Anticoagulation in patients at high risk of stroke without documented atrial fibrillation. Time for a paradigm shift?

Area of Science:

• Cardiology
• Neurology
• Biomedical Engineering

Background:

• Atrial fibrillation (AF) is a known risk factor for ischemic stroke, leading to anticoagulation recommendations based on clinical risk scores.
• The direct causal link between AF and stroke is debated due to a lack of temporal association between stroke events and AF episodes.
• Subclinical AF episodes of significant duration are infrequently detected at the time of stroke events.

Purpose of the Study:

• To question the paradigm of AF as the primary cause of stroke.
• To propose considering electrocardiographic markers of atrial fibrosis as a significant indicator for stroke risk.
• To explore the potential for stroke prevention in patients without diagnosed AF but with indicators of atrial disease.

Main Methods:

• Review of existing literature questioning the direct causality of AF in stroke.
• Proposal for incorporating electrocardiographic markers of atrial fibrosis into risk assessment.
• Discussion of an "opinion paper" framework for evaluating stroke risk.

Main Results:

• Evidence suggests that AF may not always be the direct cause of ischemic stroke.
• Atrial fibrosis, detectable via electrocardiography, is postulated as a strong indicator of AF and stroke risk.
• A significant proportion of strokes may occur in individuals without detectable AF.

Conclusions:

• The direct causal role of AF in all ischemic strokes warrants re-evaluation.
• Electrocardiographic markers of atrial fibrosis could offer a novel approach to identifying individuals at high risk for stroke.
• A paradigm shift may be necessary to consider stroke prevention strategies for patients at risk, irrespective of AF diagnosis.