Evaluation of the efficacy of anticoagulation therapy in reducing mortality in a nationwide cohort of hospitalized patients with coronavirus disease in Japan.

Abstract Objectives To determine whether anticoagulation therapy improves outcomes in patients with coronavirus disease (COVID-19) in Japan given their lower risk of thrombosis compared with Western cohorts. Methods The efficacy of anticoagulation therapy in hospitalized COVID-19 patients was evaluated using a nationwide registry, the COVID-19 Registry Japan. Inverse probability of weight treatment method was used to adjust for baseline confounders in the anticoagulation and non-anticoagulation groups. Results Of the 1748 patients included, anticoagulants were used in 367 patients (treatment group). The patients in the anticoagulant group were older and predominantly male and often presented with obesity, hyperlipidemia, hypertension, diabetes, and elevated D-dimer levels. The 29-day mortality was 7.6% in the whole cohort (treatment group, 11.2%; no treatment group, 6.6%), 6% in patients who were not treated with steroids (treatment group, 12.3%; no treatment group, 5.2%), and 11.2% in patients treated with steroids (treatment group, 10.5%; no treatment group, 11.8%). Mortality in the whole cohort was similar between the treatment and no treatment groups (p=0.99), and an insignificant decreasing trend in mortality was observed in those treated with steroids (p=0.075). Conclusions Anticoagulants may be beneficial in Asians whose comorbidity and thrombosis risk may differ from those of other ethnic groups.