Microbiological Spectrum of Infective Endocarditis Complicated by Heart Failure

Abstract

Resume. Infective endocarditis (IE) is a serious disease that can lead to severe complications and death. The study of the microbiological spectrum of pathogens in such patients is great importance for optimizing treatment and increasing the effectiveness treatment. The spectrum of IE pathogens has changed significantly over the past decades. A positive microbiological blood test remains the cornerstone in diagnosis and etiotropic antimicrobial therapy of IE. Considering the global mobility of the population and the growing resistance of microorganisms to antibiotics, it is necessary to update our knowledge about the microbiological spectrum of infective endocarditis constantly. THE AIM was to investigate the microbiological spectrum of pathogens in patients with infective endocarditis complicated by heart failure. Materials and methods. Clinical data of 120 patients with active infective endocarditis who underwent treatment at the SE «Amosov National Institute of Cardiovascular Surgery» National Academy of Medical Sciences of Ukraine from 01.01.2019 to 06.30.2020 were enrolled in the study. The diagnosis of IE was established in accordance with Duke's criteria. The average age of the studied patients was 48.1±1.37 (19-77) years. Results. The rate of gram-positive and gramnegative microorganisms was 69 (93.2 %) cases and 5 (6.8 %) cases respectively. Gram-positive microorganisms were found – Staphylococcus spp. in 42 (56.8 %) cases and Enterococcus spp. in 20 (27.0 %) cases. A high level of oxacillin-resistant (p=0.072) and vancomycin-resistant (p=0.027) strains of microorganisms were found in the group of patients with preoperative heart failure. Conclusions: The microbiological spectrum of IE pathogens in patients with heart failure is characterized by the predominance of gram-positive strains that are resistant to oxacillin and vancomycin. Positive results of bacteriologic blood tests were found in 74 cases out of the total number, which is 61.7 %. Of these, gram-positive microorganisms were detected in 69 cases (93.2 %), while gram-negative microorganisms were detected in only 5 cases (6.8 %). The most common gram-positive microorganisms were Staphylococcus spp. (56.8 %) and Enterococcus spp. (27.0%). There was also found that risk factors such as nosocomial infections, hypothermia and drug abuse can contribute to the development of UI. The overall frequency of nosocomial factors in the development of the disease was 36.7 %. Urological interventions (12.5 %) and general surgical interventions (20.8 %) were among the most common. Our study included patients with active UI who had positive bacteriologic blood tests and signs of a systemic inflammatory response. In these patients, the mean body temperature at hospitalization was 38.3 °C, and the mean heart rate was 91.0 beats/min. The organ dysfunction detected in patients with complicated IE was also confirmed by high levels of creatinine (168.2 mcg/L) and urea (13.3 mmol/L). A comparative analysis of laboratory results also revealed a high level of resistant strains of microorganisms in the group of patients with complicated IE. Thus, the data obtained confirm the seriousness of the problem of infective endocarditis and emphasize the need for further research to develop effective strategies for the diagnosis and treatment of this disease, especially in patients with complicated course.