Efficacy and safety of Naoshuantong capsule in High-Recurrence-Risk patients with Acute Ischemic Stroke (RESPACE): study protocol for a multicenter, randomized, double-blind, controlled trial

Ischemic stroke is a leading cause of death and long-term disability worldwide. The Naoshuantong capsule (NC), a traditional Chinese patent medicine, has been extensively used in the treatment of stroke in China. However, the clinical efficacy and safety of NC have not been finally verified through rigorous randomized controlled trials. Therefore, this his randomized, multicenter, double-blinded, placebo-controlled trial is designed to investigate the efficacy and safety of NC in high-recurrence-risk patients with acute ischemic stroke (AIS) within 72 h after symptom onset. An estimated 3150 participants at age of 18–80 years with Essen Stroke risk score (ESRS) ≥ 3 and National Institutes of Health Stroke Scale score ≤ 15 from approximately 100 Chinese hospitals will be randomly assigned in a 1:1 ratio to the NC group (NC 3 capsules 3 times daily for 90 days) or control group (NC placebo 3 capsules 3 times daily for 90 days). Guideline based standard medical care will be used in both groups. The primary efficacy outcome is any stroke (ischemic or hemorrhagic) within 90 days after symptom onset. The primary safety outcome is severe adverse events within 90 days. To our knowledge, this study is the first double-blind trial to assess the efficacy and safety of NC in patients with AIS. Findings of the trial will be valuable in improving evidence regarding the clinical application of NC therapy in patients with mild- to moderate-stroke at high risk of recurrence. Clinical trial registration: www.chictr.org.cn, identifier ChiCTR2300075877.