FUNCTIONAL STATE OF KIDNEYS IN PATIENTS WITH IHD

. The aim of the study: to study the functional state of the kidneys in patients with ischemic heart disease (IHD) in the long-term period after myocardial revascularization. Material and research methods. The study included 160 patients with ischemic heart disease (IHD), hospitalized for coronary angiography and decisions on the appropriateness and choice of revascularization technique. The study did not include patients with eGFR less than 60 ml/min. All patients were prescribed standard IHD therapy. On the second day after the endovascular procedure, coronary angiography/percutaneous coronary intervention (CAG/PCI), all patients underwent determination of the blood creatinine concentration to identify patients who developed contrast-induced nephropathy (CIN). In dynamics, three months later, at the end of the first and second years of observation after revascularization, all patients underwent determination of the functional state of the kidneys: the concentration of blood creatinine, with the calculation of GFR, the concentration of parathyroid hormone, phosphorus, uric acid in the peripheral blood. According to the results of coronary angiography, 21 patients underwent surgical revascularization (coronary artery bypass grafting CABG) within a month after CAG. Endovascular revascularization (stenting of the coronary arteries) was performed in 139 patients. CIN in the early period after endovascular intervention was observed in 37 patients. The study showed that during 2 years of follow-up after coronary revascularization, there was a progressive decrease in eGFR: by the 3rd month, eGFR decreased by -17.39 ± 1.17%, by the end of the 1st year - by -43.62 ± 1.28%, by the end of the second year of follow-up - by -46.50 revascularization, the decrease in eGFR was significantly more pronounced than in patients who underwent coronary artery stenting (-51.80 ± 3.51% versus -42.39 ± 1.35%, p <0.05), and the differences increased even more during the second year of observation (-57.99 ± 4.75% versus -44.76 ± 1.89%, p <0.05). Violation of the functional state of the kidneys was manifested by an increase in the concentration of blood phosphorus, parathyroid hormone and uric acid. The concentration of these markers increased during observation in parallel with a decrease in eGFR. The concentration of these substances was higher in patients after CIN. compared with patients with an uncomplicated postprocedural period. The concentration of uric acid was initially higher in the group of patients who underwent CABG compared with patients who underwent percutaneous coronary intervention PTCI. Conclusion. revascularization, there is a significant decrease in the glomerular filtration function of the kidneys by the 3rd month after the endovascular procedure and lasts at least 2 years. The most significant decrease was observed in patients with diabetes mellitus, as well as in patients who underwent CIN in the early period after endovascular intervention. The progression of CKD continues to be accompanied by an increase in the concentration of parathyroid hormone, uric acid and blood phosphates.

Actuality: Ischemic heart disease (CHD) is today one of the most common non-infectious pathologies in the world. Its prevalence reaches 6% among people over 20 years old (up to 8% among men). [11]. Ischemic heart disease in any clinical form leads to the development of ischemic cardiomyopathy, which is the structural basis of chronic heart failure (CHF) and glomerulosclerosis, the structural basis of chronic kidney disease (CKD). This web of pathophysiological mechanisms is clinically defined as type II cardiorenal syndrome. The combination of CKD and chronic heart failure (CHF) significantly worsens the prognosis and quality of life of patients [3].
Correction of the cardiorenal syndrome is based on the effect on pathogenetic mechanisms: elimination of myocardial ischemia is carried out in two directionscoronary revascularization and pharmacological drugs aimed at reducing myocardial oxygen demand. However, even after coronary revascularization, the started pathogenetic circles do not stop, and it is possible that the processes of SCIENTIFIC COLLECTION «INTERCONF» | № 49 471 myocardial fibrosis themselves increase the apoptosis of cardiomyocytes and glomerulosclerosis [4,9].
The aim of the study: to study the functional state of the kidneys in patients with ischemic heart disease (IHD) in the long-term period after myocardial revascularization.
Material and research methods. The study included 160 patients with ischemic heart disease, hospitalized for coronary angiography and a decision on the feasibility and choice of revascularization technique. In 94 patients, the cause of hospitalization was exertional angina of FC III-IV, in 60 -progressive angina, 6 patients were admitted due to heart failure as a clinical form of coronary artery disease. Due to the limitations of the method and to achieve the goal of studying the pathogenetic features of type II cardiorenal syndrome, the study did not include patients with eGFR less than 60 ml/min. On average, the concentration of creatinine was 90.08 ± 1.72 µmol / L. All patients were prescribed standard CHD therapy (antiplatelet agent -aspirin or clopidogrel, and in the case of endovascular revascularization -dual antiplatelet therapy; beta-blocker, acetyl-CoA reductase inhibitor -atorvastatin).
On the second day after the endovascular procedure, coronary angiography / percutaneous coronary intervention (CAG/PCI), all patients underwent repeated determination of the blood creatinine concentration to identify patients who developed contrast-induced nephropathy (CIN). CIN was determined when creatinine concentration increased by 25% or more from the initial level. [7]. which, provided that even a short course of hemodialysis is necessary, increases the hospitalization period, as well as mortality, both during hospitalization and in the long-term period [10 , 2].
In the course of the analysis, in order to level the effect of CIN on analytical results, we formulated a hypothesis that a decrease in the functional ability of the kidneys develops gradually and may be associated with an endovascular procedure or surgical revascularization. For this purpose, patients with IHD were divided into groups, depending on the method of revascularization: the CABG group (21 patients) and the PTCI group (139 patients). Initially, eGFR in the groups was comparable and amounted to 105.66 ± 3.74 ml / min and 102.71 ± 1.59 ml / min, respectively (unreliable). By the 3rd month of follow-up, the dynamics of eGFR in the groups, depending on the revascularization method, did not differ (-16.36 ± 3.30% and -17.55 ± 1.25%, respectively), as a result, by the 3rd month eGFR observation in the CABG and PTCI groups was also comparable, although it also differed in the initial data (90.14 ± 6.05 ml / min and 86.46 ± 2.37 ml / min, respectively). Later, by the end of the 1st year of follow-up, the following pattern emerged: in patients who underwent surgical revascularization, the decrease in eGFR was significantly more pronounced than in patients who underwent stenting of the coronary arteries (-51.80 ± 3.51% versus -42, 39 ± 1.35%, p <0.05), and the differences increased even more during the second year of observation (-57.99 ± 4.75% versus -44.76 ± 1.89%, p <0.05 ). As a result, by the end of the second year of observation, eGFR in the CABG group was significantly lower than in the PTCI group (44.63 ± 5.37 ml / min versus 56.54 ± 2.01 ml / min, p <0.05). This pattern can be explained by the fact that in the CABG group there were more patients with diabetes -80.95% (17 patients out of 21) compared with PTCA patients -12.23% (17 patients out of 139, chi square = 49.83, p < 0.001). One of the manifestations of diabetic microangiopathy is nephropathy with impaired glomerular filtration.

THEORY AND PRACTICE OF SCIENCE: KEY ASPECTS 474
Diabetes mellitus is considered one of the main causes of renal failure and an independent predictor of the risk of progression of CKD [1].
Violation of the functional state of the kidneys was manifested not only by a decrease in the glomerular filtration rate, but also by an increase in the concentration of blood phosphorus, parathyroid hormone and uric acid (Table 1)

Conclusion.
The present study has demonstrated that in patients with IHD after revascularization, there is a significant decrease in the glomerular filtration function of the kidneys by the third month after the endovascular procedure and lasts for at least 2 SCIENTIFIC COLLECTION «INTERCONF» | № 49 475 years. The most significant decrease was observed in patients with diabetes mellitus, as well as in patients who underwent CIN in the early period after endovascular intervention. CKD progression continues for at least 2 years after revascularization and is accompanied by an increase in the concentration of parathyroid hormone, uric acid, and blood phosphates, which is a reflection of the cardiorenal syndrome.  Note: * -reliability of differences with the initial data, ^ -reliability of differences between groups at the stages of observation. One sign -p <0.05, two signs -p <0.01, three signs -p <0.001