From the Guidelines
Losartan is recommended to decrease the recurrence of atrial fibrillation (AFib) due to its effects on the renin-angiotensin-aldosterone system (RAAS), which reduces blood pressure and cardiac remodeling, as evidenced by the 2024 ESC guidelines 1. The mechanism by which losartan decreases AFib recurrence is multifaceted, involving the prevention of angiotensin II binding to its receptors, thereby reducing blood pressure and decreasing cardiac remodeling, which is a major contributor to AFib development and recurrence.
- Losartan's anti-remodeling effects develop gradually over months of consistent therapy, highlighting the importance of long-term adherence to treatment.
- The reduction in blood pressure achieved with losartan is also crucial, as hypertension is a significant risk factor for AFib, and a 10 mmHg reduction in systolic BP has been associated with a 17% reduction in incident AF, as seen in the LIFE trial 1.
- Additionally, losartan reduces inflammation and oxidative stress in cardiac tissue, known triggers for AFib, further supporting its use in preventing AFib recurrence.
- In terms of dosage, losartan typically starts at 50 mg once daily, which may be increased to 100 mg daily if needed for blood pressure control, and patients should be monitored for common side effects such as dizziness and changes in blood potassium levels. The most recent and highest quality evidence supports the use of losartan, an angiotensin II receptor blocker (ARB), as a preferred agent for reducing AFib recurrence, particularly in patients with hypertension, as stated in the 2024 ESC guidelines 1.
From the Research
Mechanism of Losartan in Decreasing AFib Recurrence
- Losartan, an angiotensin II receptor blocker, has been shown to decrease the recurrence of atrial fibrillation (AFib) in hypertensive patients 2, 3, 4, 5, 6.
- The exact mechanism is not fully understood, but it is thought to be related to the drug's ability to inhibit atrial remodeling, which is a key factor in the development and maintenance of AFib 3, 4.
- Atrial remodeling refers to the changes in the atrial tissue that occur in response to conditions such as hypertension, which can lead to the development of AFib 4.
- Losartan has been shown to reduce atrial fibrosis, which is a key component of atrial remodeling, and to improve atrial conduction disturbances 3, 4.
Clinical Evidence
- A study published in the Journal of Cardiovascular Pharmacology found that losartan was more effective than amlodipine in preventing the recurrence of AFib in hypertensive patients 2.
- Another study published in the International Journal of Cardiology found that losartan improved atrial conduction disturbances and reduced the recurrence of AFib in patients with essential hypertension 3.
- A study published in Cardiovascular Pathology found that losartan reduced atrial fibrosis and AFib vulnerability in a rabbit model of AFib 4.
- The Losartan Intervention For End Point Reduction in Hypertension (LIFE) study found that losartan reduced the incidence of new-onset AFib and subsequent stroke compared to atenolol in hypertensive patients 5.
- A study published in Heart and Vessels found that losartan suppressed the maximum duration and total duration of paroxysmal AFib in patients with sick sinus syndrome 6.
Key Findings
- Losartan reduces the recurrence of AFib in hypertensive patients 2, 3, 4, 5, 6.
- Losartan inhibits atrial remodeling and reduces atrial fibrosis 3, 4.
- Losartan improves atrial conduction disturbances and reduces AFib vulnerability 3, 4.
- Losartan reduces the incidence of new-onset AFib and subsequent stroke in hypertensive patients 5.
- Losartan suppresses the maximum duration and total duration of paroxysmal AFib in patients with sick sinus syndrome 6.