Implantable Cardiac Monitoring for Atrial Fibrillation Detection in Patients with Stroke: A Systematic Review and Meta-Analysis

Abstract

Background: Atrial fibrillation (AF) is a common but frequently undiagnosed cause of ischemic stroke, particularly among patients with cryptogenic stroke and embolic stroke of undetermined source (ESUS). Implantable cardiac monitors (ICMs) enable prolonged continuous rhythm monitoring and may improve AF detection following ischemic stroke or transient ischemic attack (TIA). This systematic review and meta-analysis aimed to evaluate the diagnostic yield, clinical impact, and safety of prolonged ICM monitoring in patients with ischemic stroke or TIA. Methods: This systematic review and meta-analysis was conducted in accordance with the PRISMA 2020 guidelines and registered with PROSPERO (CRD42024573913). PubMed, Google Scholar, and the Cochrane Library were systematically searched. Randomized controlled trials and observational studies evaluating the use of ICMs after ischemic stroke or TIA were included. Randomized evidence was synthesized narratively, whereas single-arm random-effects meta-analyses of observational studies were performed to estimate pooled proportions for AF detection, oral anticoagulation initiation, recurrent ischemic stroke or TIA, and device-related adverse events. Results: Twelve completed studies involving 4563 participants met the inclusion criteria, including two randomized controlled trials and ten observational studies. One additional ongoing randomized controlled trial (Find-AF 2) involving a planned enrollment of 5200 participants was identified and is described narratively. Across the observational studies, the pooled AF detection rate during prolonged ICM monitoring was 25.9% (95% CI, 18.9–33.5%), although substantial heterogeneity was observed (I2 = 95%). Oral anticoagulation was initiated in 94.2% (95% CI, 79.4–100.0%) of patients diagnosed with AF. Device-related complications were uncommon, with a pooled incidence of 3.7% (95% CI, 2.0–6.0%; I2 = 0%), while the pooled rate of recurrent ischemic stroke or TIA during follow-up was 6.2% (95% CI, 3.9–9.2%). Narrative synthesis of the randomized evidence demonstrated that ICMs significantly increased AF detection compared with conventional monitoring but did not demonstrate a significant reduction in recurrent stroke during the available follow-up period. Conclusions: Prolonged implantable cardiac monitoring identifies AF in approximately one-quarter of patients following ischemic stroke or TIA and frequently leads to the initiation of oral anticoagulation, with a favorable safety profile. Although ICMs substantially improve AF detection, current evidence remains insufficient to confirm that increased detection translates into a reduction in recurrent stroke. Large, adequately powered randomized controlled trials are needed to determine the long-term clinical benefits of ICM-guided management and to define the optimal monitoring strategy for patients following ischemic stroke.