What medications are recommended for a patient with atrial fibrillation (Afib)?

Medications for Atrial Fibrillation

For patients with atrial fibrillation, treatment requires both anticoagulation to prevent stroke and rate or rhythm control to manage symptoms, with the specific medication choices determined by left ventricular function, symptom burden, and stroke risk.

Anticoagulation for Stroke Prevention

All patients with AF require anticoagulation unless they have lone AF or contraindications. 1

• Direct oral anticoagulants (DOACs) such as apixaban are preferred over warfarin due to lower bleeding risk and superior efficacy. 1, 2
• Apixaban dosing is 5 mg twice daily for most patients, or 2.5 mg twice daily if the patient has at least two of: age ≥80 years, weight ≤60 kg, or serum creatinine ≥1.5 mg/dL. 3
• Warfarin (target INR 2.0-3.0) is an alternative when DOACs are contraindicated or in patients with mechanical heart valves. 4, 1
• Aspirin is NOT recommended for stroke prevention in AF as it has inferior efficacy compared to anticoagulation. 2
• Anticoagulation reduces stroke risk by 60-80% compared to placebo. 2

Rate Control Strategy

Rate control is the first-line approach for most patients with AF, particularly those over 65 or with coronary disease. 1, 5

For Patients with Preserved Left Ventricular Function (LVEF >40%)

Beta-blockers, diltiazem, or verapamil are first-line agents (Class I, Level B recommendation). 1, 6

• Beta-blockers (metoprolol 25-100 mg twice daily, propranolol 80-240 mg daily in divided doses, or esmolol 0.5 mg/kg IV bolus followed by 0.05-0.2 mg/kg/min infusion for acute control). 1, 6
• Non-dihydropyridine calcium channel blockers (diltiazem 120-360 mg daily or verapamil 120-360 mg daily). 1, 6
• Digoxin (0.125-0.375 mg daily) can be added but should NOT be used as monotherapy because it only controls resting heart rate, not exercise heart rate. 1, 6, 7

For Patients with Reduced Left Ventricular Function (LVEF ≤40%)

Beta-blockers and/or digoxin are first-line agents (Class I, Level B recommendation). 1, 7

• Avoid calcium channel blockers (diltiazem, verapamil) in patients with heart failure or LVEF ≤40% as they can precipitate cardiogenic shock due to negative inotropic effects. 6, 7
• Combination therapy with beta-blocker plus digoxin is particularly effective in heart failure patients. 6, 7

Rate Control Targets

• Initial target: resting heart rate <110 bpm (lenient control strategy). 1, 6
• Strict control (60-80 bpm at rest, 90-115 bpm during moderate exercise) provides no additional benefit over lenient control. 1, 6

Acute Rate Control

• For hemodynamically stable patients: IV beta-blockers (metoprolol 2.5-5 mg IV bolus over 2 minutes, up to 3 doses) or IV diltiazem (0.25 mg/kg IV over 2 minutes). 1, 6
• For hemodynamically unstable patients: Immediate electrical cardioversion is required. 1

Rhythm Control Strategy

Early rhythm control with antiarrhythmic drugs or catheter ablation is recommended for symptomatic patients, particularly those with recent-onset AF or heart failure with reduced ejection fraction. 1, 2

Pharmacological Cardioversion

• For patients WITHOUT structural heart disease: IV flecainide or propafenone (Class I, Level A), or IV vernakalant (Class I, Level A). 1
• For patients WITH structural heart disease, left ventricular hypertrophy, or coronary disease: IV amiodarone (300 mg IV over 30-60 minutes, followed by 900 mg IV over 24 hours) is the only safe option. 1, 6, 7

Anticoagulation Before Cardioversion

• Therapeutic anticoagulation for at least 3 weeks is required before cardioversion if AF duration is >24 hours or unknown. 1
• Alternatively, transesophageal echocardiography can exclude thrombus to enable early cardioversion. 1
• Continue anticoagulation for at least 4 weeks after cardioversion and long-term in patients with stroke risk factors. 1

Critical Pitfalls to Avoid

• Never use calcium channel blockers or beta-blockers in patients with Wolff-Parkinson-White syndrome and AF, as they can accelerate conduction through the accessory pathway and cause ventricular fibrillation. 7
• Do not use digoxin as monotherapy in physically active patients or paroxysmal AF, as it fails to control exercise heart rate. 1, 6, 7
• Avoid class IC antiarrhythmic drugs (flecainide, propafenone) in patients with coronary disease or structural heart disease due to increased risk of sustained ventricular arrhythmias. 1, 8
• Do not discontinue anticoagulation based on bleeding risk scores alone, as this leads to under-use of anticoagulation. 1
• Never add antiplatelet therapy to anticoagulation for stroke prevention, as it increases bleeding without reducing stroke risk. 1

When Pharmacologic Therapy Fails

AV nodal ablation with permanent pacemaker implantation is recommended when medications fail to control rate and symptoms (Class IIa, Level B). 1, 6, 7

• For heart failure patients with reduced ejection fraction, consider biventricular pacing (cardiac resynchronization therapy) rather than standard right ventricular pacing. 6, 7
• Catheter ablation is first-line therapy for symptomatic paroxysmal AF to improve symptoms, slow progression to persistent AF, and improve outcomes in heart failure patients. 2