Therapeutic dosing of low-molecular-weight heparin may decrease mortality in patients with severe COVID-19 infection.

Background: Venous thromboembolism or extensive thrombosis is relatively common in patients with severe COVID-19 infection and has been associated with increased mortality. During the current COVID-19 pandemic, several prophylactic doses and types of low-molecular-weight heparin (LMWH) are being used worldwide; however, there are no high-quality studies or recommendations for an optimal prophylactic LMWH dose.

Objectives: Investigate the relationship between coagulation parameters and the LMWH dose, and mortality and ICU admission in hospitalized patients with severe COVID-19 pneumonia.

Design: Retrospective.

Setting: Tertiary care hospital.

Patients And Methods: Data on clinical features, coagulation parameters and anticoagulant medications of inpatients with severe COVID-19 were collected for the period between 11 March 2020 and 31 April 2020.

Main Outcome Measures: Mortality and ICU admission for prophylactic dose LMWH (0.5 mg/kg twice daily) and therapeutic dose LMWH (1 mg/kg twice daily).

Sample Size: 154 cases.

Results: Ninety-eight (63.6%) patients were treated with the LMWH prophylactic dose and 56 (36.4%) patients were treated with the therapeutic dose. Forty-four (44.9%) of 98 patients using the prophylactic dose LMWH died, while 10 (17.9%) of 56 patients using the therapeutic dose LMWH died (=.001). Mortality was 6.4-fold higher in the prophylactic dose LMWH users than in the therapeutic dose LMWH users (OR=6.5, 95% CI: 2.4-17.6, <.001).

Conclusions: Therapeutic dosing of LMWH may decrease mortality in patients with severe COVID-19 infected pneumonia. More aggressive thromboprophylaxis regimens using higher doses of heparin should be evaluated in prospective studies.

Limitations: Lack of information about bleeding complications. LMWH was not compared with other anticoagulant therapies. There was no comparison between our two groups on the APACHE score. Used different doses of LMWH in different clinics in our hospital. Single-center, retrospective study.

Conflict Of Interest: None.