GSTM1 and cardiac arrhythmia: In Model 2, we adjusted additional confounders, including laboratory findings on admission (Hb, WBC, peak cTnI, ALT, PLT and serum potassium), major presenting symptoms (chest pain, chest stuffiness, shortness of breath and syncope), arrhythmia (atrial fibrillation, atrioventricular block, bundle branch block and bradycardia), echocardiography indices (LV and RV) besides abovementioned confounders.