Background: Coronary heart disease and acute coronary syndrome is one of the most common causes of death in the world. Acute coronary syndrome can be divided into STEMI, NSTEMI and unstable angina pectoris. Primary percutaneous coronary intervention (pPCI) according to researches is the best therapeutic solution for patients with acute myocardial infarction with ST-segment elevation (STEMI) within 12 hours from the start of pain. Researches confirm that ACS can consequently lead to a development of various mental disorders. Risk factors for the development of ACS can be divided into those that can and those that cannot be controlled, and into biological and psychological risk factors. Researches has shown that Type A (anxiety) and Type D (depressed) personality affect the occurrence of ACS and because of that today psihocardiology is developing more and more. According to WHO depression remains unrecognized in 60 % of cases. Studies predict that by 2020 depression will be the second disability in developed countries. Therefore, it is necessary to conduct timely screening of cardiovascular patients with psychiatric disorders and to develop necessary instruments. Comorbid psychiatric disorders in patients with cardiovascular disease are associated with specific sociodemographic characteristics and reduced quality of life. To do appropriate interventions in these patients thay need to be detected in an early stage. Objective: To investigate whether there is a different psychological profile between patients with STEMI myocardial infarction which were subjected to the primary PCI, cardiac and non cardiac patients on the basis of three parameters such as depression, the level of pessimism / optimism and risk factors of developing cardiovascular disease and to determine their correlation with each other within the group. Patients and Methods: The study included 237 patients, of which 216 valid and completely filled questionnaires and they made the final sample. Subjects were divided into three groups of equal size depending on the status of their disease. The Department of heart disease and blood vessels in KBC Split examined 72 patients who had STEMI myocardial infarction and which were subjected to the primary PCI. Of the total number of patients with cardiac diseases, 52 were treated and tested at the Institute of the heart disease and blood vessels in KBC Split in the Department of cardiology and in the Cardiac ambulance, while the other 20 were interviewed at the Department of cardiology in the County hospital Dr. Fra Mihovil Sučić in Livno. The last group consists of 72 subject’s people who do not suffer from cardiac disease and were tested in Specialist clinic practice of general medicine at the resort of Sirobuja in Split. The measuring instrument was a questionnaire that consisted of three parts. The first part examined the demographics and risk factors for cardiovascular disease. The second part is the measurement scale for optimism and pessimism, while the third part of the survey is actually screening test for depression (PRIME-MD). Results: Examining the eleven risk factors for the development of cardiovascular disease within the three groups of patients (noncardiac, cardiac and STEMI patients) it was found that the proportion of patients who smoke, drink alcohol, have elevated BMI, psychiatric disorders and disease of the thyroid gland is not different in the study groups, and the proportion of patients who have elevated blood pressure, cholesterol, stress, exercise three or more times a week, have diabetes and history of other stroke is higher in the group of patients who had STEMI. The average number of risk factors is in STEMI patients was 4.60 and was significantly higher than in the other two groups. Furthermore, it was found that on a scale of pessimism the highest scores have STEMI patients (24.15), while the scale of optimism recorded the lowest score among the groups (20.65). In the total sample of patients non depressive constitute 41.66 %, mild depression has 25.92 %, 27.78 % high depression and suicidal is 4.63 %. Non cardiac patients are the least depressed patients and the most depressed are cardiac patients (33 % high depression, suicidal 7 %). Chi-square test was used to see the differences in the level of depression between the two groups and found that there is a statistically significant difference, except for a group of STEMI and cardiac patients among who are not recorded differences in levels of depression. Pearson correlation coefficient showed that there was no correlation between risk factors and depression, optimism and pessimism, regardless of the group of respondents. By testing the correlation, we established the existence of a significant negative correlation between optimism and depression, and a significant positive correlation between pessimism and depression, which is especially important in a group of STEMI patients. Testing of differences was determined differences between cardiac patients with varying levels of depression due to a number of risk factors, whereas the other two groups of patients did not record a statistically significant difference. Conclusion: There is a statistically significant difference in the psychological profile of patients with STEMI myocardial infarction which were subjected to the primary PCI, cardiac and non cardiac patients, while there is no significant differences between STEMI patients and cardiac patients. The number of risk factors does not affect to the level of pessimism/optimism in all groups of patients. There are significant differences in the number of risk factors and levels of depression in cardiac patients, while other groups are not reported statistical differences. The level of pessimism/optimism of a group of patients is correlated with some form of depressive behavior.