Between July 1, 2017, and May 1, 2018, we evaluated patients admitted to the center with a presumed diagnosis of STEMI. One criterion for inclusion in the study was age >=18 years old. Another inclusion criterion was the diagnosis of STEMI accompanied by the following criteria was required: chest pain or equivalent symptoms of more than 20 minutes duration within the last 24 hours before admission and, electrocardiographic changes consistent with new or presumed new ST-segment elevations or left bundle branch block, according to third universal definition of myocardial infarction defined by the European Society of Cardiology/ACCF/AHA/World Heart Federation Task Force for the Universal Definition of Myocardial Infarction. STEMI must be primary diagnosed by the emergency medical doctors. Data collection and validation of the diagnosis was then supervised by a physician who was responsible for the quality control of the project.
 Patients were excluded from the study if they developed STEMI after admission in the hospital, or developed STEMI after percutaneous coronary angioplasty or coronary bypass surgery and/or hospitalized in another hospital more than 24 hours before coming to Imam Ali hospital, or who did not sign the consent form to participate in the study.
 Using case report forms, data were collected by a nurse and a research assistant working in the Kermanshah Cardiovascular Research Center (KCRC), who were trained in uniform protocols for patient entry and data gathering. Case report form was developed by the EORP. All completed case report forms were verified and checked for errors by the quality control physician before submission for final analysis, and then forwarded online to the EORP website. We used patients' national identification numbers to avoid duplicate admissions to the registry. The collected data included demographic characteristics (e.g. age), clinical histories (e.g. previous myocardial infarction), admission process (e.g. presenting symptoms), biochemical and electrocardiographic findings (e.g. blood sugar), treatment procedures (e.g. percutaneous coronary intervention, PCI), in-hospital outcomes (e.g. vital status). Standardized definitions of all variables (e.g. clinical diagnoses) were used. Likewise, mortality data (in-hospital) were obtained for all included cases.
 Baseline data including demographic characteristics were compared between men and women. Data were described using mean +- standard deviation (SD) if they were normally distributed; otherwise, frequencies and percentages were reported. Differences between subgroups were assessed using independent t tests for continuous and normally distributed variables and chi-square (or Fisher exact tests) for other variables. We compared the in-hospital mortality rates among women and men and assessed the independent role of sex in patients' mortality using multivariable logistic regression models. Odds ratios (ORs) and 95% confidence Intervals (CIs) were calculated. The body mass index (BMI) >=25, HTN, DM, current smoking, hypercholesterolemia, congestive heart failure (CHF), Killip class (at first presentation) >= II, symptom-to-balloon (STB) time> 360 minutes and door-to-balloon (DTB) time > 90 minutes (18) used as covariates, while the dependent variable was in-hospital mortality. A test was considered statistically significant if the probability value (P value) was less than 0.05. The Statistical Package for Social Science (SPSS) software, version 23 (IBM Corp., Armonk, NY USA) was used for analyzing data.
 STB time was defined as the time between the onset of symptoms to first balloon inflation or first device delivery in the culprit vessel.
 DTB time was defined as the time between patient's arrival at the PCI hospital and the first balloon inflation or first device delivery in the culprit vessel.