eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2020-06-22 8 10 337 340 10.12691/ajmcr-8-10-5 AJMCR20208105 article Pramod Theetha Kariyanna 1 Lyudmila Aurora 1 Apoorva Jayarangaiah 2 Vivek Yadav 3 Naseem. A. Hossain 3 Nasrin Akter 3 Moro O. Salifu 3 Isabel M. McFarlane Isabel.McFarlane@downstate.edu 3 Department of Internal Medicine, State University of New York, Downstate Health Sciences University, Brooklyn, New York, U.S.A Department of Internal Medicine, Albert Einstein College of Medicine, NYC Health and Hospitals/Jacobi Medical Center, Bronx, New York-10461, U.S.A Department of Internal Medicine, Brookdale University Hospitals and Medical Center, 1 Brookdale Plaza, Brooklyn, New York- 11212, USA Coronavirus Disease-2019 (COVID-19) is currently a public health emergency and has been listed by the World Health Organization (WHO) as a pandemic. It has commonly been associated with pulmonary manifestations and there is a growing body of evidence of multisystem involvement of the virus. As evidenced by various case reports and cohort studies, COVID-19-associated coagulopathy has been a common manifestation amongst the critically ill and has been associated with increased mortality. The presence of venous thromboembolic events in patients who are critically ill due to COVID-19 has prompted the adoption of anticoagulation regimens aimed at preventing thromboembolic phenomena. Coagulation abnormalities have also been implicated in the progression and the severity of COVID-19 related acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC). There is strong evidence that D-dimer levels help predict which patients are at risk of thromboembolic events, progression to ARDS, DIC, immune dysregulation and mortality. We will review the utility of D-dimer as screening tool and in the risk stratification of COVID-19 patients prone to developing thromboembolic events, DIC, immune dysregulation and death. To date, the studies that have been published show the presence of elevated D-dimer levels in both the adult and pediatric populations and the measured level correlates with disease severity. Studies have also shown the relative increase of D-dimer levels in non-survivors compared to survivors. The elevation of D-dimer levels has shown to guide clinical decision making, namely the initiation of therapeutic anticoagulation and mortality benefit in patients with severe COVID-19 pneumonia compared to severe non COVID-19 pneumonia. Although the current body of literature suggested the use of D-dimer as a risk stratification tool and as a test to augment clinical judgement regarding the initiation of anticoagulation, randomized control trials are needed to fully understand the relationship between COVID-19 infection and the efficacy of D-dimer assays in clinical decision making. http://pubs.sciepub.com/ajmcr/8/10/5/ajmcr-8-10-5.pdf COVID-19 Corona Virus D-dimer microvascular thrombosis and macrovascular thrombosis