Detection of Atrial Fibrillation after Ischemic Stroke with an Insertable Cardiac Monitor: A Systematic Review and Individual Patient Data Meta-Analysis of Randomized Clinical Trials

Introduction: We compared the use of insertable cardiac monitor (ICM) versus non-ICM methods of cardiac monitoring in ischemic stroke patients on the detection of atrial fibrillation (AF) and other clinical outcomes. Current guidelines recommend the routine use of 12-lead electrocardiography or Holter monitoring for AF detection after ischemic stroke. Recent randomized controlled trials have investigated the impact of ICM versus non-ICM methods of cardiac monitoring for AF detection in this population. However, precise recommendations for monitoring poststroke AF are lacking, including the optimal timing, duration, and method of electrocardiography monitoring.

Methods: A systematic search was conducted on Embase and PubMed from database inception until October 27, 2022, to include randomized controlled trials that compared ICM with non-ICM methods of cardiac monitoring for poststroke AF detection. This yielded 3 randomized controlled trials with a combined cohort of 1,233 patients with a recent ischemic stroke. Individual patient data (IPD) were then reconstructed from Kaplan-Meier curves and analyzed using the shared-frailty Cox model. An aggregate data meta-analysis was conducted for 1,233 patients across all 3 studies for outcomes that could not be reconstructed using IPD.

Results: One-stage meta-analysis demonstrated an increase in the hazard ratio (6.00 95% CI: 3.40-10.58; 195 p < 0.001) of AF detection in patients undergoing monitoring via ICM compared to standard care. The cumulative incidence curves of AF events in patients undergoing ICM and non-ICM separated significantly at 24 days. Aggregate data meta-analysis revealed a significant increase in initiation of anticoagulation (RR: 2.76, 95% CI: 1.89-4.02, p < 0.00001) in the ICM group. However, no significant differences in the incidence of recurrent ischemic stroke, transient ischemic attack, or death were found.

Conclusions: In this meta-analysis, we found that the use of ICM increased the detection rate of poststroke AF and the rate of anticoagulation initiation in ischemic stroke patients. However, this did not translate into a reduced incidence of recurrent ischemic stroke.