RU2704956C1 - Method for predicting the risk of the unfavorable outcome in the patients suffering ischemic heart disease within the year following coronary arterial bypass - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to cardiology, and can be used for prediction of risk of unfavorable outcome in patients with ischemic heart disease within a year after coronary artery bypass. Patients with ischemic heart disease on the first day of admission to hospital, prior to coronary artery bypass grafting, by flow cytofluorometry, phenotyping TLR9 in peripheral blood monocytes, %, using monoclonal antibodies. A prognostic coefficient K is calculated by formula: K = exp (-11.7 + 0.15 * x)/(1 + exp (-11.7 + 0.15) * x)), where K is a prognostic coefficient reflecting a probability of developing a negative cardiovascular event, and x is a value of the initial expression of TLR9 by monocytes, %. Constant value 11.7 and coefficient 0.15 before variable x are obtained by logistic regression by experimental method. At value K ≥ 0.639 predict a high risk of developing a negative cardiovascular event in the year following coronary artery bypass grafting. If K < 0.639, the risk of developing a negative cardiovascular event is low.

EFFECT: method provides predicting a risk of developing a negative cardiovascular event in patients with ischemic heart disease within the year following coronary artery bypass grafting due to patient's phenotyping TLR9 in peripheral blood monocytes using monoclonal antibodies and calculating prognostic coefficient by formula obtained by logistic regression method.

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Description

The invention relates to medicine, namely to cardiology and can be used to predict an adverse outcome in patients with coronary heart disease within a year after coronary artery bypass grafting (CABG).

Currently, surgical is recognized as an effective method for the treatment of coronary heart disease, and coronary artery bypass graft is a variant of it. This treatment method, in terms of annual performance, is in second place compared to coronary stenting (36035 and 180948 cases, respectively) (see Bokeria L.A., Milievskaya E.B., Kudzoeva Z.F., Pryanishnikov V.V. Cardiovascular Surgery - 2017. Diseases and congenital malformations of the circulatory system. M: NIICSSH named after AN Bakulev of the Ministry of Health of the Russian Federation; 2018. 252 p.).

According to various literature, during coronary artery bypass grafting in the distant postoperative period (on average after 1 year), less sudden cardiac death, recurrent myocardial infarction, and the occurrence of unstable angina are noted than during percutaneous coronary intervention (see The adequacy of myocardial revascularization in patients with multivessel coronary artery disease disease Zimarino, Marco et al. International Journal of Cardiology, Volume 168, Issue 3, 1748-1757).

Moreover, the question of the cause of these complications is debatable, which led to the development of various specialized scales for assessing the risks of both hospital and long-term adverse outcomes.

For example, one of the commonly used scales is EuroScore, which estimates hospital mortality after coronary artery bypass grafting, regardless of the type of circulatory support. This scale includes such predictors as age, gender, chronic lung disease, impaired mobility, damage to other non-coronary arterial vessels, creatinine clearance, the presence of insulin-dependent diabetes mellitus, active endocarditis, high functional class angina, recent myocardial infarction, left ventricular ejection fraction, pulmonary hypertension, urgency of intervention, heart surgery.

However, this tool, due to its multi-component nature, underestimates the risk in patients with comorbid pathology, and underestimates it in high-risk patients, because basically, the scale was developed for patients with low and intermediate risk (see Belyalov F.I. Forecasting and scales in cardiology. M: MEDpress-inform. 2019. 208 p.).

According to various literature sources, cardiac complications such as sudden cardiac death, unstable angina pectoris, myocardial infarction in patients undergoing coronary bypass surgery are associated not only with the patient's comorbidity, but also directly with the progression of atherosclerosis.

The theory of immune inflammation in the development of atherosclerosis is not in doubt. As you know, innate immunity, which mediates the activation of an adaptive immune response, triggers this process. The primary link in the activation of innate immunity is its receptor apparatus, namely, toll-like receptors (TLRs). These molecules perform not only a receptor function, but also are signal systems for the implementation of protective reactions.

For example, a toll-like receptor-TLR9 is expressed on the membrane of endosomes and, when recognizing a pathogen, triggers a cascade of synthesis of pro-inflammatory cytokines involved in the progression of atherosclerosis. In this connection, the assessment of TLR9 expression on monocytes can serve as a reliable marker of the progression of atherosclerosis and a tool for assessing cardiac complications after coronary artery bypass grafting.

A known method for early prediction of the risk of thromboembolic complications in patients after coronary artery bypass grafting, based on determining the level of tumor necrosis factor α (TNF-α), interleukin 10 (IL-10) and matrix metalloproteinase 1 (MMP-1), before surgery and on the first day after surgery (see patent RU 2657760 C1, publ. 06/15/2018, Bull. No. 17). When determining the level of IL - 10 above 65 pg / ml in the preoperative period and above 230 pg / ml on the first day after surgery, TNF-α above 24 pg / ml and MMP-1 above 3.3 ng / ml in the preoperative period and after operations predict a high risk of thromboembolic complications. However, this method is quite laborious and financially expensive. In addition, the level of these markers may vary depending on the therapy, for example, glucocorticoids and antibacterial drugs.

More often, to predict an unfavorable outcome in patients after coronary bypass surgery, methods are applied that take into account various factors, not only laboratory, but also anamnestic, data from instrumental studies.

For example, there is a known method for assessing the risk of adverse cardiovascular complications in patients after myocardial infarction who underwent coronary artery bypass grafting for a ten-year period after the intervention (see patent RU 2347526 C1, publ. February 27, 2009, Bull. No. 6). This method takes into account the fact of smoking, the level of low and high density lipoproteins, the level of triglycerides, multivascular damage to the coronary arteries, the fact of incomplete revascularization, an indicator of exercise tolerance, the value of the final diastolic pressure. A high risk of cardiovascular complications was recorded when the patient had 6 factors or more. This method is very indicative, and is based on indicators whose values can vary over a short period of time.

The technical result of the invention is the development of a method for predicting the risk of developing a negative cardiovascular event in patients with coronary heart disease during the year of observation after coronary artery bypass grafting.

The technical result is achieved by the fact that patients with coronary heart disease on the first day of admission to the hospital, before coronary artery bypass grafting, blood is taken from the ulnar vein, flow cytofluorimetry is used to carry out phenotyping of TLR9 in peripheral blood monocytes (%) using monoclonal antibodies and calculate prognostic coefficient - K by the formula:

K = exp (-11.7 + 0.15 * x) / (1 + exp (-11.7 + 0.15 * x)), where

K - prognostic coefficient, reflecting the likelihood of a negative cardiovascular event

x is the value of the initial expression of TLR9 by monocytes in%.

A constant value of -11.7 and a coefficient of 0.15 before the variable x were obtained experimentally by logistic regression and, with a value of K≥0.639, a high risk of developing a negative cardiovascular event is predicted one year after coronary bypass surgery, if K <0.639, then the risk of development negative cardiovascular event is low.

The method is as follows.

In patients with coronary artery disease before coronary bypass surgery, on the first day of admission to the hospital, blood is taken from the ulnar vein, TLR9 phenotyping is performed in peripheral blood monocytes by flow cytofluorimetry in% (x) and according to the formula:

K = exp (-11.7 + 0.15 * x) / (1 + exp (-11.7 + 0.15 * x)) calculate the prognostic coefficient K. If K≥0.639, then the risk of developing a negative cardiovascular event is years after surgery, high, if less than 0.639, then low.

When conducting an analysis of patent and literature sources of fame for this method was not identified.

The novelty of the method lies in the fact that it allows even before surgery to assess the risk of an adverse outcome in patients with coronary heart disease within a year after coronary artery bypass grafting.

At the stage of development of the proposed forecasting method, the following steps were carried out.

When collecting an anamnesis in patients undergoing coronary bypass surgery, the absence of malignant neoplasms, rheumatological diseases, infectious-inflammatory and allergic processes was clarified.

The presence of these diseases was the criterion for not including the patient in further observation.

In patients before surgery, on the first day of admission to the hospital, in the morning on an empty stomach, from the ulnar vein, blood was drawn into a test tube with a preservative of ethylenediaminetetraacetic acid (EDTA). Monocytes were isolated on a density gradient of ficoll-verographin 1.077 g / ml.

Next, the isolated cells were permeabilized using a reagent manufactured by Immunotech according to the manufacturer's instructions.

To determine the expression of TLR9, cells were incubated with CD14-FITC / CD289-PE labeled antibodies manufactured by Beckman Coulter for 30 minutes at 4 ° C, then washed at 1200 rpm at 4 ° C and fixed with BDCellFix solution.

Further, the percentage of double positive cells expressing TLR9 was taken into account on a Cytomics FC 500 cytofluorimeter. Among individuals not suffering from clinical manifestations of atherosclerosis, the average TLR9 value on monocytes is 13.2 ± 1.7%.

Coronary bypass surgery was performed.

Then, 11-12 months after surgery, patients were invited for a follow-up visit. During the visit, they clarified the presence of myocardial infarction, sudden cardiac death (by telephone with a relative), unstable angina.

If there were indications, ECG tests with dosed physical activity were performed, with positive results, coronary angiography was performed.

After the second visit, the patients were divided into two groups: the first (n = 18) - there are negative coronary events, the second (n = 29) - there are no negative coronary events.

In patients of the first group, after performing coronary bypass surgery, myocardial infarction occurred in 3 people, 7 patients developed unstable angina, 3 patients died (sudden cardiovascular death), 3 patients developed a life-threatening rhythm disturbance (jogging of ventricular tachycardia), and 2 patients had shunt failure. After discharge from the hospital, patients took multicomponent therapy during the entire observation period.

In the second group of negative cardiovascular events, there were no ischemic changes during stress stress ECG tests.

In retrospect, taking into account the rank of patients (patients of group 1 are ranked 1 (event is), and group 2 is 0 (no event)), the obtained TLR9 values were processed by statistical analysis using the Statistica 12.0 program (StatSoft, USA).

A statistically significant difference was recorded between the two groups according to the initial TLR9 value. In group 1 before surgery, the TLR9 value (%) was 81.5 ± 1.9%, in group 2, this indicator was 72.1 ± 3.3%. The level of statistical significance was p = 0.049.

At the next stage, an equation for calculating the probability of developing adverse cardiovascular events was obtained by the method of logistic regression.

For this, the rank of the patient (1/0) was used as a grouping variable depending on the presence or absence of a negative cardiovascular event, and the initial values TLR9,%, which were determined before surgery, acted as a dependent variable (predictor).

The resulting equation was:

K = exp (-11.7 + 0.15 * x) / (1 + exp (-11.7 + 0.15 * x)), where

K - prognostic coefficient, reflecting the likelihood of a negative cardiovascular event

x - expression (content) of TLR9 in monocytes, expressed in%, before surgery;

a constant value of -11.7 and a coefficient of 0.15 in front of the variable x, obtained by experimental logistic regression.

Substituting the initial value of TLR9 expression in monocytes, expressed in%, determined before surgery, you can calculate the value of the probability of the development of adverse cardiovascular events in the first 12 months of observation after coronary artery bypass surgery.

Figure 1 shows the logit regression curve of the development of a negative cardiovascular event in patients with coronary artery disease in the long-term follow-up after coronary bypass surgery, depending on the initial value of TLR9 expression before coronary bypass surgery, illustrates the obtained dependence.

Figure 2 shows the ROC curve for determining the risk of a negative cardiovascular event in the long-term follow-up in patients with coronary artery disease after CABG according to the initial level of expression of TLR9,% before cardiac surgery.

At the final stage, the method of ROC analysis determined the threshold value of the coefficient K to form a conclusion on the prognosis of a negative cardiovascular event in patients with coronary heart disease within 12 months of observation after CABG. The threshold value of K is 0.639. If K≥0.639, then the risk of developing a negative cardiovascular event in patients with coronary heart disease in the long-term follow-up after CABG is high, if less than 0.639, then low. Diagnostic sensitivity 76.9%, specificity 96.7%. The area under the ROC curve is 0.88 ± 0.0475 (p <0.0001). The good quality of the test for the forecast was determined.

Here are clinical examples of the application of the method

Clinical example 1.

Patient A., 58 years old.

He entered the Department of Cardiac Surgery 11/24/2017, with complaints of pressing, compressing pain in the heart, radiating to the left arm, aggravated by physical exertion. Coronary heart disease for 20 years. In 1998, he suffered a myocardial infarction.

Accepts long-term therapy: angiotensin converting enzyme inhibitors, antiplatelet agents, statins, beta blockers, aldosterone receptor blockers. Over the past month, therapy has no effect.

Patient completed:

- Ultrasound of the heart. There is no left ventricular myocardial hypertrophy. The cavities of the heart are not dilated. Ejection fraction of 50%. Sealing of the aortic wall, valves AK, MK. Zones of hypokinesis of the lower basal and lower median segments. Right cameras are not changed. No evidence of pulmonary hypertension.

- Daily ECG monitoring - sinus rhythm. Supraventicular tachycardia is recorded, maximum heart rate of 150 per minute, 5 episodes. A diagnostically significant depression of the ST segment up to 2 mm was registered, accompanied by a feeling of discomfort behind the sternum, shortness of breath.

- Using the method of flow cytofluorimetry, the expression of TLR9, in% on monocytes, was studied. The results revealed a significant increase in this indicator TLR9,% - 99.1, which indicates the activation of this receptor on monocytes and the maintenance of the synthesis of pro-inflammatory cytokines.

- Coronaroangiography - stenosis of the trunk of the left coronary artery in the distal third of 60%. Stenosis of the proximal third of the anterior interventricular branch of 70%. Stenosis of the proximal third of the envelope branch of the left coronary artery 70%. Stenosis of the mouth of a branch of a blunt margin of 80%. Stenosis of the right coronary artery in the middle third of 50%. Critical stenosis of the posterior interventricular branch 99%.

The main clinical diagnosis is coronary heart disease. Angina pectoris functional class III. Postinfarction cardiosclerosis (1998) Atherosclerosis of the coronary arteries, multivascular lesion. Hypertension of the III stage, 2 degrees, the risk of cardiovascular complications is very high. Complications - chronic heart failure with a preserved ejection fraction. Stage IIA. Functional class III.

For this patient, on the first day of admission to the hospital, before CABG surgery, a prognostic coefficient (K) was calculated, which reflects the probability of an adverse outcome within 12 months, according to the formula: K = exp (-11.7 + 0.15 * 99, 1) / (1 + exp (-11.7 + 0.15 * 99.1)) = 0.96.

According to a mathematical calculation, the patient has a forecast coefficient of 0.96, i.e. To≥0.639, the risk of an adverse outcome is rated as high.

Taking into account damage to the coronary bed, on November 27, 2017, the patient underwent direct myocardial revascularization - mammary coronary artery bypass grafting with the anterior interventricular branch, sequential shunting of the diagonal and dull margin branches.

After 10 months, 07/23/2018, the patient turned to a cardiologist at Rostov State Medical University, complaining of shortness of breath, paroxysmal pain, compressive in nature, occurring in the heart region during exercise. The patient was hospitalized in the cardiac surgery department, where the indications for coronary angiography were determined. According to the results of this study, a shunt was found unsuccessful.

Thus, the determination of the expression of TLR9,% on monocytes, showed its prognostic ability.

Clinical example 2.

Patient G., 53 years old.

11/09/17, he entered the Department of Cardiac Surgery with complaints of severe shortness of breath while walking a distance of 150 meters, heart palpitations. From the anamnesis it is known that coronary heart disease for 7 years. Accepts standard therapy according to clinical recommendations. Exercise tolerance decreased.

Patient completed:

- Ultrasound of the heart. There is no left ventricular myocardial hypertrophy. The cavities of the heart are not dilated. The ejection fraction is 54%. Sealing of the aortic wall, valves AK, MK. Regurgitation on MK 1 tbsp. Right cameras are not changed. No evidence of pulmonary hypertension. Additional chord of the left ventricle.

- Daily ECG monitoring. Sinus rhythm. A single episode of atrial fibrillation with a heart rate of 180 per minute is not excluded. 2 episodes of diagnostically significant ST segment depression of up to 4 mm were recorded, accompanied by a feeling of lack of air.

- Using the method of flow cytofluorimetry, the expression of TLR9, in% on monocytes, was studied. The results revealed a significant increase in this indicator TLR9,% - 40.3, which indicates increased expression of this receptor on monocytes and maintaining the production of pro-inflammatory cytokines.

- Coronaroangiography - stenosis of the trunk of the left coronary artery in 70%. Diffuse lesion of the anterior interventricular branch with stenosis up to 90%. Diffuse lesion of the envelope branch of the left coronary artery with stenosis up to 90%. Occlusion of the proximal third of the right coronary artery.

The main clinical diagnosis is coronary heart disease. Angina pectoris functional class III. Atherosclerosis of the coronary arteries, multivascular lesion. Hypertension of the III stage, 3 degrees, the risk of cardiovascular complications is very high. Complications - chronic heart failure with a preserved ejection fraction. IIA stage. Functional class III.

For this patient, on the first day of admission to the hospital, prior to CABG surgery, a prognostic coefficient (K) was calculated, which reflects the probability of an adverse outcome within 12 months, according to the formula: K = exp (-11.7 + 0.15 * 44, 3) / (1 + exp (-11.7 + 0.15 * 44.3)) = 0.007.

According to the mathematical calculation, in this patient the prognosis coefficient is 0.007, i.e. To <0.639, the risk of an adverse outcome is rated as low.

Given the damage to the coronary bed, on November 13, 2017, the patient underwent direct myocardial revascularization - coronary bypass surgery with the anterior interventricular branch, sequential bypass surgery of the diagonal branch and the branch of the obtuse margin.

With a planned visit to a cardiologist after 12 months, 12/17/2018, the patient did not complain of shortness of breath. Increased exercise tolerance. A stress-ecg test was performed on treadmill, no ischemic changes were detected. The result of myocardial revascularization was assessed as satisfactory.

In this way, the prognosis of 123 patients was calculated.

The technical and economic effectiveness of the method lies in the fact that it allows you to calculate the risk of adverse cardiovascular events in patients with coronary heart disease in the first 12 months of observation after coronary artery bypass surgery.

Claims (3)

A method for predicting the risk of an adverse outcome in patients with coronary heart disease within a year after coronary artery bypass grafting, which consists in the fact that patients with coronary heart disease on the first day of admission to the hospital, before coronary artery bypass grafting, by flow cytofluorimetry, TLR9 phenotyping is performed in peripheral blood monocytes, % using monoclonal antibodies and calculate the prognostic coefficient K by the formula: K = exp (-11.7 + 0.15 * x) / (1 + exp (-11.7 + 0.15 * x)), where K is the prognostic coefficient reflecting the likelihood of a negative cardiovascular event, x is the value of the initial expression of TLR9 by monocytes,%, a constant value of 11.7 and a coefficient of 0.15 in front of the variable x are obtained by logistic regression experimentally and with a value of K≥0.639 a high risk of developing a negative cardiovascular event after a year of observation after coronary bypass surgery, if K <0.639, then the risk of developing a negative cardiovascular event is low.

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