239. Acute Thromboembolism in Non-ICU Hospitalized Patients with COVID-19 infection: Examining the Impact of Prior COVID Vaccination

Abstract

Abstract Background Patients hospitalized with severe COVID-19 infections are at risk for acute thromboembolism. There are few data on the impact of vaccines on COVID-associated acute thromboembolism (CA-ATE) in patients hospitalized with COVID-19 infection. Methods Retrospective cohort of CA-ATE between March 2020 and March 2022 (Torrance Memorial Medical Center, pre-pandemic ATE incidence < 1%). Inclusion criteria were confirmed COVID infection, > 18 years, not admitted to ICU, and standard-dose thromboprophylaxis. Exclusion criteria were pregnancy, partial vaccination, and therapeutic dose anticoagulation. Primary outcome was CA-ATE incidence identified by routine clinical testing. We performed a multiple logistic regression for CA-ATE risk factors. Results Of 3,218 hospitalized COVID-19 patients, 1,428 patients were included; 185 were vaccinated (13%) and 1,243 unvaccinated (87%). Vaccinated status was associated with older age, diabetes, heart failure, and chronic kidney disease (p< 0.01). CA-ATE was noted in 7.0% (2.2% deep vein thrombosis (DVT), 0.5% pulmonary embolism (PE), 2.7% myocardial infarction (MI), 1.6% Ischemic stroke (IS)) in the vaccinated and 3.9% (2.7% DVT, 1.5% PE, 1.0% MI, 0.8% IS) in the unvaccinated. In our multivariate model, we found no significant difference in incident CA-ATE between vaccinated and unvaccinated (7.0% vs 3.9%, adj OR=1.35, [95% CI 0.67-2.58], p=0.38). CA-ATE was associated with older age (68 vs 61 years, OR=1.03, [95% CI 1.01-1.05], p=0.01) and heart failure (24% vs 7%, OR=2.84, [95% CI 1.35-6.00], p=0.006). No significant difference was seen in mortality (3.8% vs 4.8%, OR=0.79, [95% CI 0.35-1.69], p=0.56), CRP AUC24hr (5.7 vs 4.7, p=0.18), or D-dimer AUC24hr (596 vs 653, p=0.77) between vaccinated and unvaccinated patients. Table 2 Primary Outcomes in SARS-CoV-2 Patients Who Received Standard Chemo-thromboprophylaxis. After performing a multiple logistic regression, there was no statistically significant difference between vaccinated and unvaccinated groups. Older age (OR=1.03, [95% CI 1.01-1.05], p=0.011) and Heart Failure (OR=2.84, [95% CI 1.35-6.00], p=0.006) were the most influential factors for thrombosis. Conclusion Adult, non-ICU, hospitalized, COVID-19 patients are at high risk for ATE. We found no association between vaccination status and ATE, but older age and congestive heart failure were predictive in this population. Decisions to anticoagulate non-ICU patients hospitalized with acute COVID-19 infections may not need to consider COVID vaccination status in as part of medical decision making, but may instead need to focus on underlying, high-risk, co-morbidities. Disclosures James McKinnell, M.D., Eli Lilly: Grant/Research Support|Eli Lilly: Funds Paid To Instituion for Clinical Research|Genentech: Grant/Research Support|Genentech: Funds to Insitution for Clinical Trial Work|Gilead: Grant/Research Support|Gilead: Paid to Institution for clinical research|Pfizer Pharmaceutc: Grant/Research Support|Pfizer Pharmaceutc: Funds to Institution for FDA Clinical Research|Thermo Fisher: Advisor/Consultant Loren G. Miller, MD MPH, ContraFect: Grant/Research Support|GSK: Grant/Research Support|Medline: Grant/Research Support|Merck: Grant/Research Support Loren G. Miller, MD MPH, ContraFect: Grant/Research Support|GSK: Grant/Research Support|Medline: Grant/Research Support|Merck: Grant/Research Support.