Histopathological evaluation of heart appendages resected during cardiac surgery in patients with atrial fibrillation

Introduction. Atrial fibrillation is among the most common forms of cardiac arrhythmias, which poses a significant risk for thromboembolic complications. Surgical excision of the atrial appendages prevents atrial fibrillation recurrence and eliminates the need for lifelong thrombolytic therapy. The study aimed to analyze histomorphological features of postoperative atrial fibrillation using surgical cardiac biopsies. Materials and methods. We used histological and morphometric methods to study biopsies of the left appendages from 32 patients with atrial fibrillation who underwent surgery for cardiovascular diseases. The comparison group included biopsies from 21 patients without atrial fibrillation. Results. In atrial fibrillation, acute cardiomyocyte injuries (myocytolysis, contractures, and wave-like deformity accompanied by stromal edema and increased vascular permeability) were more pronounced and more informative on the background of cardiosclerosis and lipomatosis. Foci of mucoid edema with parietal thrombosis were detected in endocardial sclerosis areas. Conclusion. In atrial fibrillation, histopathological changes in the heart appendages are characterized by acute and chronic nonspecific changes and are more pronounced than in the group without atrial fibrillation. Acute cardiomyocyte damage accompanied by increased vascular permeability and stroma edema is the most informative indicator in atrial fibrillation. © 2025 Elsevier B.V., All rights reserved.