Insertable cardiac monitor improves detection of AF in recent ischemic stroke
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Among patients with recent ischemic stroke, an insertable cardiac monitor detected atrial fibrillation more frequently than a device used in standard care, according to results of the STROKE AF trial.
“Currently, patients with ... small vessel occlusion or large artery atherosclerosis are typically prescribed antiplatelet medications. The rate of unsuspected AF in this population is unknown,” Lee H. Schwamm, MD, executive vice chairman of the department of neurology and director of the MGH Center for Telehealth at Massachusetts General Hospital and professor of neurology at Harvard Medical School, said during a presentation at the virtual International Stroke Conference. “The purpose of this trial was to determine the rate of AF in this population for secondary stroke prevention, not to determine the cause of the index stroke.”
Schwamm and colleagues randomly assigned 492 patients (mean age, 67 years; 62% men) with recent ischemic stroke but no prior diagnosis of AF or atrial flutter to continuous monitoring with an insertable cardiac monitor (Reveal LINQ, Medtronic) or to a control group receiving site-specific standard of care for AF detection.
At 12 months, the incidence rate of AF was 12.1% in the insertable cardiac monitor group and 1.8% in the control group (HR = 7.41; 95% CI, 2.6-21.28; P < .001), Schwamm said during the presentation, noting the median time to AF detection in the insertable cardiac monitor group was 99 days.
In the first 30 days, 2.6% of those in the insertable cardiac monitor arm and 0.4% of those in the control arm had AF detected. Schwamm said “78% of patients with AF would have been missed if only monitored for the initial 30 days,” which is standard practice at many institutions.
In the insertable cardiac monitor arm, there was no difference in AF detection rate between those who had small vessel occlusion and those who had large artery atherosclerosis (12.6% vs. 11.7%, respectively), he said.
Among those in the insertable cardiac monitor arm who had AF detected, 55.5% had an AF episode of more than 1 hour, 44.4% had an AF episode of more than 4 hours and 96.3% had a first incident that was asymptomatic, Schwamm said.
“The amount of AF detected (more than 1 hour in most patients with AF) would be considered by many physicians appropriate to treat with anticoagulation for secondary prevention,” he said.
Recurrent ischemic stroke within 12 months was numerically higher in the control group (9.8% vs. 6.7%; HR = 0.67; 95% CI, 0.35-1.38; P = .23), according to the researchers.
Among those with AF detected, 66.7% of those in the insertable cardiac monitor group (18 patients) and 75% of those in the control group (three patients) were prescribed anticoagulation, Schwamm said.
“Use of an insertable cardiac monitor in this population may be beneficial to detect post-stroke AF and inform optimal stroke prevention strategies,” Schwamm said during the presentation.