BACKGROUND Increases in cardiac troponin (cTn) in coronavirus disease 2019 (COVID-19) have been associated with worse prognosis.Nonetheless,data about the significance of cTn in elderly subjects with COVID-19 are lacking.METHODS From a registry of consecutive patients with COVID-19 admitted to a hub hospital in Italy from 25/02/2020 to 03/07/2020,we selected those ≥ 60 year-old and with cTnI measured within three days from the molecular diagnosis of SARS-CoV-2 infection.When available,a second cTnI value within 48 h was also extracted.The relationship between increased cTnI and all-cause in-hospital mortality was evaluated by a Cox regression model and restricted cubic spline functions with three knots.RESULTS Of 343 included patients (median age:75.0 (68.0-83.0) years,34.7％ men),88 (25.7％) had cTnI above the upper-reference limit (0.046 μg/L).Patients with increased cTnI had more comorbidities,greater impaired respiratory exchange and higher in-flammatory markers on admission than those with normal cTnI.Furthermore,they died more (73.9％ vs.37.3％,P ＜ 0.001) over 15(6-25) days of hospitalization.The association of elevated cTnI with mortality was confirmed by the adjusted Cox regression model (HR =1.61,95％CI:1.06-2.52,P =0.039) and was linear until 0.3 μg/L,with a subsequent plateau.Of 191 (55.7％) patients with a second cTnl measurement,49 (25.7％) had an increasing trend,which was not associated with mortality (univariate HR =1.39,95％CI:0.87-2.22,P =0.265).CONCLUSIONS In elderly COVID-19 patients,an initial increase in cTn is common and predicts a higher risk of death.Serial cTn testing may not confer additional prognostic information.