Abstract Number: Esoc2026a625 Tailored Diagnostic Approach in Embolic Stroke of Undetermined Source (Esus): The Role of Prolonged Cardiac Monitoring

Abstract Background and aims The introduction of prolonged cardiac monitoring has expanded our knowledge around ESUS. However, many uncertainties remain, mainly regarding the optimal management of these patients, making the development of individualized pathways necessary. We analyzed clinical, neuro-radiological and cardiological risk factors most strongly associated with the detection of Atrial Fibrillation (AF) via prolonged ECG-monitoring and implantable loop recorder (ILR), to identify possible predictors of AF detection. Methods We conducted a retrospective, observational, single-center study including the 77 patients discussed by our NeuroCardiology group (03/2018-10/2023), with a diagnosis of ESUS of probable cardioembolic etiology and who underwent cardiac monitoring via a 15 days-HolterECG and implantable loop recorder (ILR). Results AF was detected in 43 patients (56.5%). Patients diagnosed with AF were older (p0.001) and had a higher CHA₂DS₂VASc score (p0.001). Among patients monitored with HolterECG, those with AF had higher CHA₂DS₂VASc scores than those without AF (p=0.036), unlike patients monitored with ILR. No statistically significant correlation was found between atrial enlargement of any degree and AF detection among patients monitored with Holter-ECG; whereas in patients monitored with ILR, a statistically significant correlation (p=0.018) was found between the absence of atrial enlargement and the lack of AF detection. Conclusions Parameters such as CHA₂DS₂VASc score and presence of atrial enlargement may help guide the development of individualized diagnostic pathways, tailored to different prolonged cardiac monitoring methods: younger patients and the absence of echocardiographic abnormalities could be the main factors supporting a direct choice of ILR. Conflict of interest Diletta Rosin: nothing to disclose; Lorenzo Nesi: nothing to disclose; Simone Lorenzut: nothing to disclose; Daisy Pavoni: nothing to disclose; Mariarosaria Valente: nothing to disclose; Giovanni Merlino: nothing to disclose. Figure 1 - belongs to Results