A systematic review and meta-analysis for the primary prevention of high risk of stroke by Nao-an capsules.

Background: To date, Nao-an capsules are the only Chinese patent medicine primarily prescribed for the primary prevention of stroke.

Purpose: To evaluate the efficacy and safety of Nao-an capsules in the primary prevention of stroke in high-risk patients.

Study Design: A systematic review and meta-analysis of randomized controlled trials.

Methods: We searched 7 electronic databases and 2 registries from inception to January 13, 2022 for relevant randomized controlled trials. Two independent investigators selected trials, collected data, and judged the risk of bias. We performed a meta-analysis using the Review Manager software.

Results: Nine randomized controlled trials involving 14 744 patients at high risk of stroke were included. Nao-an capsules reduced the risk of first stroke compared with no intervention (risk ratio [RR] = 0.49, 95 % confidence interval [CI] 0.29 to 0.82, p = 0.006) or aspirin (RR = 0.47, 95 % CI 0.25 to 0.91, p = 0.03; RR = 0.46, 95 % CI 0.22 to 0.99, p = 0.05), without increased bleeding risks. The certainty of evidence was evaluated as moderate to very low.

Conclusion: In addition to controlling specific risk factors, Nao-an capsules might provide additional preventive effects on first stroke with an acceptable safety profile for populations at high risk of stroke. However, as current evidence is too weak, a firm recommendation depends on further confirmation from more studies with more rigorous methodology.