Sex and Racial Differences in Left Atrial Appendage Morphology

Area of Science:

• Cardiology
• Radiology
• Medical Imaging

Background:

• Atrial fibrillation (AF) patients who are Black or female experience higher stroke rates.
• Specific left atrial appendage (LAA) morphologies are linked to increased stroke risk.
• Racial and sexual variations in LAA anatomy and their association with stroke risk are largely unexplored.

Purpose of the Study:

• To investigate potential associations between patient race and sex with LAA morphology.
• To explore if LAA anatomical differences contribute to stroke risk disparities in Black and female AF patients.

Main Methods:

• Computed tomography (CT) scans of 211 patients were analyzed for LAA morphology.
• LAA morphologies were categorized using a scoring system based on thrombus risk (chicken wing, windsock, cactus, cauliflower).
• Statistical analyses, including Wilcoxon rank-sum and Fisher's exact tests, were used to compare morphology prevalence and scores across racial and sex groups. Logistic regression identified associations between race/sex and high-risk LAA morphologies.

Main Results:

• No significant differences in projected stroke risk scores were observed between Black and non-Black patients, or between men and women.
• The 'cauliflower' LAA morphology, associated with the highest stroke risk, was significantly more prevalent in Black patients compared to non-Black patients (adjusted OR, 4.8; P=0.035).
• While 'cauliflower' morphology was more frequent in women, this finding did not reach statistical significance (P=0.063).

Conclusions:

• The 'cauliflower' LAA morphology, a high-risk factor for stroke, shows a higher prevalence in Black patients.
• The observed difference in LAA morphology between sexes did not achieve statistical significance.
• These preliminary findings suggest potential racial disparities in stroke risk due to LAA anatomy, warranting further investigation despite the study's limitations in statistical power.