Troponin I

Clinical characteristics including detailed medical history and physical examination were obtained from each patient by experienced cardiologists. All data were stored in the database of our institution. Routine biochemistry including blood urea nitrogen, creatinine, glucose, complete blood count, CK-MB, troponin I, and C-reactive protein (CRP) was measured at admission. The FPA concentration (Boehringer, Mannheim) was measured by sandwich enzyme-linked immunosorbent assay method from centrifuged blood samples. Peak CK-MB and peak troponin-I levels were monitored with blood samples taken at 8-h intervals in the coronary care unit.
Systolic and diastolic arterial pressure, previous history of CAD, hypertension (HT), diabetes mellitus (DM), hyperlipidemia (HL), and smoking status were evaluated [6 (link)]. HT was defined by considering the following parameters: (i) patients who were diagnosed with HT with the international diagnostic code and/or (ii) patients who were taking one or more of the following medications: angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, beta-blockers, and diuretics treatments for at least 6 months. DM was diagnosed according to at least one of the following criteria: (1) History of DM and taking any anti-diabetic medication; (2) randomly measured blood glucose value of 200 mg/dL or higher; (3) blood glucose level of 126 mg/dL or above after at least 8 h of fasting; and (4) A1c value of 6.5% or higher. Smoking was defined as a regular smoker if occurred at least one cigarette a day in the past month. Family history presence of CAD was defined as the development of atherosclerotic CVD or death from CVD in a first-degree relative (i.e., parent or sibling) before age 55 for males or 65 for females. The presence of HL was defined according to age and sex-adjusted percentiles from the National Health and Nutrition Examination Survey III data [7 (link)]. The height and weight data of the patients were recorded, and body mass index was calculated according to the weight/height(cm)² formula.

This prospective observational study was conducted between January 2015 and April 2017 with patients that were diagnosed with ACS and CCS. ACS diagnoses was created according to the following criteria: Patients with ≥1 mm ST-elevation in consecutive leads related to one of the major coronary arteries’ tertiaries on electrocardiography were accepted ST-elevated myocardial infarction (STEMI) and delivered to angiography laboratory, immediately. In addition, those with ischemic symptoms (typical chest discomfort, shortness of breath, etc.) and ischemic ST-segment depression, or T-wave inversion were taken blood sample for cardiac biomarkers. Elevation in Troponin I/T or creatine kinase myocardial bant (CK/MB) levels was considered to be non-STEMI (NSTEMI) and if these cardiac biomarkers were in normal range, patients were accepted as unstable angina pectoris (USAP) [4 (link)]. Patients incompatible with above-mentioned criteria and have stable ischemic symptoms without elevated cardiac biomarkers were considered to be the CCS. Patients were demonstrated not to have coronary obstructive stenosis and were considered to be the control group [5 (link)]. The study was performed in accordance with the principles stated in the Declaration of Helsinki. The Kanuni Training and Research Hospital Clinical Research Ethics Committee approved the study with 2015/51 number and February 24, 2016 date.