key: cord-288222-8fqfbys2 authors: Hardy, Michaël; Michaux, Isabelle; Lessire, Sarah; Douxfils, Jonathan; Dogné, Jean-Michel; Bareille, Marion; Horlait, Geoffrey; Bulpa, Pierre; Chapelle, Celine; Laporte, Silvy; Testa, Sophie; Jacqmin, Hugues; Lecompte, Thomas; Dive, Alain; Mullier, François title: Prothrombotic Disturbances of Hemostasis of Patients with Severe COVID-19: a Prospective Longitudinal Observational Study date: 2020-10-24 journal: Thromb Res DOI: 10.1016/j.thromres.2020.10.025 sha: doc_id: 288222 cord_uid: 8fqfbys2 nan studies only describe the longitudinal follow-up of hemostasis parameters -a worrying gap in the close assessment of the course of the hemostasis disturbances during the acute phase of the disease. The aim of this prospective study was therefore to describe the longitudinal changes in hemostasis parameters assessed daily in 21 COVID-19 patients during their intensive care unit (ICU) stay. Our main findings were that (i) daily standard measurements consistent with a prothrombotic state persisted over the first days and improved thereafter, but did not normalize in all patients; (ii) increased thrombin potential (hypercoagulability) and decreased fibrinolysis were frequent and (iii) a high inter-patient variability was observed. The study was conducted at the CHU UCL Namur (Godinne site, Belgium) after approval from the local Ethics Committee (NUB: B0392020000031). All adult patients managed at the ICU for an RT-PCR-confirmed SARS-CoV-2 infection from March 27 to April 24, 2020 were considered for inclusion. One patient was not included due to refusal of advanced respiratory support or resuscitation. 2-12). The patient who fulfilled ISTH criteria for overt DIC died, as two other did after confirmed thrombotic complications, which were considered as main contributors of death. Twelve patients presented at least one bleeding event during the study period (major according to the ISTH in six; no deaths). Changes in hemostasis parameters and C-reactive protein (CRP) monitored daily during ICU stay are represented in Figure 2 ; in total there were 354 patients-days. Patients initially were in a high inflammatory state (median CRP levels of 204 mg/dL during the first ten days after ICU admission); CRP levels progressively decreased over time thereafter. Daily platelet counts were often normal and never below 70x10 9 /L. Prothrombin time was only moderately (+3 to +6 seconds) and transiently increased in four patients, and markedly increased (+6 seconds) in the patient who fulfilled overt DIC criteria. Fibrinogen levels were markedly and persistently high (median value over the ICU stay: 665 mg/dL). The same held true for factor VIII levels (median value over the ICU stay: 304 %). The median value of D-dimers levels was 3'440 ng/mL, reaching very high levels in seven patients, above the upper limit of measurement (20,000 ng/mL), and tended to decrease over time. These findings are in line with previous reports (2) . In addition they show that the increase in D-Dimers levels is a sustained process despite heparin administration (even with intensified prophylactic regimens), clinical improvement and decrease in CRP levels. Antithrombin deficiency (<80%) was detected in 13 patients, severe (<50%) in three, contributing to hypercoagulability. There was very little evidence for a consumptive process though since platelet counts were preserved, clotting times were only slightly prolonged, and fibrinogen was increased, not decreased. One of the best approaches to evidence hypercoagulability in vitro is thrombin generation, which is now more accessible in the clinical environment thank to automated analyzers. Neutralization of heparin permitted the use of reagents more sensitive to coagulation abnormalities (i.e. STG-ThromboScreen) (5) . At variance with previous reports we observed increased thrombin potential (5-7), median ETP values being above the published reference range (8) over the first week after ICU admission. Further work is required to understand the discrepant reports. PAI-1 plasma levels were increased at some time-points at least since the start of the observation period of all patients, fitting with the reduced global fibrinolytic capacity we observed. Published data so far are consistent with defective fibrinolysis in COVID-19 patients (which is not unique to this infectious condition), using viscoelastometric assays modified with tPA addition (5, 6, 9) . It is intriguing that D-dimers plasma levels can be so high with defective fibrinolysis. As already hypothesized, this could be due to extravascular (e.g. pulmonary alveoli) fibrin deposits and tissue, not intravascular, fibrinolysis (10). Importantly, laboratory markers showed complex temporal profiles during the ICU stay, which were quite variable among patients (Figure 2 see also companion paper with individual data). For the two functional integrative tests (ETP and GFC), median ranges between daily extreme values among patients were 96% and 94 minutes respectively; median ranges for intraindividual extreme values over the whole ICU observation period were 49% and 25 minutes, respectively. This is a hint for a varying thrombotic risk, and anticoagulation intensity could be tailored in a timely manner with frequent reassessments to minimize the bleeding risk. In light of these results and of the current knowledge on hemostasis disturbances of COVID-19 patients, we suggest that a close monitoring of a sensible set hemostatic parameters would be useful to assess individual thrombotic risk. We identified an increased thrombin potential and a decreased fibrinolytic capacity using newly available tests, which are suitable for clinical use and decision making in real time. Further prospective and preferably multicenter studies using standard operating protocols for the management of COVID-19 patients are required to validate the clinical usefulness of such a monitoring approach. (8)). The population with laboratory testing at each day is shown under the individual plots. D0 is the day of admission to an ICU, but not necessarily in Namur (there were 11 transfers from a Belgian ICU to Namur ICU and one patient already admitted to Namur ICU before the start of the study). Of note there were less tests during the first few days (transfers), and less results as well beyond D20 (censoring or discharge). Results of GFC are represented with a logarithmic scale. COVID-19 versus HIT hypercoagulability Features of severe COVID-19: A systematic review and meta-analysis Prevention of thrombotic risk in hospitalized patients with COVID19 and hemostasis monitoring: Proposals from the French Working Group on Perioperative Haemostasis (GIHP) the French Sdy Group on Thrombosis and Haemostasis (GFHT), in collaboration with the French Society for Anaesthesia and Intensive Care (SFAR) A new assay for global fibrinolysis capacity (GFC): Investigating a critical system regulating hemostasis and thrombosis and other extravascular functions Studies on hemostasis in COVID-19 deserve careful reporting of the laboratory methods, their significance and their limitations Hypofibrinolytic state and high thrombin generation may play a major role in sars-cov2 associated thrombosis Evaluation of COVID-19 coagulopathy; laboratory characterization using thrombin generation and nonconventional haemostasis assays Thrombin generation measurement using the ST Genesia Thrombin Generation System in a cohort of healthy adults: Normal values and variability Fibrinolysis Resistance: A Potential Mechanism Underlying COVID-19 Coagulopathy Management of the thrombotic risk associated with COVID-19: guidance for the hemostasis laboratory The authors would like to thank Professor Bernard Chatelain (Université catholique de Louvain) for providing very sound and helpful advice on the content of the manuscript. The authors would like also to thank Mrs Justine Baudar, Mrs Maité Guldenpfennig and Mr Philippe Devel for performing the experiments. Finally, we would like to thank Ms Norma Ceesay for carefully editing the manuscript.