Less Known but Clinically Relevant Comorbidities of Atrial Fibrillation: A Narrative Review

Background: The important risk factors for atrial fibrillation (AF) in the general population are not always equally important in specific and relatively prevalent diseases. Objective: The main goal of this narrative review is to focus attention on the presence and the relationship of AF with several important diseases, such as cancer or sepsis, in order to: 1) stimulate further research in the field, and 2) draw attention to this relationship and search for AF in clinical practice. Methods: We searched PubMed, SCOPUS, Elsevier, Wiley, Springer, Oxford Journals, Cambridge, SAGE, and Google Scholar for less-known comorbidities of AF. The search was limited to publications in English. No time limits were applied. Results: AF is widely represented in cardiovascular and other important diseases, even in those in which AF is rarely mentioned. In some specific clinical subsets of AF patients (e.g., patients with sepsis or cancer), the general risk factors for AF may not be so important. Patients with new-onset AF have a several-fold increase in relative risk of cancer, deep vein thrombosis, and pulmonary thromboembolism (PTE) during the follow-up. Conclusion: AF presence, prognosis, and optimal therapeutic approach are insufficiently recognised in several prevalent diseases, including life-threatening ones. There is a need for a better search for AF in PTE, pulmonary oedema, aortic dissection, sepsis, cancer and several gastrointestinal diseases. Improved AF detection would influence treatment and improve outcomes.