Atrial Fibrillation

Atrial Fibrillation (AF) statistics:

  • Prevalence is 1.6%, although in the over 90s it is nearer 10%.
  • AF increases the stroke risk 5-fold .

Scope

The assessment and management of adults presenting with AF

For more information please refer to the joint formulary guidance on Atrial Fibrillation (AF)

Please note pre-referral criteria may be applied to referrals for this condition.

To see information required please see Referral Section, referrals submitted without this information may be returned.

Key referral criteria summary:

  • Acute onset of less than 48 hours where a rhythm control strategy is preferred
  • Treatment with rate control has failed to manage the symptoms and a rhythm control strategy is to be considered.
  • Underlying significant structural heart disease or heart failure.

Out of scope

  • AF assessment and management in children
  • Management of valvular AF
  • Postoperative AF
  • AF after an ischaemic event
  • AF requiring emergency admission

Assessment

Consider the causes of AF:

  • Cardiac: hypertension, valvular heart disease, heart failure, ischemic heart disease, cardiomyopathy, pre-excitation
  • Respiratory: chest infection, pulmonary embolism, lung cancer
  • Systemic: excess alcohol, thyrotoxicosis, electrolyte disturbance, infection, diabetes, obstructive sleep apnoea

Signs and Symptoms

Look for AF by opportunistic case finding

Take the pulse in those with:

  • Breathlessness
  • Palpitations
  • Syncope/dizziness
  • Chest discomfort
  • Stroke/transient ischemic attack (TIA)

An irregular pulse has a good sensitivity and specificity especially in patients over 75 years old and if regular, the chance of AF is very small – negative predictive value around 99%

AF may also be detected as an incidental finding on clinical examination

Red Flags

Acute admission is indicated if:

  • HR more than 150 +/- systolic BP less than 90
  • Loss of consciousness, severe dizziness, ongoing chest pain
  • TIA/cerebrovascular accident (CVA) or acute heart failure

Investigations

Perform or refer for electrocardiography (ECG)

  • If paroxysmal AF suspected then arrange 24 hour ECG, or
  • Event recorder ECG where episodes are less than daily

When the ECG confirms AF or flutter:

  • Take bloods
    • Full blood count (not recommended by NICE however please perform according to clinical suspicion)
    • Renal function test
    • Thyroid function test
    • Liver function test
    • Clotting studies
    • HbA1c

Management

  • Assess for structural or functional heart disease.
  • Ensure patient has up to date information on AF.
  • In patients presenting acutely with symptomatic AF of new onset, consider long acting heparin where stroke risk is high, pending a decision about oral anticoagulation.

NICE Guidance CG 180-Patient decision aid - medicines to help reduce your risk of a stroke –what are the options?

Stroke prevention/ bleeding risk assessment:

  • Assess bleeding risk using HAS-BLED scoring system (see table below) – if the result is equal or more than 3, the patient has a high risk of bleeding

HAS-BLED table:

Letter Clinical Characteristic Points Awarded
H Hypertension 1
A Abnormal renal and liver function (1 point each) 1 or 2
S Stroke 1
B Bleeding 1
L Labile INRs 1
E Elderly 1
D Drugs or alcohol (1 point each) 1 or 2
Maximum possible score is 9

Assess stroke risk using CHA2DS2VASc (see table below) for AF (unless the cause is a rheumatic valve where the risk is 17 times higher and anticoagulation needed)

Risk Factor Points
Congestive heart failure/LV dysfunction
+1
Hypertension +1
Age older than 75 years +2
Diabetes mellitus +1
Stroke/TIA/thromboembolism +2
Vascular disease (MI, aortic placque, PAD +1
Age 65-74 years +1
Sex category (female) +1
Cumulative score Range 0-9

Score 2 or more (men and women) offer anticoagulants; Warfarin or a DOAC taking into account bleeding risk. If indicated but contraindicated or not tolerated, left atrial appendage occlusion may be a consideration

Score 1 in men: consider anticoagulants bearing in mind bleeding risk

Score 1 in women: no antithrombotics

Score 0 in men: no antithrombotics

In the latter 2, reassess annually – do not offer aspirin as the risks outweigh the benefits

Aspirin should not be used – no benefit compared to placebo

Other or dual antiplatelet therapy should not be used – no evidence

Warfarin reduces:

  • All-cause mortality 22/1000 treated per year
  • Ischaemic strokes 37/ 1000 treated per year
  • Showed no increase in significant bleeds

New oral anticoagulants (DOACs) may be used instead of warfarin in patients with:

  • stroke or TIA
  • diabetes
  • heart failure
  • hypertension
  • aged over 75

There remain concerns related to safety data in poor compliers, renal impairment, with no antidote and a higher risk of GI bleeds (though less intracranial bleeds)

Do not offer stroke prevention therapy to people aged under 65 years old with AF and no other risk factors other than their sex.

Rate/rhythm control

  • Rate control is the treatment of choice for the majority, based on the clinical judgement for the individual.
    • Any betablocker (not Sotalol) may be offered or a rate limiting calcium channel blocker such as Diltiazem (unlicensed but recommended by NICE)
  • If monotherapy is ineffective, try dual therapy prior to referral (please note interaction between some calcium channel blockers and betablockers)
    • If dual therapy is ineffective, refer for rhythm control or ablation will be offered
  • Do not use Digoxin unless non-paroxysmal AF and sedentary (only controls ventricular rate at rest)
    • Do not use Amiodarone

Rhythm control (minority) may be indicated if:

  • AF with reversible cause (e.g. pneumonia)
  • Heart failure thought to be caused mainly by AF

Echocardiogram is not routinely required if a decision to anticoagulate has already been made on clinical grounds.

For more information please refer to the joint formulary guidance on Atrial Fibrillation (AF)

Referral

Referral Criteria

Referral is not routinely required

Refer if:

  • Patients judged most suitable for first line rhythm control strategy e.g. the young and active and those with a reversible cause for AF
  • Treatment with rate control fails to manage the symptoms when a rhythm control strategy is to be considered
  • Underlying significant structural heart disease or heart failure

Referrals may be returned if the criteria are not evident in the referral letter.

Referral Instructions

e-Referral Service Selection

  • Specialty: Cardiology
  • Clinic Type: Arrhythmia/Not Otherwise Specified
  • Service: DRSS--Cardiology-Devon CCG- 15N

Referral Forms

Cardiology referral form

Supporting Information

Patient Information

British Heart Foundation Heart Health Atrial Fibrillation information

Atrial Fibrillation Association

Pathway Group

This guideline has been signed off by the Eastern Locality on behalf of NEW Devon CCG

Publication date: December 2015

 

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