Prior studies have found that in patients with cryptogenic ischemic strokes, extended post-stroke cardiac monitoring detects intermittent atrial fibrillation (AF) in up to 20% of cases. Now, an industry-sponsored study from Germany randomized 400 patients all over 60 years old to 10-day cardiac rhythm monitor recordings at three time points following ischemic stroke (baseline, 3 months, and 6 months) or to standard monitoring (≥24-hour Holter or telemetry monitoring). Patients with severe, ipsilateral carotid or intracranial stenosis or prior AF diagnosis were excluded. The primary endpoint was detection of AF or atrial flutter lasting at least 30 seconds.
The extended-monitoring group had detected AF in 14% of the cohort whereas standard telemetry monitoring only detected AF in 5% of the cohort (number needed to screen, 11). The median time from study enrollment to detection of AF about one month. The vast majority of the AF cases were detected using two 10-day cardiac monitoring sessions.
These findings support the recommendation for extended cardiac rhythm monitoring to screen for AF in older patients with cryptogenic stroke. The 14% detection rate is clinically significant. This extended cardiac rhythm screening can be performed by using a transdermal patch or an implantable loop recorder.