Detection of Atrial Fibrillation via Adhesive Single-Lead ECG vs. Holter Monitoring in Embolic Stroke of Undetermined Source: The AVANT-GARDE Trial

BACKGROUND: Detecting atrial fibrillation (AF) is crucial for preventing stroke recurrence in embolic stroke of undetermined source (ESUS). However, prospective data directly comparing a single-lead patch electrocardiogram (ECG) with standard Holter monitoring remain limited. METHODS: The AVANT-GARDE trial was a prospective, multicenter study comparing a 72-h patch ECG with 24-h Holter monitoring. Among 113 acute ischemic stroke patients, 90 with ESUS formed the primary cohort, and 23 non-ESUS patients with left atrial enlargement were included as an ancillary cohort. Patients underwent simultaneous monitoring at baseline, with an additional 72-h patch monitoring at 6 months for the ESUS cohort. RESULTS: At baseline, AF was identified in 13.3% of the cohort, associated with larger LA size (41.8±5.1 mm vs. 38.3±5.9 mm; p=0.037). The 72-h patch ECG monitor demonstrated a higher AF detection rate at baseline than 24-h Holter in both the ESUS cohort (16.7% vs. 5.6%, p=0.002) and the overall cohort (14.2% vs. 4.4%, p=0.001). At 6 months, two additional AF episodes (any duration) were identified, increasing cumulative detection rates to 18.9% in the ESUS cohort and 15.9% in the overall cohort (p<0.001 vs. baseline Holter). However, the number of prolonged AF episodes lasting ≥30 seconds did not differ significantly between the two modalities. CONCLUSIONS: Extended patch ECG monitoring enhances the AF detection rate over conventional Holter in patients with ESUS. For short-duration AF (<30 seconds), it should be interpreted as an exploratory marker of subclinical atrial cardiopathy requiring long-term clinical surveillance. Large-scale studies are warranted to confirm these clinical findings.