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Published on: November 26, 2013
Effect of Thromboprophylaxis on Clinical Outcomes After COVID-19 Hospitalization
Tracy Y Wang1, Abdus S Wahed2, Alison Morris3
1Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina (T.Y.W., A.P.).
Insights
Extended anticoagulation with apixaban after COVID-19 hospitalization did not significantly reduce death or thromboembolism. This study on post-COVID-19 thromboprophylaxis was inconclusive due to early termination and low event rates.
Area of Science:
- Cardiology
- Infectious Diseases
- Pharmacology
Background:
- Patients hospitalized with COVID-19 face a higher risk of thromboembolism.
- The effectiveness of extended thromboprophylaxis post-discharge remains uncertain.
Purpose of the Study:
- To evaluate if anticoagulation with apixaban is more effective than placebo in preventing death and thromboembolic events in patients after COVID-19 hospitalization.
Main Methods:
- A prospective, randomized, double-blind, placebo-controlled trial involving 1217 adult patients hospitalized with COVID-19.
- Participants received either 2.5 mg of apixaban or a placebo twice daily for 30 days post-discharge.
- Primary endpoints included a composite of death, arterial, and venous thromboembolism; safety endpoints were major and clinically relevant nonmajor bleeding.
Main Results:
- The primary endpoint occurred in 2.13% of the apixaban group and 2.31% of the placebo group, showing no significant difference.
- Major bleeding occurred in 0.4% with apixaban versus 0.2% with placebo. Clinically relevant nonmajor bleeding was 0.6% vs 1.1% respectively.
- The study was terminated early due to low event rates and declining COVID-19 hospitalizations, leading to imprecise results.
Conclusions:
- The incidence of death or thromboembolism was low in this post-COVID-19 hospitalization cohort.
- Due to early termination and low event rates, the study's findings are imprecise and inconclusive regarding apixaban's efficacy for extended thromboprophylaxis.
Background:
Patients hospitalized with COVID-19 have an increased incidence of thromboembolism. The role of extended thromboprophylaxis after hospital discharge is unclear.
Objective:
To determine whether anticoagulation is superior to placebo in reducing death and thromboembolic complications among patients discharged after COVID-19 hospitalization.
Design:
Prospective, randomized, double-blind, placebo-controlled clinical trial. (ClinicalTrials.gov: NCT04650087).
Setting:
Done during 2021 to 2022 among 127 U.S. hospitals.
Participants:
Adults aged 18 years or older hospitalized with COVID-19 for 48 hours or more and ready for discharge, excluding those with a requirement for, or contraindication to, anticoagulation.
Intervention:
2.5 mg of apixaban versus placebo twice daily for 30 days.
Measurements:
The primary efficacy end point was a 30-day composite of death, arterial thromboembolism, and venous thromboembolism. The primary safety end points were 30-day major bleeding and clinically relevant nonmajor bleeding.
Results:
Enrollment was terminated early, after 1217 participants were randomly assigned, because of a lower than anticipated event rate and a declining rate of COVID-19 hospitalizations. Median age was 54 years, 50.4% were women, 26.5% were Black, and 16.7% were Hispanic; 30.7% had a World Health Organization severity score of 5 or greater, and 11.0% had an International Medical Prevention Registry on Venous Thromboembolism risk prediction score of greater than 4. Incidence of the primary end point was 2.13% (95% CI, 1.14 to 3.62) in the apixaban group and 2.31% (CI, 1.27 to 3.84) in the placebo group. Major bleeding occurred in 2 (0.4%) and 1 (0.2%) and clinically relevant nonmajor bleeding occurred in 3 (0.6%) and 6 (1.1%) apixaban-treated and placebo-treated participants, respectively. By day 30, thirty-six (3.0%) participants were lost to follow-up, and 8.5% of apixaban and 11.9% of placebo participants permanently discontinued the study drug treatment.
Limitations:
The introduction of SARS-CoV-2 vaccines decreased the risk for hospitalization and death. Study enrollment spanned the peaks of the Delta and Omicron variants in the United States, which influenced illness severity.
Conclusion:
The incidence of death or thromboembolism was low in this cohort of patients discharged after hospitalization with COVID-19. Because of early enrollment termination, the results were imprecise and the study was inconclusive.
Primary Funding Source:
National Institutes of Health.
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