Occult Paroxysmal Atrial Fibrillation in Non-Cryptogenic Ischemic Stroke

Recent studies suggest that their is a relatively high incidence of silent paroxysmal atrial
fibrillation (PAF) in cryptogenic ischemic stroke patients. Detection of silent PAF in this
population, however, requires prolonged cardiac monitoring. On the other hand, there is no
understanding of the frequency of silent PAF in patients with a "known" or presumed etiology
for their ischemic stroke other than AF. If this incidence is also found to be significant, a
dramatic change in stroke evaluation and management would likely occur. This study intends to
find the incidence of PAF in a population of recent (within 7 days) ischemic stroke patients
(or MRI positive "transient ischemic attack (TIA)" patients) who have presumed etiology for
their stroke other than atrial fibrillation or other high risk cardiac lesion. Stroke
etiology will be determined through a standard post-stroke evaluation that includes:

- Brain MRI

- 12-lead electrocardiogram (ECG) for AF detection

- 24-h ECG monitoring for AF detection (eg, Holter monitor or cardiac telemetry)

- Transthoracic and/or Transesophageal echocardiogram

- CT or MR angiography of the head and neck

- Hypercoagulable blood panel for patients less than 55 years-old. Preliminary
hypercoagulable work-up within 7 days will include the antiphospholipid antibody
syndrome results, which will be needed to determine stroke management. All other
results, which could take longer to return, including genetic tests of
hypercoagulability, rarely change stroke management.

To find occult PAF in this population, participants will have an insertable cardiac monitor
(Reveal LINQ ICM) implanted within 7 days of the incident stroke and will be monitored for at
least 1 year.

Inclusion Criteria:

- Patients with a recent ischemic stroke or transient ischemic attack (TIA) with brain
infarction on brain imaging.

- No history of atrial fibrillation or finding of atrial fibrillation on standard
inpatient monitoring (electrocardiogram, telemetry, 24-hour Holter monitor)

- Have a presumed stroke etiology: Lacunar or small vessel thrombosis, extra-cranial or
intracranial atherosclerotic stenosis or dissection, arteriopathy or vasculitis,
hypercoagulable state, aortic arch plaque with or without mobile elements, or evidence
of a low-risk cardiac source (e.g., patent foramen ovale with or without atrial septal
aneurysm and with or without evidence of venous thromboembolic source).

- Have virtual CHADS2 score ≥3 or

- Have 2 or more of the following co-morbidities: obstructive sleep apnea, coronary
artery disease, (Chronic Pulmonary Obstructive Disease (COPD), hyperthyroidism, Body
Mass Index> 30, prior myocardial infarction, prolonged PR interval (>175 ms) or renal
impairment (GFR 30-60).

- Patient or legally authorized representative who is willing to sign written consent
form.

- Patient is ≥40 years old (patients younger than 40 years old have a very low
likelihood of having atrial fibrillation and are therefore excluded from the study).

- Patient can have the device implanted within 7 days of the incident ischemic event

Exclusion Criteria:

- Documented history of AF or atrial flutter.

- Evidence of a high-risk cardiac source of embolism (Left Ventricular or Left Atrial
thrombus or "smoke," emboligenic valvular lesion or tumor)

- Untreated hyperthyroidism.

- Myocardial infarction or coronary bypass grafting within 1 month prior to the
stroke/TIA.

- Valvular disease requiring immediate surgical intervention.

- Permanent indication for anticoagulation at enrollment.

- Permanent oral anticoagulation contraindication.

- Already included in another clinical trial that will affect the objectives of this
study.

- Life expectancy is less than 1 year.

- Pregnancy. Urine or serum pregnancy test is required for women of child bearing
potential to exclude pregnancy.

- Patient is indicated for implant with a pacemaker, implantable
cardioverter-defibrillator, CRT device, or an implantable hemodynamic monitoring
system

- Patient is not fit, or is unable or unwilling to follow the required procedures of the
Clinical Investigation Plan.

- Cryptogenic Stroke: A stroke/TIA will be considered cryptogenic if no cause is
determined despite extensive inpatient workup according to the standard diagnostic
protocol at North Shore University Hospital.