2.1 Study Design and Participants
This single-center retrospective study included consecutive patients
diagnosed with COVID-19 at Wuhan Huoshenshan Hospital in China, between
February 4 and April 10, 2020. The Wuhan Huoshenshan Hospital was built
in ten days due to the extent of the pandemic, which exceeded the
existing health system capacity. Most of the patients admitted to the
Huoshenshan Hospital were transferred from other hospitals. The study
design was approved by the institutional ethics board. Written informed
consent was waived due to the urgency of the COVID-19 pandemic.
A total of 3,046 adult patients with COVID-19 were initially screened
for the study. Individuals without information regarding disease
severity, survival status, and patients with suspected CAD but not
diagnosed were excluded. In the remaining cohort of 2,954 patients,
1,439 patients were mild/moderate cases and 1,515 were severe/critical
cases. The disease severity was determined according to the clinical
classification criterion in the Diagnosis and Treatment Protocol for
Novel Coronavirus Pneumonia released by the National Health Commission
of China (7th edition) (Pan et al., 2020). Patients who met any of the
following criteria were diagnosed as a severe case: (1) shortness of
breath defined by respiration rate ≥30 breaths/min, (2) oxygen
saturation ≤ 93 at rest, and (3) alveolar oxygen partial
pressure/fraction of inspiration O2(PaO2/FiO2) ≤ 300 mmHg (1 mmHg=0.133
kPa). Patients whose pulmonary imaging showed significant progression of
lesions > 50% within 24-48 hours were also treated as
severe cases. Patients who met any of the following conditions were
diagnosed as critically severe: (1) respiratory failure requiring
mechanical ventilation, (2) shock, and (3) organ failure needing
intensive care unit (ICU) monitoring and treatment. In addition, the
severe/critical cohort was categorized into two groups based on the
presence or absence of pre-existing CAD (165/1,515 [10.9%] and
1350/1,515 [89.1%], respectively), according to clinical diagnosis
and/or medical history on admission.