Long-term Cardiac Monitoring After Cryptogenic Stroke (CMACS)
Long-term Cardiac Monitoring After Cryptogenic Stroke (CMACS)
Atrial fibrillation (AF) is a common and treatable cause of ischemic stroke, but it can be
 paroxysmal and asymptomatic, and therefore difficult to detect. Patients with stroke
 routinely undergo 24 hours of continuous cardiac telemetry during hospitalization for stroke
 as a means of excluding AF. Small studies indicate that extending the duration of monitoring
 with portable outpatient telemetry devices detects more cases of AF. However, these studies
 are small and lack control groups, and cannot demonstrate that prolonged cardiac monitoring
 detects more cases of AF than routine clinical follow-up. The investigators therefore propose
 a pilot study to determine the feasibility of randomizing patients to prolonged cardiac
 monitoring or routine clinical follow-up. The investigators will enroll 40 consecutive adult
 patients seen at the University of California at San Francisco (UCSF) Neurovascular service
 with cryptogenic stroke or high-risk TIA (ABCD2 score 4 or greater). Enrolled patients will
 be randomized in a 1:1 fashion. Group A will be assigned to wear an ambulatory cardiac event
 monitor for 21 days. Group B will be discharged home without a monitor and will serve as
 controls during routine clinical follow-up. The investigators' primary outcome will be
 feasibility, defined as more than 80% of randomized patients completing full clinical
 follow-up and more than 70% of cardiac monitoring if applicable. The investigators' secondary
 outcomes will be diagnoses of AF at 90 days and 1 year and diagnoses of recurrent stroke at 1
 year.
Inclusion Criteria:

 -  Age > 18 years

 -  Seen at UCSF Medical Center for cryptogenic stroke or high-risk TIA

 -  Onset of stroke or TIA symptoms within the previous 60 days

 Exclusion Criteria:

 -  Definite small-vessel etiology by history or imaging

 -  Source found on vascular imaging of possible culprit vessels

 -  Source found by echocardiography (TEE not required)

 -  History of atrial fibrillation

 -  Atrial fibrillation on admission ECG

 -  Atrial fibrillation detected by inpatient cardiac telemetry (at least 24 hours
 required)

 -  Obvious culpable systemic illness such as endocarditis

 -  Patient unable to provide written, informed consent