Evaluation of epidemiological and microbiological characteristics, clinical features, and outcomes of adult patients with infective endocarditis in Mashhad, Iran.

INTRODUCTION: Infective endocarditis (IE) is a serious problem with high morbidity and mortality. However, there is a paucity of data regarding its epidemiology in non-high-income settings. Here, we described the characteristics of patients with IE.

METHODOLOGY: Between March 2012 to March 2020, all adults (≥ 16 years) with a diagnosis of IE who were admitted to a university hospital in Mashhad, Iran, were included in the study.

RESULTS: We evaluated 46 cases of IE with a median age of 42 years (interquartile range 31 to 58.3 years), of whom 21 (46%) had a definite diagnosis. The presence of a prosthetic valve or intracardiac device was the leading predisposing factor (N = 14, 30%). The etiology of IE in 22 subjects (48%) remained unknown. Staphylococcus aureus (N = 12, 26%) was the most common causative pathogen. Echocardiography revealed the mitral valve as the most affected valve (N = 18, 39%). Intravenous drug users (IVDU) had a higher chance of right-sided IE, as compared to no IVDU patients (odds ratio: 35, 95% CI: 3.7 to 425.0). The most prevalent complications were lung infarction, acute heart failure, and neurologic involvement (N = 5, 11% for each), and 15 patients (33%) died because of IE.

CONCLUSIONS: In our study, the median age of IE onset was relatively low. The most frequent predisposing factor was a prosthetic valve or intracardiac device. The proportion of negative blood cultures was unacceptably high. Thus, our findings emphasize promoting laboratory infrastructure, developing a national protocol for early initiation of appropriate treatment, and eliminating predisposing factors.