Anticoagulation after embolic stroke of undetermined source - therapeutic dilemmas.

Background Etiology of embolic stroke of undetermined source (ESUS) is still unclear. Antiplatelet therapy remains the current standard of care after ESUS, however heterogeneity of potential thromboembolic sources may suggest other strategies. Decision on anticoagulation is not obvious in the absence of atrial fibrillation (AF) but AF is no longer considered as the most important mechanism of ESUS. Concept of atrial cardiopathy (AC) was proposed understood as a complex of atrial tissue abnormalities leading to arrhythmic and thromboembolic complications. AC is defined as at least 1 of the following: elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration, enlarged left atrial volume index (LAVI) in echocardiographic examination or high P-wave terminal force in electrocardiogram (ECG) lead V1 (PTFV1). The aim of the study was to analyze modes of antithrombotic treatment along with cardiovascular risk factors in patients after ESUS episode. Material and methods The study was performed in two reference centers. Patients aged 30-70 after ESUS episode were referred to our center from the neurology department for further clinical evaluation. Thrombophilia was excluded in each case. Results Total number of 114 patients were enrolled in the study between 2020 Jan and 2024 Dec. Mean age was 55.0±12.2 years, 68 (59.6%) were males. Patients were discharged from the neurology department on aspirin, 3 were additionally obtaining clopidogrel for 14 days after stroke. Patent foramen ovale (PFO) was revealed in 58 patients (55.8%) and was closed in 45 with 3-month dual antiplatelet therapy with clopidogrel and further long-term aspirin, the rest did not consent to the intervention. AF was detected in six patients (5.3%) and they were switched to direct oral anticoagulant (DOAC). Six patients were treated with DOAC due to a history of deep vein thrombosis. Twenty patients (16.7%) with frequent episodes of supraventricular tachycardia and high CHA2DS2-VASc score were started on DOAC. Their mean CHA2DS2-VASc score was 4.95±1.39. When compared to patients treated with antiplatelet therapy, they were more likely to have hypertension (18 patients, 90.0% vs. 53, 56.4%; p=0.005) and supracardiac nonstenosing atherosclerosis (16, 80%, vs. 39, 42.4%; p=0.002). They also had significantly higher NT-proBNP concentrations (110 pg/ml [76 –262] vs. 58 [28 – 135]; p=0.002). There was no significant difference in terms of LAVI (36.6 ml/m2± 11.2 vs. 32.9 ±9.8; p=0.146) or PTFV1 (1100 [0 – 2500] vs. 2000 [400 – 4000]; p=0.170). Conclusions Systemic empiric anticoagulation might be considered in patients with high cardiovascular risk after ESUS episode. The use of DOAC especially in patients with frequent supraventricular tachycardia episodes and high CHA2DS2-VASc score may be an option in patients with atrial cardiopathy.