial Fibrillation (AF)

Introduction

Establish risk of stroke and bleeding when making decisions about anticoagulation.

In scope

symptomatic AF (paroxysmal, persistent or permanent)
asymptomatic AF (paroxysmal, persistent or permanent)
atrial flutter
other atrial arrhythmia
a continuing risk of arrhythmia recurrence after cardioversion back to sinus rhythm or catheter ablation.

Not in scope:

cardiac arrythmias other than those mentioned above
people aged under 65 years with AF and no risk factors other than their sex (that is, very low risk of stroke equating to a CHA₂DS₂-VASc score of 0 for men or 1 for women).

Red Flag Features

New onset AF/flutter, or other atrial arrhythmia within the last 48 hours associated with haemodynamic instability (e.g. pulse of >150bpm or <40bpm and/or systolic BP < 90mmHg)
AF/flutter, or atrial arrhythmia associated with syncope, chest pain, heart failure and/or shortness of breath.

In the context of any of these red flag features, follow the Atrial Fibrillation guideline.

Investigations

Creatinine Clearance (Cockcroft-Gault Equation) (requires patient’s weight)
FBC, LFTs, Coagulation screen
HbA1c-for calculating CHA₂DS₂-VASc stroke risk score if not known to have diabetes.

Management

Assess Stroke Risk:

Use CHA₂DS₂-VASc stroke risk score
Do not offer stroke prevention therapy with anticoagulation to people aged under 65 years with atrial fibrillation and no risk factors other than their sex (that is, very low risk of stroke equating to a CHA₂DS₂-VASc score of 0 for men or 1 for women).

Assess Bleeding Risk

Assess the risk of bleeding when:

Considering starting anticoagulation in patients with atrial arrhythmia and when reviewing people already taking anticoagulation
Use the ORBIT or HASBLED score.

Evidence shows that ORBIT is the most accurate tool for predicting the risk of bleeding in people with AF.However, HAS-BLED was previously recommended by NICE and may need to be used until ORBIT is embedded in clinical pathways and electronic systems used by clinicians. *

Use a shared decision-making approach to discuss the risk:benefit of anticoagulation, taking into consideration the patient’s comorbidities and preferences. For most people the benefit of anticoagulation outweighs the bleeding risk.

Prescribing information

When selecting an anticoagulant, consider renal function, preference of once/twice daily dosing and whether a tablet needs to be crushed.

If DOACs are contraindicated, not tolerated or not suitable, offer a vitamin K antagonist eg Warfarin

Review of patients with AF

For those who are not taking an anticoagulant, review bleeding and stroke risk when they reach 65 years or if they develop any of the following at any age:

diabetes
heart failure
peripheral arterial disease
coronary heart disease
stroke, transient ischaemic attack or systemic thromboembolism.

Advice and Guidance

See RCHT guidance for helpful tips on special circumstances, consider sending advice and guidance to the relevant speciality by eRS

Referral

Anticoagulation for AF is usually managed in the community, so referral is generally not needed. AF in the context of any red flag features may warrant hospital admission. Follow the Atrial Fibrillation guideline or Acute GP if considering admission for new AF.

Supporting Information

For professionals:

For patients:

References

Page Review Information

Review date 08 August 2025

Next review date 08 August 2026

GP Speciality lead Dr Melanie Schick

Contributors Dr Lucy Walker, Consultant Cardiologist RCHT