Drug management of atrial fibrillation

There are three main therapeutic aims in the drug treatment of atrial fibrillation:

• control of the ventricular rate (1):
  • in patients with permanent AF, who need treatment for rate-control:
    • beta-blockers or rate-limiting calcium antagonists should be the preferred initial monotherapy in all patients
    • digoxin should only be considered as monotherapy in predominantly sedentary patients
• chemical cardioversion to sinus rhythm:
  • class IV, I and III drugs
• prevention of thromboembolism:
  • anticoagulation with warfarin or aspirin

Note: there is evidence from two large randomised trials (2,3) that have shown that a rate-control strategy is at least as effective as rhythm control

• there was a strong trend for patients in the rate-control group to have fewer major clinical events (and patients in this treatment group had fewer adverse events)
• t is unclear when a rhythm-control strategy might be preferred. Possible instances might be (4):
  • a recent-onset AF with a low risk of recurrence - in a case where there is an obvious precipitant and no underlying structural heart disease, for example, a patient with a pyrexial illness such as pneumonia or AF occurring after an alcoholic binge or following an operation
  • intolerable symptoms despite adequate rate control
  • patients at high risk from warfarin or aspirin therapy
    
    
• NICE have stated that (1):
  • When to offer rate or rhythm control Rate control
    • offer rate control as the first-line strategy to people with atrial fibrillation, except in people:
      • whose atrial fibrillation has a reversible cause
      • who have heart failure thought to be primarily caused by atrial fibrillation
      • with new-onset atrial fibrillation
      • with atrial flutter whose condition is considered suitable for an ablation strategy
      • to restore sinus rhythm for whom a rhythm control strategy
      • would be more suitable based on clinical judgement
    • offer either a standard beta-blocker (that is, a beta-blocker other than sotalol) or a rate-limiting calcium-channel blocker as initial monotherapy to people with atrial fibrillation who need drug treatment as part of a rate control strategy. Base the choice of drug on the person's symptoms, heart rate, comorbidities and preferences when considering drug treatment
      
      
    • digoxin should only be considered as monotherapy if
      • the person does no or very little physical exercise or
      • other rate-limiting drug options are ruled out because of comorbidities or the person's preferences
        
        
    • if monotherapy does not control symptoms, and if continuing symptoms are thought to be due to poor ventricular rate control, consider combination therapy with any 2 of the following:
      • a beta-blocker
      • diltiazem
      • digoxin
        
        
    • do not offer amiodarone for long-term rate control

Notes:

• previous NICE guidance had stated that:
  
  
  • in patients with permanent AF, where monotherapy is inadequate:
    • to control the heart rate only during normal activities, beta-blockers or rate-limiting calcium antagonists should be given with digoxin
    • to control the heart rate during both normal activities and exercise, rate-limiting calcium antagonists should be given with digoxin
  • patients unsuitable for cardioversion include those with:
    • contraindications to anticoagulation
    • structural heart disease (e.g. large left atrium >5.5 cm, mitral stenosis) that precludes long-term maintenance of sinus rhythm
    • a long duration of AF (usually >12 months)
    • a history of multiple failed attempts at cardioversion and/or relapses, even with concomitant use of antiarrhythmic drugs or non-pharmacological approaches
    • an ongoing but reversible cause of atrial fibrillation (e.g. thyrotoxicosis)

Reference:

1. NICE (April 2021). Atrial Fibrillation.
2. Wyse DG, Waldo AL, DiMarco JP, et al. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med 2002;347:1825-33.
3. Van Gelder IC, Hagens VE, Bosker HA, et al. A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation. N Engl J Med 2002;347:1834-40.
4. Prescriber 2003; 14(14): 25-33