Infl uence of concomitant pathology on the clinical course of ischemic mitral regurgitation and on the choice of mitral valve surgical correction tactics

Objective. To determine the features of the clinical course of ischemic mitral regurgitation depending on the surgical correction of the mitral valve. Materials and methods. The study involved 140 patients with ischaemic mitral regurgitation (99 men and 41 women) who underwent myocardial revascularisation and mitral valve reconstruction – its plastic (experimental group) or prosthetic (control group). The average age of the patients was (65.9 ± 4.0) years. All patients had a history of coronary heart disease and ischaemic mitral regurgitation. The data of primary medical records were analysed: medical histories, primary medical records, physical, clinical,

Ischaemic mitral regurgitation (IMR) is a heart disease characterised by incomplete closure of the mitral valve (MV), which leads to backflow of blood from the left ventricle (LV) into the left atrium during systole [1].This is accompanied by a systolic murmur that is heard at the apex of the heart and often radiates to the left axilla.IMR is a common valve abnormality (more than 2%) and has various causes, including congenital diseases, rheumatic fever, and degenerative valve changes [1].The involvement of MCs can be primary (organic IMR) or secondary (functional IMR).Primary MR occurs when the mitral annulus is ruptured as a complication of myocardial infarction (MI).Secondary MR develops in structurally normal mitral leaflets and chords due to imbalance between the forces of its closure and gravity secondary to abnormalities in LV geometry [2,3].According to the evidence, both types of IMR are associated with critical stenosis (>70%) of at least one major coronary artery [3].Secondary IMR is most often observed in ischaemic cardiomy-opathy.Compared with degenerative mitral insufficiency, the degree of mitral annular dilatation in IMR is much less [4].The anatomical and pathophysiological mechanisms of the development and progression of IMR are still not fully understood.It is known that LV remodelling due to severe myocardial ischaemia is the main factor that triggers the pathophysiological process along with the involvement of papillary muscles.Therefore, the cause of IMR is the effect of spatial displacement of the MV apparatus due to LV geometry disorders or due to the direct effect of ischemia on myocardial contractility.The displacement of the papillary muscles, which results in greater tension of the MV leaflets, usually occurs in the posterolateral and apical directions, which explains why the lower location of acute MI can cause more significant IMR, while the frequency of significant IMR in the anterior location of acute MI is much lower [3].Identification of the etiology of mitral regurgitation in coronary heart disease (CHD) is difficult, as a significant proportion The Ukrainian Journal of Clinical Surgery of patients already had preexisting mitral regurgitation of degenerative genesis [4].
Today, IMR is considered to be one of the most difficult complications in the treatment of patients with coronary artery disease, which is known to significantly affect the duration and quality of life [5,6].IMR is a common complication of the clinical course of CHD.Usually, the presence of IMR in patients significantly worsens the prognosis for life compared to patients with only CHD, which is directly related to IMR and affects its severity [7].In patients, the acute phase of MI is often complicated by IMR, which usually indicates a poor prognosis.
Thus, based on the pathogenetic basis of UTI development from its etiology to diagnostic assessment and choice of treatment tactics, the importance of early detection of this pathology and appropriate intervention for optimal clinical outcomes is clear.
The aim of the study was to establish the peculiarities of the clinical course of IMR depending on the surgical correction of MC.

Materials and methods
The study involved 140 patients with STEMI, 99 men and 41 women, who underwent myocardial revascularisation and MV repair/prosthetics.The age range of study participants was 45 to 84 years, with a mean age of (65.9 ± 4.0) years.
The data of primary medical records were analysed: medical histories, primary medical records, physical, clinical, laboratory and instrumental examinations, as well as protocols of surgical interventions.Depending on the surgical intervention performed on the MC for IMR, patients were divided into two groups: experimental -69 patients who underwent organ-preserving surgery on the MC, namely its plastic, and control -71 patients who underwent MC prosthetics.
The materials used in the study do not violate the principles of bioethics and can be published.All patients who participated in the study signed an informed voluntary consent.Statistical analysis was performed using the test with the Yates correction.Differences between the study groups were considered statistically significant if the significance level was 0.05.

Results
During the clinical trial, it was found that the main cardiovascular complaints of patients before surgical treatment were shortness of breath, heart pain, nosebleeds, haemoptysis, dizziness, peripheral edema, decreased tolerance to physical activity, chest heaviness, shortness of breath, etc. (Table 1).

The Ukrainian Journal of Clinical Surgery
According to Table 1, the frequency of the most common complaints of patients in the study and control groups was similar (p 0.05).
Next, we analysed the presence of MI, mitral insufficiency and its severity, arterial hypertension (AH) and other comorbidities in the history of the study participants, which are known to have a significant adverse effect on the prognosis in patients with MI in the setting of CHD [8-10] (Table 2).
As shown in Table 2, patients in the study groups were diagnosed with mitral insufficiency of varying severity.Severe mitral insufficiency (30 -59 ml) prevailed, with an average frequency of 90% in the sample, 82.6% in the study group, and 97.2% in the control group (p = 0.03; 2 = 4.69).The incidence of moderate mitral insufficiency was statistically significantly higher in the study group (13.0%) than in the control group (2.8%) (p = 0.05, = 3.74), which confirms the irreversible nature of morphological changes in mitral insufficiency and IMR.
The presence of a history of MI in patients indicates an unfavourable prognosis in CHD and MVD.It was found that the incidence of MI was statistically significantly higher in patients of the control group (64.8%) than in patients of the study group (46.4%) (p = 0.04, = 4.09).
Further, we studied the anamnestic data of the study participants regarding the presence of hypertension, which can also lead to the development of LV remodelling or accelerate it.In this sample, 93.6% of patients had hypertension: 97.1% in the study group and 90.1% in the control group (p 0.05).The frequency of hypertension was analysed according to its current classification.It was found that the incidence of grade II hypertension was statistically significantly higher in the study group (49.3%) than in the control group (25.4%) (p = 0.01, = 6.08).And the incidence of grade III hypertension was statistically significantly higher in the control group (64.8%) than in the study group (46.4%) (p = 0.008, = 6.93).This indicates that in patients undergoing MC prosthetics, hypertension debuted at an earlier age (39.5 years) and, accordingly, lasted longer (27.3 years), and therefore, hypertension for a longer period of time influenced the development or acceleration of LV remodelling, which causes IMR.

Discussion
The analysis of the complaints of the study participants revealed that the complaints of the bond group dominated: shortness of breath with minor physical activity, which was experienced by the majority of patients, but the frequency of this complaint in the groups did not differ statistically (p 0.05); pain in the sternum and heart, the most common variant was recurrent pain in the sternum, but the frequency of this complaint in the study groups also did not differ statistically significantly (p 0.05).
Among the complaints of the optional group were: cyanosis during physical activity, this complaint was reported by only 7.1% of patients, its frequency was not characterised by a statistically significant difference between the study groups (p 0.05); peripheral edema, noted by 39.3% of patients, this complaint had the same frequency in the study groups (p 0.05); The Ukrainian Journal of Clinical Surgery a decrease in exercise tolerance was observed in all study participants; there was no statistically significant difference in the frequency of this complaint between the groups (p 0.05).
The neurotic group of complaints varied greatly depending on the comorbidities present, with no statistically significant differences in the frequency of these complaints in the study groups (p 0.05).
The analysis of the groups of complaints of the study participants showed the correspondence of the results obtained with those of other researchers who also studied the features of the clinical course of UTI [11,12].
By analysing the concomitant pathology, the features that definitely influenced the clinical course of the IMR, accelerating the development of LV remodelling, were identified.According to echocardiography, mitral insufficiency of varying severity was diagnosed and its frequency was analysed.It was found that the vast majority of patients had severe mitral insufficiency, and its frequency was statistically significantly higher in patients who underwent MV prosthetics (p = 0.03; = 4.69).The incidence of moderate mitral insufficiency was statistically significantly higher in patients who underwent organ-preserving MV surgery -its plasticity (p = 0.05, = 3.74).This difference clearly indicates that MV prosthetics was performed exclusively in the presence of significant irreversible morphological changes, which consisted of LV remodelling and eventually led to mitral insufficiency and IMR [3,4].
The analysis of patients' history of MI revealed statistically significant patterns in its frequency between the study groups.It was found that the incidence of MI was statistically significantly higher in patients who underwent MC prosthetics (p = 0.04, = 4.09).
The study of the prevalence of hypertension as a comorbidity revealed that this rate was 93.6%.Differences in the incidence of grade II and grade III hypertension in the study and control groups were also found.Thus, the incidence of grade II hypertension was statistically significantly higher in the study group -49.3% (p = 0.01, = 6.08), and the incidence of grade III hypertension was statistically significantly higher in the control group -64.8% (p = 0.008, = 6.93).The established statistically significant patterns prove that patients in the control group had a long period and more clinically justified reasons for the development of LV remodelling or its acceleration, which is the main pathogenetic mechanism of IMR [1,10].

Conclusions
The study revealed the peculiarities of the influence of concomitant pathology on the clinical course of IMR and the choice of tactics for surgical correction of MC.It was found that the clinical picture was dominated by the complaints of the bonded group: dyspnoea with mild physical exertion and pain behind the sternum and in the heart.The clinical features of the course of IMR in the setting of CHD that distinguished patients in the control group from patients in the experimental group were determined: the onset of hypertension occurred 4.8 years earlier and, accordingly, its duration was 5.7 years longer; statistically significantly higher rates of grade III hypertension (p = 0.008, = 6.93),MI (p = 0.04, = 4.09) and severe mitral insufficiency (p = 0.03; = 4.69).
Thus, the results obtained demonstrate that patients undergoing MV prosthetics had more significant morphological changes due to concomitant pathology: Hypertension, MI and mitral insufficiency, as they affect the geometry of the LV and the rate of development of its hypertrophy, and therefore are important when choosing a method of surgical correction of MV.
Funding.This work is a fragment of the research work of the Department of Surgery #2 of the Ternopil Gorbachevsky National Medical University "Mitral regurgitation in coronary heart disease, algorithm of diagnosis and surgical treatment" (state registration number 0119U002806, years of implementation 2020 -2024).
Authors' contribution.Moroz V. S. -objective, study design, collection of clinical material, writing the text, revision of the article, preparation of the article for publication, conclusions; Lazoryshynets V. V. -concept, idea.
Conflict of interest.The authors who participated in this study have declared that they have no conflicts of interest regarding this manuscript.
Consent for publication.All authors have read and approved the final version of the manuscript.All authors have agreed to the publication of this manuscript.
Ethical aspects.All procedures performed in the study with the involvement of patients complied with ethical standards for clinical practice and the Declaration of Helsinki, 1964, as amended.