Which Angiotensin Receptor Blocker (ARB) is best for atrial fibrillation (a-fib), olmesartan or losartan?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 14, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Research

Neither olmesartan nor losartan is considered the best ARB for atrial fibrillation (A-fib), but among the two, losartan has shown some benefits in preventing the recurrence of atrial fibrillation in hypertensive patients 1. For A-fib management, when an ARB is indicated, the choice should be based on the specific clinical context and evidence. The study by 1 found that losartan, in combination with amiodarone, was more effective than amlodipine/amiodarone combination in preventing new episodes of atrial fibrillation in hypertensive patients with recurrent atrial fibrillation. While olmesartan is effective for hypertension and has been shown to have a greater blood pressure-lowering effect compared to other ARBs, including losartan 2, 3, it lacks specific evidence for A-fib patients. ARBs, including losartan and olmesartan, work by blocking angiotensin II receptors, which may help reduce structural remodeling of the heart that contributes to A-fib. However, for primary A-fib management, medications like beta-blockers, calcium channel blockers, or antiarrhythmics are typically used first. It's also worth noting that the most recent and highest quality study on the topic is crucial for guiding clinical decisions, but in this case, the provided studies do not directly compare olmesartan and losartan in the context of A-fib management, with the exception of their general efficacy in hypertension management. Given the available evidence, losartan might be considered over olmesartan for patients with A-fib and hypertension due to its specific study showing benefits in preventing A-fib recurrence 1, but this should be weighed against individual patient factors and the broader clinical context.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.