Maria-Daniela Tanasescu, Andrei-Mihnea Rosu, Alexandru Minca, Maria-Mihaela Grigorie, Delia Timofte, D Ionescu
Atrial fibrillation (AF) frequently coexists with chronic kidney disease (CKD), and their combination confers a disproportionate risk of both thromboembolic and bleeding events. Conventional anticoagulation strategies rely primarily on creatinine clearance-based dosing, which reflects pharmacokinetic safety but does not fully capture the biological processes underlying thrombohemorrhagic instability. This narrative review synthesizes recent mechanistic and translational evidence regarding the bidirectional cardio-renal axis in AF and CKD, focusing on systemic inflammation, endothelial dysfunction, platelet dysregulation, and altered coagulation. A structured literature search of PubMed/MEDLINE, Scopus, and Web of Science (2018-2026) was performed, complemented by manual review of key references and guidelines. The evidence indicates that inflammatory cytokine activation, oxidative stress, glycocalyx degradation, von Willebrand factor dysregulation, uremic platelet dysfunction, and enhanced thrombin generation converge to create a disrupted vascular interface in which stroke and bleeding arise from shared pathophysiological mechanisms. Renal trajectory and selected circulating biomarkers further highlight the dynamic and heterogeneous nature of risk in advanced CKD. These findings support reframing anticoagulation decision-making in AF with CKD from a static filtration-based model toward a biology-informed approach that integrates renal dynamics, endothelial and platelet phenotype, and clinical context to better align thromboembolic protection with hemorrhagic safety.