Atrial Cardiomyopathy and Cryptogenic Stroke

Abstract

Background The frequency of cryptogenic stroke (CS) is about 30% of all cases of ischemic stroke (IS). Patients with CS represent a heterogeneous group of patients and require an individualized approach to antithrombotic therapy for secondary prevention. The frequency of development of repeated acute cerebrovascular events in patients with CS is 4.5% per year, which exceeds this indicator in patients with an established pathogenetic variant of IS. Until recently, the dominant point of view, suggesting that the main cause of CS is paroxysmal atrial fibrillation (AF) and for the secondary prevention of IS in this cohort of patients, oral anticoagulants may be more effective than antiplatelet agents, has not been confirmed. The causal relationship between IS and AF is currently not fully understood. Apparently, AF serves as a marker of atrial cardiomyopathy, which is the direct cause of IS. Aim of study Raising the awareness of neurologists about the causes, pathogenetic mechanisms of development and methods for diagnosing IS in patients with atrial cardiomyopathy. Material and methods To achieve this aim, the results of scientific studies on atrial cardiomyopathy as a risk factor for CS were analyzed. The literature search was carried out in electronic search systems Scopus, eLibrary, PubMed using the keywords: ischemic stroke, cryptogenic stroke, atrial cardiomyopathy, pathogenesis of ischemic stroke. Scientific articles published between 1957 and 2021 were selected to be analyzed. And 36% of the analyzed papers on the topic of CS were published no more than 5 years ago. Conclusion The cumulative evidence suggests that atrial fibrillation is not the only cause of embolic events in patients with evidence of atrial dysfunction. Atrial cardiomyopathy can be the cause of thromboembolic syndrome and cryptogenic stroke, even in the absence of atrial fibrillation, therefore, the latter should be considered as a common manifestation of the underlying atrial cardiomyopathy. Since the majority of cardiac thrombi in patients with atrial fibrillation originate in the left atrium, it is likely that patients with atrial cardiomyopathy and cryptogenic stroke represent a group of patients who may be indicated for anticoagulant therapy as a secondary prevention of ischemic stroke and systemic embolism. However, this hypothesis needs to be confirmed.