Introduction: Patients with COVID-19 can have various and complex coagulation disorders that cause hypercoagulable conditions. Investigating the role of anticoagulants with different doses in the outcome of patients with COVID-19 seems to be needed. Therefore, the present study was conducted with the aim of predicting factors of severe disease, including the number of lymphocytes, LDH, and the recovery status of patients. 
Methods: A cross-sectional study was conducted in patients with COVID-19 hospitalized in Hazrat Rasool Akram (PBUH) Hospital. Study entry includes acute respiratory symptoms caused by COVID-19 disease (uncontrollable cough, dyspnea, prolonged medicine and blood saturation drop) along with lung involvement in chest spiral CT scan without injection, SARS RT-PCR–CO virus test was positive and transfer to intensive care unit (ICU) was indicated. Anticoagulant starting time, type and dose of anticoagulant received and duration of use were recorded. Two groups of prophylaxis dose, higher dose than prophylaxis (medium dose and therapeutic dose) were divided.
Results: Out of the total number of patients referred to Rasul Akram Hospital, 90 people (43 women (47.8%) and 47 men (52.22%)) participated in this study. The average hospitalization in the ICU was 13.50 ± 12.39 days and 17.18 ± 13.36 days in the hospital. Also, the duration of coagulant therapy was 17.13 ± 13.38 days. 53 patients (58.9%) received a prophylactic dose, 28 patients (31.1%) received a therapeutic dose, and 9 patients (10%) received a moderate dose of anticoagulant. Anticoagulant in 74 patients (82.2%) was unfractionated heparin (UFH) and in 16 cases (17.8%) low molecular weight heparin (LMWH). The changes of LDH, number of lymphocytes, dimer, fibrinogen, ferritin and FDP according to the dose of anticoagulant assessed in the three groups of prophylaxis, treatment and no statistically significant difference. The mean of ICU admission days according to different doses of anticoagulant did not show a statistically significant difference.
Conclusions: Finally, the findings obtained from the study showed that the use of different doses of anticoagulant does not cause a difference in the level of LDH, number of lymphocytes, ferritin and FDP at different measurement times. Also, the length of stay in the hospital and the time of hospitalization in the intensive care unit did not differ between the groups receiving prophylactic anticoagulant, medium dose and therapeutic dose.