(P78) The Impact of Concurrent Antithrombotics on COVID-19 Nursing Home Mortality

Introduction/

Objective: COVID-19 is associated with inflammation and increased risk of thrombotic events. Many long-term nursing home (NH) residents are on antithrombotics (ATs) for reasons unrelated to COVID-19 such as anticoagulants for atrial fibrillation or antiplatelets for coronary artery disease. We sought to determine whether coexistent use of ATs among NH residents was associated with reduced mortality at 30 days and 90 days.

Design/Methodology: Using a retrospective cohort design, we reviewed NH residents diagnosed with their initial COVID-19 infection from 6/1 - 12/31/2020. Propensity score matching was used to mimic randomization. Review of electronic medical records and pharmacy claims was performed to identify medications used, date of initial COVID-19 diagnosis, and mortality.

Results: There were 6,957 patients identified as having an initial diagnosis of COVID-19 and a preexisting order for a heparin, an antiplatelet, warfarin or a direct-acting oral anticoagulant (DOAC), or a combination. Eleven percent were under age 65 years, 26% were 65-74 years, 31% were 75-84 years, and 33% were 85 years or older. Sixty-four percent were female. Comorbid conditions were common: 57% had CAD or CHF, 49% had COPD, 47% had DM, 39% had HTN, 33% had CKD, and 25% had AF. Fewer than 10% had a diagnosis of cancer, thrombosis, or sickle cell anemia.
Within 30 days of COVID diagnosis, 15% of the 6,536 patients who were consistently on ATs died. Odds of 30-day mortality for those with anticoagulant (warfarin or DOAC) use was 0.66 (95% CI = [0.51, 0.85]; p = 0.0019) times lower when compared to those not on ATs, by logistic regression. Odds of 30-day mortality for those with antiplatelet use (primarily aspirin or clopidogrel) was 0.81 (95% CI = [0.67, 0.97]; p = 0.0203) times lower when compared to those not on ATs.
Within 90 days of COVID diagnosis 21% of the 6,536 patients who were consistently on ATs died. Odds of 90-day mortality for those with anticoagulant use was 0.69 (95% CI = [0.52, 0.89]; p = 0.0050) times lower when compared to those not on ATs. Antiplatelet use was not associated with a statistically significant reduction in death at 90 days.

Conclusion/

Discussion: Concurrent use of anticoagulant agents significantly reduced mortality in newly diagnosed COVID-19 patients living in NHs after 30 days and 90 days. The use of antiplatelet agents reduced NH mortality at 30 days of COVID-19 diagnosis, but not at 90 days. Further research should explore whether starting ATs in NH residents at the time of a COVID-19 diagnosis or outbreak would reduce mortality, emergency department use, or hospitalization.