Investigation of patients diagnosed with infective endocarditis: a 15-year single center study

Objective: This study aimed to comprehensively evaluate patients with infective endocarditis (IE) and to identify the clinical, laboratory, and microbiological factors associated with mortality and the development of complications. Accordingly, patients' demographic characteristics, symptoms, comorbidities, causative microorganisms, valve involvement, laboratory findings, and treatment processes were analyzed, and predictors associated with mortality were determined. In addition, the effectiveness of empirical treatment approaches, indications for treatment modification, and clinical outcomes were evaluated. Based on the obtained data, it was aimed to develop a prognostic scoring system to predict mortality risk at admission, thereby contributing to the timely implementation of early diagnosis, appropriate antimicrobial therapy, and surgical decision-making. Materials and Methods: This retrospective study was conducted at Karadeniz Technical University Faculty of Medicine, Farabi Hospital, among patients diagnosed with IE between January 1, 2010, and December 31, 2024. The study was approved by the Karadeniz Technical University Scientific Research Ethics Committee (Protocol No: 2025/33). Data were obtained from the hospital's electronic medical records, consultation notes, patient follow-up cards of the Department of Infectious Diseases and Clinical Microbiology, and the Infection Control Committee database. Results: A total of 197 patients diagnosed with IE were included. The mean age was 61.2 ± 16.8 years, with 63.5% male and 36.5% female. The most common comorbidities were coronary artery disease (58.9%), hypertension (57.4%), heart failure (42.6%), and diabetes mellitus (25.4%). Most cases presented in the acute form (70.6%). According to acquisition, 59.4% were community-acquired, 18.3% hospital-acquired, and 22.3% healthcare-associated non-nosocomial IE. Regarding valve type, 61.9% of cases involved native valves, 29.4% prosthetic valves, and 8.6% intracardiac device-associated IE. The most frequently isolated microorganisms were methicillin-susceptible Staphylococcus aureus (MSSA, 21.3%), Enterococcus faecalis (12.7%), methicillin-resistant Staphylococcus aureus (MRSA, 10.7%), and iii viridans group streptococci (VGS, 10.2%). Culture-negative IE was detected in 16.8% of cases. Cardiac imaging revealed pathological findings in 88.8% of patients, most commonly involving the mitral (44.7%) and aortic (29.9%) valves. Embolic events occurred in 48.7% of patients, most frequently affecting the central nervous system. During follow-up, 55.3% required intensive care unit (ICU) support. Although 58.4% had surgical indications, only 25.9% underwent surgery. The in hospital mortality rate was 24.3%. Advanced age, high Charlson Comorbidity Index (CCI), hypotension, altered mental status, dyspnea, tachycardia, chronic kidney disease, atrial fibrillation, and peripheral catheter presence were significantly associated with mortality. Laboratory predictors included elevated BUN, LDH, bilirubin, AST, and decreased platelet and albumin levels. A mortality risk score developed using these parameters demonstrated high predictive accuracy and effectively stratified patients according to early mortality risk. Conclusion: This study revealed the clinical characteristics, diagnostic challenges, and mortality-associated factors in patients with IE. The findings indicate that IE predominantly occurs in elderly individuals with a high comorbidity burden and that the clinical course becomes more severe with the development of complications. The prognostic value of laboratory parameters supports early identification of high-risk groups. Therefore, comprehensive clinical evaluation and close laboratory monitoring are crucial in patients with suspected IE. Our findings suggest that integrating prognostic scoring systems into clinical practice may significantly improve patient management and outcomes. Keywords: Infective Endocarditis, Mortality, Comorbidity, Prognosis, Microbiology