Incidence of Silent Atrial Fibrillation in Patients With Clinically Silent Brain Ischemic Lesions
Incidence of Silent Atrial Fibrillation in Patients With Clinically Silent Brain Ischemic Lesions
Arterial Fibrillation (AF) is well-recognized as a cause for cryptogenic Acute Ischemic
 Stroke (AIS) and is associated with Silent Brain Infarction (SBI). However, the role of AF in
 the formation of lesions (SBIs) is less well established than its role in AIS and needs
 clarification.

 The investigators hypothesize that continuous rhythm monitoring will yield a similar
 incidence of AF diagnosis in patients with SBI as compared to patients with cryptogenic AIS.

 The primary objective is to assess the cumulative incidence of AF diagnosis at 24 months in
 patients with SBI.
Arterial Fibrillation (AF) is well-recognized as a cause for cryptogenic Acute Ischemic
 Stroke (AIS) and searched for in clinical practice. However, although AF is associated with
 Silent Brain Infarction (SBI), its role in the formation of these lesions is less well
 established and needs clarification. A multitude of clinical, laboratory, echocardiographic
 and electrocardiographic parameters are associated with AF. Although no single one of these
 parameters has sufficient specificity to rule-in AF, their combined use may nevertheless help
 to identify patients with SBI at highest risk for AF. The study is expected to provide
 evidence that long term monitoring in subjects with SBI yields similar rates of AF as in AIS
 patients.

 Patients aged ≥65 years with a presumably silent brain lesion in a brain magnetic resonance
 imaging fulfilling inclusion criteria and consenting get a subcutaneous implantation of a
 cardiac monitor (Reveal LINQ). Data will be directly transferred to the treating physician by
 the Medtronic MyCareLink Patient Monitor. In case of a relevant arrhythmia, the respective
 study site will be informed by the staff of Inselspital. Relevant arrhythmias are defined as
 follows:

 -  First episode of atrial fibrillation (≥30 seconds)

 -  Sustained ventricular tachycardia (≥30 seconds)

 -  Sustained supraventricular tachycardia (≥30 seconds)

 -  Asystoly of ≥6 seconds duration

 -  Atrial fibrillation with pause of ≥6 seconds duration

 -  Higher degree atrioventricular (AV) block (3° AV bloc; 2:1 AV conduction; 2° AV block
 type Mobitz)

 -  Sustained bradycardia <30 beats per minute (≥30 seconds) It is the responsibility of the
 respective study sites to take appropriate actions and inform the patients and treating
 physicians about relevant findings. The maximal timeframe from data transmission to data
 analysis is one week and from data transmission to patient notification two weeks.

 The expected results of the study would be supportive in introducing long term monitoring to
 the care pathway in subjects with SBI. Since SBI are more prevalent than AIS and current
 recommendations very restrictive, this would have a relevant impact on SBI management.
Inclusion Criteria:

 -  Age ≥ 65 years

 -  Written informed Consent

 -  Any clinically silent ischemic lesions of the brain parenchyma detected on
 neuroimaging defined according to established criteria as either:

 -  Diffusion weighted imaging (DWI) positive lesions: Focus of restricted diffusion
 (high DWI signal and low apparent diffusion coefficient value) occurring in
 either white or gray matter, located in the cerebrum, cerebellum, or brain stem
 AND not satisfying the diagnostic criteria for multiple sclerosis OR

 -  Cavitatory Lesions: ≥ 3 mm in size that follow cerebro-spinal fluid on all
 sequences that are slit or wedge shaped with an irregular margin AND NOT
 longitudinally aligned with perforating vessels or with a multiple, bilateral
 symmetrical distribution OR

 -  T2 weighted (T2W) hyperintense/T1 weighted (T1W) hypointense lesions:

 -  Focal lesion with high T2W signal and low T1W signal that have prior evidence of
 restricted diffusion; OR

 -  Present within cortical gray matter or deep gray matter nuclei OR

 -  A lesion that is new, compared with an MRI performed within 3 months OR

 -  T2W hyper/T1W hypointense lesions in the white matter, which are discontinuous but
 associated with the classic confluent periventricular T2 intense change of
 leukoaraiosis (Fazekas ≥2) AND NOT satisfying the diagnostic criteria for multiple
 sclerosis or with a significant patient history of severe trauma, radiation, drug
 toxicity, or carbon monoxide poisoning

 Exclusion Criteria:

 -  History of AF or atrial flutter

 -  Patients with a history of symptoms compatible with an AIS, covert neurological
 deficits are allowed.

 -  Cardiac implantable electronic devices (pacemaker, implantable cardiac defibrillator
 (ICD), implantable cardiac monitor (ICM))

 -  Indication for cardiac implantable electronic device implantation (pacemaker, ICD,
 ICM)

 -  History of or indication for major cardiac surgery or transcutaneous aortic valve
 implantation

 -  Indication for permanent oral anticoagulation

 -  Contraindication for permanent oral anticoagulation

 -  Projected life expectancy of less than 2 years

 -  Active intra- or extracranial high-grade malignancy

 -  Patient is already included in another clinical trial that will affect the objectives
 of this study

 -  Patient's lack of accountability, inability to appreciate the nature, meaning and
 consequences of the study and to formulate his/her own wishes correspondingly

 -  Inability to follow the procedures of the study, e.g. due to language problems,
 psychological disorders, dementia, etc.

 -  Known or suspected non-compliance, drug or alcohol abuse