Abstract:Objective To analyze the etiology and clinical characteristics of elderly patients with infective endocarditis, and to provide scientific evidence for the prevention and treatment of the disease. Methods Ninety-six elderly patients with infective endocarditis, who were treated in Shanghai Eighth People's Hospital from March 2015 to February 2016, were selected, and arterial blood was collected for bacterial culture. The pathogens were identified by Phoenix-100 automatic bacterial identification/drug sensitive system. Results In the 96 patients, 76 cases (79.17%) had lesions located in the left heart, 7 cases (7.29%) had lesions in the right heart, 7 cases (7.29%) had lesions in both left and right hearts, 6 cases (6.25%) had uncertain lesion location. Among the 96 cases, 45 bacterial strains were found, mainly Streptococcus pyogenes(25 strains,55.56%). Underlying heart diseases were found in 46 cases accounting for 47.92%. In the multivariate analysis, hemoglobin < 90 g/L and hospital infections were the major factors of insecurity for the elderly patients with infective endocarditis, and surgical treatment was the safety factor. Conclusions Infective endocarditis is a serious threat to the life of elderly patients. Streptococcus pyogenes is the major pathogen,so early diagnosis, rational use of antibiotics and surgical treatment have good effect.