International Journal of Research and Review DOI: https://doi.org/10.52403/ijrr.20210890 Vol.8; Issue: 8; August 2021 Website: www.ijrrjournal.com Original Research Article E-ISSN: 2349-9788; P-ISSN: 2454-2237 International Journal of Research and Review (ijrrjournal.com) 682 Vol.8; Issue: 8; August 2021 Immature Platelet Fraction (IPF) Levels in Acute Coronary Syndrome (ACS) Patients Enna Berkah Sari 1 , Nizam Zikri Akbar 2 , Herman Hariman 1 1 Department of Clinical Pathology, Faculty of Medicine, Universitas Sumatera Utara (USU) / Haji Adam Malik Hospital Medan 2 Department Cardiovascular and Vascular Disease, Faculty of Medicine, Universitas Sumatera Utara (USU) / Haji Adam Malik Hospital Medan Corresponding Author: Enna Berkah Sari ABSTRACT Background: Acute Coronary Syndrome (ACS) is a major cardiovascular problem because it causes high hospital admissions and mortality rates. Acute Coronary Syndrome is divided into 3 (three), namely: unstable angina pectoris (UAP), myocardial infarction without ST segment elevation (NSTEMI), and myocardial infarction with ST segment elevation (STEMI). In addition to changes in biomarkers of heart injury, the platelet index (IPF = immature platelet fraction) will also change the level difference between STEMI with NSTEMI/UAP. Objective: To determine the differences in IPF levels of ACS patients with STEMI and NSTEMI/UAP Method: Observational analytic with cross sectional approach. The subjects of this study were 80 patients who came to the emergency installation of integrated heart center Emergency Room Haji Adam Malik Hospital Medan from May 2019 to September 2019 and was diagnosed with ACS (STEMI or NSTEMI/ UAP). The sample in the study was the patient's venous blood and put it in an EDTA tube, then immediately checked the IPF value/level using the automatic hematology analyzer. Patients with heart failure or patients with thrombocytopenia were not included in this study. Results: In this study, the demographic characteristics of the ACS patients based on gender were male 77.5% STEMI and 87.5% NSTEMI/UAP while women 22.5% STEMI and 12.5% NSTEMI/UAP. The results of the STEMI patient's IPF levels Compared with NSTEMI/UAP, the median is 6.2 (3.5-16.8) VS 2.9 (0.7-12) with a p-value of 0.0001. Conclusion: The characteristics of ACS patients based on the results of sex were that there were more men with NSTEMI/UAP than those with STEMI. There was a significant difference in the IPF levels of STEMI with NSTEMI/UAP. Keywords: Immature Platelet Fraction (IPF), Acute Coronary Syndrome (ACS), ST-Segment Elevation Myocardial Infarction (STEMI), Non ST-Segment Elevation Myocardial Infarction (NSTEMI), Unstable Angina Pectoris (UAP). BACKGROUND Acute coronary syndrome (ACS) is a group of symptoms caused by an acute disruption of coronary artery blood flow, generally caused by narrowing of the coronary arteries due to atherosclerotic plaques which then experience a tear and this triggers the occurrence of blood clots (Ibanez B, 2017), and is a a major cardiovascular problem because it causes high hospital admissions and mortality rates (PERKI, 2018). Acute coronary syndrome is a process that begins with atherosclerosis in the form of waxy plaques or crusts that cause total or sub-total narrowing and blockage of the coronary arteries, so that blood flow is not sufficient to drain the heart muscle and then symptoms of ischemia and damage to the heart muscle (necrosis / infarction). Plaque caused by narrowing of the coronary arteries can be mild to severe,