RU2406091C2 - Method for risk evaluation of fatal outcome in myocardial infarction - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: for risk evaluation of fatal outcome in myocardial infarction, the patient's peripheral blood is analysed for haemoglobin concentration, leukocyte count in 1 mm³ and erythrocyte sedimentation rate; as well as two biochemical indices: aspartate aminotransferase activity and alanine aminotransferase activity; further, stratification intervals of the analysed values are determined; then in the intervals determined for each value the relative risks of fatal outcome is evaluated for each of 5 values. Thereafter, total relative risk is calculated by summing up the evaluated relative risks of each value, and total relative risk of 5.6 indicates the 20 % risk of fatal outcome in macrofocal myocardial infarction, 6.25 shows the 25 % risk, 9.5 - the 50 % risk, 11.4 - the 66.6 % risk.

EFFECT: invention provides the risk evaluation of fatal outcome of myocardial infarction and reduced percent of errors in estimated results of laboratory assessment.

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Description

The invention relates to medicine, namely to cardiology.

There is a method for determining the increased risk of death of myocardial infarction by recording the level of troponin I above 2 ng / ml, and the correlation of the increased risk of death with an increase in the level of troponin I is determined (Shamseev M.R., Bondareva Z.G., Aronov E.A. Acute coronary syndrome: diagnostic and prognostic value of troponin I and cardiospecific enzymes. Bulletin SB RAMS No. 3 (109), 2003). The disadvantage of this method is the lack of numerical information about the level of risk of death, which complicates the process of adopting the right tactics in the treatment process.

There is also a method for predicting the complications of a patient with myocardial infarction, in which according to the first days of myocardial infarction, taking into account the most unfavorable sign, arterial hypotension, as well as a history of stroke, shortness of breath on the 1st day with a respiratory rate of up to 2 per minute, less or more than 26 breaths per minute, taking into account the development of complete atrioventricular and intraventricular blockade on the 1st day of myocardial infarction, average ST segment elevation after thrombolytic therapy and the magnitude of the constant member of the regression equation, etc. usual analysis on a personal computer (RF patent №2197173). Moreover, if when solving the obtained discriminant equations, the reliability or overall percentage of correctness of which was 95.6%, the value of the first equation for surviving patients will be greater, then with a probability of 96.8% it is determined that this patient will survive an acute period of the disease, and if If the value of the second equation is higher, then with a probability of 78.6% they predict that a fatal outcome will occur in the acute period of myocardial infarction. The disadvantages of this method are the need to use computer equipment, special software and skills to work with the program, as well as the fact that the method does not quantify the risk of developing a fatal outcome, but unequivocally, with the possibility of an error of 25%, states a fatal outcome without indicating the time of its onset.

As a prototype, the authors propose a method for predicting the risk of sudden death after myocardial infarction, which assesses heart rate variability from 5-minute ECG records in the patient’s supine position during voluntary breathing, during an active orthostatic test, and also in the patient’s supine position when performing the test with deep breathing (RF patent No. 2217044). Moreover, the parasympathetic tone of the autonomic nervous system is estimated by the dynamics of the sum of the shares of high and low frequencies in the total spectrum power (% SF =% LF +% HF). The prognosis of the risk of sudden death is carried out according to the formula: PIVS = -0.03 · X1-0.23 · X2 + 3 · X3 + 1.44 · X4 + 4.65 · X5 + 5.05 · X6,

where X1 - dRR is the variation range in the supine position with voluntary breathing;

X2 - SD - standard deviation in the supine position during voluntary breathing;

X3 - RMSSD (AOP) - standard deviation during an active orthostatic test, 1 - with an increase in the indicator compared to the original value, 2 - with a decrease;

X4 -% VLF (AOP) - the share of very low frequencies in the total spectrum power during an active orthostatic test, 1 - with an increase in the indicator compared to the initial value, 2 - with a decrease;

X5 -% VLF (PGD) - the share of very low frequencies in the total power of the spectrum when conducting tests with deep breathing, 1 - with an increase in the indicator compared to the initial value, 2 - with a decrease;

X6 -% SF (PGD) - the share of the total frequency in the total power of the spectrum when conducting an active orthostatic test, 1 - with an increase in the indicator compared to the initial value, 2 - with a decrease.

If PIVS> 11.47, a high risk of sudden death is predicted.

The disadvantages of the prototype are the impossibility of its use in case of cardiac arrhythmias and the absence of quantitative parameters that demonstrate the absolute risk of death.

The authors propose a method for determining the risk of death of myocardial infarction based on the determination of three indicators of peripheral blood: hemoglobin concentration, leukocyte count in 1 mm ³ and erythrocyte sedimentation rate; and two biochemical parameters: aspartate aminotransferase activity and alanine aminotransferase activity.

Research methodology: hemoglobin level determination is carried out by the hemichromic method according to V.I. Pupkova et al. (1998); determination of the number of leukocytes in a unit of peripheral blood volume - by the unified method of counting in an automatic meter, erythrocyte sedimentation rate - by the capillary unified Panchenkov micromethod (1972). To determine the activity of aspartate aminotransferase and alanine aminotransferase, we used the colorimetric dinitrophenylhydrazine method for studying the activity of aminotransferases in blood serum (according to Reitman and Frenkel, 1957).

A personal computer was used to analyze 7 indicators of a clinical blood test and 11 biochemical parameters at the time of admission in 232 patients who, according to the results of dynamic observation and standard 12 channel electrocardiography, were subsequently diagnosed with large focal myocardial infarction, and 95 patients who died from complications of large focal myocardial infarction diagnosed with autopsy. The most distinguished indices were distinguished in patients with myocardial infarction and those who died from complications of myocardial infarction. Their average values and average errors of the average values are presented in Table 1.

Table 1 Mean values and average errors of mean values most differing at the time of admission to the hospital indicators of patients with myocardial infarction and who died from complications of myocardial infarction Indicator Acute myocardial infarction Fatal outcome Average value Average error Average value Average error Hemoglobin (g / l) 136.8 1.22 124.8 2.17 White blood cells × 10 ⁹ / L 8240 0.17 9960 0.37 ESR (mm / h) 18.9 0.84 23.3 1,6 ACT (mmol / h · l) 0.86 0,038 1.23 0,095 ALT (mmol / h · l) 0.91 0,043 1.23 0,097

Next, the numerical series of similar indicators, the average values of which are presented in Table 1, were combined among themselves, the minimum and maximum numerical values in the numerical series were revealed, and the numerical values of the four boundaries dividing each numerical array into 5 equal intervals were determined (see Table 2 )

table 2 Numerical values of the minimum and maximum values of parameters and boundaries dividing the numerical series of measurement results into 5 equal intervals Hemoglobin in g / l White blood cells in 1 mm ³ ESR mm per hour ACT mmol / h · l ALT mmol / h · l Minimum value 54 3600 one 0.1 0.13 First border 79.2 7560 fourteen 1.15 0.98 Second border 104.4 11520 27 2.2 1.84 Third border 129.6 15480 40 3.25 2.69 Fourth boundary 154.8 19440 53 4.3 3,55 Maximum value 180 23400 66 5.35 4.4

Correspondingly to the boundaries, each parameter was divided into 5 identical, numerically equal intervals, presented in Table 3.

Table 3 Intervals for stratification of the studied indicators Interval name Hemoglobin in g / l White blood cells in 1 mm ³ ESR mm per hour ACT mmol / h · l ALT mmol / h · l The first <54-79.2 <3600-7560 <1-14 <0.1-1.15 <0.13-0.98 Second > 79.2-104.4 > 7560-11520 > 14-27 > 1.15-2.2 > 0.98-1.84 Third > 104.4-129.6 > 11520-15480 > 27-40 > 2.2-3.25 > 1.84-2.69 Fourth > 129.6-154.8 > 15480-19440 > 40-53 > 3.25-4.3 > 2.69-3.55 Fifth > 154.8-> 180 > 19440-> 23400 > 53-> 66 > 4.3-> 5.35 > 3.55-> 4.4

Next, we counted the number of cases of deaths from complications of myocardial infarction and successfully transferred myocardial infarction in each interval. Given the maximum 5% error allowed in medicine, the number 0.05 was substituted for the number of cases 0. Using the number of cases of deaths from complications of myocardial infarction and patients with myocardial infarction in each interval, according to the contingency table "2 by 2" in all intervals, the relative risks of developing a fatal outcome were calculated in comparison with the intervals of the minimum values, in the latter, the relative risk was assumed to be 1 (see table 4).

Table 4 The relative risks of the development of a fatal outcome in comparison with the first interval, combining the minimum values of the parameters Hemoglobin White blood cells ESR ACT ALT Parameter interval with minimum values one one one one one Second interval 0.772 1,875 1,563 1,226 1,266 Third interval 0.46 2,393 1,267 2,611 1,971 Fourth interval 0.39 4,048 1,935 3,027 3.45 Parameter interval with maximum values 0.116 2,833 3.01 3,844 2.07

Using tables 3 and 4 for each individual patient, one can find the relative risks of death for each of the 5 indicators and, summing them up, determine the total relative risk, taking values from 4.116 to 15.352. We calculated the total relative risks in all patients with myocardial infarction (average value - 5.31 ± 0.063) and in all those who died from complications of myocardial infarction (average value - 6.49 ± 0.15).

The calculation of the confidence coefficient for the reliability of the difference (t) proves the increase in the reliability of the total indicator compared with each of the methods used in assessing the condition of a patient with myocardial infarction: the confidence coefficient for the reliability of the difference t between the living and the dead for the hemoglobin level is 4.8; for the content of leukocytes - 4.2, for ESR - 2.46, for ACT - 3.7, for ALT - 3.0, for the total indicator - 7.3.

If the number of parameters that did not coincide in the numerical value of the dead and living patients was 2 cases for hemoglobin content, 4 cases for leukocyte concentration, 2 cases for erythrocyte sedimentation rate, 4 cases for aspartate aminotransferase activity, and 3 cases for alanine aminotransferase activity, 3 cases, the number of indicators of total relative risk mismatching in their digital expression amounted to 27 cases.

Beginning with a total relative risk of 9.5, a high risk of death should be noted (according to our data, every fifth patient dies with a total relative risk of 5.6, with a large focal myocardial infarction, every fourth patient dies with a total relative risk of 6.25 ; every second patient with a total relative risk of 9.5 dies; with a total relative risk of 11.4, two out of three patients with large focal myocardial infarction die).

Example 1. Patient C., 61 years old. When observed in the cardiology department and subsequent autopsy (death occurred on the 5th day), the patient revealed transmural myocardial infarction of the anterior wall of the left ventricle, complicated by ventricular fibrillation.

At the time of admission, the subject:

hemoglobin level - 138 g / l (4 intervals);

the content of leukocytes - 11000 in 1 mm ³ (2 interval);

erythrocyte sedimentation rate - 27 mm / h (3 interval);

the activity of aspartate aminotransferase - 1.30 mmol / h · l (1 interval);

the activity of alanine aminotransferase - 1.05 mmol / h · l (2 interval).

The total relative risk is 0.39 + 1.875 + 1.267 + 1 + 1.266 = 5.798.

Example 2. Patient P., 62 years old. When observed in the cardiology department and subsequent autopsy (death occurred on the 4th day), the patient revealed transmural myocardial infarction of the anterior, posterior and lateral walls of the left ventricle, complicated by pericarditis and ventricular fibrillation.

At the time of admission, the subject:

hemoglobin level - 113 g / l (3 interval);

the content of leukocytes - 9400 in 1 mm ³ (2 interval);

erythrocyte sedimentation rate - 12 mm / h (1 interval);

the activity of aspartate aminotransferase - 0.87 mmol / h · l (1 interval);

the activity of alanine aminotransferase - 2.3 mmol / h · l (3 interval).

The total relative risk is 0.46 + 1.875 + 1 + 1 + 1.971 = 6.306.

Example 3. Patient I., 51 years old. When observed in the cardiology department and subsequent autopsy (death occurred on the 6th day), the patient revealed transmural myocardial infarction of the posterior wall of the left ventricle, complicated by pericarditis, thrombosis of the right coronary artery and ventricular fibrillation.

At the time of admission, the subject:

hemoglobin level - 123 g / l (3 interval);

the content of leukocytes - 13200 in 1 mm ³ (3 interval);

erythrocyte sedimentation rate - 59 mm / h (5 interval);

the activity of aspartate aminotransferase - 2.55 mmol / h · l (3 interval);

the activity of alanine aminotransferase - 2.1 mmol / h · l (3 interval).

The total relative risk of death is 0.46 + 2.393 + 3.01 + 2.661 + 1.971 = 10.445.

Thus, in comparison with the prototype of the claimed method has the following advantages:

1. The method allows to quantify the risk of developing a fatal outcome of myocardial infarction.

2. The method presents its results in a single number, which facilitates the stratification of the examined contingents.

3. The use of total relative risk reduces the percentage of errors in evaluating laboratory results.

Claims (1)

A method for determining the risk of a fatal outcome of myocardial infarction, including a study of peripheral blood parameters and biochemical blood tests, characterized in that the hemoglobin concentration, leukocyte content in 1 mm ³ , and erythrocyte sedimentation rate are determined in a patient with myocardial infarction; activity of aspartate aminotransferase and alanine aminotransferase and determine the intervals for stratification of the studied parameters, where the hemoglobin concentration in the range from 54-79.2 g / l, the content of leukocytes 3600-7560 in 1 mm ³ , ESR 1-14 mm / h, ACT 0 , 1-1.15 mmol / (h · l), ALT 0.13-0.98 mmol / (h · l); the second interval corresponds to a hemoglobin concentration in the range from more than 79.2 to 104.4 g / l, white blood cell count more than 7560 to 11520 in 1 mm ³ , ESR more than 14 to 27 mm / h, ACT more than 1.15 to 2.2 mmol / (hl) ALT from more than 0.98 to 1.84 mmol / (hl); a third interval correspond to the concentration of hemoglobin in the range of more than 104.4 to 129.6 g / l, a content of leukocytes 11520 to 15480 in 1 mm ^3, the ESR 40 mm / h, ACT of more than 2.2 to 3.25 mmol / (hl) ALT from more than 1.84 to 2.69 mmol / (hl); the fourth interval corresponds to a hemoglobin concentration in the range from more than 129.6 to 154.8 g / l, leukocyte count more than 15480 to 19440 in 1 mm ³ , ESR from more than 40 to 53 mm / h, ACT more than 3.25 to 4.3 mmol / (h · l), ALT more than 2.69 to 3.55 mmol / (h · l); the fifth interval corresponds to a hemoglobin concentration ranging from more than 154.8 to 180 g / l, white blood cell count from more than 19440 to 23400 in 1 mm ³ , ESR more than 53 to 66 mm / h, ACT more than 4.3 to 5.35 mmol / (h · l), ALT from more than 3.55 to 4.4 mmol / (h · l); then in the intervals that are determined for each indicator, find the relative risks of death for each of the 5 indicators, while if the hemoglobin value is in the first interval, the relative risk is taken as 1, if in the second - 0.772, in the third - 0 , 46, in the fourth - 0.39, in the fifth - 0.116; if the white blood cell count is in the first interval, the relative risk is taken as 1, if in the second it is equal to 1.875, in the third - 2.393, in the fourth - 4.048, in the fifth - 2.833; if the ESR value is in the first interval, the relative risk is taken as 1, if in the second - equal to 1.563, in the third - 1.267, in the fourth - 1.935, in the fifth - 3.01; if the ACT value is in the first interval, the relative risk is taken as 1, if in the second - equal to 1.226, in the third - 2.611, in the fourth - 3.027, in the fifth - 3.844; if the ALT value is in the first interval, the relative risk is taken as 1, if in the second it is equal to 1.266, in the third - 1.971, in the fourth - 3.45, in the fifth - 2.07; further, the relative risks of each indicator identified in this way are summarized, thereby determining the total relative risk, while the total relative risk of 5.6 corresponds to a 20% risk of death of large focal myocardial infarction, 6.25 to 25% risk, 9, 5 - 50% risk, 11.4 - 66.6% risk.