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    • Study design

    • Randomized, controlled clinical trial with 441 patients
    • Compared continuous, long-term monitoring with Reveal LINQ™ ICM versus conventional follow-up
    • Assessment at scheduled and unscheduled visits
    • ECG monitoring performed at the discretion of the site investigator

    Patient inclusion criteria

    • 40 years of age or more
    • Cryptogenic stroke (or clinical TIA) with infarct seen on MRI or CT within the previous 90 days and no mechanism identified after:
      • 12-lead ECG
      • 24-hour ECG monitoring (e.g., Holter)
      • Transesophageal echocardiography
      • CTA or MRA of head and neck to rule out arterial source
      • Screening for hypercoagulable states in patients less than 55 years old

    End points

    Primary

    The primary end point is the time to first detection of AF at six months of follow-up.

    Secondary

    • Time to first detection of AF at 12 months of follow-up
    • Recurrent stroke or TIA
    • Actions taken after patient diagnosed with AF

    Study results

    The landmark CRYSTAL-AF study found that continuous monitoring with the Reveal LINQ™ ICM is superior to standard monitoring for detection of atrial fibrillation (AF or AFib) in patients with a cryptogenic stroke.1

    Key findings

    30% AF detected at three years versus 3% for standard of care:

    • 6.4 times more AF detected at six months: 8.9% in ICM group versus 1.4% in control
    • 7.3 times more AF detected at 12 months: 12.4% in ICM group versus 2.0% in control
    • 8.8 times more AF detected at 36 months: 30% in ICM versus 3.0% in control

    At 12 months, 97% of patients in whom AF was detected received oral anticoagulant.

    79% of first AF episodes were asymptomatic at 12 months.

    Detection of AF by 36 months
    Hazard ratio, 8.8 (95% CI, 3.5–22.2) p < 0.001 by log-rank test

    30 days of monitoring is not enough.

    • Extensive external monitoring found few patients with AF.
      • In the control group at six months, only three patients were found to have AF; yet there were 88 conventional ECGs, 20 24-hour Holters, and one event recorder used.
    • Reveal LINQ™ ICM detected over seven times more patients with AF at the 12-month end point.
    • 88% of patients who had AF would have been missed if only monitored for 30 days.†

    † Based on Kaplan-Meier estimates.

    “Atrial fibrillation after cryptogenic stroke was most often asymptomatic and paroxysmal and thus unlikely to be detected by strategies based on symptom-driven monitoring or intermittent short-term recordings.”1

    On-demand education

    Watch webinars on secondary stroke prevention and the role of insertable cardiac monitoring.

    View webinars (open in new window)

    Resources and downloads

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