Objective To investigate the effects of recombinant human brain natriuretic peptide in elderly patients with acute myocardial infarction patients with emergency percutaneous coronary intervention (PCI). Methods 84 patients with ST segment elevation acute myocardial infarction were divided into control group (42 cases) and observation group (42 cases). The control group was treated with postoperative routine treatment. The observation group was treated with postoperative routine treatment combined with recombinant human brain natriuretic peptide. The cardiac troponin, vascular angiotensin II, aldosterone, CRP (C-reactive protein), plasma renin activity and heart function indexes of LVEDV and LVEF, LVESV and other clinical indicators were observed.Results The troponin 24h after operation of observation group was significantly decreased, compared with that of control group (P＜0.05). CRP 10h, 24h and a week after operation of observation group were significantly decreased, compared with that of control group (P＜0.05). LVEDV LVESV 4 weeks after operation of observation group were significantly decreased, compared with that of control group (P＜0.05). LVEF 1D, 1 week, 4 weeks after operation of observation group were significantly decreased, compared with that of control group (P＜0.05). The angiotensin II and aldosterone levels were significantly decreased after operation.Conclusion The elderly patients with acute myocardial infarction treated by primary percutaneous coronary intervention using recombinant human brain natriuretic peptide can effectively reduce the renin, angiotensin and aldosterone level, block cardiac remodeling and improve cardiac function in patients and the prognosis.