Fibroblast Activation Protein Inhibitor Positron Emission Tomography Imaging in Atrial Fibrillation: Current Evidence and Future Perspectives.

Fibroblast activation protein inhibitor (FAPI) positron emission tomography/computed tomography (PET/CT) has emerged as a promising molecular imaging modality for visualizing fibroblast activation and extracellular matrix remodeling. In addition to its established role in oncology imaging, FAPI PET/CT is gaining recognition in the evaluation of cardiovascular disease. Emerging evidence suggests that this technique may provide molecular insights into atrial fibroblast activation and the development of a fibrotic substrate in atrial fibrillation. Meanwhile, related findings from other arrhythmias further support a potential link between myocardial fibroblast activation and electrophysiological remodeling. This review summarizes the current evidence on FAPI PET/CT imaging in atrial fibrillation, discusses related findings in other cardiovascular conditions, and highlights future directions for research in arrhythmia imaging.