Demographic and clinical characteristics
A total of 194 death patients with COVID-19 were included in the present study. The demographics and baseline characteristics were shown in Table 1. The average age of patients was 69.62 ± 10.98 years, and 133 (68.6%) were male. Of these patients, 145 (74.7%) had at least one of following chronic illnesses: hypertension (92 [63.4%]), diabetes (40 [27.5%]), cardiovascular diseases (39[26.9%]), chronic pulmonary diseases (18 [12.4%]), chronic hepatitis (10 [6.9%]), cerebrovascular diseases (9[6.2%]), malignances (9 [6.2%]), chronic kidney diseases (9 [6.2%]). 66 (45.5%) patients had more than two kinds of these chronic medical illnesses.
The most common symptoms on admission were fever (83%), cough (69.3%), and dyspnea (65.6%). Malaise, myalgia and chills or fatigue were also seen in patients with incidences of 30.2%, 14.9% and 14.1% respectively. In addition, 39 of 194 (20.1%) patients complained of diarrhea, 5 (2.6%) showed abdominal pain, and 39 (20.1%) experienced vomiting, which meant the digestive system was involved on the course of COVID-19. Besides, consciousness disorder occurred in 14 (7.2%) and palpitation occurred in 5 (2.6%) patients, which hinted that the disease might have affected the central nervous system and cardiac system.
Laboratory findings
Among the 194 cases, 185 had laboratory test results and the last test results for each parameter before death were recorded and showed in Table 2. The increased neutrophil (12.84 ± 8.56×109/L) and decreased lymphocyte count (0.58 ± 0.42×109/L) in blood were commonly observed. Nearly half of the patients had elevated ALT and AST test values. Abnormal hs-cTnI and NT-proBNP levels occurred in 82.9% and 91.1% patients. Besides, the other abnormal results included the increased levels of hs-CRP (100%), IL-6 (99.1%) and D-dimer (98.9%) etc.
The serum level of hs-cTnI is an important indicator of myocardial damage and usually used for diagnosing myocardial infarction. (5) We tracked all the results of hs-cTnI tested during 14 days before death. As shown in Figure 1A, the hs-cTnI level began to rise beyond the normal range from Day 13, and peaked at Day 1 with an average value of 1311±2762 pg/mL.
For different age groups, there were significant differences between the group younger than 49 (10.7±8.4) and the other different age groups. The group aged 60-69 years and 70-79 years both had significant higher levels of hs-cTnI than the group aged 50-59 years (37.9±79.8). Besides, there was no significant difference in hs-cTnI levels between the group aged 60-69 years (99.9±206.2) and the group aged 70-79 years (78.8±169.1), meanwhile both groups has notably higher hs-cTnI levels than the group over 80 (37.2±98.0).(Figure 1B) For different sex groups, male patients tended to suffer from apparently higher hs-cTnI levels (83.5±183.4) than female patients (49.5±112.3). (Figure 1C)
Correlations between hs-cTnI and inflammatory parameters
There were 141 (82.9%) patients with abnormal hs-cTnI levels. As shown in Table 3, the inflammatory cytokines were out of the normal range in 20.9%-99.1% patients. Over 95% patients had abnormal ESR, hs-CRP and D-dimer levels. There was a week positive correlation between hs-cTnI and D-dimer levels with a correlation coefficient of 0.343 (p<0.0001). The correlations were of no significances between hs-cTnI and ESR, hs-CRP, IL-1β, IL-6, IL-2R, IL-8, IL-10 and TNF-α levels (all p values>0.05; Supplementary Table 1).
Complications and treatments
Specific complications were documented in 110 (110/194 [55.4%]) patients according to the electronic medical records. (Table 3)ARDS occurred in 62.7% patients, which was the major cause of death. Besides, 45.4% patients underwent cardiac injury with four patients diagnosed as fulminant myocarditis. Other severe complications included acute kidney injury (14.5%), septic shock (9.1%) and DIC (11.8%). Moreover, 56 of 110 death patients developed two or more kinds of these complications.
All patients received supportive treatments as soon as admitted into the hospital. 67.5% patients were treated with oxygen support and 80.9% underwent mechanical ventilation. 70.1% patients received antiviral drugs and 87.6% were empirically given antibacterial medication. Besides, systemic glucocorticoids (e.g., methylprednisolone 40-80mg) and intravenous immune globulin were daily used in 90% and 40.7% patients, respectively. Two patients underwent ECMO support and four patients underwent CRRT therapy.