Since December 2019, a pandemic caused by a new coronavirus has spread to more than 170 countries around the world. Worsening infected patients requiring intensive care unit (ICU) admission, associated with 30% of mortality. A part of worsening is mediated by haemostasis deregulation. The primary aim of this study was to determine if haematological biomarkers, in addition to clinical risk factors on hospital admission, predict worsening (defined by ICU admission and/or death) in Covid-19 infected patients, and secondary, if they could predict the occurrence of thrombotic events. Thirty-five of the 99 patients got clinically worse and 8 developed pulmonary embolism (PE). Final model of the logistic regression analysis revealed that oxygenodependence (RR=7.27[1.50-19.31]), fibrinogen levels (RR=1.45[1.17-1.82]), thrombin peak (RR=1.28[1.03-1.59]), monocytes counts below 0.2 G/L (RR=2.88[1.67-3.19]) and prothrombin fragment 1+2 (F1+2) higher than 290 pM (RR=2.39[1.20-3.30]) were associated with clinical worsening. Fibrinogen level threshold of 5.5 g/L, thrombin peak measurement threshold of 99 pM and oxygenodepence allowed prediction of clinical outcome in near than 80% of our cohort. Moreover, using ROC curves, thrombin peak and F1+2 on admission with a threshold of 204 nM and 393 pM were sensitive and specific to predict PE (AUC: 85.7% Se: 70.8% Sp: 100% and AUC: 81.5% Se: 75.0% Sp: 86.8% respectively). In conclusion, we described a rapid decision tree to predict outcome of SARS-CoV-2 infected patients based on fibrinogen, TGA peak and oxygen dependence. Furthermore, thrombin peak and F1+2 seem to be specific haematological marker to predict PE, even in patients with thromboprophylaxis.
Haematological factors of SARS-CoV-2 infection aggravation: a COVID'HEMOS study