 The study is randomized, opened, controlled. 45 patients with the first anterior STEMI will be enrolled. On admission all patients will receive reperfusion therapy during the first 24 h. Patients will be randomized by the open envelope method and after that some of the participants will be on doxycycline 100 mg b.i.d. for 7 days in addition to routine medical therapy for STEMI, but other will be on routine medical therapy of STEMI. After that they will have echocardiography at 3-d, 7-th, 14-th days and 6 month after STEMI. The investigators will evaluate left ventricular function of these patients by routine and speckle-tracking echocardiography, incidence of cardiovascular end points death, recurrent myocardial infarction, angina, heart failure, stroke and their combinations, also the investigators will take blood samples to assess metalloproteinases MMPs and other biomarkers. 