Critically-ill COVID-19 patients have frequent thrombotic complications and laboratory evidence of hypercoagulability. The relationship of coagulation tests and thrombosis requires investigation to identify best diagnostic and treatment approaches. We assessed for hypercoagulable characteristics in critically-ill COVID-19 patients using Rotational Thromboelastometry (ROTEM) and explored relationships of D-dimer and ROTEM measurements with thrombotic complications.
Critically-ill adult COVID-19 patients receiving ROTEM testing between March-April 2020 were analyzed. Patients receiving therapeutic anticoagulation prior to ROTEM were excluded. ROTEM measurements from COVID-19 patients were compared to non-COVID-19 patients matched by age, sex, and body mass index. Intergroup differences in ROTEM measurements were assessed using t-tests. Correlations of D-dimer levels to ROTEM measurements were assessed in COVID-19 patients who had available concurrent testing. Intergroup differences of D-dimer and ROTEM measurements were explored in COVID-19 patients with and without thrombosis.
Of 30 COVID-19 patients receiving ROTEM, we identified hypercoagulability from elevated fibrinogen compared to non-COVID-19 patients (FIBTEM MCF: 47+/-13mm vs 20+/-7mm; mean intergroup difference: 27.4mm; 95%CI: 22.1mm-32.7mm; p<0.0001). In our COVID-19 cohort, thrombotic complications were identified in 33%. In COVID-19 patients developing thrombotic complications, we identified higher D-dimer levels (17.5+/-4.3ug/mL vs 8.0+/-6.3ug/mL; mean difference: 9.5ug/mL; 95%CI: 13.9-5.1; p<0.0001) but lower FIBTEM MCF (39.7+/-10.8mm vs 50.1+/-12.0mm; mean difference: -11.2mm; 95%CI: -2.1 to -20.2; p=0.02) compared to patients without thrombosis. We identified negative correlations of D-dimer levels and ROTEM MCF in these patients (r: -0.61; p=0.001).
We identified elevated D-dimer levels and hypercoagulable blood clot characteristics from increased fibrinogen on ROTEM testing in critically-ill COVID-19 patients. However, we identified lower, albeit still hypercoagulable, ROTEM measurements of fibrinogen in COVID-19 patients with thrombotic complications compared to those without. Further work is required to externally validate these findings and to investigate the mechanistic drivers for these relationships to identify best diagnostic and treatment approaches for these patients.
Class IV; epidemiologic.