From the Guidelines
DOACs can be used in most cases of valvular atrial fibrillation, but with important exceptions, as recommended by the most recent guidelines 1.
Overview of DOAC Use in Valvular Atrial Fibrillation
DOACs are recommended for patients with atrial fibrillation and native valve disease, including mitral regurgitation, aortic regurgitation, and aortic stenosis. Common DOACs include apixaban, rivaroxaban, dabigatran, and edoxaban.
Exceptions to DOAC Use
However, DOACs should not be used in patients with:
- Mechanical heart valves
- Moderate to severe mitral stenosis (usually of rheumatic origin) For these patients, warfarin remains the anticoagulant of choice, as stated in the 2024 ESC guidelines 1.
Dosing and Monitoring
When prescribing DOACs, follow standard dosing guidelines based on the specific medication, patient's age, weight, and renal function. For example, apixaban is typically dosed at 5 mg twice daily, but reduced to 2.5 mg twice daily in patients meeting certain criteria.
Rationale for DOAC Use
The rationale for using DOACs in most valvular AF is that they have shown similar or superior efficacy to warfarin in preventing stroke, with a lower risk of intracranial hemorrhage, as supported by the 2021 ACC/AHA clinical performance and quality measures for adults with atrial fibrillation or atrial flutter 1. They also offer practical advantages such as fixed dosing and no need for regular INR monitoring.
Key Considerations
The exceptions (mechanical valves and mitral stenosis) are due to the higher thrombotic risk in these conditions and limited data on DOAC efficacy in these specific patient groups, highlighting the need for careful patient selection and consideration of individual risk factors, as emphasized in the 2024 ESC guidelines 1.
From the Research
Use of Direct Oral Anticoagulants (DOACs) in Valvular Atrial Fibrillation
- Current guidelines recommend DOACs over warfarin in patients with atrial fibrillation (AF) and valvular heart disease (VHD) without a mechanical valve or moderate to severe mitral stenosis 2.
- A study found that in patients with AF and VHD, rates of major bleeding were similar among the DOACs and valve types; however, more patients receiving dabigatran experienced stroke or systemic embolism 2.
- Another study found that DOACs were associated with a lower risk of ischemic stroke or systemic embolism and major bleeding events compared to warfarin in patients with valvular AF 3.
- The suitability of DOACs in patients with valvular AF is still a topic of debate, with some studies suggesting that they may be a reasonable alternative to warfarin in certain patient populations 4, 5, 6.
Patient Populations Where DOACs May Not Be Recommended
- Patients with mechanical prosthetic valves or moderate/severe mitral stenosis may not benefit from DOACs 4, 6.
- The use of DOACs in patients with bioprosthetic valves or rheumatic mitral stenosis is still uncertain and requires further research 5, 6.
Key Findings
- Apixaban and rivaroxaban were found to be effective and safe in patients with valvular AF, with lower risks of ischemic stroke or systemic embolism and major bleeding events compared to warfarin 3.
- Dabigatran was associated with a higher risk of stroke or systemic embolism in patients with AF and VHD 2.
- The choice of anticoagulant should be individualized based on patient characteristics and risk factors 3, 6.