Thromboprophylaxis in hospitalized COVID-19 patients: the efficacy and safety of the approved hospital protocol

INTRODUCTION Prothrombotic coagulopathy in COVID-19 has led to a strong recommendation for throm-boprophylaxis in all hospitalized patients, although there are large differences in the dosage regimens among hospitals and their outcomes remain uncertain. OBJECTIVES We aimed to determine the incidence of thrombotic events and bleeding in patients with COVID-19 using the approved local thromboprophylaxis protocol. PATIENTS AND METHODS We adapted a self-developed pharmacological thromboprophylaxis protocol based on clinical and laboratory risk assessment of thrombosis in 350 consecutive patients (median age, 67 years) with confirmed COVID-19, treated in designated wards at a single center in Krakow, Poland from October 10, 2020, to April 30, 2021. We recorded in-hospital venous and arterial thromboembolic events, major or clinically relevant bleeding, and deaths along with other complications related to heparin administration. RESULTS Thromboprophylaxis with low-molecular-weight heparin was administered in 99.7% of patients, 57 (16%) were treated in the intensive care unit. As many as 92% of patients followed the protocol for more than 85% of hospitalization time. Thromboembolic events occurred in 16 patients (4.4%): venous thromboembolism (n = 4; 1.1%), ischemic stroke (n = 4; 1.1%), and myocardial infarction (n = 8; 2.2%). Hemorrhagic complications were observed in 31 patients (9%), including fatal bleeds (n = 3; 0.9%). The overall mortality was 13.4%. The prophylactic, intermediate, and therapeutic anticoagulation preventive strategies with heparin were not related to any of the outcomes. CONCLUSION The thromboprophylaxis protocol approved in our institution was associated with a relatively low risk of thromboembolism and bleeding, which provides additional evidence supporting the adoption of institutional strategies to improve outcomes in hospitalized patients with COVID-19.