Table 1 Participant inclusion and exclusion criteria and criteria for randomization

Inclusion criteria

Exclusion criteria

1. Informed consent as documented by signature

2. Admission to one of the participating centres

3. Age 18–85 years

4. Ischaemic stroke detectable by neuroimaging, affecting internal carotid artery, anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA) and/or branches thereof

5. Symptom onset to admission < 24 h

6. AHI > 20/h or < 5/h

1. Primary haemorrhagic stroke or secondary parenchymal haemorrhage (PH 1 and PH 2 according to ECASS)

2. Small strokes (diameter < 1.5 cm)

3. Coma/Stupor

4. Clinically unstable or life-threatening condition

5. Heart failure defined as congestive heart failure (CHF) functional class NYHA III-IV OR CHF NYHA II and hospitalization caused by CHF in the preceding 24 months OR left ventricular ejection fraction ≤ 45%

6. Intubation or oxygen supply > 2 L/min.

7. Known progressive neurological diseases

8. Drug or alcohol abuse

9. Inability to follow study procedure

10. Pregnancy

11. Any given contraindications to MRI or MRI-contrast agent

12. Any given contraindications to ASV treatment

13. Protocol addendum made on 28.05.2020: Exclusion of patient with clinical symptoms of COVID-19 infection (fever, signs of acute respiratory infection, loss of taste or smell) during hospitalization due to acute stroke*