Correlation between Carotid Intimal-Media Thickness and Coronary Artery Disease Severity in Stable Coronary Artery Disease Patients

Background: Atherosclerosis is a fundamental process in the natural course of coronary heart disease (CHD), carotid artery disease and peripheral artery disease. Atherosclerosis is caused by an imbalance of homeostasis in the level of the endothelial layer and the presence of risk factors. The manifestations of coronary atherosclerosis have a wide spectrum of diseases, ranging from subclinical to clinical phases. In patients without CHD symptoms, changes in carotid artery morphology include carotid intimal-media thickness (CIMT) and carotid plaques which correlated with CHD. This study aims to see the relationship between CIMT with the severity of coronary lesions in stable coronary artery disease. Methods: The study was an analytical observational research using cross sectional design. Data was taken by consecutive sampling from outpatient hospital clinic. The CIMT score was obtained from the examination of a communis carotid artery using a B-mode ultrasound device. The value of CIMT is divided into 2 groups based on the value of the sensitivity curve and the specificity curve. The value of Syntax was obtained from the catheterization laboratory and the factors that influenced it were recorded. Pearson correlation test is used to analyze the relationship of CIMT and Syntax value. The logistic regression test used for multivariate test. Results: Of the 58 patients, there were 33 subjects who had a CIMT score of > 0.71 mm and 25 subjects who had a CIMT score of ≤0.71 mm. There is a positive correlation (r = 0.403; p <0.05) between CIMT value and Syntax value. Subjects who have high Syntax value in the group with a CIMT value >0.71 mm compared to CIMT values ≤0.71 mm were 29 versus 4 (RR: 1.831; CI 95%: 1.194-2.807; p = 0.01). A multivariate test showed CIMT consistently as a independent risk factor of Syntax value in stable coronary artery disease with RP 5.27 (CI 95%: 1.306-25.047; p = 0.021). Conclusion: The increase in CIMT value has a significant positive correlation with the Syntax value. A CIMT > 0.71 mm is a independent risk factor of high Syntax value in stable coronary artery disease with prevalence ratio 5.27.


INTRODUCTION
Atherosclerosis is the most common cause of coronary heart disease (CHD), carotid artery disease (CAD) and peripheral arterial disease (PAD).Atherosclerosis itself is not a fatal disease but the process of thrombosis which is the process of rupture of atherosclerosis plaque is the cause of serious events such as acute coronary syndrome and stroke. 1 Atherosclerosis is a fundamental process in the natural course of CHD.The manifestations of coronary atherosclerosis have a wide spectrum of diseases, ranging from subclinical to clinical phases. 2 In patients without CHD symptoms, changes in carotid artery morphology include carotid intimal-media thickness (CIMT) and carotid plaques were correlated with CHD. 2 The relationship between CIMT and risk of cardiovascular events has been extensively studied in large studies and it is expected that asymptomatic plaque can be used for predict future cardiovascular events. 3In addition to predicting a subclinical process, CIMT examination is also common in monitoring the progression of the disease and treatment due to good reproductive rates.
In the Atherosclerosis Risk in Commmunities study (1993) revealed that CIMT has a limited value that varies by race, gender and age. 5 Rilantoro and Fadilah (1999) examined the association of CIMT with the severity of coronary lesions (grouping according to the number of blood vessels) in the diabetes mellitus population (DM) but no statistically significant relationship. 6e relationship of CIMT degree to the severity of coronary lesions (Syntax system) has not been studied in Indonesia therefore this study aims to look at the relationship between CIMT and the severity of coronary lesions (Syntax system) in the stable coronary artery disease (SCAD) population.

METHODS
The design of this study was a cross sectional study, which assessed the relationship between the CIMT value and the severity of coronary lesions in SCAD populations This study used the approval of the ethics committee of Faculty of Medicine, University of Gadjah Mada Yogyakarta and permission from the Dr. Sardjito Hospital, Yogyakarta, Indonesia.

RESULT
This study took place from May 2017 to August 2017 at Dr. Sardjito Hospital, Yogyakarta, Indonesia.During this study period, as many as 302 patients with suspected SCAD underwent TMT and coronary MSCT.Total subjects met the inclusion criteria were 152 (figure 1).As many as 94 subjects were excluded because of a history of ischemic stroke, history of myocardial infarction and chronic heart failure.Therefore, 58 subjects were enrolled in the study, consisting of men as many as 50 subjects (86%) and women as many as 8 subjects (14%   14 In some previous studies, diabetes mellitus was an independent risk factor for the severity of coronary lesions. 15,16However, it is not found in this study.This may be due to the limited number of research subjects so it is not strong enough to see the difference in proportions and risk factors.

CONCLUSION
There was a positive correlation relationship between CIMT value and Syntax value in stable CAD patient.The CIMT value >0.71 mm was an independent risk factor of high Syntax value stable CAD patient with prevalence ratio 5.27.
with positive treadmill test (TMT) results or significant lesions results on multi-slice computed tomography (MSCT) examination at Dr. Sardjito Hospital, Yogyakarta, Indonesia from May 2017 to August 2017.The independent variables in this study were the thickness of communis carotid intimalmedia while the dependent variable on this study was the severity of the coronary lesions, both of which were taken during hospitalization.The confounding variables include age, sex, blood pressure, diabetes mellitus, history of smoking and dyslipidemia.In this study the inclusion criteria of the study subjects were as follows: (1) male or female patients with suspected SCAD from positive TMT or coronary MSCT with significant lesions, (2) sinus rhythm on ECG recordings, (3) age 18-75 years, and (4) neck examination area can be well visualized.The exclusion criteria were patients with a history of myocardial infarction, history of ischemic stroke and suffering from chronic renal failure.The patients were performed coronary angiography and ultrasound CIMT, after being detected as SCAD based on positive TMT or coronary MSCT with significant lesions.All TMT and MSCT results as well as coronary angiography and ultrasound CIMT were well listed in the medical record.The standard difference of examination is minimized by performing a suitability analysis between the two CIMT examiners and the severity of the coronary lesions using a kappa.The data were analyzed using SPSS for Windows software version 22.0.The basic characteristics were displayed as a mean or percentages.Categorical variables were compared using Chi Squared (X 2 ) test.The relationship between CIMT value and Syntax value were tested by Pearson correlation test.The numerical variables in the CIMT group and the severity parameters of the coronary lesions were analyzed for their correlations using the independent sample T Test or Mann Whitney Test based on the normality of the data distribution.Confounding variables were analyzed using multivariate analysis with logistic regression test.The p value <0.05 was considered statistically significant.

Table 1 .
The subject baseline characteristics 7isk factors, body mass index (BMI) and laboratory data (lipid profile).Statistically the age and number of blood vessels had a significant difference between the two groups (Table2).During the study, subjects who had a high Syntax value were 41 out of 58 subjects (70%).The significantly different variables between groups with low Syntax values and those with high Syntax values included age, hypertension and DM, while the other variables did not differ significantly between the two groups (Table3).7Theage is an unmodified cardiovascular risk factor.The incidence of cardiovascular disease significantly increased Figure 2. A scatter-plot shows positive correlation between CIMT and Syntax (r = 0.403; p <0.05).meanage in the high Syntax group had a higher value than the low Syntax group (p = 0.025).Age

Table 2 .
Comparison of the basic characteristics of the CIMT group >0.71 mm and CIMT ≤0.71 mm in stable CHD patients

Table 3 .
Comparison of the basic characteristics of the high Syntax group and low Syntax group in stable CHD patients CIMT is carotid intima media thickness; BMI is the body mass index; LDL is low density lipoprotein; HDL is high density lipoprotein.*distribution of normal data, shown in mean and standard deviation and analyzed with unpaired T test.**abnormal data distribution, shown in median and analyzed by Mann-Whitney test.

Table 4 .
Multivariate analysis of several variables that affect the value of Syntax