[Clinical and diagnostic value of including PCR blood test in the traditional algorithm for identifying causative agents of infective endocarditis: a cohort study of 124 patients].

BACKGROUND: If infective endocarditis (IE) is suspected, the determination of the etiology is of fundamental importance for the verification of the disease and the appointment of effective therapy. Microbiological diagnostic features are important, but they often need to be supplemented by culture-independent studies of pathological agents. AIM: To investigate of the diagnostic advantage and value of quantitative analysis of molecular biological methods (polymerase chain reaction - PCR, sequencing) in addition to microbiological examination of whole venous blood in IE. MATERIALS AND METHODS: We examined 124 patients with suspected or significant IE (DUKE 2015) hospitalized in the Vinogradov City Clinical Hospital (2015-2021). All patients underwent parallel microbiological (cultural) and molecular biological (PCR or PCR followed by sequencing) examination of venous whole blood samples. RESULTS: The introduction of an early parallel PCR study into the algorithm for the etiological diagnosis of IE made it possible to obtain an additional advantage in 43/124 (34.7%) patients, which made it possible to exclude unreliable results in the determination of CoNS skin commensals and pathogens atypical for IE or contamination and identify the true pathogens, and also for the first time to isolate the etiopathogenetic pathogen with a negative microbiological study. It was shown that in IE associated with CoNS, the association with the disease was confirmed by PCR in 21.4% (3/14) and refuted in 71.4% (10/14). The coincidence of the results of microbiological and PCR studies of blood samples was obtained only in 35/95 (36.8%). Positive results of PCR analysis of blood of biological material with negative results of culture were obtained in 22/51 (43.1%), of which 2/22 (9.0%) were able to confirm the presence of Bartonella spp DNA. The presented complex algorithm made it possible to significantly increase the possibility of intravital identification of the pathogen in the blood from 58.9 to 76.6%. IE with unknown etiology was present in 29/124 (23.4%) patients. A parallel PCR study allowed timely correction of antibiotic therapy in 43/124 (34.7%) patients. CONCLUSION: Expansion of indications for the use of PCR studies, primarily whole venous blood samples, is justified, not only in IE with negative results of microbiological examination, but also as a control method for the reliability of the results of traditional (cultural) diagnostic methods.

[Focus ultrasound for cardiology practice. Russian consensus document].

This document is a consensus document of Russian Specialists in Heart Failure, Russian Society of Cardiology, Russian Association of Specialists in Ultrasound Diagnostics in Medicine and Russian Society for the Prevention of Noncommunicable Diseases. In the document a definition of focus ultrasound is stated and discussed when it can be used in cardiology practice in Russian Federation.

[Infective Endocarditis with Unknown Etiology: Possibilities of Conquering and Role of Microbiologistics].

Current infectious endocarditis (IE) is characterized by changes in its etiological and epidemiological profiles associated with increased incidence of IE of undetermined etiology. This requires a search for ways to enhance the effectivity of diagnosis. Microbiologistics along with high-tech methods becomes decisively important for identifying the pathogen by studying cultures of blood and tissues from the affected heart valve. This determines timely diagnosis and treatment to be introduced to medical practice as a component of personalized medicine. The article focuses on the validity and features of microbiological (cultural), immunochemical, and molecular biological [MALDI-TOF MS (matrix-activated laser desorption/ionization with time-of-flight mass spectrometry), polymerase chain reaction, sequencing] studies.

Infective Endocarditis in Moscow General Hospital: Clinical Characteristics and Outcomes (Single-Center 7 Years' Experience).

AIM: to investigate clinical properties of course and outcomes of infective endocarditis (IE) depending on source of infection, to find predictors of mortality in a Moscow general hospital. MATERIALS AND METHODS: We included in this study 176 patients with definite and possible infective endocarditis (the Duke criteria), admitted in our hospital in 2010-2017. Patients were divided in three groups according to source of infection. All patients underwent standard clinical and laboratory assessment, echocardiography, blood culture test combined with blood PCR with sequencing. Inhospital and 1-year outcome were evaluated. RESULTS: Among 176 patients with IE 65.3 % were men (median age 57 [35-72] years), most patients (n=149, 84.7 %) had native valve IE. Etiological factor was identified in 127 (72.2 %) cases. Gram-positive infective agents prevailed (54 %). Surgery in active phase of the disease was performed in 30 (17 %) patients. Among patients with healthcare-associated IE (n=76, 43.9 %) prevailed those older than 60 years, with high Charlson comorbidity index, with culture-negative IE, and complicated clinical course (mainly progressing heart failure). Patients with intravenous drug use associated IE (n=50, 28.4 %) had low Charlson index, association with hepatitis C viral infection, involvement of tricuspid valve with big vegetations, high frequency of embolic complications, and low inhospital mortality. Group of patients with community acquired IE (n=50, 28.4 %) more often had uncommon causative microorganisms, and had better long-term outcome. In-hospital mortality was 30.1 % (n=53) mostly due to sepsis with multi-organ failure, and heart failure. Risk factors of inhospital death were history of cardiovascular diseases, old age, kidney damage, methicillin-resistant Staphylococcus aureus (MRSA) infection, uncontrolled infection, and embolic events. Risk factors of 1-year mortality were history of stroke, and heart failure as IE complication. Independent predictors of in-hospital death were MRSA infection (odds ratio [OR] 50.32, 95 % confidence interval [CI] 1.66-213.92; p=0.002), persistent infection (OR 18.6, 95 %CI 5.37-64.40; p=0.001), duration of fever >7 days after initiation of antibacterial therapy (OR 13.41, 95 %CI 3.51-51.24; p=0.001); and of death during first year - history of cerebral infarction (OR 4.39, 95 %CI 1.32-14.70; p=0.016)), and heart failure as IE complication (OR 8.1, 95 %CI 1.97-67.09; p=0.016). Among patients subjected to surgery there were no fatal outcomes during 1 year after hospital discharge, while among conservatively treated patients were 21 (14.4 %) deaths (p<0.009). CONCLUSION: Main clinical features of IE course in patients urgently admitted to a general hospital was dominance of healthcare-associated  IE among patients, who were older than 60 years with severe comorbidities. These patients had more complications and worse outcome. Modeling of prognosis identified uncontrolled infection as key factor of unfavorable outcome. Surgery significantly reduced long-term mortality.

[Infective endocarditis: Importance of molecular biological techniques in etiological diagnosis]. / Infektsionnyi endokardit: znachenie molekulyarno-biologicheskikh metodov v etiologicheskoi diagnostike.

AIM: To investigate the specific features of conventional bacteriological methods and current molecular biological techniques for the etiological diagnosis of infective endocarditis (IE). SUBJECTS AND METHODS: Examinations were made in 53 patients treated at City Clinical Hospital Sixty-Four, Moscow Healthcare Department, in 2012-2015 who underwent simultaneous bacteriological and molecular biological (polymerase chain reaction (PCR) or PCR with further sequencing) examinations of blood or resected cardiac valve tissues. RESULTS: The investigation included 53 patients (31 men; median age, 62 years) with IE (Duke 2009); its primary form was observed in 32 (60.4%) patients. Blood bacteriological tests and PCR assays were positive in 28 (52.8%) and 34 (64.2%) patients, respectively. There were concordant results in 21 of the 28 positive blood culture cases and discordant results in 7 (25%); at the same time 3 cases showed a compete discordance in the detected causative agents (the growth of Enterococcus spp. was revealed by bacteriological examination and that of Staphylococcus spp., Streptococcus spp., and Escherichia coli by DNA PCR) and a pathogen could not be identified by DNA PCR in 4 patients who had positive blood bacteriological results. The positive PCR results for cocci and fungi were obtained in 10 of the 25 (47.2%) examinees with culture-negative IE. Rare causative agents were not revealed. The tissues obtained from 8 resected damaged heart valves displayed a wider spectrum of pathogens than did blood samples, which was associated with the formation of bacterial films. CONCLUSION: The etiological agent of IE was revealed in venous blood by bacteriological examination in 52.8% of the examinees, by PCR in 64.2%, and by either in 71.7%. There were concordant and discordant results in 67.9 and 32.1% of the patients, respectively; among whom 18.9% were found to have pathogen DNA revealed by PCR in culture-negative IE.