Background: A few patients with coronavirus disease MESHD 2019 (COVID-19) may progress into irreparable outcomes. Early identification of patients with serious symptoms who may develop critical illness MESHD and even death MESHD is of considerable importance for personalizing treatment and balancing medical resources.Methods: In this retrospective study, demographic, clinical characteristics and laboratory tests from 726 patients with serious COVID-19 from Tongji Hospital (Wuhan, China) were analyzed. The standards for the serious type are guided by the Chinese management guideline for COVID-19. Patients were classified into critical group (174 cases) and severe group (552 cases) based on whether the composite endpoint was reached, and the former group was divided into the survivors (47 cases) and non-survivors (127 cases). Univariable and multivariable logistic regression and receiver operating characteristic (ROC) curve analysis were performed to investigate the risk factors associated with poor prognosis and mortality outcomes.Results: Male TRANS patients accounted for 62.1% and 51.6% in the critical group and severe group, with a median age TRANS of 68 and 65 years, respectively. Among critical cases there was a higher prevalence SERO of chronic obstructive lung disease MESHD obstructive lung disease HP (p = 0.029) and chest distress (p = 0.040) than in severe cases. In the multivariable analysis, the risk factors associated with poor prognosis in severe cases were advanced age TRANS (p = 0.002), high respiratory rate (RR) (p < 0.0001), high lactate dehydrogenase (LDH) level (p = 0.021), high hypersensitive cardiac troponin I (hs-cTnI) level (p < 0.0001), and low platelet counts (p = 0.005) at admission. In the adjusted models, higher mortality outcomes in critical patients were associated with high hs-cTnI level (p = 0.037). By plotting ROC curves of different indices, hs-cTnI and LDH were found to be predictive factors for poor prognosis in patients with severe COVID-19.Conclusions: For the risk assessment of serious COVID-19 patients on admission, advanced age TRANS, high level of RR, LDH, hs-cTnI, and low platelet counts, constitute important risk factors for poor prognosis in severe cases, and the hs-cTnI level can be helpful in predicting fatal outcomes in critically ill patients.