Association of anticoagulation dose and survival in hospitalized COVID‐19 patients: A retrospective propensity score‐weighted analysis

Background Hypercoagulability may contribute to COVID‐19 pathogenicity. The role of anticoagulation (AC) at therapeutic (tAC) or prophylactic doses (pAC) is unclear. Objectives We evaluated the impact on survival of different AC doses in COVID‐19 patients. Methods Retrospective, multi‐center cohort study of consecutive COVID‐19 patients hospitalized between March 13 and May 5, 2020. Results A total of 3480 patients were included (mean age, 64.5 years [17.0]; 51.5% female; 52.1% black and 40.6% white). 18.5% (n = 642) required intensive care unit (ICU) stay. 60.9% received pAC (n = 2121), 28.7% received ≥3 days of tAC (n = 998), and 10.4% (n = 361) received no AC. Propensity score (PS) weighted Kaplan‐Meier plot demonstrated different 25‐day survival probability in the tAC and pAC groups (57.5% vs 50.7%). In a PS–weighted multivariate proportional hazards model, AC was associated with reduced risk of death at prophylactic (hazard ratio [HR] 0.35 [95% confidence interval {CI} 0.22‐0.54]) and therapeutic doses (HR 0.14 [95% CI 0.05‐0.23]) compared to no AC. Major bleeding occurred more frequently in tAC patients (81 [8.1%]) compared to no AC (20 [5.5%]) or pAC (46 [2.2%]) subjects. Conclusions Higher doses of AC were associated with lower mortality in hospitalized COVID‐19 patients. Prospective evaluation of efficacy and risk of AC in COVID‐19 is warranted.