Detection rates of atrial fibrillation by prolonged rhythm monitoring with or without preselection by biomarkers in patients with embolic strokes of undetermined source – a single center experience

Background
Cryptogenic stroke (CS) makes up about one quarter of all ischemic strokes. ESUS defines a subset of CS with embolic stroke pattern and no evidence of major risk cardioembolic sources, significant atherosclerosis and lacunar stroke. Up to 25% of patients with ESUS have underlying atrial fibrillation (AF). Robust risk factors for AF are age, left atrial volume index (LAVI) and blood biomarkers. We aim to evaluate if a biomarker based preselection for 30d rhythm monitoring increases detection rate of AF in patients with ESUS.

Methods
Monocentric, retrospective data analysis of patients with ESUS between May 2019 and September 2021, fulfilling the ESUS criteria, with in-hospital rhythm monitoring for at least 24 hours without evidence of AF, who received ambulatory extended, non-invasive patch ECG monitoring with the evismo-CardioFlex® device for 28-32 days. Comparison of detection rates with or without the use of biomarkers (age, MR-proANP, left atrial volume index (LAVI), supraventricular extrasystoles during 24 hour Holter-ECG/atrial runs with >20 beats, additional chronic embolic infarct on MRI).

Results
Out of 186 patients, in 14 AF was detected by extended rhythm monitoring (7.53 %). There were 7 AF-cases in each of the two groups (without further selection criteria: 94 Patients, 7.45 %; with selection criteria: 92 Patients, 7.61 %).