Here is a recent article 2023 that basically is inclusive that Afib leads to TAA directly or they happen to occur as dual pathologies independent of each other. At least that is how I understand it. "Thoracic aortic aneurysm and atrial fibrillation: clinical associations with the risk of stroke from a global federated health network analysis"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10017617/#:~:text=The%20findings%20regarding%20AF%20and,as%20hypertension%20and%20heart%20failure.
Conclusion
Our retrospective analysis from a large global federated dataset reports a clinical concomitance of AF and TAA. Importantly, in a PSM analysis, an increased risk of ischemic events in patients affected by both TAA and AF was evident, compared to AF alone. Whether this association simply reflects shared risk factors or commonality in pathophysiological pathways, it raises relevant clinical implications that deserve further investigation.