Tongxinluo capsule as supplementation and cardiovascular endpoint events in patients with coronary heart disease: A systematic review and meta-analysis of randomized, double-blind, placebo-controlled trials

Tongxinluo Capsule(TXLC) is a well-known traditional Chinese medicine prescription with effects of tonifying Qi and activating blood based on the Chinese herbal medicine theory that has been recommended as routine adjuvant treatment in patients with coronary heart disease (CHD) in China.This meta-analysis aimed to evaluate the efficacy and safety of TXLC as supplementation in the prevention of adverse cardiovascular events in patients with CHD.We performed a literature search in Pubmed, Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP), Wan Fang Database, and Chinese Biomedical Database (CBM) from their inceptions to March 2020. Only randomized controlled trials (RCTs) that assessed supplementation with TXLC or placebo and with adverse cardiovascular outcomes, were included in this meta-analysis. Primary end points were myocardial infarction (MI), target vessel revascularization (TVR) or in-stent restenosis (ISR), and cardiovascular death. Secondary end points included cerebrovascular accidents, heart failure (HF), and unscheduled readmission for cardiovascular diseases (CVDs). Adverse drug events were also evaluated. Trial sequential analysis (TSA) was conducted to reduce random errors introduced by possible insufficient sample size.Eleven RCTs involving 1505 patients were analyzed. The mean(SD) age of included patients were 59.03(9.7) years. Treatment duration varied from 2 months to 12 months. Compared with placebo, TXLC supplementation showed significant effects on reducing the risk of MI (RR = 0.44, [95% CI, 0.24-0.80]), TVR or ISR (RR = 0.43, [95% CI, 0.31-0.58]), cerebrovascular accidents(RR = 0.17, [95% CI, 0.06-0.46]), HF (RR = 0.41, [95% CI, 0.21-0.79]), and unscheduled readmission for CVDs (RR = 0.72, [95% CI], P = 0.04), but did not have associations with incidence of cardiovascular death (RR = 0.53, [95% CI, 0.15-1.91]). Subgroups of trials with 2-month (MI: RR = 0.44, [95% CI, 0.13-1.53]; cardiovascular death: RR = 0.30, [95% CI, 0.01-7.67]; cerebrovascular accidents: RR = 0.04, [95% CI, 0.01-0.26]; unscheduled readmission for CVDs: RR = 0.43, [95% CI, 0.20-0.94]) and 12-month (MI: RR = 0.42, [95% CI, 0.20-0.89]; TVR or ISR: RR = 0.42, [95% CI, 0.31-0.58]; HF: RR = 0.34, [95% CI, 0.14-0.78]; unscheduled readmission for CVDs: RR = 0.85, [95% CI, 0.59-1.22]) intervention period were analyzed. The adverse drug reactions were mild with no significant difference between TXLC and placebo.This meta-analysis indicated that TXLC supplementation had beneficial effects on the prevention of cardiovascular adverse events, especially in TVR or ISR after coronary revascularization and may possibly lower the incidence of first or recurrent MI and HF within 12 months in patients with CHD, while insufficient sample size implied that these results lacked certain stability. And the effects of TXLC on cardiovascular mortality, cerebrovascular events, and unscheduled readmission for CVDs could not be confirmed due to insufficient cases. Clinical trials with large-sample sizes and extended follow-up time are of interest in the future researches.