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CRYSTAL AF STUDY ICM EVIDENCE FOR CRYPTOGENIC STROKE

Landmark CRYSTAL AF study of insertable cardiac monitor use in cryptogenic stroke patients

CRYSTAL-AF STUDY1

Reveal™ ICM IS SUPERIOR TO STANDARD MONITORING FOR AF DETECTION IN CRYPTOGENIC STROKE PATIENTS

The landmark CRYSTAL AF Study found that continuous monitoring with Reveal insertable cardiac monitoring (ICM) is superior to standard monitoring for detection of atrial fibrillation (AF or AFib) in patients with a cryptogenic stroke1

As published in the New England Journal of Medicine

CRYSTAL-AF Study Results Chart

  • 6.4x more AF detected at 6 months: 8.9% in ICM group vs. 1.4% in control
  • 7.3x more AF detected at 12 months: 12.4% in ICM group vs. 2.0% in control
  • 8.8x more AF detected at 36 months: 30% in ICM vs. 3.0% in control

KEY FINDINGS

CRYSTAL-AF Study Results Chart

CLINICAL IMPACT: MORE APPROPRIATE CARE

Crystal AF Boxes Chart

30 Days of Monitoring is NOT Long Enough for AF detection in cryptogenic stroke

  • Extensive external monitoring found few patients with AF
    • In the control group at 6 months, only 3 patients were found to have AF; yet there were 88 conventional ECGs, 20 24-hour Holters, and 1 event recorder used
  • Reveal ICM detected over 7 times more patients with AF at the 12-month end point

CRYSTAL-AF Study Results Chart

STUDY DESIGN

  • Randomised, controlled clinical trial with 441 patients
  • Compared continuous, long-term monitoring with Reveal™ ICM vs. 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
  • 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 < 55 years old

END POINTS

Primary

  • Time to first detection of AF at 6 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
1

Sanna T, Diener HC, Passman RS, et al. Cryptogenic Stroke and Underlying Atrial Fibrillation (CRYSTAL AF). N Engl J Med. 2014; 370(26):2478-2486.