A large group of cardiovascular diseases (CVD), including coronary artery disease (CAD) as the leading cause of death worldwide is a major public health problem slowly growing into a real epidemic of global proportions. The process of occurrence, risk factors and pathological changes that accompany them are well known. Regarding cardiovascular risk factors, we can mention some of the most important ones, such as arterial hypertension, smoking cigarettes, dyslipidemia, diabetes, reduced physical activity (1, 2). CVD accounts for 30.5% in total mortality worldwide (3). According to the Croatian National Institute of Public Health for the year 2011, the frequecy of the CVD group as a cause of death in Croatia is 48.7% and it is the leading cause of death, confirming a great public health importance of this group of diseases (4).

There are significant differences in the incidence of CVD recorded between the genders. The risk for the development of this group of diseases rises in women after menopause (5). During this period of the woman’s life, there are some changes that occur such as an sudden increase in the value of total cholesterol, LDL cholesterol and triglyceride levels, lowering of the HDL cholesterol values and impairment of blood glucose regulation all as a result of the lack of estrogen (6). The fact is that on the average women start suffering from CAD 10-15 years later, which is considered to be the result of the protective effect provided mainly by estrogen in the woman’s generative age. The risk of developing hypertension after menopause rises by 3.5 times, and the occurrence of hypertension in 70% of women leads to the occurrence of coronary events (7). This is demonstrated by the fact that women with CAD are on the average hospitalized at the age of 68, while the men are hospitalized at the age of 61. (8) Pathological coronarogram is five times more common in men, but in case it is diagnosed, men have better results after the percutaneous coronary intervention procedure (PCI) (9-12).

The above-mentioned large epidemiological significance of CAD, differences in the prevalence of the disease, and the need for defining the impact of some other factors on this disease made us conduct this investigation. The aim was to determine the prevalence of cardiovascular risk factors in hospitalized patients undergoing coronary angiography placing a special emphasis on gender.

The study analyzed the data of patients treated in the hospital in the Coronary Intensive Care of the University Hospital Ceter (KBC) Osijek in 2010, who underwent the coronary angiography procedure. The sample of patients whose data were collected is the stratified randomized sample (stratified by gender).

In addition to demographic data and body mass index, the analysis included the data of coronary angiography procedure, a type of CAD and characteristics of narrowing of coronary arteries and the data obtained by aortography and left ventriculography.

Kolmogorov-Smirnov and Shapiro-Wilk tests were used for testing normal distribution of numerical variable values. The comparison of nominal variables in the case of a large number of samples was made by using Pearson c2 test, whereas Fisher’s Exact Test was used in the case of a small number of samples. In case of comparison of numerical variables with nominal variables, the parametric Student’s t-test was applied for variables with normal distribution of the value, while Mann-Whitney and Kruskal-Wallis nonparametric tests were used for those that do not have a normal distribution. The level of statistical significance for all tests used for conducing comparisons is p<0.05.

Analyzing the data on 196 patients (54.1% men and 45.9% women), we have determined an average age of 61.9, with a minimum age of 29 and maximum age of 83. An average BMI is 28.4kg/m2.

Coronary angiography was successfully conducted in 99% of patients involved in the investigation. The procedure itself takes 49 minutes and 25 seconds from the moment of entering of a patient into room by the time he/she leaves it. If we consider only the duration of the procedure, it lasts for 25 minutes and 27 seconds on the average. The most frequently used contrast agent is Visipaque (70.4%), with an average amount of 248.9mL.

The analysis of the type of domination found that in 88.8% of patients it is on the side of the right coronary artery and in 6.1% of patients the left coronary artery is dominant and 4.1% of them have mixed dominance. As for the type, 32% have a one-vessel, 21.6% have two-vessel and 12.9% have three-vessel CAD, while in 33.5% of patients there are no significant changes in the coronary arteries. Stenoses usually affect 2 or more arteries (55.1% of patients), and the other distribution of stenoses is shown in Figure 1.

The average value of stenosis in the left main coronary artery (LMCA) was 53.8%, in the left anterior descending artery (LAD) it was 73.4%, in the right coronary artery (RCA) it was 73.3% and in circumflex artery (Cx) it was 66.4%. The segments that show the narrowing in some blood vessels (Figure 2) have been observed, and the majority of coronary arteries are mostly narrowed in the medium part.

In 89.2% of patients the systolic function was normal. Of regional contractility disorders, dyskinesia was recorded in 19.1% of patients, and the apex was the most common anatomical location of dyskinesia (40.5% of patients), to be followed by inferior (24.3%) and anterior wall (8.1%), while the two or several locations affected by dyskinesia were recorded in 27% of patients. The average value of the ejection fraction (EF) was 54.2%, whereas the lowest measured EF was 15% and the highest 80%. Regurgitation was recorded in 25.3% of patients that underwent coronary angiography, whose mitral valve was most often affected (63.3%), aortic valve was affected by regurgitation in 30.6%, and the both valves were affected at the same time in 6.1% of patients. Valvular stenosis was recorded in 8.2% of patients, while it is located in the aortic valve in 93.8% of patients.

PCI was also performed in 79 patients (40.7%) at the time of coronary angiography. Cardiac surgery was recommended to 27.3% of patients, aortic valve replacement to 7.7% of them and mitral valve replacement was recommended to 5.1% of patients.

If we compare gender with other variables, there are several differences between men and women. With the expected differences in weight and height, a statistically significant difference lies in the age, and women also have a higher BMI than men, as shown in Table 1.

A statistically significant difference exists when making a comparison between the length of the procedure of coronary angiography and gender, because the procedure in men, on the average, lasts for 27 min and 29 s, and in women it lasts for 23 min and 2 s (p=0.036). There are no significant differences in the application of contrast agent and in its quantity depending on gender.

Figure 3 shows the differences in the type of CAD, according to which the one-vessel disease is somewhat more often in men, the three-vessel disease is more often in women, but statistically there is no significant difference (p=0.149, Pearson c2 test). A significant difference is recorded in the average value of LAD stenosis (69.2% for men versus 78.5% for women, p = 0.012, Mann-Whitney test).

Previous studies have shown the utmost importance of CAD on the overall rate of mortality, especially in developed countries. It was also found that women are more likely to have non-obstructive CAD, whereas men often show obstructions (13-19). Considering the risks for the development of obstructive coronary artery disease, we can notice that the prevalence of obstructive CAD is low in premenopausal women, but it rises after 50 years of age, suggesting a protective role of estrogen (16).

We focused our investigation on the Slavonia and Baranja, the Croatian part that is the most exposed region to and the most affected region by the CAD epidemic. Monitoring the death rate from CVD in the population aged up to 64 over the period from 1998 to 2009, higher age-standardized mortality rates from CVD in total, cerebrovascular diseases and coronary artery diseases were recorded in Slavonia than in the Republic of Croatia. In the region of Slavonia there is a falling rate trend, similar to the trend in the Croatian state, of CVD rates in total, cerebrovascular diseases and CAD only in women, while death rates from CAD in men show no changes over the aforementioned ten years’ period of monitoring (20).

The basic data from this study suggest that patients weigh more and are shorter ih height than the average population. It is not surprising that according to the body mass index which is 28.37 kg/m2, they are classified in the group of people who are overweight, similar to the studies of some other authors (21).

The process of performing coronary angiography takes about 50 minutes, thereby most commonly using the Visipaque contrast agent in the amount of 250 mL. Coronary angiography could not be performed only on 1 percent of patients, so we can conclude that it is a widely applicable procedure.

As expected, the RCA is in most cases dominant and supplies most of the heart. LAD stenosis is the most common of all specific stenoses. Average values of stenosis of main coronary vessels are around the lower limit for the actual diagnostics of significant stenosis, that is, for LMCA they account for 50%, while for the other coronary arteries they account for 70%. These limit values can contribute to an artificially lower number of arteries with significant stenosis and milder diagnosis, but the fact is that these marginal stenoses will worsen over time. The medial segment of the main coronary arteries is the most common location of stenosis in all cases.

Of other cardiac disorders, our patients more frequently suffer from dyskinesia (usually on the apex) than from systolic dysfunction (19% vs. 11%). Regurgitation occurs in as many as 25% of patients, we can consequentially assume impaired function of valves as a result of the existence of wall ischemia. Mitral valve is usually insufficient, while in case of stenosis (only 8% in these patients) aortic valve is the most affected.

The role of coronary angiography in the treatment of CAD has been confirmed by a high rate of patients that have been subjected to percutaneous coronary intervention and who underwent the stent implantation, and this percentage is around 40%.

In our investigation, we also wanted to identify specific variables affecting the development of CAD in women, similar to other authors. Much of this is explained by an older age of women than men, which implies a relative protection of women prior to menopause and equalization of risk for coronary disease after the menopause. Women have a higher rate of comorbidity and less regulated risk factors as a result of their older age, and all these facts commonly lead to poorer outcome of coronary artery disease in women (22, 23). Women are also shorter in height and have somewhat lower weight, but statistically they have significantly higher BMI than men, which is another risk factor as described by some other authors (24, 25).

Although it is contradictory at a first glance that the process of angiography lasts shorter in women, it should be borne in mind that higher prevalence of non-obstructive coronary artery disease is recorded in women, where no PCI procedure is indicated. One statistically significant difference between the genders that is particularly intriguing is significantly increased narrowing of LAD in women than in men.

To conclude, the patients undergoing coronary angiography already have risk factors for CAD, such as high BMI and older age. The coronarography findings usually indicate the one-vessel disease. Main coronary artery stenoses are on the border of normal values, the same as the average value of the ejection fraction. The analysis by gender found that female patients were older, with the presence of multiple risk factors, with greater and more frequent LAD stenosis. Earlier conduction of screening, and subsequent early detection of CAD is needed. Primary prevention of cardiovascular risk factors is also very important, while the identification of as many protective factors as possible should be a priority.