D-dimer is a fibrin degradation product, widely used as a biomarker for thrombotic disorders. A D-dimer value less than 0.5 μg/mL is usually considered normal, and values increase with increasing age and in pregnancy.
The level of D-dimer rises with increased severity of community-acquired pneumonia . Following the outbreak of the COVID-19 pandemic, D-dimer has been identified as a potential indicator for its prognosis in COVID-19 patients.
Admission day D-dimer has shown promise for predicting the disease severity in multiple studies [6–9].
Accurate and widely available prognostic biomarkers can be very useful in the management of COVID-19. This multi-center study aims to assess elevation in D-dimer at the time of admission as a possible prognostic indicator of mortality in COVID-19 patients.
The cutoff value used for D-dimer shows significant variation between the published studies, and there seems to be no consensus yet on what the best cutoff value is to predict severity or mortality. We thus aim to establish the optimal cutoff value for D-dimer that can be used clinically for predicting mortality in COVID-19 patients.
reference link : https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0256744
COVID-19 is a hypercoagulable disorder, with an increased risk of venous and arterial thrombosis6. Numerous studies have been con- ducted to investigate the frequency of PE among COVID-19 patients, and their findings clearly and unambiguously show that the incidence of PE is higher than in non-COVID-19 patients. However, the PE incidence significantly varied across dif- ferent research.
Even though retrospective studies from the beginning of the pandemic reported the incidence of PE usually between 20-30%4,7,9, in a recent
meta-analysis by Longchamp et al3, the PE incidence was estimated to be smaller – 8% over- all and 17% in ICU patients. Compared to those in the medical ward and outpatients, patients in ICU had a higher incidence of PE in the majority of other research3,9. In several studies, the pres- ence of PE in COVID-19 patients was associated with a worse clinical outcome, resulting in more frequent ICU admission, mechanical ventilation, and a longer hospital treatment4,5,9. Table I sum- marizes the most important findings from sev- eral meta-analyses3,6,10-12 that investigated PE in COVID-19 patients.
Elevated D-dimer levels have been linked to pulmonary embolism and poor prognosis in pa- tients with COVID-19 in almost every study that investigated this topic5,9. D-dimer values over 500 μg/L and greater than 1000 μg/L showed high sensitivity (96% and 91%, respectively) but low specificity (10% and 24%, respectively) for the diagnosis of PE in COVID-19 patients in a meta-analysis by Suh et al10.
Even though some studies have suggested using conventional cut-off D-dimer values when considering CTPA in COVID-19 patients suspected of pulmonary embolism10, such an approach should be used with caution. Even though there have been previously a few reports of pulmonary embolism with D-dimer values within the referent range in the literature13, to the best of our knowledge, our report is the first such case description in a patient with COVID-19. In other words, during the COVID-19 pandemic, clinical suspicion of PE is more im- portant than ever in the diagnostic algorithm and should serve as the foundation for implementing other diagnostic methods.
reference link: https://www.europeanreview.org/wp/wp-content/uploads/7971-7975.pdf