Cardiac injury and mortality in patients with Coronavirus disease 2019 (COVID-19): insights from a mediation analysis

BACKGROUNDS: Patients at greatest risk of severe clinical conditions from coronavirus disease 2019 (COVID-19) and death are elderly and comorbid patients Increased levels of cardiac troponins identify patients with poor outcome The present study aimed to describe the clinical characteristics and outcomes of a cohort of Italian inpatients, admitted to a medical COVID-19 Unit, and to investigate the relative role of cardiac injury on in-hospital mortality METHODS AND RESULTS: We analyzed all consecutive patients with laboratory-confirmed COVID-19 referred to our dedicated medical Unit between February 26th and March 31st 2020 Patients' clinical data including comorbidities, laboratory values, and outcomes were collected Predictors of in-hospital mortality were investigated A mediation analysis was performed to identify the potential mediators in the relationship between cardiac injury and mortality A total of 109 COVID-19 inpatients (female 36%, median age 71 years) were included During in-hospital stay, 20 patients (18%) died and, compared with survivors, these patients were older, had more comorbidities defined by Charlson comorbidity index ≥ 3(65% vs 24%, p = 0 001), and higher levels of high-sensitivity cardiac troponin I (Hs-cTnI), both at first evaluation and peak levels A dose-response curve between Hs-cTnI and in-hospital mortality risk up to 200 ng/L was detected Hs-cTnI, chronic kidney disease, and chronic coronary artery disease mediated most of the risk of in-hospital death, with Hs-cTnI mediating 25% of such effect Smaller effects were observed for age, lactic dehydrogenase, and D-dimer CONCLUSIONS: In this cohort of elderly and comorbid COVID-19 patients, elevated Hs-cTnI levels were the most important and independent mediators of in-hospital mortality