J Cardiovasc Disease Res., 2018; 9(4):164-168 A Multifaceted Peer Reviewed Journal in the feld of Cardiology www.jcdronline.org | www.journalonweb.com/jcdr 164 Journal of Cardiovascular Disease Research, 9, Issue 4, Oct-Dec, 2018 Original Article Blood Urea Nitrogen, Creatinine and Urea Nitrogen-to-creatinine Ratio as Predictors of In-Hospital Adverse Cardiac Events in Acute Myocardial Infarction ABSTRACT Background: Kidney dysfunction affects cardiovascular outcome in patients with acute myocardial infarction. Creatinine, urea nitrogen and urea nitrogen-to-creatinine ratio (UCR) are kidney biomarkers routinely measured in patients with acute myocardial infarction. Their implication in acute myocardial infarction has not been validated. Aims: The study aims to investigate the association between urea nitrogen, creatinine and UCR and in-hospital adverse cardiac events in patients with acute myocardial infarction. Methodology: The study design was cohort. Subjects were patients with acute myo- cardial infarction. Blood urea nitrogen and creatinine were measured on admission. The UCR was calculated as ratio of urea nitrogen to creatinine. The observation was performed during hospitalization in ICCU to detect the adverse cardiac events, i.e. death, acute heart failure, cardiogenic shock, reinfarction and rescucitated ventricular arrhytmia. The ROC curve was designed to determine the cut-off point of high urea nitrogen, creatinine and UCR. The bivariate and multivari- able analysis were performed to establish the independent predictors of adverse cardiac events. A p value < 0.05 was a limit of statistics signifcance. Results: The subjects of this research were 424 patients. Among them, 96 subjects (22.6 %) developed in-hospital adverse cardiac events. Subjects with adverse cardiac events had signifcantly higher level of urea nitrogen, creatinine and UCR. The bivariate analysis showed that high urea nitrogen, high creatinine and high UCR were associated with adverse cardiac events. The multivariable analysis showed only high urea nitrogen as an indepen- dent predictor for adverse cardiac events (adjusted OR 3.14 (95 % CI:1.37-7.19, p value 0.007)). Conclusion: High urea nitrogen, creatinine and UCR were associated with increased in-hospital adverse cardiac events. Only high urea nitrogen was an independent predictor for in-hospital adverse cardiac events in patients with acute myocardial infarction. Key words: Urea nitrogen, Urea nitrogen to creatinine ratio, Adverse cardiac events, Acute myocardial infarction. Anggoro Budi Hartopo 1, *, Ira Puspitawati 2 , Irsad Andi Arso 1 , Budi Yuli Setianto 1 1 Department of Cardiology and Vascular Medicine, Faculty of Medicine, Public Health and Nursing Universitas Gadjah Mada – Dr. Sardjito Hospital, Yogyakarta, INDONESIA. 2 Department of Clinical Pathology, Faculty of Medicine, Public Health and Nursing Universitas Gadjah Mada – Dr. Sardjito Hospital, Yogyakarta, INDONESIA. Correspondence Dr. Anggoro Budi Hartopo Department of Cardiology and Vascular Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Radiopoetra Building 2nd Floor West Wing, Jalan Farmako Sekip Utara, Yogyakarta- 55281, INDONESIA. Ph.no: +62 90312 508 25 27 E-mail address: a_bhartopo@ ugm.ac.id Submission Date: 16-05-2017; Revision Date: 27-07-2017; Accepted Date: 09-09-2017. DOI : 10.5530/jcdr.2018.4.37 INTRODUCTION Acute kidney injury and chronic kidney disease have been proven to afect short and long term cardiovascular outcome in patients with acute coronary syndrome and acute myocardial infarction. 1 Serum creatinine level has became popular biomarker for establishing the acute injury or chronic impairment of the kidney. Creatinine clearance calculation has been routinely used to predict outcome in acute myocardial infarction. 2-4 Furthermore, creatinine level has been incorporated in the risk prediction in patients admitted with non ST elevation acute myocardial infarction. In addition to creatinine and creatinine clearance, urea nitrogen is a omnipresent kidney biomarker which is routinely measured in patients with acute myocardial infarction. Urea nitrogen also refects glomerular fltration rate, however its increase is autonomous to the alteration of glomerular fltration rate or serum creatinine level. 5 Activation of renin- angiotensin-aldosterone (RAA) system and neurohormonal system, two proven biological systems prevail in acute myocardial infarction, may cause enhanced kidney proximal tubular reabsorbtion and, therefore, increased urea nitrogen in the blood circulation. 5 Increased blood urea nitrogen due to RAA and neurohormonal system activation may greatly exceed the increase of creatinine level due to intrinsic kidney disease. Te urea nitrogen-to-creatinine ratio (UCR) is a widely used marker of prerenal kidney dysfunction rather than intrinsic parenchymal kidney disease. 6 Tis ratio has been used to diferentiate prerenal azotemia from renal azotemia, due to intrinsic kidney disease, in various clinical settings. 6 In heart failure, the low renal perfusion is associated with prerenal dysfunction due to the increase of neuro- hormonal activation and therefore higher UCR. 7 In acute myocardial infarction, its role is still unknown. Te study aims to investigate the as- sociation between urea nitrogen, creatinine and UCR and in-hospital adverse cardiac events in patients hospitalized with acute myocardial infarction. MATERIALS AND METHODS Te study design is a cohort study. It comprises in-hospital observation of patients with acute myocardial infarction. Subjects were patients with acute myocardial infarction, both ST elevation and non ST elevation acute myocardial infarction, whom were hospitalised in Dr. Sardjito Hospital, Yogyakarta, Indonesia. Te subjects were enrolled consecutively from July 2013 until April 2015. Te inclusion criteria were as follows: (1) diagnosis of ST elevation and non ST elevation acute myocardial infarction, (2) age between 30 and 75 years, (3) onset of anginal pain less than 24 hrs for ST elevation acute myocardial infarction and (4) agree to participate in the study by signing an informed consent. Te exclusion criteria were as follows: (1) history of chronic kidney disease stage V, chronic heart failure NYHA ≥ II, hepatic cirrhosis and malignancy, (2) comorbidites of acute infection and sepsis, (3) previous revascularisation before reaching the hospital, (4) creatinine level ≥ 2.5 mg/dL on admis- sion, (5) comorbidities of upper gastrointestinal bleeding and (6) history of valvular heart disease. All subjects were given an informed consent. Te study has been approved by ethics committee of Faculty of Medicine, Universitas Gadjah Mada. Subjects were admitted, assessed and managed in emergency unit based on the diagnosis. Te diagnosis of ST elevation and non ST elevation acute myocardial infarction were defned according to international guideline