Prior studies demonstrated that elevated troponin in patients with COVID-19 was associated with increased in-hospital mortality. However, the association of cardiac injury and electrocardiogram (ECG) changes remains unclear. The aim of this study was to investigate the association of cardiac injury with ECG abnormality and with in-hospital mortality.

We conducted a retrospective cohort study of patients who were hospitalised with COVID-19 between 13 March and 31 March 2020. Those patients with troponin I measurement were included in the study and divided into those who had elevated troponin I (cardiac injury group) and those who did not (no cardiac injury group). Statistical analyses were performed to compare differences between the groups, and a multivariate logistic regression model was constructed to assess the effect of cardiac injury on in-hospital mortality.

One hundred and eight-one (181) patients were included, 54 of whom were in the cardiac injury group and 127 in the no cardiac injury group. The mean age was 64.0±16.6 years and 55.8% were male. The cardiac injury group was more likely to be older, have a history of coronary artery disease, atrial fibrillation and congestive heart failure compared to the no cardiac injury group (all p<0.05); there was no difference in presence of chest pain (cardiac injury group versus no cardiac injury group: 17.0% versus 22.5%, p=0.92); the cardiac injury group had a significantly higher value of brain natriuretic peptide, procalcitonin, interleukin-6 and D-dimer (all p<0.05); they had numerically more frequent ECG abnormalities such as T wave inversion (13.2% versus 7.5%, p=0.23) and ST depression (1.9% versus 0.0%, p=0.13) although statistically not significant; they had significantly higher in-hospital mortality (42.3% versus 12.6%, p<0.001). With a multivariate logistic regression model, age (odds ratio [95% confidence interval]: 1.033 [1.002–1.065], p=0.034) and cardiac injury (3.25 [1.40–7.54], p=0.006) were independent predictors of in-hospital mortality.

Patients with COVID-19 with elevated troponin I had a relatively low proportion of chest pain and ECG abnormality. Cardiac injury was independently associated with in-hospital mortality.