Научная статья на тему 'Coronary CT angiography and conventional coronary angiography: comparative analysis of diagnostic capabilities'

Coronary CT angiography and conventional coronary angiography: comparative analysis of diagnostic capabilities Текст научной статьи по специальности «Медицинские технологии»

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European science review
Ключевые слова
CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY (CCTA) / CORONARY ARTERIES / ATHEROSCLEROTIC PLAQUE / INVASIVE CORONARY ANGIOGRAPHY

Аннотация научной статьи по медицинским технологиям, автор научной работы — Djuraeva Nigora Mukhsumovna, Ikramov Adham Ilhаmovich, Zufarov Mirdjamol Mirumarovich, Pirnazarov Maruf Mahmudzhanovich, Maksudov Muzaffar Fathullaevich

Coronary CT angiography is an upcoming alternative for the direct non-invasive assessment of coronary arteries with a fair overall accuracy for diagnosis of coronary artery disease. Rationale: Cardio vascular diseases including coronary heart disease (CHD) remain the leading cause of mortality and disability of population. This matter requires development of early non-invasive methods of atherosclerotic lesions diagnostics. The coronary computed tomography angiography (CCTA) is among these methods. Continual improvement of the CCTA technologies requires data correlation between CCTA and coronary angiography (CA) at each new stage; the fact served as a trigger for the research. Materials and Methods: the study involved 31 patients with clinical signs of CHD and indications for coronary angiography. All patients underwent evaluation of coronary bed by radiological methods: CCTA and classic invasive CA. Diagnostic accuracy of CCTA was assessed using the CA results as a “gold standard”. Results: sensitivity of CCTA compared to CA was 80.4% and specificity was 88%. Predictive value of positive test was 80% and predictive value of negative test made 96%. The accuracy made 93%. Conclusion: thus the CCTA has higher accuracy in detection of coronary arteries lesions compared to CA, along with especially significant predictive value of negative result.

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Текст научной работы на тему «Coronary CT angiography and conventional coronary angiography: comparative analysis of diagnostic capabilities»

DOI: http://dx.doi.org/10.20534/ESR-17-3.4-23-31

Djuraeva Nigora Mukhsumovna, JSC "Republic Specialized Centre of Surgery named after Academician V. Vakhidov" PhD, Head of "MRI and CT" Department.

E-mail: [email protected] Ikramov Adham Ilhamovich, Professor, Head of Medical Radiology Department of Tashkent Institute of Postgraduate Medical Education, Tashkent, Uzbekistan

E-mail: [email protected] Zufarov Mirdjamol Mirumarovich, Professor, Deputy Director, Head of Interventional Cardiology Department

JSC "Republic Specialized Centre of Surgery named after Academician V. Vakhidov", Tashkent, Uzbekistan

E-mail: [email protected] Pirnazarov Maruf Mahmudzhanovich, Radiologist of "MRI and CT" Department JSC "Republic Specialized Centre of Surgery named after Academician V. Vakhidov", Tashkent, Uzbekistan

E-mail: [email protected] Maksudov Muzaffar Fathullaevich, PhD, Head of Radiology Department of Fedorovich Clinic,

Tashkent, Uzbekistan E-mail: [email protected]

Coronary CT angiography and conventional coronary angiography: Comparative analysis of diagnostic capabilities

Abstract: Coronary CT angiography is an upcoming alternative for the direct non-invasive assessment of coronary arteries with a fair overall accuracy for diagnosis of coronary artery disease.

Rationale: Cardio vascular diseases including coronary heart disease (CHD) remain the leading cause of mortality and disability of population. This matter requires development of early non-invasive methods of atherosclerotic lesions diagnostics. The coronary computed tomography angiography (CCTA) is among these methods. Continual improvement of the CCTA technologies requires data correlation between CCTA and coronary angiography (CA) at each new stage; the fact served as a trigger for the research.

Materials and Methods: the study involved 31 patients with clinical signs of CHD and indications for coronary angiography. All patients underwent evaluation of coronary bed by radiological methods: CCTA and classic invasive CA. Diagnostic accuracy of CCTA was assessed using the CA results as a "gold standard".

Results: sensitivity of CCTA compared to CA was 80.4% and specificity was 88%. Predictive value of positive test was 80% and predictive value of negative test made 96%. The accuracy made 93%.

Conclusion: thus the CCTA has higher accuracy in detection of coronary arteries lesions compared to CA, along with especially significant predictive value of negative result.

Keywords: coronary computed tomography angiography (CCTA), coronary arteries, atherosclerotic plaque, invasive coronary angiography.

Introduction

The achievements of modern medicine resulted in changing of a "leader" among principal reasons of death rate. Cardiovascular diseases (CVD) displaced infectious diseases from a "pedestal" and continue to occupy the first place [1, 5-9]. So the CHD and its complications represent one of the major reasons of morbidity and mortality of population.

Routine methods of CHD diagnostics (clinical examination, ECG, echocardiogram, Holter monitor) make it possible to confirm the diagnosis, evaluate the disease functional class, to determine presence and severity of cardio sclerotic lesions. However, the ef-

forts to apply the methods for determination of precise location and extent of affection of the coronary arteries by atherosclerosis, and nature and constriction due to soft plaques and calcific plaques, failed [2, 4-9]. It is possible to obtain such data in direct CA study only, up to the present time performed using CA.

This study is the "gold standard", however due to its invasive nature it is accompanied by a risk of complications. The CA is an invasive intervention, therefore the patients and physicians typically deny it [2, 4-9]. In this connection the interest ofphysicians as well as public opinion in the methods of non-invasive coronary arteries evaluation is very high.

The emergence of possibility to apply coronary computed tomography angiography (CCTA) for non-invasive detection of coronary arteries lesions and determination of stenosis degree created new opportunities for diagnostics of atherosclerotic process. The diagnostic accuracy of the method increases significantly with increase in X-ray tube rotation rate, with reduction of section thickness, increase in number of CT detectors [2, 4-9; 3, 61-65]. Use of 64-320 slice [4, 2485-2490] CT scanners transferred the CCTA from the field of research to the sphere of clinical practice. Today using the procedure it is possible to assess coronary arteries condition non-invasively to identify and characterize atherosclerotic plaques, to determine stenosis degree and to clarify indications for selection of a method for CHD prevention or treatment. CCTA may be performed on an outpatient basis (without anesthesia and sedation), it takes less than 10 minutes and ensures high information capability of diagnostics of coronary arteries lesions [3, 61-65].

A direct comparison of the exercise tolerance test and a 16-slice CCTA conducted by Dewey et al [4, 2485-2490] in 2006 on 80 patients showed significant advantage of CCTA in detection of the coronary heart disease: sensitivity was 73% versus 91%, specificity: 31% vs. 83%; p = 0.039 (CA was used as a reference method). The findings demonstrated that even 16-slice CCTA had a higher diagnostic value than the exercise tolerance tests for detection of coronary artery disease [3, 61-65].

Pugliese F. et al [5, 384-393] comparing results of CCTA on a 4-slice CT scanner and finishing the comparison on a 64-slice CT scanner have noted sensitization of the study from 57% to 99% and increase of specificity from 91% to 96% [2, 4-9].

The current generation of CT scanners enables performance of about 64-320 consecutive cross-sectional images of half-millimeter sections covering from 4 to 16 cm in one x-ray tube turnover (about 227-420 ms). Duration of scanning in one breath-holding spell reduced to 3-7 seconds enabling the examination in almost all patients. Reduction of the time resolution of the method up to 165-210 ms reduces artifacts from movements associated with arrhythmias [3, 61-65; 5, 384-393].

Most studies have shown that 64-slice CT of coronary arteries in the diagnostics of hemodynamically significant stenotic lesion in comparison with CAG has sensitivity of94-100% and specificity of 95-97%, positive predictive value of87-97%, and negative predictive value of99-100% [6, 564-571; 7, 373-379; 8, 797-806; 9, 64-72; 10, 911-916].

Continuous improvement of CCTA technologies requires comparison of CCTA coronary angiography and CT data at each new stage that was the reason of our work.

Objective. To compare capabilities of CCTA in evaluation of coronary bed of stents, shunts and their viability compared with CA.

Materials and methods. The study included patients undergoing examination in the CT and MRI department of JSC "RSCS named after Academician V. Vahidov" with suspected coronary arteries abnormal changes and the proven CHD.

Diagnostic coronary angiography was performed with ECG monitoring. A puncture of an artery by the Seldinger technique was performed under local anesthesia. Left and right coronary arteries were sequentially catheterized by a diagnostic catheter with inj ected contrast medium in volume of 5-10 ml at the rate of 5 ml per second. Total amount of contrast agent administered to a patient was 50-70 ml. The study was performed in standard projections.

The CA findings were accepted as the standard definition of significant stenosis. In the segments with more than one stenosis the diagnostic accuracy was determined by more pronounced

reduction in the diameter. Stenosis exceeding 75% was considered as significant stenosis.

CCTA was conducted on 128-slice scanner GE Optima 660 with bolus injection of 60-100 ml of nonionic contrast agent (350 mg/ml) using an injector Missouri Ulrich at a rate of 4-6 ml/sec. Software Auto Coronary Analysis, Auto Ejection Fraction in AW5 was used for data processing.

Stenosis exceeding 75% were determined in CCTA as significant ones and were isolated as a separate borderline group of 50-75% (in general calculations these data were considered as significant results); stenosis less than 50% were determined as nonsignificant ones. In analysis of CCTA significance in diagnostics and degree of stenosis, we proceeded from comparison of these values with the results of coronary angiography. The following segments of the coronary arteries were evaluated: left main coronary artery (LCA), anterior interventricular artery (AIVA), circumflex artery (Cx), right coronary artery (RCA).

Software Statistica 6 (Stat Soft, USA) was used for statistical processing of results.

Assessment of significance of differences between quality indicators of the compared groups was performed using a criterion x2 (chi-square) to compare binary trait frequencies in two unrelated groups of paired comparisons.

Student's t-test for independent samples (after checking the distribution of features against normal distribution by Kolmogorov-Smirnov test) or non-parametric Mann - Whitney U-test were used for evaluation of differences in the values of quantitative indicators.

The critical confidence level of statistical null hypothesis is accepted as equal to 0.05.

Quantitative evaluation of the CCTA method effectiveness in examination of vessels was conducted by calculation of sensitivity and specificity indicators, and the method accuracy using generally accepted formulas:

Sensitivity = TP/(TP +FN) • 100%, (1)

Specificity = TN/(TN + FP) • 100%, (2)

Accuracy = (TN + TP)/(TN + FN + TP + FP) • 100%, (3)

PPV = TP (TP + FP) • 100%, (4)

NPV = TN (FN + TN) • 100%, (5)

where: TP — true positive result; TN — true negative result; FP — false positive result; FN — false negative result, PPV — positive predictive value, NPV — negative predictive value.

Results

The study involved 31 patients, including: 22 men (71%), 9 women (29%). Average age was 58.6 (36-81) (fig.1). The majority of the patients 18 (58%) was under 60 and 1 patient (3%) was over-80.

Average height was 168.7 cm (131-182), average weight - 77.8 kg (52-105), average body mass index: 27.9 (20.8-39.6) (Fig. 2).

Figure 2 shows that the majority of patients: 18 (58%) had overweight; including: 6 patients (19%) had first degree obesity, 3 (10%) - second degree obesity.

The average value of systolic blood pressure (BP) was 135.2 mmHg (110-180), diastolic blood pressure was 82 mmHg (60-110). Average heart rate (HR) - 72.5 beats per minute (60-86).

The analysis of patients by a degree of coronary bed lesion demonstrated that 5 (16%) patients showed single vessel disease, 13 (42%) patients showed two vessel disease, and 12 (39%) patients had multi-vessel disease. Figure 3 shows that women (33.3%) predominate among patients with multi-vessel disease; and men (45.5%) predominate in patients with single vessel disease.

80,00% 70,00% 60,00% 50,00% 40,00% 30,00% 20,00% 10,00% 0,00%

67,00%

54,50%

33,30%

18,30%

I

0,00%

4,50% 0,00%

Up to 60 yea rs 60-69 yea rs 70-79 yea rs Over 80 yea rs

(M - 12 F - 6) (M - 5; F - 3) (M - 4) (M - 1)

M

F

Figure 1. Patients by gender and age (n = 31)

10% Normal body mass

19%% 42%%

Overweight

First degree obesity

29% ^T Second degree obesity

Figure 2. Patients by body mass index (n = 31)

50,00% 45,00% 40,00% 35,00% 30,00% 25,00% 20,00% 15,00% 10,00% 5,00% 0,00%

4,50%

44,50%

45,50%

41,00%

33,30%

9,00%

22,20%

No changes (M Single vessel (M Two vessel

- 1) - 2; F - 3) (M - 9; F - 4)

Multi-vessel (M - 10; F - 2)

MF

Figure 3. Patients by degree of coronary bed lesion based on gender (n = 31) Evaluation of dependence of a degree of the coronary bed lesion observed only in the group with normal BMI (Fig. 4). Dependence on BMI revealed that the higher the BMI, the greater probability of of degree of the coronary bed lesion on age is shown in Figure 5. multi-vessel disease, the absence of pathological changes in CA was

23,00%

34,00%

33,00%

w 1 vessel J 2 vessel U Multifocal

A Normal body weight (n = 12)

29,00%

71,00%

/

B Overweight (n = 9)

67,00%

^ 1 vessel 2 vessel

C Obesity I (n = 7) D Obesity II (n = 3)

Figure 4. Patients by degree of coronary bed lesion based on gender (n = 31)

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

100% 20% 15% 8%

25%

85%

80%

42%

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25%

No changes Single vessel

Two vessel

Multi-vessel

Up to 60 yea rs _ 60-69 yea rs - 70-79 yea rs - Over 80 yea rs Figure 5. Dependence of degree of the coronary bed lesion on age (n = 31)

Analysis of patients by type of blood supply showed that a left type occurred in 10 (32%) patients, right type - in 6 (19%) patients, a mixed type occurred in almost half ofpatients 15 (49%). Distribution of patients by type of blood supply based on gender is represented in Figure 6, where no significant differences in the type ofblood supply of the myocardium between men and women were detected.

An important advantage of CCTA is an opportunity not only to detect a vessel lumen, but also visualize an artery wall, examine a structure of atherosclerotic plaques: soft - lipid, mixed - fibrous

(soft tissue density), and calcified. The CCTA enables revealing not only significant stenosis and occlusions, but even insignificant plaques. It is believed that the majority of acute coronary syndromes are associated with rupture of soft plaques. Exposure of a plaque to rupture is the higher the greater the amount of lipids. At the same time, high calcium content ensures stability of the plaque. These data give an opportunity to predict the disease development and stability in course of the disease in an individual patient [2, 4-9].

60,00%

50,00%

40,00%

30,00%

20,00%

10,00%

0,00%

Left

Right

Mixed

Figure 6. Distribution of patients by of blood supply based on gender (n = 31]

In this connection, in the process of CCTA data analysis atten-

3) calcified plaques: calcifications is more than 50% of the

tion was paid to a type of atherosclerotic plaques. The plaques were plaque area.

classified as follows: Analysis of plaques type showed that mixed plaques 20 (67%)

1) a soft plaque: plaque density is less than density of contrasted occurred in more than half of patients: 20 (67%); soft plaques oc-lumen of the vessel and/or there is no "coronary" calcium;

curred in 7 (23%) patients, and calcified plaques occurred in 3 2) mixed plaques: there are calcined and non-calcined ele- (10%) patients. Patients by type of plaques according based on

ments; calcination is less than 50% of the total plaque area;

gender are shown in Figure 7.

90,00% 80,00% 70,00% 60,00% 50,00% 40,00% 30,00% 20,00% 10,00% 0,00%

77,00%

Soft

Calcic

Mixed

■ M

Figure 6. Distribution of patients by

Comparison of the data obtained using CCTA and CA based on calculation of number of arteries examined showed that according to the CCTA data the intermediate coronary lesions were detected in 15 cases (12.6%); CA data: 14 patients (11.7%). At the same time, according to CAG data subtotal stenosis was observed more often (in 9 cases (7.5%)), whereas in CCTA this value made 7 (5.8%) cases. CAG also showed a higher proportion of patients with no changes in the coronary arteries: 67 (55.8%) ver-

- F

blood supply based on gender (n = 31)

sus 54 (45%) (Fig. 8). This abnormality was detected in evaluation of coronary arteries occlusion using CCTA in 7 (5.8%) cases, whereas CA data showed 3 (2.5%) cases. Also, hemodynamically not significant stenosis were detected more often in CCTA data: in 30 segments (25%), whereas the CA data revealed this type of stenosis in 21 (17.5%) cases. However, not significant differences in indicators in the process of evaluation of the state of arteries by different methods were noted.

60,0%

50,0%

40,0%

30,0%

20,0%

10,0%

0,0%

55,80%

25,00%

17,50%

■IIP

ill I

12,60%11,70%

7,50%

5,80%5,00% 5,80%

5,80%

2,50%

No changes Less than 50%

From 50 to

70% ■CCTA

More than 75%

Subtotal stenosis

Occlusion

CA

Figure 8. Comparison of coronary arteries study results according to CCTA and CA data based on the total number of arteries (n = 120)

Comparison of CCTA and CA data on LCA state showed that HDN stenosis were identified more often in CCTA data: in 3 cases (9.7%); according to CA data: 2 cases (6.5%); and intermediate stenosis were detected in 2 (6.5%) and 1 (3.2%) cases, respectively. CA results showed no changes in this artery a bit more often: in 25 (80.6%) patients, while CCTA showed 23 (74.1%) of these cases

(Fig. 9). One patient was diagnosed calcification of LCA mouth in CA; the CCTA did not identify the change. Also, no changes were found in one patient in evaluation of LCA stent state using CA and CCTA. Values of other indicators in evaluation of coronary arteries states by various methods in examined patients were identical. No significant cross-sectional differences in the indicators were identified.

90,0% 80,0% 70,0% 60,0% 50,0% 40,0% 30,0% 20,0% 10,0% 0,0%

80,60%

74,10%

CCTA

CA

9,70% 6,50% 6,50%

9,70%9,70%

No changes Less than 50% From 50 to 70% More than 75%

Subtotal stenosis

Occlusion

Figure 9. Comparison of LCA study results according to CCTA and CA data in examined patients (n = 31)

Comparison of data on RCA state indicated that one patient occlusion was detected in 4 (13%) cases; and in CA: 2 (6.4%) (3.1%) showed HDS stenosis per the CCTA data; and according cases (Fig. 10). At the same time, according to CA, there were to CA data the pathology was not identified; also in CCTA a RCA 3 cases (9.6%) of subtotal stenosis of a vessel, whereas only 2 cases

were showed by CCTA (6.4%). CA results showed no changes in this artery a bit more often: 12 (38.9%) patients; whereas CCTA showed no changes in 9 (29%) cases. The incidence of hemo-

45,0%

dynamically insignificant stenosis was the same. Not significant cross-sectional differences in the indicators were identified.

40,0%

35,0%

30,0%

25,0%

20,0%

15,0%

10,0%

5,0%

0,0%

38,70%

32,30%

3,00%

13,00%

9,60%

No changes Less than 50% From 50 to More than Subtotal

70% 75% stenosis

- CCTA - CA

Occlusion

Figure 10. Comparison of RCA study results according to CCTA and CA data in examined patients (n = 31)

Comparison of evaluation of the AIVA state showed that according to the CCTA data the hemodynamically significant stenosis were identified rather less frequently: in 4 segments (14.9%), whereas in CA it was more often: in 5 cases (18.5%). According to the CCTA data hemodynamically not significant stenosis were identified more often as well: in 10 segments (37%), whereas in CA

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this type of stenosis was identified in 6 (22.2%) cases. No cases of subtotal stenosis in these segments were detected by CCTA, versus 1 (3.7%) in CA. The incidence of occlusion was 3 (11.1%) in CCTA, when CA it was 1 (3.7%). No chang es were identified in 3 patients in evaluation ofAIVA stents using CA and CCTA. Not significant cross-sectional differences in the indicators were identified.

40,00%

35,00%

30,00%

25,00%

20,00%

15,00%

10,00%

5,00%

0,00%

37,00%

No changes Less than 50% From 50 to More than Subtotal

70% 75% stenosis

■ CCTA - CA

Occl usion

Figure 11. Comparison of AIVA study results based on CCTA and CA data in examined patients (n = 31)

Analysis of results of evaluation of the BA proximal segments state showed that in accordance with the CCTA data hemodynamically significant stenosis were detected in 2 (6.5%) cases, in CA: in 1 case (3.2%). Also, hemodynamically not significant stenosis

were detected more often according to CCTA data: in 7 segments (22.6%), while this type of stenosis was observed in 3 (9.7%) cases in CA. There were no cases of occlusion in these segments, frequency of detection of subtotal stenosis was 2 (6.5%) cases in

evaluation using both methods. No changes were identified using CCTA and CA in one patient in evaluation of BA stent state. CA showed higher incidence of lack of changes in these segments of

80,00% 70,00% 60,00% 50,00% 40,00% 30,00% 20,00% 10,00% 0,00%

Figure

According to our data, CCTA sensitivity compared to coronary angiography was 80.4%, specificity - 88%. Predictive value of a positive test (probability that a patient does have significant coronary artery disease with a positive result of examination) was 80%. The predictive value of a negative test (probability that a patient does not have significant coronary artery lesions with a negative result of examination) was 96%.

The general accuracy was 93%.

Discussion

Today, CA is the most informative method in diagnostics of coronary artery stenosis. However, modern CCTA is already acknowledged to be an accessible, highly informative, non-invasive method of coronary artery evaluation [9, 64-72].

The CCTA reliably excludes presence of coronary artery stenosis, and in case of atherosclerotic plaques it helps to determine a treatment strategy.

the coronary arteries - 22 (70.9%) compared with the results of CCTA: 17 cases (54.7%) (Fig. 12). Not significant differences in indicators in evaluation of BA proximal segments state were noted.

According to data given in the literature, the CCTA sensitivity is 57-99%, value of a positive predictive test is 87%, value of a negative predictive test is up to 100%; all of these indicators increase with the use of more modern CCTA units and accumulation of lessons learned from the studies [2, 4-9; 11, 1413-1419]. The similar results were obtained in our work.

Conclusion

Thus the CCTA has a high diagnostic value in detection of coronary artery lesions. The advantages of the method are its noninvasive nature and an opportunity to evaluate not only a lumen of the coronary artery, patency of coronary artery bypasses and stents, but also condition of vessel wall and structure of atherosclerotic plaque. Considerable reduction in radiation doze on a patient (less than 2 mSv) shall be an additional incentive for development of CCTA in the coming years that will give a chance to use the method as CHD screening.

70,90%

54,70%

I

No changes Less than 50% From 50 to More than Subtotal Occlusion

70% 75% stenosis

■ CCTA - CA

12. Comparison of BA study results based on CCTA and CAG data in examined patients (n = 31) Table 1. - Comparison of CCTA results with coronarography data

Total TP TN FP FN Total

CCTA 45 (12,4%) 297 (81,6%) 11 (3%) 11 (3%) 364 (100%)

CAG 302 (83%) 62 (17%) 364 (100%)

TP - true positive result; TN - true negative result; FP - false positive result; FN - false negative result

70,90%

54,70%

I

22,60%

References:

1. Corotcevich A. A., Cocov A. N. Hybrid technology ofbeam diagnostics in the diagnosis of coronary heart disease: Current opportunities and prospects. Complex issues of Cardiovascular diseases. - 2015; 1:5-9.

2. Fedorov V. D., Kokov L. S., Tarbaeva N. V. et al. Clinical Value of Coronary Computed Tomography Angiography. Surgery. The Magazine named after N. I. Pirogov, - 2010; - 4-9.

3. Ternovoy S. K., Nasnikova I.Yu., Morozov S. P. et al. Application of Coronary Computed Tomography Angiography in clinical conditions. Kremlin medicine. Clinical Bulletin, - 2008; 1:61-65.

4. Dewey M. et al. Head-to head comparison of multislice computed tomography angiography and exercise electrocardiography for diagnosis of coronary artery disease.//Eur. Heart. J., - 2007; 28:2485-2490.

5. Pugliese F., Mollet N. R., Myriam Hunink M. G. et al. Diagnostic Performance of coronary CT angiography by using different generations of multisection scanners: single-center experience. Radiology - 2008; 246: 384-393.

6. Ehara M., Surmely J. F., Kawai M.et al. Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population: comparison with conventional invasive angiogra-phy//Circ.J., - 2006;70 (5): 564-571.

7. Ferencik M., Nomura C. H., Maurovich-Horvat P. et al. Quantitative parameters of image quality in 64-slice computed tomography angiography of the coronary arteries//Eur. J. Radiol., - 2006; 57 (3): 373-379.

8. Hoffmann U., Ferencik M., Cury R. C. et al.Coronary CT angiography//J. Nucl. Med., - 2006; 47 (5): 797-806.

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DOI: http://dx.doi.org/10.20534/ESR-17-3.4-31-33

Zakhidov Ulugbek Basitovich, CMS, applicant of Tashkent advanced medical studies institute, Eye diseases department E-mail: [email protected]

Pathogenic course of general conservative treatment of patients with juvenile glaucoma occurring on the base of progressive myopia

Abstract: we observed 44 patients, aged from 11 to 18 years, with progressive myopia, juvenile glaucoma, juvenile glaucoma on the base of progressive myopia. All patients were investigated by biochemical methods to the level of oxyproline in blood serum and on the base of this method there were prescribed the conservative treatment. Keywords: progressive myopia, juvenile glaucoma.

Introduction. One of the major pathogenetic links ofmyopia's progression is a weakening of the supporting properties of the sclera on the base of damage its metabolism and structure [7]. With the progression of myopia in the sclera there occur biochemical, bio-mechanical and structural changes in the anterior segment of the eyeball and then in the rear section of the zone. The collagen framework changes, the fibrils split and as a result of it there the collagen's disaggregation occurs, which leads to the weakening and stretching of the sclera. In the posterior part the eyeball takes elongated shape, there occurs a tendency to increase the intraocular pressure, which further leads to the progression of myopia [1; 3].

In recent years, we study the connection between myopia and glaucoma. In addition, currently myopia has been regarded as one of the risk factors of appearing glaucoma [3,4]. Epidemiological data indicate a high risk of glaucoma in patients mainly with high and middle degrees of myopia [5]. A common feature of the analyzed diseases (myopia and glaucoma) are expressed by trophic changes, celebrated not only in the posterior of the eyeball, but also by the presence of the imbalance of contenting microelements in the sclera [2].

The study of the fractional composition of collagen gives an indication of changes in the catabolic processes, namely the content of the free oxyproline and decreasing total collagen in the tissues. The major metabolite of characterizing the rate of collagen decay is oxyproline. Increasing its content in blood plasma indicates disorders of collagen maturation. Since the free oxyproline is not included in the new chains of collagen biosynthesis, its content in the blood reflects the rate of collagen's decay [6].

The aim of the research: set the effectiveness of the general pathogenetic conservative treatment in patients with juvenile glaucoma occurring on the base of progressive myopia

The materials and methods. This study presents the results of surveys of 44 patients, aged from 11 to 18 years (mean age 16,8 ± 2,4 years), there are 14 boys and 30 girls. Patients were divided into 3 groups. The1st group is of 16 patients with JG on the base PM, the 2nd group is of 17 patients with PM and the third group is of 11 patients with JG. Control data of biochemical results were 9 healthy subjects of different ages. Each patient is examined with the use of traditional ophthalmological methods (visometry, tonometry, tonography, static and kinetic perimetry, biomicroscopy, Gonioscopy using a three-mirror Goldmann gonioscopy). The daily tonometry of patients received every two hours, starting from 6-00 to 22-00 for a more detailed study of the IOP fluctuations. Also there were carried ultrasound echobiometry (Oftascan mini-B «Alcon»), computerized perimetry (Peritest-300, Russia) and also on the testimony the Doppler of brachiocephalic vessels and vessels of the eyeball. In the blood serum there were determined the total index of connective tissue metabolism of oxyproline. To determine the amount of oxyproline in the blood serum the work was divided into two stages. In the preparatory phase proteins of collagen of various fractions subjected to alkaline hydrolysis in sealed glass ampoules. Hydrolysis was carried out daily, 3, 5, 10 and 15 days of a complete hydrolysis time. Further, hydrolysates of proteins were evaporated in a ceramic dish at water bath. The dry residue was dissolved in a precise volume of water. The resulting solutions were

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