Prognostic implications of serial high-sensitivity cardiac troponin testing among patients with COVID-19: A Danish nationwide registry-based cohort study.

Background: Although troponin elevation is associated with worse outcomes among patients with coronavirus disease 2019 (COVID-19), prognostic implications of serial troponin testing are lacking. We investigated the association between serial troponin measurements and adverse COVID-19 outcomes. Methods: Using Danish registries, we identified COVID-19 patients with a high-sensitivity troponin measurement followed by a second measurement within 1-24 h. All measurements during follow-up were also utilized in subsequent time-varying analyses. We assessed all-cause mortality associated with the absence/presence of myocardial injury (≥1 troponin measurement >99th percentile upper reference limit) and absence/presence of dynamic troponin changes (>20% relative change if first measurement elevated, >50% relative change if first measurement normal). Results: Of 346 included COVID-19 patients, 56% had myocardial injury. Overall, 20% had dynamic troponin changes. In multivariable Cox regression models, myocardial injury was associated with all-cause mortality (HR = 2.56, 95%CI = 1.46-4.51), as were dynamic troponin changes (HR = 1.66, 95%CI = 1.04-2.64). We observed a low incidence of myocardial infarction (4%) and invasive coronary procedures (4%) among patients with myocardial injury. Conclusions: Myocardial injury and dynamic troponin changes determined using serial high-sensitivity troponin testing were associated with poor prognosis among patients with COVID-19. The risk of developing myocardial infarction requiring invasive management during COVID-19 hospitalization was low.