SUMMARY:

Atrial fibrillation, the most common cardiac arrhythmia, increases stroke risk and can exacerbate underlying heart disease. The 2014 ACC/AHA/HRS Guideline for the Management of Patients with Atrial Fibrillation offers a comprehensive approach to treating this condition. A focused update released in 2019 includes new evidence in support of novel drugs and devices to prevent thromboembolism, as well as other clinical considerations. Of note, these recommendations apply to atrial fibrillation (AF) and atrial flutter, regardless of the pattern of arrhythmia (i.e. paroxysmal, persistent, or permanent).

• Diagnosis and Workup
• Treatment Highlights
• Risk stratification
• Anticoagulation
• Alternatives to Anticoagulation
• Rate Control
• Rhythm Control

Diagnosis and Workup

• Diagnosed by EKG or cardiac monitoring: Characteristic irregular rhythm without discrete p-waves
• Workup at time of diagnosis should include
  • TTE | Thyroid function tests | CBC | Renal function and electrolytes | LFTs | CXR (if suspicion for heart failure or pulmonary disease) | Sleep study (if suspicion for sleep apnea)
• Outpatient management appropriate for hemodynamically stable patients without evidence of severe volume overload or acute coronary syndrome

Treatment Highlights

• Mainstays of treatment for most patients are anticoagulation (warfarin vs. NOAC) and rate control (typically beta blocker or nondihydropyridine calcium channel blocker)
• For some patients, attempted cardioversion to sinus rhythm may be preferred initially
• Invasive procedures to ablate AF or occlude the LAA are appropriate for select patients

KEY POINTS:

• Valvular vs. non-valvular AF
  • Valvular: AF associated with moderate to severe mitral stenosis or mechanical heart valve
  • Non-valvular: All other AF (much more common)

Risk stratification

• CHA₂DS₂-VASc:  Estimates annual stroke risk for non-valvular AF, based on various demographic and comorbid factors
  • Anticoagulation is recommended for score ≥2 in men, ≥3 in women
  • Anticoagulation “may be considered” for score 1 in men, 2 in women; aspirin is also an option
• Stroke risk can be weighed against bleeding risk using clinical calculators such as HAS-BLED
  • However per ACC/AHA “their clinical utility is insufficient for use as evidence”
  • Higher bleeding risk may warrant closer monitoring of anticoagulated patients, but should not necessarily preclude anticoagulation

Anticoagulation

Choosing an anticoagulant

• Goal is to prevent thromboembolic events
• Decision to start anticoagulation should always involve discussion of risks vs benefits

Medications

• Warfarin
  • Indicated for all valvular AF
  • Goal INR 2-3
• Novel oral anticoagulants (NOACs) recommended over warfarin for non-valvular AF in absence of contraindications
  • Dabigatran (Pradaxa) | Rivaroxaban (Xarelto) | Apixaban (Eliquis) | Edoxaban (Savaysa)
  • All either superior or non-inferior to warfarin | Do not require INR monitoring | Have lower risk of major bleeding
  • All have reduced dose options for CKD

• ESRD
  • Use warfarin or apixaban (limited data to support this)
• Bridging
  • For patients with mechanical heart valves undergoing surgery or other invasive procedure, bridge with unfractionated or low molecular weight heparin to provide uninterrupted anticoagulation
  • For all others, a brief interruption of therapy without bridging is considered safe

• Anticoagulation with antiplatelet therapy
  • Patients with AF and recent coronary stenting who are on triple therapy (oral anticoagulant + aspirin + P2Y₁₂ inhibitor) may be narrowed to double therapy (warfarin, dabigatran, or rivaroxaban + P2Y₁₂ inhibitor) to reduce bleeding risk

Dosing

• Apixaban (Eliquis)
  • Usual dose: 5 mg twice a day
  • Adjusted dose: 2.5 mg twice a day if ≥2 of the following
    • Age: ≥80 years
    • Body weight: ≤60 kg
    • Serum creatinine: ≥1.5 mg/dL

Note:  Caution with use of apixaban and the following 

• Other medications that can interfere with hemostasis: May increase risk of bleeding
  • Aspirin and antiplatelet agents | Other anticoagulants | Heparin | Thrombolytic agents | SSRIs | SNRIs | NSAIDs (chronic use) | Fibrinolytics
• Combined P-gp and strong CYP3A4 inhibitors
  • Ketoconazole | Itraconazole | Ritonavir
  • Reduce dose by 50% in usual dosing regimen and do not use with 2.5 mg reduced dose | Dose does not need to be altered with clarithromycin
• Combined P-gp and strong CYP3A4 inducers: Avoid concomitant use
  • Rifampin | Carbamazepine | Phenytoin | St. John’s wort

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• Dabigatran (Pradaxa)
  • CrCl >30 mL/min: 150 mg orally, twice daily
  • CrCl 15 to 30 mL/min: 75 mg orally, twice daily

Note: Exercise caution with use of dabigatran and the following

• P-gp inducers rifampin: Avoid coadministration
• P-gp inhibitors in patients with CrCl 30-50 mL/min: Reduce dose or avoid
• P-gp inhibitors in patients with CrCl <30 mL/min: Not recommended

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• Rivaroxaban (Xarelto)
  • 15 or 20 mg, once daily with food

Note: Exercise caution with use of rivaroxaban and the following

• Avoid combined P-gp and strong CYP3A inhibitors and inducers
• Anticoagulants: Avoid concomitant use
• Renal impairment: Avoid or adjust dose
• Hepatic impairment: Avoid use in Child-Pugh B and C hepatic impairment or with any degree of hepatic disease associated with coagulopathy

Alternatives to Anticoagulation

• Since thromboemboli tend to develop in the left atrial appendage (LAA), non-pharmacologic strategies for minimizing stroke risk involve occluding or removing the LAA
  • Percutaneous LAA occlusion (Watchman device): For patients with a contraindication to long-term anticoagulation (however, must be able to receive periprocedural anticoagulation)
  • Surgical LAA occlusion/excision: Only for patients already undergoing cardiac surgery for another indication

Rate Control

• Goal: To reduce symptoms, improve intra-cardiac hemodynamics and perfusion, and prevent tachycardia-induced cardiomyopathy
• Choosing a rate control strategy
  • Beta blockers (metoprolol, carvedilol, atenolol) or nondihydropyridine calcium channel blockers (diltiazem, verapamil) are first-line
  • Avoid CCBs in heart failure with reduced EF
  • Second-line options include digoxin (possibly associated with increased mortality) and amiodarone (not for long-term use due to toxicities)
• Strict (<80 bpm) vs. lenient (<110 bpm) rate control
  • Lenient approach acceptable as long as patient is asymptomatic and with preserved EF

Rhythm Control

• Not superior to rate control and associated with increase in hospitalizations
• May be indicated for new-onset AF, persistent symptoms, difficulty achieving rate control, young age, or tachycardia-induced cardiomyopathy
  • These approaches generally require expert consultation
• Electrical cardioversion
  • In non-emergent setting, requires anticoagulation three weeks pre- and four weeks post-procedure (if duration of AF >48 hours or unknown)
  • Often preceded by TEE to exclude LA thrombus
• Maintaining sinus rhythm
  • Typically achieved with antiarrhythmics (e.g. amiodarone, dofetilide, flecainide)
  • Caution: These drugs have significant side effects and toxicities
• Catheter ablation
  • For symptomatic paroxysmal AF not responding to antiarrhythmic therapy

Learn More – Primary Sources:

2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation

2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society in Collaboration With the Society of Thoracic Surgeons

AAFP: Diagnosis and Treatment of Atrial Fibrillation

NOAC trials: RE-LY (dabigatran)

ROCKET-AF (rivaroxaban)

ARISTOTLE (apixaban)

CHA₂DS₂-VASc Calculator

HAS-BLED Calculator

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