Embolism prophylaxis for patients with non-valvular, persistent or permanent atrial fibrillation (Guidelines)

On-line calculators:

• MDCalc: CHA₂DS₂VASc
• To assess combined CHA2DS2VASc stroke risk and HAS-BLED bleeding risk: http://sparctool.com/

• Consider restoration of sinus rhythm in patients in atrial fibrillation for less than 1 year where there is no significant structural heart disease.
• In asymptomatic patients, over 65 years of age, there is no justification in restoring sinus rhythm.
• Elective anticoagulation with apixaban or another DOAC for 4 weeks prior to direct current cardioversion is required unless the patient is already well established on warfarin. 
• Continue anticoagulation for at least 1 month after cardioversion as the recurrence rate and embolic risk extend into the period after restoration of sinus rhythm.
• Patients with risk factors for thromboembolism should remain on an anticoagulant (preferably warfarin) indefinitely, even if sinus rhythm is restored. Otherwise, discontinue oral anticoagulant one month post-cardioversion, if ECG shows sinus rhythm

For full details see BNF and SPC.

First-line: Apixaban

• Avoid if creatinine clearance is less than 15mL/min

Second-line: alternative DOAC

Edoxaban

• Avoid if creatinine clearance less than 15mL/min

Rivaroxaban

• Avoid if creatinine clearance less than 15mL/min
• To be taken with food

Dabigatran

• Avoid if creatinine clearance less than 30mL/min
• Patient must be able to swallow capsule whole before prescribing.
• Unsuitable for storage in monitored dosage systems (MDS).

Alterative: Warfarin

• Initiating warfarin: LMWH is not usually required to cover slow initiation of warfarin.
• For patients who fail to achieve more than 60% time in therapeutic range on warfarin, consider switching to apixaban, or another DOAC, if no contra-indication is present.
• Moving from warfarin to a DOAC: see Anticoagulant switching guidance

Contraindications: 

• Many contra-indications to warfarin therapy will also apply to DOACs, eg, high bleeding risks, coagulation disorders, non-compliance and, for dabigatran only, liver enzymes 2 or more times the upper limit of normal.

Renal function:

• Monitor renal function before starting a DOAC, and at least annually.

Elderly:

• Take particular caution especially in the frail elderly where adverse events are higher for almost all medication.