Introduction: Coronary heart disease is the most frequent form of cardiovascular disease (CVD), and also one of the most common causes of death in the world. Acute coronary syndrome (ACS) is highlighted in this work as the most widespread clinical syndrome in everyday practice. Several manifestation of ACS are unstable angina pectoris (API); non ST elevation myocardial infarction (NSTEMI) and ST elevation myocardial infarction (STEMI). Due to its specific treatment and given the newly emerging circumstances caused by the spread of COVID-19, we chose to investigate NSTEMI patients in this study Research goals: The main aim of this research is to compare the diagnostic parameters, treatment and outcomes in two groups of patients hospitalized in 2019 and 2021 because of NSTEMI . Data subjects and methods: By inspecting the KBC Rijeka electronic patient database, a retrospective survey included 217 patients hospitalized at the Clinic for Heart and Blood Vessel diseases, divided in two groups. Inclusion criteria were patient's age above18 years and discharge diagnosis of NSTEMI. Consequently, the conditions for a comparative analysis of the 2021 with the 2019 database, referring to the graduate thesis of “Lenčić, D. (2020). TRENDOVI U LIJEČENJU I ISHODI PACIJENATA S AKUTNIM INFARKTOM MIOKARDA BEZ ST ELEVACIJE U KLINIČKOM BOLNIČKOM CENTRU RIJEKA“ were reached. Results: The COVID-19 pandemic has reduced the number of hospitalizations in 2021. The study analysis shows that the hospitalised subjects are predominantly of the male sex. Looking at CVD risk factors, the emphasis is placed on changing the bad living habits by active participation of the individual. In 2021, significantly more PCIs have been made. The second group of patients presents an evident increase in the Troponin T with a significant drop in LVEF. The length of the hospitalisation duration in 2021 is significantly shorter. Conclusion: Despite the COVID-19 pandemic, the treatment of NSTEMI patients in KBC Rijeka remains successful.