Management of Atrial Fibrillation

Atrial Fibrillation is the commonest sustained cardiac arrhythmia, occurring in 1-2% of the population.  Its incidence increases with age: <0.5% of the population are affected aged 40-50 but up to 15% are affected by the age of 80.

This article focuses on the management of AF, looking at:
    A) Management of permanent/persistent AF
    B) Management of paroxysmal AF 

A) Management of permanent/persistent atrial fibrillation

This requires consideration of 2 questions:
       1) rhythm control or rate control?
       2) to anticoagulate or not?

So to consider question 1:
  • Rhythm control?
    • NICE suggests rhythm-control first in:
      • younger patients
      • those with symptoms
      • presenting for the first time with lone AF
      • those with AF secondary to a treated or correct precipitant
      • with congestive heart failure
    • Treatment options are:
      • DC cardioversion
      • Chemical cardioversion 
        • amiodarone, sotalol or flecanide (the latter only in a structurally normal heart)
  • Rate control?
    • NICE recommends trying rate-control first in:
      • over 65s
      • patients with coronary artery disease
      • in those with contraindications to antiarrhythmic drugs
      • in patients who are unsuitable for cardioversion
        • left atrium >5.5cm
        • mitral stenosis
        • contraindications to anticoagulation
        • longstanding AF (>12 months)
        • multiple failed attempts at cardioversion 
    • Treatment options are:
      • beta blocker
      • rate-limiting calcium antagonist
      • digoxin

And then there is question 2: to anticoagulate or not:
  • You can stratify risk using either the NICE stroke risk stratification (2006) or the CHA2DS2-VASc score (2010):
    • Using the Nice Stroke Risk stratification:
      • Define the 'risk' in the patient:
        • High Risk
          • Previous ischaemic stroke/TIA/thromboembolic event
          • age >/= 75 with hypertension, diabetes or vascular disease
          • clinical evidence of valve disease, heart failure or LV dysfunction
        • Medium Risk
          •  age >/=65 with no high risk factors or age <75 with hypertension, diabetes or vascular disease
        • Low Risk
          • age <65 with no high or moderate risk factors
      • Unless contraindications, anticoagulate all high risk patients with warfarin (target INR 2.5) and all low risk patients with aspirin.
      • Consider whether to use warfarin or aspirin in moderate risk patients on an individual basis
      • NB: 2012 European Society of Cardiology guidelines suggest that use of aspirin monotherapy should be avoided now there are 'novel oral anticoagulants'
    • Using the CHA2DS2-VASc score
      • Depends on points
        • Congestive heart failure/LV dysfunction: 1 point
        • Hypertension: 1 point
        • Age >/= 75: 2 points
        • Diabetes: 1 point
        • Stroke/TIA/thromboembolism: 2 points
        • Vascular disease (= MI, PVD, aortic plaque): 1 point
        • Age 65-74: 1 point
        • Sex catagory: if female, 1 point
      • Any score of 1 or more warrants anticoagulation
  • The world of AF anticoagulation has recently got far more complex, as in addition to warfarin and aspirin you must now consider dabigatran and rivaroxaban:
    • Dabigatran (= oral direct thrombin inhibitor)
      • can be considered instead of warfarin in patients with nonvalvular AF who have one or more of the following risk factors:
        • previous stroke/TIA/systemic embolism
        • LVEF <40%
        • HF NYHA class 2 or above
        • age 75 or older
        • age 65 or older with diabetes, hypertension or coronary artery disease
      • The trial that proved non-inferiority compared to warfarin was the RE-LY trial
    • Rivaroxaban (mechanism of action: directly inhibits factor Xa
      • can be considered instead of warfarin in patients with nonvalvular AF who have one or more of the following risk factors:
        • previous stroke/TIA
        • hypertension
        • congestive cardiac failure
        • age 75 or older
        • diabetes mellitus 
      • The trial that proved non-inferiority compared to warfarin was the ROCKET-AF trial

DC Cardioversion
  • Anticoagulation:
    • Before cardioversion, patients should be on warfarin with an INR of 2-3 for at least 3 weeks.
    • After successful cardioversion, they should remain on warfarin with an INR of 2-3 for at least 4 weeks.
    • If cardioversion cannot be postponed for 3 weeks, give heparin beforehand and warfarin for at least 4 weeks afterwards
    • If the duration of AF is confirmed as less than 48 hrs no anticoagulation pre-cardioversion is needed.
  • If previous DCCV was unsuccesful, give amiodarone or sotalol for at least 4 weeks prior to subsquent cardioversion attempt
  • If no cause for the AF identified, consider medications post cardioversion to help maintain sinus rhythm:
    • beta blocker first line
    • if beta blocker fails:
      • sotalol or flecainide if heart structurally normal
      • amiodarone if not structurally normal

B)  Management of paroxysmal AF

Again, this requires consideration of 2 questions:

1) Pill in pocket therapy or 'normal' ongoing treatment?
2) To anticoagulate or not?

To answer question 1:
  • 'Pill in pocket' therapy is used if:
    • Patient has no LV dysfunction, valvular heart disease or IHD
    • Patient have infrequent symptomatic episodes
    • Patient has a SBP >100 and resting HR >70
    • Patient is able to understand how to use this approach
  • If all of the above criteria are not fullfilled:
    • give standard beta blocker
    • if this fails
      • try sotalol in CAD
      • amiodarone in LV dysfunction
      • flecanide in a structurally normal heart
    • If sotalol/flecanide fails, amiodarone can be trialled

The method of determining whether to anticoagulate or not is exactly the same as in permanent AF.

Other points
  • Post-TIA, give warfarin as soon as possible once bleed/infarct has been excluded
  • Post stroke, start warfarin 2 weeks afterwards as long as no bleed/large infarct on CT

author profile image

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.

Secret collector of interesting anonymised ECGs. Fan of the Bath Photomarathon. Lover of cream teas. [Sarah Hudson] (Your Picture)