Clinical question: In patients with recent ischemic stroke, does monitoring for 12 months with an implantable loop recorder (ILR) detect more atrial fibrillation (AF) than 30 days with an external loop recorder (ELR)?
Background: ILRs and ELRs have AF detection rates of 12-16%, but no head-to-head comparisons have been completed.
Study Design: Open-label RCT: the PER DIEM clinical trial.
Setting: Three hospitals in Alberta, Canada in 300 adults with ischemic stroke but no known AF.
Synopsis: Patients received either 12 months of ILR or 30 days of ELR. The primary outcome of AF >2 minutes within 12 months occurred in 15% of the ILR versus 4.7% of the ELR group (HR 3.36, 95% CI 1.44-7.84). Patients with new AF were started on anticoagulation. A post-hoc analysis found only age as a significant risk factor associated with AF detection. Clinical outcomes with ILR versus ELR monitoring strategies were not assessed.
Bottom line: ILR monitoring for 12 months in patients with ischemic stroke is superior at detecting AF compared to ELRs for 30 days, but the effect on clinical outcomes is unclear.
Citation: Buck BH et al. Effect of implantable vs prolonged external electrocardiographic monitoring on atrial fibrillation detection in patients with ischemic stroke. The PER DIEM randomized clinical trial. JAMA 2021; 325(21) 2160-2168.
Dr. Winget is a clinical instructor at the University of Colorado School of Medicine hospital medicine section, Rocky Mountain Regional VA Medical Center, Aurora, Colo.