Continuous electrocardiographic monitoring improves atrial fibrillation detection after ischemic stroke

Background Current electrocardiographic monitoring for AF detection after unexplained ischemic stroke is usually sequential. This strategy may delay AF detection in the post-stroke period. Purpose The aim of this study was to assess whether admission-initiated continuous ECG monitoring improves AF detection compared with the conventional sequential ECG monitoring strategy in patients with ischaemic stroke. Methods In this pragmatic study, patients were allocated to treatment groups depending on material availability in routine clinical practice. Consecutive patients admitted for ischaemic stroke, without known AF at admission, were prospectively included. In the continuous monitoring group, Holter monitoring was started at admission and maintained throughout the aetiological workup (minimum 3 days), then patients classified as having cryptogenic stroke were proposed for in-hospital implantable loop recorder (ILR) implantation. In the sequential monitoring group, patients underwent standard stepwise monitoring (≥48-hour telemetry initiated at admission followed by 24-hour Holter monitoring; minimum 3 days total), and cryptogenic stroke patients were scheduled for ILR implantation depending on team availability. The primary endpoint was the AF detection rate. Results A total of 365 patients (35.3% women, age 63.5±14.1 years) were included; 126 (35.2%) underwent continuous monitoring and 239 sequential monitoring. Baseline characteristics and follow-up period (518±262 vs 482±265 days; p=0.21) were similar between groups. The in-hospital ECG monitoring time was longer in the continuous group compared with the sequential group (137±56 vs 118±75 hours; p=0.007). In the cryptogenic stroke patients (63 patients in continuous group; 111 patients in sequential group), ILR implantation was more frequent in the continuous monitoring group (81.0% vs 60.4%; p=0.005), with a shorter time from stroke to implantation (16±22 vs 81±75 days; p<0.001). In the overall cohort, AF documentation rate was significantly higher in the continuous monitoring group after accounting for death as a competing event (HR 1.68, 95% CI 1.01-2.80; p=0.04). The difference was driven by the first 6 months after stroke (HR 1.89, 95% CI 1.04-3.43; p=0.04), while AF documentation rates were similar beyond 6 months (HR 1.15, 95% CI 0.42-3.16; p=0.77). Conclusion Admission-initiated continuous ECG monitoring after ischaemic stroke was associated with higher AF detection rates than the conventional sequential strategy, driven mainly by increased detection within the first 6 months.