Introduction: Cardiovascular diseases are one of the leading causes of death in the world. Acute coronary syndrome, as one of the seven forms of coronary heart diseases, is the most common form we encounter in everyday practice. Acute coronary syndrome can be divided into three different clinical entities, NAP, STEMI and NSTEMI. Treatment of STEMI includes emergency PCI and drug treatment while NAP is an entity that requires drug treatment and follow-up due to the possibility of transition to IM. NSTEMI is treated depending on the degree of risk of every patient and, due to the specificity of treatment, is the subject of this study. Aim: The aim of this study was to demonstrate differences in treatment between the two groups of patients 5 years apart and to study their outcomes. Materials and methods: This research was retrospective. A total of 247 patients were treated and the data of their treatment was collected through the hospital information system. Patients were divided into two groups, the first from year 2014 and the second from year 2019. The condition for inclusion in the study was that they were admitted to the Clinic for Cardiovascular Diseases at the University Hospital Center Rijeka between January 1st and April 31st and discharged under the diagnosis of NSTEMI. Hospital treatment, outcomes, and follow-up for up to 12 months after discharge were also monitored. Results: Patients treated in 2014 had fewer coronary angiograms and invasive treatments and were treated more with standard drug therapy. In patients treated in 2019, multiple diagnostic coronary angiograms and PCIs were performed. The duration of hospitalization was significantly shortened in the second group of patients. The total number of MACEs, hospitalizations, and mortality in the total follow-up of 12 months were significantly lower in patients treated in 2019. Conclusion: Treatment of patients with NSTEMI requires a specific approach based on recent guidelines. The diagnostic and therapeutic approach to these patients at the Clinical Hospital Centre Rijeka shows a significant qualitative shift through the examined years.