Biomarker Signature of Stroke Aetiology Study: The BIOSIGNAL-Study

Objectives and specific aims:

The investigators propose to prospectively evaluate the predictive value of the most
promising blood biomarkers to identify treatable stroke etiologies on admission and risk of
recurrence in 3000 consecutive ischemic stroke patients enrolled by 10 centers in Europe and
the US.

The clinical endpoints of the study are 1) recurrent stroke within one year, 2) all types of
atrial fibrillation (AF) detected on admission or by prolonged ambulatory cardiac rhythm
monitors, 3) presence of cerebrovascular atherosclerosis detected by ultrasound
investigations and 4) new silent ischemic brain lesions and progression of chronic cerebral
ischemic lesion volume detected by repeated magnetic resonance imaging (MRI and MRA) and
(i.e. on admission and after 12 months).

Aim 1: To determine whether the proposed biomarkers independently predict recurrent stroke
among all patients. Hypothesis 1: Elevated levels of one or more of the proposed biomarkers
will independently predict recurrent strokes during trial follow-up, assessed by structured
interviews, as well as chart reviews 90 days and 1 year after the index stroke.

Aim 2: To determine whether cardioembolic (CE) biomarkers are associated with atrial
fibrillation among all patients. Hypothesis 2: Baseline values of one or more of the proposed
CE biomarkers will be independently associated with AF, including history of AF, AF detection
at baseline, or AF detected during the follow up period by prolonged ambulatory cardiac
rhythm monitors and structured interviews as well as chart reviews 90 days and 1 year after
the index stroke.

Aim 3: To determine whether large artery atherosclerosis (LAA) biomarkers are associated with
a) the presence of cerebrovascular atherosclerosis among all patients. Hypothesis 3: Baseline
values of one or more of the proposed LAA biomarkers will be independently associated with
the presence of extra and intracranial atherosclerosis among patients with ischemic stroke,
assessed by duplex sonography.

Exploratory Aim 4: To determine whether the proposed biomarkers will predict b) new silent
strokes and c) progression of chronic cerebral ischemic lesion (white matter hyper-intensity)
volume (WMHV) among cryptogenic stroke patients. Hypothesis 4: Baseline values of one or more
of the proposed biomarkers will independently predict a) silent stroke b) progression of
WMHV, during study follow-up, assessed by repeated magnetic resonance imaging (MRI) (on
admission, and 1 year after the index stroke).

This study will be conducted in compliance with the protocol, the current version of the
Declaration of Helsinki, and Good Clinical Practice (GCP) guidelines as well as all national
legal and regulatory requirements.

Inclusion Criteria:

All consecutive patients (above the age of 18) who are admitted with a suspected ischemic
stroke within 24 hours of symptom onset are eligible.

Ischemic stroke is defined as an acute localized ischemic lesion in the brain not
attributable to central nervous system infection, tumor, demyelinating, or degenerative
neurologic diseases due to an occlusive vascular disorder.

Detailed Inclusion Criteria:

1. Rapid onset of a focal neurologic deficit, with signs or symptoms persisting beyond 24
hours & NOT associated with:

- infection

- trauma

- tumor of the brain

- severe metabolic disorders

- chronic degenerative neurologic disease

2. The development of an acute focal neurologic deficit persisting >24 hours in
conjunction with brain imaging consistent with acute ischemic stroke.

The CT or MRI may either show a new infarct or no change from the study performed at entry,
i.e. the diagnosis is clinical and does not require CT/MRI confirmation. Secondary
hemorrhagic infarction is permissible.

Exclusion Criteria:

1. Hemorrhagic stroke

2. All patients discharged from the hospital with a diagnosis different from ischemic
stroke (i.e. stroke mimics)