Safety and Efficacy of Therapeutic INduced HYPERTENSION in Acute Non-cardioembolic Ischemic Stroke (SETIN-HYPERTENSION)

Inclusion Criteria: * Patients with acute ischemic stroke confirmed by diffusion-weighted imaging (DWI) performed within 24 hours of symptom onset or symptom worsening(defined by a 2-point or more increase in NIH stroke scale (NIHSS)score including one or more increase in the motor score of affected upper and lower limbs in NIHSS during hospitalization or clear history of symptom worsening judged by investigator before hospitalization) confirmed by DWI performed within 24 hours of aggravation. * Baseline NIHSS score 4-18 points * Alert mental status * Newly developed paresis, aphasia, or neglect Exclusion Criteria: * Patients underwent recanalization therapy * Systolic blood pressure \>170 mmHg at baseline * Patients with history or at risk of hemorrhagic stroke * History of significant arrhythmia (e.g. atrial fibrillation) * Unable to perform MRI scans or undergo MRI scans \> 24 hours of symptom onset or progression * Large cortical infarction on DWI (more than 1/2 of middle cerebral artery territory) * 3 or more cortical microbleeds on gradient-echo MRI * Coronary artery disease, congestive heart failure, or hypertrophic cardiomyopathy * Anticoagulation therapy (phenylephrine group only) * Patients with high-risk cardioembolic sources * Cervical or cerebral artery dissection or unruptured aortic/cerebral arterial aneurysm * Decreased consciousness * Pregnant or Lactating patient * Seizure at stroke onset * Life expectancy \< 6 months * Pre-stroke modified Rankin scale (mRS) \>= 2 * Patients without informed consent