Do left atrial appendage morphology and function help predict thromboembolic risk in atrial fibrillation?

Area of Science:

• Cardiovascular Medicine
• Medical Imaging
• Thrombosis Research

Background:

• Clinical scores like CHA2DS2-VASc are standard for managing thromboembolic risk in nonvalvular atrial fibrillation.
• These scores have limitations in precisely assessing the risk-benefit of oral anticoagulation, particularly in low-intermediate risk patients.

Purpose of the Study:

• To explore the role of cardiovascular imaging in refining thromboembolic risk stratification in nonvalvular atrial fibrillation.
• To review novel imaging parameters for predicting embolic events.

Main Methods:

• Review of existing literature on cardiovascular imaging parameters for thromboembolic risk.
• Focus on left atrium and left atrial appendage (LAA) functional and morphological variables.
• Inclusion of parameters like LAA strain, LAA morphology, and left atrium fibrosis (LGE-MRI).

Main Results:

• Established parameters like left atrium volume and LAA peak flow velocity are linked to increased risk.
• Newer parameters such as LGE-MRI for fibrosis, atrial/LAA strain, and LAA morphology show predictive ability.
• Clinical implementation is limited due to inconsistent cutoffs and technical/validation challenges.

Conclusions:

• Cardiovascular imaging currently plays a limited role in clinical practice for this indication.
• Further validation and wider adoption of advanced imaging techniques could significantly refine risk stratification.
• Potential exists to improve oral anticoagulation decision-making in atrial fibrillation patients.