The effectiveness of COVID-19 vaccination remains unknown in patients with hematologic malignant disease who have an impaired humoral immunity from both treatment and disease. Phase 3 registration studies of COVID-19 vaccines excluded patients with immunosuppression or immunosuppressive therapies. 1,2 Despite this, professional organizations suggest vaccination, or even its prioritization, for patients with cancer. 3 As the US Centers for Disease Control loosens pandemic-related precautions for vaccinated people, a better understanding of the vaccine response among patients with hematologic malignant disease is critical.

Background SARS-CoV-2 infection has noted derangements in coagulation markers along with significant thrombotic complications. Post-mortem examinations show severe endothelial injury and widespread thrombotic microangiopathy in the pulmonary vasculature. Early reports describing the use of prophylactic anticoagulation demonstrated improved survival, leading to the adoption of prophylactic and therapeutic anticoagulation guided by D-dimer levels. The clinical usefulness of D-dimer values, trends, and more intensive anticoagulation remains an area of clinical interest. Objectives Assess the outcomes and laboratory trends in COVID-19 patients stratified by intensity of anticoagulation at time of admission. Patients and methods Retrospectively review the differences in clinical outcomes and laboratory trends in patients hospitalized with COVID-19 in the Lifespan Health System. Results Between 27 February and 24 April 2020, 468 patients were hospitalized. Initial use of high-intensity thromboprophylaxis was associated with improved 30-day mortality (adjusted RR 0.26; 95% confidence interval [CI], 0.07–0.97; p = 0.045) without a significant increased rate of bleeding ( p = 0.11). In severe COVID-19, D-dimer significantly increased during hospitalization with standard thromboprophylaxis ( p < 0.001) but remained stable or decreased with high-intensity prophylaxis or therapeutic anticoagulation. Conclusion Patients who received high-intensity prophylactic anticoagulation had a downtrend in D-dimer levels and improved 30-day mortality. This suggests a role in anticoagulation in mitigating adverse outcomes associated with COVID-19; however, further randomized, prospective studies are needed.