Elevated Troponin and Mortality in Patients with COVID-19: A Multicenter Retrospective Cohort Study

Introduction: Myocardial injury, causing elevated troponin levels, have been associated with worse outcomes in coronavirus disease 2019 (COVID-19) disease patients. However, our anecdotal experience did not consistently reflect this pattern. Therefore, we evaluated the outcomes of COVID-19 patients with elevated troponin. Methods: This is a retrospective study of 1,024 COVID-19 patients admitted to two hospitals in Southern California in the United States. We categorized the troponin levels as normal (=1x upper reference limit (URL)), mildly elevated (>1 to =3x URL), and severely elevated (>3x URL). We compared the characteristics of the three troponin groups using chi-square for categorical variables and one-way Anova for the continuous variables. Finally, backward selection Cox regression analysis was carried out using mortality as a dependent variable. Results: Of the COVID-19 1,024 patients included in the study, 944 (92%) had normal troponin, 45 (4.4%) had mild elevation, and 35 (3.4%) had a severe elevation in troponin levels. In the multivariate Cox regression analysis, troponin elevation in patients without ST-elevation on ECG was not independently associated with mortality (hazard ratio 0.92, 95% CI 0.64-1.3). Increased risk of death was independently associated with age as well as serum C-reactive protein and serum creatinine levels. Conclusion: Elevated troponins without ST-elevation on ECG on hospital admission were not independently associated with increased mortality in hospitalized COVID-19 patients. However, further research is needed to fully understand the absence of a relationship between troponin elevation and mortality in our study population.