Xinmailong Injection for Improvement of Cardiac Function in Patients with Heart Failure: A Systematic Review and Meta‐Analysis

Background . Insect drugs have great potential for treating cardiovascular diseases. Xinmailong (XML) injection, a bioactive composite extracted from Periplaneta americana (a species of cockroach), was wildly used in treating heart failure in China. This meta‐analysis aimed to assess the efficacy and safety of XML injection for the improvement of cardiac function in HF. Materials and Methods . Online literature search for relevant studies was performed using databases including PubMed, EMBASE, Cochrane Library, CNKI, and Wanfang. Left ventricular ejection fraction (LVEF), six‐minute walk test (6MWT), and brain natriuretic peptide (BNP) were selected as target outcomes. The analysis was performed using Stata 12.0, and sources of heterogeneity were explored by subgroup analysis and metaregression. Results . 32 studies were included in this meta‐analysis after meeting the inclusion/exclusion criteria. The results demonstrated that additional use of XML improved LVEF (WMD = 5.82, 95% CI: 5.52–7.13, P < 0.00001) and 6MWT (WMD = 51.48, 95% CI: 35.83–67.13, P < 0.00001) and reduced BNP (WMD = −172.84, 95% CI: −205.79 to −139.89, P < 0.00001). The results of subgroup analyses and metaregression suggested that XML injection has more cardiac function improvement for middle‐aged HF patients than youth, and greater LVEF and 6MWT improvement were associated with higher average age. Conclusions . XML plus conventional treatment demonstrated a significant effect in reducing cardiac dysfunction in HF patients, and age is a potential factor of higher efficacy. Given the heterogeneity and bias of the included RCTs, large, prospective, rigorous trials are still needed.