Cardiac troponin in hospitalized COVID-19 patients: Incidence, predictors, and outcomes

Background: The incidence, predictors, and association of cardiac troponin with mortality in hospitalized COVID-19 were not adequately studied in the past and were also not reported from an Indian hospital.

Methods: In this retrospective cohort study, the cardiac troponin of 240 hospitalized COVID-19 patients was measured. The incidence, predictors, and association of elevated cardiac troponin with in-hospital mortality were determined among hospitalized COVID-19 patients.

Results: The cardiac troponin was elevated in 12.9% (31/240) of the patients. The troponin was elevated in the patients in the older age group (64 years vs. 55 years, p = .002), severe COVID-19 illness (SpO2 < 90%) (93.5% vs. 60.8%, p < .001), low arterial oxygen saturation (SpO2) (80% vs. 88%, p = .001), and low PaO2/FiO2 ratio (p < .0001). The patients with elevated cardiac troponin had elevated total leukocyte counts (TLC) (p = .001), liver enzyme (p = .025), serum creatinine (p = .011), N-terminal-Pro Brain natriuretic peptide (p < .0001), and d-dimer (p < .0001). The majority of the patients with elevated cardiac troponin were admitted to the intensive care unit (90.3% vs. 51.2%; p < .0001), were on a ventilator (61.3% vs. 21.5%; p < .0001), and had higher mortality (64.5% vs. 19.6%; p < .0001). The Kaplan-Meir survival analysis showed that the patients with elevated troponin had worse survival (p log-rank<.0001). Age, NT-ProBNP, d-dimer, and ventilator were the predictors of elevated troponin in multivariate logistic regression analysis. The Cox-regression analysis showed a significant association between elevated cardiac troponin and in-hospital mortality (adjusted hazard ratio 2.13; 95% confidence interval [CI] 1.145-3.97; p = .017). Two-thirds (65%) of patients with elevated cardiac troponin died during their hospital stay.

Conclusions: COVID-19 patients with elevated cardiac troponin had severe COVID illness, were more commonly admitted to an intensive care unit, were on a ventilator, and had high in-hospital mortality.