The purpose of this academic lead study is to explore ideal blood pressure targets and optimum individualized anti-hypertension strategies in acute severe stroke.

Of high mortality and morbidity, severe stroke is associated with devastating damages in neurologic, respiratory, circulatory and many other systems. The outcomes of patients with severe stroke depend largely on medical strategies on acute stage, especially on blood pressure (BP) management. Unfortunately, so far no ideal BP range has been scientifically determined for patients with acute severe stroke.

The CHASE study aims to provide reliable data on the effects of individualized anti-hypertension strategy in patients with acute severe stroke (target recruitment 250) compared to standard guideline-based management of BP (target recruitment 250). Patients presenting with acute (<72h) severe stroke (GCS ≦ 12 or NIHSS ≧ 11) and elevated BP (systolic blood pressure ≧150 mmHg or diastolic blood pressure ≧ 100 mmHg) will be randomly assigned to individualized anti-hypertension treatment or guideline-based treatment for 7 days.

Inclusion Criteria:

1. age ≥ 18 years;
2. the randomly assigned BP-lowering regimen is able to be commenced within 72 h after the onset of stroke (ischemic or hemorrhagic), confirmed by a computed tomography (CT) or magnetic resonance imaging (MRI) scan of the brain (if the precise timing of the onset of symptoms or signs of the qualifying event is unknown, then the time of onset will be taken as the last time the patient was known to be well);
3. GCS on admission ≤ 12 or NIHSS on admission ≥ 11;
4. there are at least two SBP measurements of ≥ 150 and ≤ 210 mmHg, recorded ≥5 min apart (patients with an initial SBP < 150 mmHg may be randomized when the SBP fulfils entry criteria on rechecking up to 72 h after the onset of stroke);
5. written informed consent is able to be obtained directly from the patient or an appropriate surrogate, based on local ethics committee recommendations.

Exclusion Criteria:

1. patients who have received thrombolytic therapy, embolectomy, or decompressive craniectomy for the current stroke;
2. patients with subarachnoid hemorrhage;
3. known definite contraindication to acute BP lowering (e.g. known severe carotid, vertebral, or cerebral arterial stenosis, Moyamoya disease or Takayasu's arteritis, high grade stenotic valvular heart disease);
4. secondary to a structural abnormality in the brain (e.g. an arteriovenous malformation, intracranial aneurysm, tumor, or trauma);
5. unstable vital signs and requiring the use of vasoactive agents;
6. known existing dementia or prestroke disability (e.g. score 3-5 on the modified Rankin scale);
7. concomitant medical illness that would interfere with the outcome assessments and/or follow-up (advanced cancer; severe pulmonary dysfunction [forced expiratory volume in 1 s < 50%]; severe cardiac dysfunction [ejection fraction ≤ 50%]; severe hepatic failure [Child-Pugh score ≥ 7]; severe renal failure [glomerular filtration rate ≤ 30 mL/min or serum creatinine ≥ 4 mg/dL]);
8. patients who are currently participating in other investigational trials;
9. patients who are considered to have a high likelihood of not adhering to the study treatment or the follow-up regimen.