Study of Continuous Cardiac Monitoring to Assess Atrial Fibrillation After Cryptogenic Stroke (CRYSTAL-AF)

This study has been completed.
Medtronic Bakken Research Center
Information provided by (Responsible Party):
Medtronic Cardiac Rhythm Disease Management Identifier:
First received: June 17, 2009
Last updated: January 9, 2014
Last verified: January 2014

The 2006 American Heart Association / American Stroke Association Council on Stroke Guidelines for Prevention of Stroke in Patients With Ischemic Stroke or Transient Ischemic recommended that patients with cryptogenic stroke take antithrombotic drugs (i.e. aspirin) in order to prevent a second stroke. When a stroke patient is found to have atrial fibrillation (AF), the guidelines recommend oral anticoagulation due to its superior efficacy over aspirin for stroke prevention. Physicians can best optimize the use of medicines only if they can precisely and correctly diagnose a patient's AF. The purpose of this study is to evaluate the time to first AF by 6 months' continuous rhythm monitoring versus control treatment in subjects with a recent cryptogenic stroke or Transient Ischemic Attack (TIA) without history of AF.

Condition Intervention Phase
Cryptogenic Symptomatic Transient Ischemic Attack
Cryptogenic Ischemic Stroke
Device: Reveal® XT Insertable Cardiac Monitor
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: CRYptogenic STroke And underLying AF Trial

Resource links provided by NLM:

Further study details as provided by Medtronic Cardiac Rhythm Disease Management:

Primary Outcome Measures:
  • Time to first documented episode of AF [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Time to first documented episode of AF [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  • Incidence of stroke and Transient Ischemic Attack (TIA) [ Time Frame: Follow-up Closure ] [ Designated as safety issue: No ]
  • Cardiovascular drug changes [ Time Frame: Follow-up closure ] [ Designated as safety issue: No ]
  • Health outcome [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  • Clinical disease burden and care pathway [ Time Frame: Follow-up closure ] [ Designated as safety issue: No ]
  • Patient Assistant impact on AF diagnosis [ Time Frame: Follow-up closure ] [ Designated as safety issue: No ]

Enrollment: 448
Study Start Date: June 2009
Study Completion Date: May 2013
Primary Completion Date: May 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Continuous Monitoring
Continuous cardiac monitoring by the Reveal® XT Insertable Cardiac Monitor
Device: Reveal® XT Insertable Cardiac Monitor
The Insertable Cardiac Monitor is implanted under the skin in the region of the thorax. It continuously monitors the heart's electrical activity for up to three years. ECG data are stored when the device detects a cardiac arrhythmia.
Other Name: Reveal® XT
No Intervention: Control Arm
Follow-up at the same frequency, but with no Insertable Cardiac Monitor


Ages Eligible for Study:   40 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Recent cryptogenic symptomatic transient ischemic attack (TIA) or cryptogenic ischemic stroke.

Exclusion Criteria:

  1. Known etiology of TIA or stroke.
  2. Untreated hyperthyroidism.
  3. Myocardial infarction less than 1 month prior to stroke or TIA.
  4. Coronary bypass grafting less than 1 month prior to stroke or TIA.
  5. Valvular disease requiring immediate surgical intervention.
  6. History of AF or atrial flutter.
  7. Patent Foramen Ovale (PFO) and PFO is or was an indication to start oral anticoagulation (OAC).
  8. Permanent indication for OAC at enrollment.
  9. Permanent contra-indication for OAC.
  10. Included in another clinical trial.
  11. Life expectancy less than 1 year.
  12. Pregnant.
  13. Indicated for Implantable Pulse Generator (IPG), Implantable Cardioverter-Defibrillator (ICD), Cardiac Resynchronization Therapy (CRT) or an implantable hemodynamic monitoring system.
  14. Not fit, unable or unwilling to follow the required procedures of the protocol.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00924638

  Show 57 Study Locations
Sponsors and Collaborators
Medtronic Cardiac Rhythm Disease Management
Medtronic Bakken Research Center
Principal Investigator: Johannes Brachmann, MD Klinikum Coburg, Germany
Principal Investigator: Tommaso Sanna, MD Catholic University, Italy
Principal Investigator: Hans Christoph Diener, MD Klinik für Neurologie, Essen, Germany
Principal Investigator: Carlos Morillo, MD McMaster Clinic, Hamilton, Ontario, Canada
Principal Investigator: Richard Bernstein, MD, PhD Davee Department of Neurology, Chicago, IL USA
Principal Investigator: Vincenzo Di Lazzaro, MD Catholic University Rome, Rome Italy
Principal Investigator: Rod Passman, MD Northwestern Memorial Hospital, Chicago, IL USA
Principal Investigator: Marilyn Rymer, MD St. Lukes Hospital of Kansas City, Kansas City, MI USA
  More Information

Additional publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Medtronic Cardiac Rhythm Disease Management Identifier: NCT00924638     History of Changes
Other Study ID Numbers: CRYSTAL-AF
Study First Received: June 17, 2009
Last Updated: January 9, 2014
Health Authority: Germany: Federal Institute for Drugs and Medical Devices

Keywords provided by Medtronic Cardiac Rhythm Disease Management:
atrial fibrillation
cryptogenic stroke
continuous monitoring
implantable loop recorder
insertable cardiac monitor

Additional relevant MeSH terms:
Atrial Fibrillation
Ischemic Attack, Transient
Cerebral Infarction
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Brain Ischemia
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Brain Infarction processed this record on July 22, 2014