title: A Comparison of Atrial Fibrillation Monitoring Strategies After Cryptogenic Stroke (from the Cryptogenic Stroke and Underlying AF Trial).
abstract: Ischemic stroke cause remains undetermined in 30% of cases, leading to a diagnosis of cryptogenic stroke. Paroxysmal atrial fibrillation (AF) is a major cause of ischemic stroke but may go undetected with short periods of ECG monitoring. The Cryptogenic Stroke and Underlying Atrial Fibrillation trial (CRYSTAL AF) demonstrated that long-term electrocardiographic monitoring with insertable cardiac monitors (ICM) is superior to conventional follow-up in detecting AF in the population with cryptogenic stroke. We evaluated the sensitivity and negative predictive value (NPV) of various external monitoring techniques within a cryptogenic stroke cohort. Simulated intermittent monitoring strategies were compared to continuous rhythm monitoring in 168 ICM patients of the CRYSTAL AF trial. Short-term monitoring included a single 24-hour, 48-hour, and 7-day Holter and 21-day and 30-day event recorders. Periodic monitoring consisted of quarterly monitoring through 24-hour, 48-hour, and 7-day Holters and monthly 24-hour Holters. For a single monitoring period, the sensitivity for AF diagnosis was lowest with a 24-hour Holter (1.3%) and highest with a 30-day event recorder (22.8%). The NPV ranged from 82.3% to 85.6% for all single external monitoring strategies. Quarterly monitoring with 24-hour Holters had a sensitivity of 3.1%, whereas quarterly 7-day monitors increased the sensitivity to 20.8%. The NPVs for repetitive periodic monitoring strategies were similar at 82.6% to 85.3%. Long-term continuous monitoring was superior in detecting AF compared to all intermittent monitoring strategies evaluated (p <0.001). Long-term continuous electrocardiographic monitoring with ICMs is significantly more effective than any of the simulated intermittent monitoring strategies for identifying AF in patients with previous cryptogenic stroke.
authors.affiliation: South Denver Cardiology Associates, Littleton, Colorado.
authors.forename: William C
authors.initials: WC
authors.lastname: Choe
authors.affiliation: Bluhm Cardiovascular Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois. Electronic address: r-passman@northwestern.edu.
authors.forename: Rod S
authors.initials: RS
authors.lastname: Passman
authors.affiliation: FHRS Hospital Klinikum Coburg, Teaching Hospital of the University of Wurzburg, Coburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Brachmann
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Morillo
authors.affiliation: Catholic University of the Sacred Heart, Institute of Cardiology, Rome, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Sanna
authors.affiliation: Davee Department of Neurology Northwestern University, Chicago, Illinois.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bernstein
authors.affiliation: Institute of Neurology, Campus Bio-Medico University, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Di Lazzaro
authors.affiliation: Department of Neurology and Stroke Center, University Hospital Essen, Essen, Germany.
authors.forename: Hans-Christoph
authors.initials: HC
authors.lastname: Diener
authors.affiliation: Kansas University Medical Center, Kansas City, Kansas.
authors.forename: Marilyn M
authors.initials: MM
authors.lastname: Rymer
authors.affiliation: Medtronic, Maastricht, the Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Beckers
authors.affiliation: Medtronic, Mounds View, Minnesota.
authors.forename: Jodi
authors.initials: J
authors.lastname: Koehler
authors.affiliation: Medtronic, Mounds View, Minnesota.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Ziegler
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis*; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D020521:Stroke / Q000209:etiology*; D013997:Time Factors