Coagulation Abnormalities in Severe COVID-19

Consecutive patients with severe COVID‐19 admitted to Tongji Hospital of Huazhong University of Science and Technology in Wuhan from January 1 to February 13, 2020, were retrospectively enrolled. Exclusion criteria were a bleeding diathesis, hospital stay < 7 days, lack of information about coagulation parameters and medications, and age < 18 years. A retrospective review of the characteristics of these patients was performed through the electronic medical record system of our hospital, the medications and outcomes (28‐day mortality) were monitored up to March 13, 2020. This study was approved by the Ethics Committee of Tongji Hospital (Wuhan, China).
The diagnosis of COVID‐19 was according to World Health Organization interim guidance⁸ and confirmed by RNA detection of the SARS‐CoV‐2 in a clinical laboratory of the Tongji hospital. Severe COVID‐19 was defined as meeting any one of following items, according to the Diagnosis and Treatment Plan of COVID‐19 suggested by National Health Commission of China⁹ : Respiratory rate ≥30 breaths/min; arterial oxygen saturation ≤93% at rest; PaO₂/FiO₂ ≤ 300 mm Hg.
The SIC score system including prothrombin time (PT), platelet count, and sequential organ failure assessment (SOFA) was described in Table 1,⁶ (link) in which the SOFA score contained four items and was originally developed by an international group of experts to describe the time course of muitiple organ dysfunctions using a limited number of routinely measured variables.¹⁰ (link) Meanwhile, in our previous study,³ (link) higher D‐dimer and PT on admission were associated with poor prognosis in patients with COVID‐19. Hence these three parameters were included in this study and the results were recorded at the time the patient meeting the definition of severe COVID‐19. Anticoagulant treatment group was defined as receiving unfractionated heparin or low molecular weight heparin (LMWH) for 7 days or longer,¹¹ (link) which was the most commonly used anticoagulant therapy for COVID‐19 in our hospital.Table 1

ISTH SIC scoring system

Table 1

Item	Score	Range
Platelet count (×109/L)	1	100‐150
	2	<100
PT‐INR	1	1.2‐1.4
	2	>1.4
SOFA score	1	1
	2	≥2
Total score for SIC	≥4

Abbreviations: INR, International Normalized Ratio; SOFA, sequential organ failure assessment.

The coagulation tests, including PT and D‐dimer, were detected using a STA‐R MAX coagulation analyzer and original reagents (Diagnostica Stago). The platelet counts were analyzed by a Sysmex XE‐2100 hematology analyzer (Sysmex).
Normally and abnormally distributed quantitative variables were compared using the Student's t‐test and the Mann‐Whitney U test, respectively. Categorical variables were compared using the chi‐squared test. The results were given as the mean ± standard deviation, median (interquartile range), or number (percentage), wherever appropriate. Categorical and consecutive variables were evaluated by logistic regression analysis for their ability to predict 28‐day mortality. A P value of < .05 was considered statistically significant. Data were analyzed using SPSS 21.0 for Windows (SPSS Inc).