Qidong Yixin Oral Liquid for Viral Myocarditis: A Systematic Review and Meta‐Analysis

Objective . This study aimed to evaluate the efficacy and safety of Qidong Yixin (QY) oral liquid in the treatment of viral myocarditis (VMC). Methods . We searched seven databases for randomized clinical trials on QY for treating VMC. The retrieval period was from database establishment to December 31, 2019. Cochrane risk of bias tool in the Cochrane Handbook was used to assess the methodological quality. Review Manager (RevMan) 5.3 was used to analyze the results. Results . We included 19 studies comprising 2,608 patients, albeit with low methodological quality. Our meta‐analysis revealed that combination therapy with QY and western medicine was more effective than western medicine alone (QY vs other Chinese patent medicines: RR = 1.37, 95% Cl: 1.23∼1.52, P < 0.00001; QY + coenzyme Q10 + routine treatment vs coenzyme Q10 + routine treatment: RR = 1.20, 95% Cl: 1.14∼1.27, P < 0.00001; QY + trimetazidine + acyclovir vs trimetazidine + acyclovir: RR = 1.59, 95% Cl: 1.38∼1.83, P < 0.00001; QY + routine treatment vs routine treatment: RR = 1.09, 95% Cl: 1.03∼1.15, P < 0.003). A study on posttreatment myocardial enzyme levels revealed that QY with western medicine downregulated creatine kinase isoenzyme (CK‐MB) (QY + antiviral treatment + routine treatment vs antiviral treatment + routine treatment group: MD = −11.28, 95% CI: −13.33∼−9.22, P < 0.00001; QY + routine treatment vs routine treatment: MD = −4.96, 95% CI: −5.56∼−4.32, P < 0.00001), creatine kinase (CK) (MD = −32.10, 95% CI: −35.63∼−28.57, P < 0.00001), and lactate dehydrogenase (LDH) (QY + antiviral treatment + routine treatment vs antiviral treatment + routine treatment: MD = −48.76 95% CI: −58.18∼−39.33, P < 0.00001; QY + routine treatment vs routine treatment: MD = −23.52, 95% CI: −30.10–16.94, P < 0.00001) rather than western medicine alone, with no evidence of aspartate aminotransferase (AST) downregulation on treatment with QY with western medicine (MD = 2.88, 95% CI: −0.95∼6.71, P < 0.00001) in patients. Two studies reported adverse events, indicating that QY is relatively safe. Conclusion . Although QY may have potential advantages in treating VMC, they remain unclear owing to the poor methodological quality of most studies. Larger, multicenter, high‐quality randomized controlled trials are required to verify the effectiveness of QY.