What is the treatment for acute atrial fibrillation (AFib)?

From the Guidelines

Acute atrial fibrillation treatment should prioritize rate control as the initial therapy, using beta-blockers, diltiazem, verapamil, or digoxin as first-choice drugs to control heart rate and reduce symptoms, as recommended by the 2024 ESC guidelines 1.

Key Considerations

• The choice of rate control medication depends on the patient's left ventricular ejection fraction (LVEF), with beta-blockers, diltiazem, verapamil, or digoxin recommended for patients with LVEF >40% 1.
• For patients with LVEF ≤40%, beta-blockers and/or digoxin are recommended to control heart rate and reduce symptoms 1.
• Anticoagulation should be initiated promptly to prevent stroke, with the choice of anticoagulant depending on the patient's stroke risk and bleeding risk 1.

Treatment Strategies

• Rate control is often preferred in older patients with minimal symptoms, while rhythm control may be better for younger patients with symptomatic AF.
• Rhythm control therapy, including electrical or pharmacological cardioversion, antiarrhythmic drug therapy, and catheter ablation, may be considered for symptom improvement in patients with AF 1.
• The decision to use rate or rhythm control should be based on symptom severity, duration of AF, comorbidities, and patient preference.

Important Medications

• Beta-blockers: metoprolol (5-15 mg IV, followed by 25-100 mg orally twice daily)
• Calcium channel blockers: diltiazem (0.25 mg/kg IV over 2 minutes, then 5-15 mg/hour infusion)
• Digoxin: dose dependent on renal function and patient's condition
• Anticoagulants: heparin, enoxaparin, apixaban (5 mg twice daily), or rivaroxaban (20 mg daily with food)

From the FDA Drug Label

Atrial fibrillation or atrial flutter In clinical studies with diltiazem hydrochloride injection for AF/Fl, 135 of 257 patients were over 65 years of age No overall differences in safety or effectiveness were observed between these patients and younger patients, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out

Diltiazem hydrochloride injection can be used for the treatment of atrial fibrillation or atrial flutter (AF/Fl).

• The drug has been studied in clinical trials for AF/Fl, with a significant number of patients over 65 years of age.
• No overall differences in safety or effectiveness were observed between older and younger patients.
• However, greater sensitivity of some older individuals cannot be ruled out, and dose selection for elderly patients should be cautious, usually starting at the low end of the dosing range 2.

From the Research

Acute Atrial Fibrillation Treatment

• The treatment of acute atrial fibrillation (AF) involves rate control, which can be achieved using intravenous (IV) medications such as metoprolol or diltiazem 3, 4, 5, 6, 7.
• A study comparing IV metoprolol and diltiazem for rate control in AF found no significant difference in the achievement of rate control between the two medications, with 35% and 41% of patients achieving rate control, respectively 3.
• Another study found that metoprolol was associated with a 26% lower risk of adverse events compared to diltiazem, with a total incidence of 10% and 19%, respectively 5.
• A systematic review and meta-analysis of adverse events found that metoprolol had lower rates of adverse events compared to diltiazem, with no difference in rates of hypotension or bradycardia 5.
• A study comparing diltiazem and metoprolol for rate control of atrial fibrillation or flutter with rapid ventricular rate in the emergency department found that diltiazem was more effective in achieving rate control, with 95.8% of patients reaching the target heart rate of <100 beats per minute compared to 46.4% of patients treated with metoprolol 6.
• In patients with heart failure with reduced ejection fraction (HFrEF), a study found that there was no difference in total adverse events between patients treated with IV diltiazem and metoprolol, but the diltiazem group had a higher incidence of worsening heart failure symptoms 7.

Medication Comparison

• Metoprolol and diltiazem are both commonly used for rate control in AF, with metoprolol being a beta-blocker and diltiazem being a non-dihydropyridine calcium channel blocker 3, 5, 6, 7.
• The choice of medication may depend on patient-specific factors, such as the presence of HFrEF, with some studies suggesting that metoprolol may be preferred in these patients due to the potential negative inotropic effects of diltiazem 7.
• However, other studies have found no difference in adverse events between metoprolol and diltiazem in patients with HFrEF, suggesting that both medications can be used safely in this population 3, 5.

Treatment Goals

• The primary goal of treatment for acute AF is to achieve rate control, which can be defined as a heart rate of <100 beats per minute 3, 6.
• Secondary goals of treatment may include preventing adverse events, such as hypotension and bradycardia, and improving patient outcomes, such as reducing the risk of stroke and other complications 4, 5, 7.
• The choice of treatment should be individualized based on patient-specific factors, such as medical history, comorbidities, and medication tolerance 3, 5, 6, 7.