Causative Microorganisms in Infective Endocarditis: Prospective Data from the Iranian Registry of Infective Endocarditis (IRIE)

Background: infective endocarditis (ie) is a life-threatening disease. regardlessof improved healthcare, the incidence of ie has increased over time. a variety ofmicroorganisms have been found to be associated with ie.objectives: this study aimed to determine the incidence of various microorganisms inpatients admitted with ie and to assess their relationships with in-hospital complications.methods: this prospective cross-sectional study was conducted on patients with definiteor possible ie based on the duke criteria at a tertiary referral center between 2016 and2021. blood cultures were performed for all the patients to document the positive ornegative blood cultures as well as the types of microorganism. statistical analyses wereperformed using the spss 18 software.results: the study population consisted of 286 patients (181 males (63.3%) and 105 females(36.7%)) with the mean age of 49.67 ± 17.11 years. the most common cardiac predisposingfactor was the prosthetic valve (n = 110, 38.5%) followed by a history of congenital heartdisease (n = 68, 23.8%), while the most frequent non-cardiac predisposing factors werea history of chronic kidney disease (n = 75, 26.2%) and diabetes mellitus (n = 53, 18.5%).the most frequent causative microorganisms were coagulase-negative staphylococcus (n= 37, 12.9%), staphylococcus aureus (n = 31, 10.4%), enterococcus (n = 29, 10.1%), andstreptococcus viridans (n = 14, 4.9%). the most common complications were acute renalfailure (26.6%), heart failure (17.5%), and pulmonary involvement (8.4%).conclusions: the frequencies of microorganisms related to ie, especially culturenegativeie, vary in different countries, precluding the practical use of a specificguideline around the world. further research is, therefore, required to determine theepidemiology and microbiology of ie in different countries with a view to eventuallydevising an individualized guideline appropriate to the epidemiology and microbiologyof ie in every country.