Association of mortality and aspirin use for COVID-19 residents at VA Community Living Center Nursing Homes

Background/Objectives: Coronavirus disease 2019 (COVID-19) is associated with a hypercoagulable state and increased thrombotic risk in infected individuals. Several complex and varied coagulation abnormalities were proposed for this association1 .Acetylsalicylic acid(ASA, aspirin) is known to have inflammatory, antithrombotic properties and its use was reported as having potency to reduce RNA synthesis and replication of some types of coronaviruses including human coronavirus-299E (CoV-229E) and Middle East Respiratory Syndrome (MERS)-CoV 2,3. We hypothesized that chronic low dose aspirin use may decrease COVID-19 mortality relative to ASA non-users. Methods: This is a retrospective, observational cohort analysis of residents residing at Veterans Affairs Community Living Centers from December 13, 2020, to September 18, 2021, with a positive SARS-CoV-2 PCR test. Low dose aspirin users had low dose (81mg) therapy (10 of 14 days) prior to the positive COVID date and were compared to aspirin non-users (no ASA in prior 14 days). The primary outcome was mortality at 30 and 56 days post positive test and hospitalization within 14 days of positive test result. Results: We identified 1.823 residents who had SARS-CoV-2 infection and 1,687 residents were eligible as a final analytic sample after excluding high dose and intermittent/partial dose aspirin users. Overall mean age was 72.28+/-11.66 years and 3.3% (n=67) female in the final analytic sample. Among the 511 (30.3%) residents taking chronic low dose aspirin, 30-day mortality after an initial SARS-CoV-2 test establishing infection was 6.46% (n=33) compared to 10.29% (n=121) of non-users (SMD >0.1). 56-day mortality after initial SARS-CoV-2 test establishing infection was 9.0% (n=46) compared to 13.18% (n=155) not taking low dose aspirin (SMD >0.1). Cox proportional hazards model showed that aspirin use was independently associated with a reduced risk of 30 days of mortality (adjusted HR, 0.60, 95% CI, 0.40-0.90) and 56 days of mortality (adjusted HR, 0.67, 95% CI, 0.47-0.95) Conclusion: In this retrospective observational study of VA Community Living Center residents infected with SARS-CoV-2, low dose aspirin use for primary or secondary prevention of cardiovascular events is associated with lower COVID-19 mortality and fewer breakthrough cases. Although additional randomized controlled trials are required to understand these associations and the potential implications more fully for improving care, aspirin remains a medication with known side effects and clinical practice should not change based on these findings.