Junnan Li,1,2,* Ling Lin,3,* Wenjuan Peng,1,2,* Wei Zhou,4 Ligang Zhang,3 Wenjuan Ji,3 Ziruo Ge,5 Jianming Lai,6 Wei Zhang,5 Zhenghua Zhao,7 Jianping Duan,6 Zhihai Chen5 

1Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China; 2Beijing Institute of Infectious Diseases, Beijing, People’s Republic of China; 3Department of Infectious Disease, Yantai City Hospital for Infectious Disease, Yantai, People’s Republic of China; 4Department of Public Health Clinical Center, Dalian, People’s Republic of China; 5Center of Infectious Disease, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China; 6Department of Infectious Disease, Qingdao No 6 People’s Hospital, Qingdao, People’s Republic of China; 7Department of Infectious Disease, Tai’an City Central Hospital, Tai’an, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Jianping Duan, Department of Infectious Disease, Qingdao No 6 People’s Hospital, Qingdao, People’s Republic of China, Email 156354361@qq.com Zhihai Chen, Center of Infectious Disease, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China, Email chenzhihai0001@126.com

Background: Myocardial injury is common in severe fever with thrombocytopenia syndrome (SFTS) patients. Currently, research on the prognostic value of cardiac troponin I (cTnI) for predicting the mortality of SFTS patients, especially death within 7 days is limited.
Methods: Between May 2011 and October 2022, clinical and laboratory data on admission of consecutive SFTS cases were collected from six medical centres in China. The clinical endpoint was in-hospital all-cause death within seven days. Risk factors of myocardial injury and death were analysed using multivariable regression models. Prognostic models were established using Cox regression and performance of indicators was evaluated in terms of calibration, discrimination.
Results: A total of 1379 laboratory-confirmed patients were enrolled, in which 686 subjects were included for analysis. The median age was 66 years, with 48.1% of male. Eighty-seven patients died within seven days and 396 patients diagnosed with myocardial injury during hospitalization. Non-survivors had significant higher levels of cardiac indices than survivors, including cTnI, aspartic transaminase (AST) and lactate dehydrogenase (LDH). Elevated levels of cTnI (HR = 1.058, 95% CI:1.032– 1.085), AST (HR = 1.191, 95% CI:1.150– 1.234) and LDH (HR = 1.019, 95% CI:1.009– 1.029) predicted risk of early in-hospital mortality. cTnI model performed best, with area under curve of 0.850 (0.774– 0.926) and concordance index of 0.842, respectively. Statistical differences were found between high and low levels of cTnI for mortality (P< 0.001) using 0.35 ng/mL as the optimal cut-off.
Conclusion: The risk of early in-hospital death can be predicted by cTnI. Clinical doctors should remind vigilant concerning the elevation of cardiac enzyme as soon as possible.

Keywords: severe fever with thrombocytopenia syndrome, cardiac troponin I, early death, mortality, risk