A protocol for the impact of Tongmai Jiangtang capsules on the risk of cardiovascular and cerebrovascular events in metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS) significantly increases the risk of major adverse cardiovascular events (MACE), yet evidence-based complementary therapies remain limited. Tongmai Jiangtang Capsule (TJC), a traditional Chinese medicine (TCM) compound, has demonstrated benefits for glycolipid metabolism and microvascular complications, but its effect on hard cardiovascular and cerebrovascular (CCV) endpoints remains unconfirmed. OBJECTIVE: To explore whether TJC, as an adjunctive therapy to standard care, reduces the incidence of MACE in patients with MetS and Qi deficiency-blood stasis syndrome. METHODS: This is a randomized, double-blind, placebo-controlled, multicenter trial. A total of 530 participants aged ≥65 years, diagnosed with MetS and the TCM pattern of Qi Deficiency and Blood Stasis, and at high CCV risk, will be enrolled. They will be randomly assigned (1:1) to receive either TJC or a matched placebo, in addition to standard care, for 26 weeks, followed by a 26-week follow-up. The primary endpoint is the composite of 3P-MACE (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke). Secondary endpoints include metabolic parameters, vascular assessments, TCM symptom scores, and quality of life. Omics analyses will explore potential mechanisms. The trial was registered on ClinicalTrials.gov (NCT06908473). DISCUSSION: This rigorously designed trial is expected to provide high-level evidence regarding the role of TJC in preventing CCV events in MetS. If positive, it will offer a novel, multi-target integrative treatment strategy. The findings will also advance the evidence-based evaluation of TCM compounds and contribute to chronic disease prevention goals. Regardless of the primary outcome, the mechanistic insights will inform future research on formula optimization and precision intervention. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/expert-search?term=NCT06908473, identifier, NCT06908473.