Noninvasive Cardiac Event Monitoring to Detect Atrial Fibrillation After Ischemic Stroke

Background and Purpose— Atrial fibrillation (AF) elevates risk of recurrent stroke but is incompletely identified by standard investigation after stroke, though detection rates correlate with monitoring duration. We hypothesized that 7 days of noninvasive cardiac-event monitoring early after stroke would accelerate detection of AF and thus uptake of effective therapy. Methods— We performed a pragmatic randomized trial with objective outcome assessment among patients presenting in sinus rhythm with no AF history, within 7 days of ischemic stroke symptom onset. Patients were randomized to standard practice investigations (SP) to detect AF, or SP plus additional monitoring (SP-AM). AM comprised 7 days of noninvasive cardiac-event monitoring reported by an accredited cardiac electrocardiology laboratory. Primary outcome was detection of AF at 14 days. Results— One-hundred patients were enrolled from 2 centers. Within 14 days of stroke, sustained paroxysms of AF were detected in 18% of patients undergoing SP-AM versus 2% undergoing SP ( P <0.05). Paroxysms of any-duration were detected in 44% of patients undergoing SP-AM versus 4% undergoing SP ( P <0.001). These differences persisted at 90 days. Anticoagulant therapy was commenced within 14 days in 16% of SP-AM patients versus none randomized to SP ( P <0.01). This difference persisted to 90 days (22% versus 6%; P <0.05). Conclusions— Routine noninvasive cardiac-event monitoring after acute stroke enhances detection of paroxysmal AF and early anticoagulation. Extended monitoring should be offered to all eligible patients soon after acute stroke. Guidelines on investigation for AF in stroke patients could be strengthened. Clinical Trial Registration— URL: http://www.controlled-trials.com/isrctn/ . Unique identifier: ISRCTN97412358.