Etiopathogenetic factors of infective endocarditis in patients undergoing mitral valve surgery

Objective. To determine the etiopathogenetic risk factors for the development of infective endocarditis, taking into account demographic and gender characteristics in patients undergoing mitral valve surgery. Materials and methods. The study included 107 patients who underwent mitral valve surgery. There were 74 men and 33 women. The age of the patients ranged from 20 to 76 years, with a mean age of (50.6 ± 4.8) years. All patients had a history of infective endocarditis with subsequent mitral valve disease. All patients underwent mitral valve repair/prosthetics at the Amosov National Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine. Data from the primary medical records (medical histories, primary medical records, physical, clinical, laboratory and instrumental examinations) were used as the basis for the analysis. Results. Depending on the surgical treatment performed, patients were divided into two groups: experimental – 67 patients who underwent organ–preserving surgery (mitral valve repair), and control – 40 patients who underwent mitral valve prosthetics. The peculiarities of age and gender distribution of patients with mitral valve disease in the setting of infective endocarditis were studied. The frequency of etiopathogenetic risk factors for the development of infective endocarditis, taking into account the sex of patients in both study groups, was determined. Conclusions. Determination of etiopathogenetic risk factors for the development of infective endocarditis is extremely important, as it allows to plan surgical treatment and rehabilitation period taking into account all anamnestic features of the patient

Infective endocarditis (IE) is a disease of septic genesis caused by pathogenic or opportunistic microflora with predominant involvement of valves and/or parietal endocardium, characterised by rapid development of valvular insufficiency, systemic embolic complications and immunopathological symptoms [1].IE occurs due to the development of bacteremia and direct penetration of the pathogen into the heart structures.Many scientists consider IE to be a specific form of sepsis, as evidenced even by its old name -"prolonged septic endocarditis" (from the Latin sepsis lenta).
IE is characterised by a high incidence of 3-15 per 100 thousand, with mortality in the surgical treatment of IE reaching 15-30%, and patients die without treatment [2].IE is the fourth most important cause of death in infectious diseases after urogenic sepsis, pneumonia and intra-abdominal sepsis.IE is also characterised by a high incidence of mitral valve (MV) damage, which reaches 45% and ranks second after the incidence of aortic valve damage [3].
Over the past decade, researchers from many countries have published scientific reports on the increase in the incidence of IE by 6-8 times [4].This is facilitated by such current factors as an increase in the number of cardiac surgeries, including valve replacement, after which IE develops in 1.2-9.5% of patients; widespread use of invasive instruments inserted into the heart and blood vessels (in 40% of patients, IE is preceded by medical or diagnostic instrumental procedures); and the threatening spread of injection drug addiction.
The risk factors for MC lesions in various clinical forms of IE include population ageing; congenital and acquired pathology of intracardiac structures; invasive diagnostic and therapeutic medical procedures such as renal replacement therapy [5]; and an increase in the number of HIV-infected people who inject drugs.
Scientists note that men suffer from IE 2-3 times more often than women.IE can occur at any age, but it is most often detected in patients aged 20 to 50 years [6].
The current progress in antimicrobial therapy does not completely solve the problems of timely diagnosis and selection of the best tactics and surgical techniques for the treatment of IE, and therefore, there is no reduction in mortality and complications from IE, even after surgical treatment of infected MC.
Thus, EI remains a disease potentially life-threatening, so further scientific research by researchers remains relevant in order to ensure its timely prevention, rapid diagnosis, effective treatment and timely detection of complications.
The aim of the study was to determine the etiopathogenetic risk factors for the development of IE, taking into account demographic and gender characteristics in patients undergoing MI surgery.

Materials and methods
The study included 107 patients with IE.The age of the patients ranged from 20 to 76 years, with a mean age of (50.6 ± 4.8) years.There were 74 men (69.2%)UJCS.2023 November/December; 90 (6)

Український журнал клінічної хірургії
The Ukrainian Journal of Clinical Surgery and 33 women (30.8%).All patients were treated at the Amosov National Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine for MV lesions in the setting of IE.A comparative analysis of the causes and risk factors for the development of IE, which could create unfavourable prerequisites in the perioperative period, was performed.Depending on the surgical treatment performed, patients were divided into two groups: experimental -67 patients who underwent organ-preserving surgery on the MV (its plasticity), and control -40 patients who underwent MV prosthetics.In both groups, the following factors were analysed: gender, age, the most common causes and risk factors for the development of IE.The material for study and analysis was based on data from primary medical records: medical histories, primary medical records, data from physical, clinical, laboratory and instrumental examinations provided for by the standards of inpatient care.
The materials used in the study do not violate the principles of bioethics and can be published (extract from the minutes of the meeting of the Bioethics Committee No. 02578 of 03.09.2021).All patients who participated in the study signed an informed voluntary consent.
To analyse the statistical significance of intergroup differences, the χ² test with the Yates correction and the significance level of 0.05 were used.

Results
The average age of men was (50.4 ± 5.8) years, and of women (51.2 ± 8.7) years.Thus, women were on average 0.8 years older than men, i.e. men on average were almost a year earlier than women in developing IE (Table 1).
Table 1 shows that the study and control groups are comparable in terms of gender: in the study group, women are on average 1.2 years older than men, and in the control group, 1.6 years older.
The anamnestic data from the primary medical records were analysed and the causes that led to the development of IE were established (Table 2).
Based on the analysis of the data in Tab. 2, a rating of the most common causes of IE in the study sample of patients was formed: the cause of IE was not established in the anamnesis -30.8%; bronchopulmonary pathology -18.7%; urological pathology -12.1%; general surgical diseases -10.3%;COVID-19 -8.4%; drug use -8.4%; cooling -5.6%; odontogenic pathology -4.7%; obstetric and gynaecological diseases and nosocomial infections were not encountered.
A comparative analysis of the prevalence of the causes of IE between the groups showed that in the study group there were no patients in whom odontogenic pathology

Український журнал клінічної хірургії
The Ukrainian Journal of Clinical Surgery caused the development of IE, and in the control group the number of such patients was 12.5% (p = 0.01, χ 2 = 6.20).This can be explained by the fact that the control group included patients who underwent MV prosthetics, and therefore, valve-preserving operations were not possible in them.It is also known from the literature that oral cavity sanitation is mandatory before surgical intervention on the heart and great vessels, which is recognised and implemented in the practice of the world's leading cardiac surgery centres [7,8].The incidence of other causes of IE in the comparative analysis between the study and control groups did not differ statistically significantly (p  0.05).
The causes of IE development between the groups were also analysed, taking into account the sex of the patients.It was established that in the control group, 5 (16.1%) men developed IE on the background of odontogenic pathology, and among men in the study group, such a cause of IE was not recorded (p = 0.024, χ 2 = 5.10).Comparison of the causes of IE development among patients in the study and control groups showed that the frequency of bronchopulmonary pathology in women of the study group (29.2%) was statistically significantly higher (p = 0.002, χ 2 = 9.18) than in women of the control group (11,1%), and the incidence of IE after COVID-19 in patients of the control group was 33.4%, and in patients of the study group -8.3%, indicating the statistical significance of the difference (p = 0.001, χ 2 = 17.60).
The etiological risk factors for the development of IE in the study groups were further analysed (Table 3).
When studying the structure of the most common etiological risk factors for the development of IE, it was found that degenerative (47.7%) and primary (42.1%)IE were the most common.At the same time, primary IE was most often detected in patients of the study group -47.8%, and in the control group this figure was 32.5% (p = 0.03, χ 2 = 4.25).The incidence of other etiological risk factors for the development of IE in the study and control groups was not statistically significant (p  0.05).
The etiological risk factors for the development of IE were analysed taking into account the sex of patients (Table 4).
A comparative analysis of the etiological factors of IE development between the groups, taking into account the sex of patients, revealed that the incidence of primary IE in men of the study group was 46.5% and was statistically significantly higher than in the control group -29.0%(p = 0.03, χ 2 = 4.57).Whereas, the incidence of degenerative (or secondary) IE was statistically significantly higher in men of the control group -61.3% (p = 0.05, χ 2 = 3.83).The incidence of other etiological factors in patients of the study and control groups did not differ statistically significantly by sex (p  0.05).

Discussion
As a result of the analysis of socio-demographic factors of IE development in patients undergoing MI surgery, it was

Український журнал клінічної хірургії
The Ukrainian Journal of Clinical Surgery found that in the study sample (n = 107) the number of men (69.2%) prevailed over the number of women (30.8%) statistically significantly (p = 0.001, χ 2 = 28.40).The data obtained complement the results of studies by foreign authors on the establishment of gender and age characteristics in patients undergoing UC surgery [6,9].It was also found that the average age of the study participants was (50.6 ± 4.8) years: men -(50.4 ± 5.8) years, women -(51.2 ± 8.7) years, i.e. women were on average 0.8 years older than men.In the groups, women were also older than men: in the experimental group -by an average of 1.2 years, and in the control groupby an average of 1.6 years.
The rating of the most common causes of IE in the study sample of patients was determined: bronchopulmonary pathology -18.7%; urological pathology -12.1%.The cause of IE was not established from the anamnesis in 31.8% of patients.It was found that odontogenic pathology did not cause the development of IE in patients of the study group, and in the control group it was noted in 12.5% of patients (p = 0.01, χ 2 = 6.20).The data obtained confirm the recommendations of foreign authors on the mandatory sanitation of the oral cavity of patients before surgery on the heart and great vessels, which has been introduced into the practice of leading cardiac surgery centres in the world [7,8].It was found that the incidence of bronchopulmonary pathology in women in the study group was 29.2% and was statistically significantly higher than in patients in the control group -11.1% (p = 0.002, χ 2 = 9.18).The incidence of IE after COVID-19 in patients of the control and study groups was 33.4 and 8.3%, respectively, and statistical analysis of the difference showed its statistical significance (p = 0.001, χ 2 = 17.60).
In the structure of etiological factors for the development of IE, the most common were secondary and primary IE.At the same time, primary IE was statistically significantly more common in patients of the study group (47.8%) than in patients of the control group (32.5%) (p = 0.03, χ 2 = 4.25).The incidence of primary IE in men of the study group was statistically significantly higher than in the control group (p = 0.03, χ 2 = 4.57), while the incidence of degenerative IE was statistically significantly higher in men of the control group (p = 0.05, χ 2 = 3.83).

Conclusions
The study established the frequency of the most common causes of IE development, taking into account the sex of patients.It was found that among patients with IE, the number of men statistically significantly prevails over the number of women (p = 0.001, χ 2 = 28.40).In patients who underwent MC prosthetics, the incidence of odontogenic pathology as a cause of IE is statistically significantly higher than in patients who underwent organ-preserving surgery (p = 0.01, χ 2 = 6.20).The incidence of bronchopulmonary pathology is statistically significantly higher in women who underwent organ-preserving surgery than in women who underwent MC prosthetics (p = 0.002, χ 2 = 9.18).The incidence of IE after COVID-19 in patients who underwent MC prosthetics is statistically significantly higher than in patients who underwent organ-preserving surgery (p = 0.001, χ 2 = 17.60).The incidence of primary IE in men who underwent organpreserving surgery is statistically significantly higher than in men who underwent MC prosthetics (p=0.03,χ 2 = 4.57), while they have a statistically significantly higher incidence of degenerative IE (p=0.05,χ 2 = 3.83).
Thus, the results of the study prove the importance of age and gender characteristics of patients undergoing surgical treatment for MC lesions in the setting of IE, as they affect the choice of surgical intervention technique.
Funding.This work is a fragment of the research work of the Department of Internal Medicine No. 1 on the topic "An integrated approach to symptom control, immediate and long-term prognosis in the conditions of comorbid pathology in the clinic of internal diseases and the practice of a family doctor" of the Ternopil Gorbachevsky National Medical University.
Authors' contribution.Soltani SE -design, collection and processing of material, writing the text, preparation of the article for publication; Yarema NI -definition of the purpose, concept of the study, formulation of conclusions.
Conflict of interest.The authors have declared that they have no conflict of interest.
Consent for publication.Both authors have read and approved the final version of the manuscript and agreed to its publication.

Table 4 .
The