Clin Biochem. 2021 Jan 30:S0009-9120(21)00022-9. doi: 10.1016/j.clinbiochem.2021.01.006. Online ahead of print.
BACKGROUND: The spectrum of Coronavirus Disease 2019 (COVID-19) is broad and thus early appropriate risk stratification can be helpful. Our objectives were to define the frequency of myocardial injury using high-sensitivity cardiac troponin I (hs-cTnI) and to understand how to use its prognostic abilities.
METHODS: Retrospective study of patients with COVID-19 presenting to an Emergency Department (ED) in Italy in 2020. Hs-cTnI was sampled based on clinical judgment. Myocardial injury was defined as values above the sex-specific 99th percentile upper reference limits (URLs). Most data is from the initial hospital value.
RESULTS: 426 unique patients were included. Hs-cTnI was measured in 313 (73.5%) patients; 85 (27.2%) had myocardial injury at baseline. Patients with myocardial injury had higher mortality during hospitalization (hazard ratio = 9 [95% confidence interval (CI) 4.55-17.79], p < 0.0001). Multivariable analysis including clinical and laboratory variables demonstrated an AUC of 0.942 with modest additional value of hs-cTnI. Myocardial injury was associated with mortality in patients with low APACHE II scores (<13) [OR (95% CI): 4.15 (1.40, 14.22), p = 0.014] but not in those with scores >13 [OR (95% CI): 0.48 (0.08, 2.65), p = 0.40]. Initial hs-cTnI < 5 ng/L identified 33% of patients that were at low risk with 97.8 % sensitivity (95% CI 88.7, 99.6) and 99.2% negative predictive value. Type 1 myocardial infarction (MI) and type 2 MI was infrequent.
CONCLUSIONS: hs-cTnI at baseline is a significant predictor of mortality in COVID-19 patients. A value < 5 ng/L identified patients at low risk.