What is the recommended treatment for chronic atrial fibrillation?

Treatment of Chronic Atrial Fibrillation

For most patients with chronic atrial fibrillation, rate control with anticoagulation is the recommended initial strategy, using beta-blockers or non-dihydropyridine calcium channel blockers (diltiazem/verapamil) as first-line agents, combined with direct oral anticoagulants (DOACs) for stroke prevention. 1, 2

Anticoagulation: The Foundation of Treatment

All patients with chronic AF require anticoagulation unless they have lone AF (no risk factors) or contraindications. 2

First-Line Anticoagulant Selection

• Direct oral anticoagulants (apixaban, rivaroxaban, dabigatran, or edoxaban) are recommended over warfarin due to superior safety profiles and at least equivalent efficacy for stroke prevention 1, 2
• Apixaban ranks highest for efficacy and safety outcomes, with demonstrated superiority over warfarin (hazard ratio 0.79,95% CI 0.66-0.94) and significantly less major bleeding 2
• Apixaban dosing: 5 mg twice daily, or 2.5 mg twice daily if patient has ≥2 of: age ≥80 years, weight ≤60 kg, or serum creatinine ≥1.5 mg/dL 2

When Warfarin is Mandatory

• Warfarin is the only option for patients with mechanical heart valves or moderate-to-severe rheumatic mitral stenosis 2, 3
• Target INR 2.0-3.0 for most AF patients; 2.5-3.5 for certain mechanical valves depending on type and position 3
• Monitor INR weekly during initiation, then monthly once stable 2, 3

Critical Pitfall to Avoid

Never use aspirin alone in moderate-to-high risk patients—it is substantially less effective than anticoagulation for stroke prevention. 2 A high HAS-BLED score (≥3) is rarely a reason to withhold anticoagulation; instead, address modifiable bleeding risk factors. 2

Rate Control Strategy

Rate control with chronic anticoagulation is recommended for the majority of patients with chronic AF, as rhythm control has not been shown superior in reducing morbidity and mortality. 1

First-Line Rate Control Agents

For patients with LVEF >40%:

• Beta-blockers (atenolol, metoprolol), diltiazem, or verapamil are recommended as first-choice drugs 1
• These agents demonstrate efficacy in controlling heart rate both at rest and during exercise 1

For patients with LVEF ≤40% (heart failure with reduced ejection fraction):

• Beta-blockers and/or digoxin are recommended 1
• Avoid non-dihydropyridine calcium channel blockers in decompensated heart failure 1

Target Heart Rate

Lenient rate control with resting heart rate <110 bpm should be the initial target, with stricter control (<80 bpm at rest) reserved for patients with continuing AF-related symptoms 1. The RACE II trial demonstrated that lenient rate control was non-inferior to strict control for clinical outcomes. 1

Digoxin: Second-Line Agent

Digoxin is only effective for rate control at rest and should be used as a second-line agent, not first-line monotherapy 1. However, digoxin is effective for controlling resting heart rate in patients with heart failure with reduced ejection fraction 1. Combination therapy with digoxin plus a beta-blocker (or calcium channel blocker in HFpEF) is reasonable to control both rest and exercise heart rate 1.

Combination Therapy

When a single drug fails to control symptoms or heart rate, combination therapy should be considered, ensuring bradycardia can be avoided 1. The combination of digoxin with either a beta-blocker or calcium antagonist provides better symptom control than monotherapy 4.

Refractory Cases

For patients unresponsive to or ineligible for intensive rate and rhythm control therapy:

• AV node ablation combined with pacemaker implantation should be considered 1
• For severely symptomatic patients with permanent AF and at least one HF hospitalization, AV node ablation combined with cardiac resynchronization therapy should be considered to reduce symptoms, physical limitations, recurrent HF hospitalization, and mortality 1
• Never perform AV node ablation without first attempting pharmacological rate control 1

When to Consider Rhythm Control

Rhythm control is appropriate when based on patient symptoms, exercise tolerance, and patient preference, particularly in patients whose quality of life is compromised by AF despite adequate rate control 1. In chronic heart failure patients who remain symptomatic from AF despite a rate-control strategy, it is reasonable to use a rhythm-control strategy. 1

Rhythm Control Agents (When Indicated)

For selected patients requiring rhythm maintenance, the recommended pharmacologic agents are amiodarone, disopyramide, propafenone, and sotalol, with choice depending on specific risk of side effects based on patient characteristics 1. However, most patients converted to sinus rhythm should not be placed on rhythm maintenance therapy since the risks outweigh the benefits. 1

Special Populations

Heart Failure with Preserved Ejection Fraction (HFpEF)

• Beta-blocker or non-dihydropyridine calcium channel antagonist is recommended for persistent or permanent AF 1

Heart Failure with Reduced Ejection Fraction (HFrEF)

• In the acute setting with AF and rapid ventricular response, IV digoxin or amiodarone is recommended to acutely control heart rate 1
• IV non-dihydropyridine calcium channel antagonists, IV beta-blockers, and dronedarone should not be given with decompensated heart failure 1

Hyperthyroidism

• Beta-blockers are recommended to control ventricular rate with AF complicating thyrotoxicosis, unless contraindicated 1
• Non-dihydropyridine calcium channel antagonist is recommended when beta-blocker cannot be used 1

COPD

• Non-dihydropyridine calcium channel antagonist is recommended to control ventricular rate with COPD and AF 1

WPW and Pre-excitation Syndromes

IV amiodarone, adenosine, digoxin, or non-dihydropyridine calcium channel antagonists are potentially harmful in patients with WPW who have pre-excited AF 1. Use IV procainamide or ibutilide instead. 1

Monitoring Requirements

• Assess heart rate during exercise and adjust pharmacological treatment in symptomatic patients during activity 1
• For patients on DOACs, regularly assess renal function and periodically reassess bleeding risk 2
• For patients on warfarin, check INR weekly during initiation and monthly once stable 2, 3

Key Clinical Pitfalls

• Underdosing DOACs in high-risk patients due to bleeding concerns increases stroke risk without proven safety benefit 2
• Failing to reassess anticoagulation needs and bleeding risk periodically 2
• Inappropriate discontinuation of anticoagulation before procedures—many procedures can be performed safely without interrupting anticoagulation 2
• Using bleeding risk scores to withhold anticoagulation in patients with stroke risk factors leads to underuse of life-saving therapy 2