Fig. 4

The effect of SM plus conventional treatment versus conventional treatment on NYHA classification. The RR calculated as the ratio between the proportion of responders in treatment group and the proportion of responders in control group and 95 % CI of fixed effect model were used. Responders were defined as an improvement of at least one class on NYHA classification. The meta-analysis showed that SM plus conventional treatment showed greater improvement on NYHA classification than conventional treatment alone(RR, 1.26; 95 % CI, 1.20–1.32; P < 0.00001). SM: Shenmai injection; NYHA classification: New York Heart Association classification; RR: Risk ratio; CI: Confidence interval