RecruitingPhase 4Drug trialMetformin Hydrochloride Sustained-release Tablets (Ⅲ) in Patients With Type 2 Diabetes Mellitus Complicated With Coronary Heart DiseaseThe purpose of this study is1. Compare the differences in the changes of glycated hemoglobin after 24 weeks of treatment between the new metformin sustained-release tablets (Ⅲ) group and the metformin ordinary tablets group. 2\. Compare the differences in the changes of fasting blood glucose, gastrointestinal adverse reactions of the drug and compliance after 24 weeks of treatment between the new metformin sustained-release tablets (Ⅲ) group and the metformin ordinary tablets group.