Long-term course of ambulatory patients with COVID-19 initially treated with enoxaparin vs. no anticoagulation: Final analysis of the OVID randomized trial

Background Early thromboprophylaxis does not prevent hospital admissions and death among outpatients with symptomatic COVID-19. Its impact on long-term outcomes, including long-COVID symptoms and performance status, is unknown. Methods The OVID trial randomized outpatients older than 50 years with acute COVID-19 to receive either subcutaneous enoxaparin 40 mg once daily for 14 days or standard of care (no thromboprophylaxis). In this follow-up study, we assessed the 2-year outcomes, including all-cause hospitalization and death, cardiovascular events, long-COVID symptoms, and functional limitations based on the post-COVID-19 functional status scale (PCFS) and EQ-5D5L scale. Results Of 469 potentially eligible patients, 468 survived, of whom 439 (mean age: 59 years; 54% men) participated in the post-OVID study. There was no difference in term of hospitalization and death (8.3% in the treatment group vs 10% in controls; RR: 0.83, 95%CI: 0.5-1.5), and of cardiovascular events between groups. The risk of presenting with long-COVID symptoms was similar in the two groups (44% in the treatment group vs 47% in the standard of care group), with no difference between groups also concerning individual symptoms. A PCFS grade of 1-3, indicating light-to-moderate functional limitation, was recorded in 15% of patients in each group (OR: 0.98, 95% CI: 0.6-1.7). No patients reported severe limitations (PCFS grade 4). Median EQ-VAS score was 85 on 100 points (IQR: 80-90 for the Standard of Care group and 75-90 for the Enoxaparin group). Conclusion Early thromboprophylaxis does not improve long-term, two-year clinical and functional outcomes among symptomatic ambulatory patients with acute COVID-19.