Correlation of coronary artery disease risk factors with the coronary artery calcification

Material and purpose: Cardiovascular diseases are the most frequent cause of mortality and morbidity and it is foreseen that it will be the first cause of mortality and morbidity in the world in 2020 according to 1999 World Health Organization data. 50% death of the cardiovascular diseases results from coronary artery atherosclerosis. Vascular calcification takes place in the pathogenesis of atherosclerosis. It is thought that calcium phosphate micro crystals are accumulated in the atherosclerotic arteries which are similar to bone formation and destruction mechanism. When coronary artery calcification is present in the atherosclerotic vein, it does not exist in the normal vein. Calcium is an easily noticeable and localizable target because of its high radio opacity and it is first viewed by the coronary artery calcification fluoroscopy in 1958. In 1983; calcium accumulation in the coronary arteries is quantitatively shown by Electron Beam Computerized Tomography (EBBT) for the first time. Because the coronary artery calcium scores (CACS) are higher than zero, this situation refers to atheromatous coronary plaque with 100% specificity. Several studies are performed showing that there is a relationship between the calcium accumulation quantity in the coronary arteries which are determined by computerized tomography and the development risk of coronary artery disease in the future. BT is accepted as a golden standard in the determination of the calcium quantity in the coronary arteries. Because multi-slice computerized tomography (MCT) is much better than the single slice computerized tomography about showing the anatomy of the coronary arteries and temporal resolution by courtesy of the last developments in technology, it has been come to the forefront.The purpose of this study is to show the conventional risk factors and correlation of calcium accumulation in the coronary arteries with MCT.Instrumentation and method: Age, gender, smoking, hypercholesterolemy, DM, obesity, HT, family anamnesis and low HDL are determined as the conventional risk factors.In different studies researching the correlation between the coronary artery calcification and coronary artery disease risk factors; statistical analysis is performed according to different CACS threshold values. We have intended five different correlation analysis by using different CACS threshold values used in the other studies and comparing them with each other.In the first analysis; 4 groups are determined according to the CACS values as 0, between 0 and 100, between 100 and 400 and more than 400.In the second analysis, 5 groups are determined as %10, %25, %50, %75 and %90 by comparing the average determined according to the age and gender with the CACS.In the third analysis, the average determined according to the age and gender is compared with CACS and 3 groups are determined according to their coronary artery disease risk or MI risks as low, medium and high.In the fourth analysis, 2 groups are determined as less than 130 and more than 130 according to the CACS values.In the fifth analysis, 2 groups are determined according to the CACS values as 0 and more than 0.Separate correlation analyses are performed between the specified conventional risk factors and he CACS groups.Statistical analysis is performed by using the SPSS 17.0 programme. It is benefited from the average, standard deviation, frequency and ratio measurements in the definitive statistics of the data. Chi-square test is applied in the analysis of the categorical data and when the chi-square test conditions are not provided; Fischer Exact test is used. Pearson correlation analysis is used in the correlation analysis between the variants. The tests are performed at 95% confidence interval.The study is performed by retrospectively scanning the calcium scoring of 410 patients between the ages 22 and 88 with 16-slice MCT (average 53.3 ± 23,4 years). 264 of the patients (64,4 %) was male and 146 (35,6 %) was female. The lowest CACS value is determined as 0 and the highest CACS value is determined as 1517 (average 118±486,7 HU).Findings: In these five analyses; we have determined a positive correlation between age, gender, smoking, hypercholesterolemy, DM, obesity and HT and the CACS values. Between family anamnesis and CACS; a weak positive correlation is determined in the second and third analyses which are performed only according to the ratio and risk classification. Low HDL is determined as a significant risk factor in four analysis except the fifth analysis which is performed according to the CACS zero threshold value.Result: Based on the data that we have gained during our study, it is found that calcium accumulation in the coronary arteries is related to the conventional risk factors as similar with the previously performed studies. The correlation between hypertension, age, diabetes mellitus, hypercholesterolemy and male gender and CACS is determined as strongly positive when compared to the other risk factors. A weaker correlation is determined between CACS and low HDL and family anamnesis.