What is the diagnosis and treatment for valvular atrial fibrillation (AFib)?

From the Guidelines

Valvular atrial fibrillation requires anticoagulation with warfarin rather than direct oral anticoagulants (DOACs) for patients with mechanical heart valves or moderate to severe mitral stenosis, with a target INR of 2.0-3.0, as recommended by the 2024 ESC guidelines 1. The diagnosis of valvular atrial fibrillation should be confirmed by an electrocardiogram (12-lead, multiple, or single leads) to establish the diagnosis of clinical AF and commence risk stratification and treatment 1.

Key Considerations

• The standard treatment includes rate control with beta-blockers (metoprolol 25-200 mg daily), calcium channel blockers (diltiazem 120-360 mg daily), or digoxin (0.125-0.25 mg daily), along with warfarin anticoagulation 1.
• Rhythm control strategies may be considered in symptomatic patients using antiarrhythmic medications like amiodarone (200 mg daily after loading) or cardioversion, but anticoagulation must be maintained 1.
• DOACs (apixaban, rivaroxaban, dabigatran, edoxaban) are contraindicated in valvular AF because they have not demonstrated adequate protection against thromboembolism in these patients, as stated in the 2024 ESC guidelines 1.

Management Principles

• The management of valvular atrial fibrillation should follow the AF-CARE pathway, which includes comorbidity and risk factor management, avoidance of stroke and thromboembolism, reduction of symptoms by rate and rhythm control, and evaluation and dynamic reassessment 1.
• Patient-centered management according to the AF-CARE principles is recommended in all patients with AF, regardless of gender, ethnicity, and socioeconomic status, to ensure equality in healthcare provision and improve outcomes 1.
• Identification and management of risk factors and comorbidities is recommended as an integral part of AF care, including blood pressure lowering treatment, diuretics, and effective glycaemic control 1.

From the FDA Drug Label

For patients with AF and mitral stenosis, anticoagulation with oral warfarin is recommended (7th ACCP) For patients with AF and prosthetic heart valves, anticoagulation with oral warfarin should be used; the target INR may be increased and aspirin added depending on valve type and position, and on patient factors. Oral anticoagulation therapy has not been evaluated by properly designed clinical trials in patients with valvular disease associated with atrial fibrillation, patients with mitral stenosis, and patients with recurrent systemic embolism of unknown etiology. A moderate dose regimen (INR 2.0 to 3.0) is recommended for these patients.

The diagnosis of valvular atrial fibrillation (AFib) is not explicitly stated in the label, but it can be inferred that it refers to atrial fibrillation associated with valvular heart disease. The treatment for valvular AFib is anticoagulation with oral warfarin.

• The target INR for valvular AFib patients is not explicitly stated, but a moderate dose regimen (INR 2.0 to 3.0) is recommended for patients with valvular disease associated with atrial fibrillation.
• The use of aspirin in addition to warfarin may be considered depending on valve type and position, and on patient factors 2.

From the Research

Diagnosis of Valvular Atrial Fibrillation (AFib)

• Valvular AFib is typically diagnosed using electrocardiogram (ECG) and medical history, although the provided studies do not directly address the diagnosis of valvular AFib 3, 4, 5, 6, 7.
• The studies focus on the treatment and management of AFib, including antithrombotic therapy and cardioversion.

Treatment of Valvular Atrial Fibrillation (AFib)

• For patients with AFib and mitral stenosis, anticoagulation with an oral vitamin K antagonist (VKA) is recommended 3, 4.
• For patients with AFib and prosthetic heart valves, anticoagulation with an oral VKA is also recommended, with the target international normalized ratio (INR) potentially increased and aspirin added depending on valve type and position 3, 4.
• The choice of antithrombotic therapy depends on the patient's risk factors for stroke, including age, history of hypertension, diabetes mellitus, and left ventricular systolic function 3, 4, 6.
• Warfarin is effective in reducing the risk of stroke in patients with AFib, with a target INR of 2.0-3.0 3, 4, 6.
• Aspirin is less effective than warfarin in reducing the risk of stroke, but may be used in patients who are unable to take warfarin or have a low risk of stroke 3, 4, 6.
• Low-intensity warfarin therapy (INR 1.5-2.0) may be as effective as standard-intensity warfarin therapy (INR 2.0-3.0) in reducing thromboembolic risk in patients over 65 years with non-valvular AFib, with a safer profile of bleeding 7.

Antithrombotic Therapy

• Antithrombotic therapy is an effective method for preventing stroke in patients with AFib who cannot be converted and maintained in normal sinus rhythm 5, 6.
• The choice of antithrombotic therapy depends on the patient's risk factors for stroke and the presence of other medical conditions 3, 4, 6.
• Anticoagulation with an oral VKA, such as warfarin, is recommended for patients with AFib who are at high risk of stroke 3, 4, 6.
• Aspirin may be used in patients who are unable to take warfarin or have a low risk of stroke 3, 4, 6.

Cardioversion

• Cardioversion is a procedure used to convert AFib to normal sinus rhythm 3, 4, 5.
• Anticoagulation with an oral VKA is recommended for at least 3 weeks before and 4 weeks after cardioversion in patients with AFib who are at high risk of stroke 3, 4.
• Transesophageal echocardiography (TEE) may be used to screen for thrombus before cardioversion 3, 4.