[Clinical characteristics and outcome of 64 patients with severe COVID-19]

Objective: To investigate the causes of death in patients with severe COVID-19. Methods: A retrospective analysis was performed on 64 patients with severe COVID-19 admitted to Wuhan Pulmonary Hospital from January 12, 2020 to February 28, 2020. There were 36 males and 28 females, aging from 44 to 85 years[median 68 (62, 72)]. Fifty-two patients (81%) had underlying comorbidities. The patients were divided into the death group (n=40) and the survival group (n=24) according to the treatment outcomes. In the death group, 24 were male, and 16 were female, aging from 49 to 85 years [median 69 (62, 72)], with 31 cases (78%) complicated with underlying diseases. In the survival group, there were 12 males and 12 females, aging from 44 to 82 years[median 66 (61,73)], with 21 cases (88%) with comorbidities. Clinical data of the two groups were collected and compared, including general information, laboratory examinations, imaging features and treatments. For normally distributed data, independent group t test was used; otherwise, Mann Whitney test was used to compare the variables. χ(2) test and Fisher exact test was used when analyzing categorical variables. Results: The median of creatine kinase isozyme (CK-MB) in the death group was 19.0 (17.0,23.0) U/L, which was higher than that in the survival group 16.5 (13.5,19.6) U/L. The median level of cTnI in the death group was 0.03 (0.03, 0.07) μg/L, which was significantly higher than that in the survival group (0.02, 0.03) μg/L, with a statistically significant difference between the two groups (P=0.007). The concentration of myoglobin in the death group was 79.5 (28.7, 189.0) μg/L, which was higher than 33.1 (25.7, 54.5) μg/L in the survival group. The level of D-dimer in the death group was 2.0 (0.6, 5.2) mg/L, which was higher than 0.7 (0.4, 2.0) mg/L in the survival group. The LDH level of the death group was 465.0 (337.5,606.5) U/L, which was higher than that of the survibal group, 341.0 (284.0,430.0) U/L, the difference being statistically significant (P=0.006). The concentration of alanine aminotransferase in the death group was 40.0 (30.0, 48.0) U/L, which was higher than 32.5 (24.0, 40.8) U/L in the survival group, and the difference was statistically significant (P=0.047).Abnormal ECG was found in 16 cases (62%) in the death group, which was significantly higher than that in the survival group (29%), the difference being statistically significant (P=0.024) .The main causes of death were severe pneumonia with acute respiratory distress syndrome (ARDS, n=20), acute heart failure(n=9), atrial fibrillation(n=3) and multiple organ dysfunction syndrome (MODS, n=3). Conclusions: ARDS caused by severe pneumonia and acute heart failure and atrial fibrillation caused by acute viral myocarditis were the main causes of death in severe COVID-19 patients. Early prevention of myocardial injury and treatment of acute viral myocarditis complicated with disease progression may provide insights into treatment and reduction of mortality in patients with severe COVID-19.